ORGANOMETALLIC COMPOUNDS FOR USE AS ANTHELMINTICS FIELD OF THE INVENTION

The present invention relates to organometallic compounds and their use as anthelmintics.

BACKGROUND OF THE INVENTION

Parasites cause significant economic losses to agriculture worldwide due to poor

productivity, limited growth rates and death. According to some estimates, the financial damage caused by parasites to the livestock industry is in the order of tens of billions of dollars per annum. Decreased productivity influences not only the livestock industry but also substantially affects global food production. Moreover, in spite of the anthelmintic drugs discovered and marketed in the last decades, problems of parasitic worms persist and multidrug resistance to most classes of anthelmintics is widespread. The development of new classes of anthelmintics is a major priority. Any anthelmintic developed for parasites of livestock would also have application to parasites of humans and other animals, including companion animals, such as dogs, cats and equids. One sixth of the human population in earth is affected chronically by at least one parasitic helminth, and the socioeconomic burden (in DALYs) is greater than that of cancer and diabetes. Some helminths, such as

Schistosoma haematobium, Opisthorchis viverrini and Clonorchis sinensis induce malignant cancers in humans.

An important problematic is that nematodes are rapidly developing resistance against anthelmintics on the market. Thus, the recent discovery of Amino-Acetonitrile Derivatives (AADs, see WO2005/044784A1 ), commercially developed under the trade name Zolvix ^® for the treatment of infected sheep, as a new class of anthelmintics effective against drug- resistant nematodes has been a major breakthrough. However, it can be expected that resistance to this anthelmintic could be unveiled in the near future.

Monepantel (AAD 1566)

The precise mode of action of monepantelis is not yet elucidated, although an interaction of AADs with a specific acetylcholine receptor (nAChR) subunit has been proposed. This target is only present in nematodes but not in mammals, making it relevant for the development of a new class of anthelmintic drugs. Of high importance, a mutant of Haemonchus contortus with a reduced sensitivity to monepantel was recently identified using a novel in vitro selection procedure (L. Rufener, R. Baur, R. Kaminsky, P. Maeser and E. Sigel, Mol. Pharmacol., 2010, 78, 895-902), indicating that resistance will develop in gastrointestinal nematodes of livestock. This observation has been noticed for all current anthelmintics on the market. In light of the above referenced state of the art, the objective of the present invention is to provide novel compounds to control parasites of human beings and livestock.

This objective is attained by the subject-matter of the independent claims.

SUMMARY OF THE INVENTION

According to a first aspect of the invention provided herein are organometallic compounds characterized by a general formula (1 ),

R- OM R ^R

(1 )

wherein OM is an organometallic compound independently selected from the group of an unsubstituted or substituted metal sandwich compound, an unsubstituted or substituted half metal sandwich compound or a metal carbonyl compound, wherein at least one of R ^L and R ¹ is selected from

(formula A),

(formula B),

(formula C), or

(formula D),

with R ^A being selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ² or -R ^2a , with each R ^2a independently from any other R ^2a being a hydrogen or an unsubstituted or substituted Ci-C ₄ alkyl, with R being selected from H, -R , -C(=0)R , -C(=0)OR , -C(=0)NR ₂ , -C(=0)SR , -C(=S)OR ^2b or -C(=S)R ^2b , in particular from H, R ^2b or -C(=0)R ^2b , with each R ^2b

independently from any other R ^2b being a hydrogen or an unsubstituted or substituted C C ₄ alkyl,

with each R ^D being selected independently from any other R ^D from H, R ^2d , -C(=0)R ^2d , -C(=0)OR ^2d , -C(=0)NR ^2d ₂ , -C(=0)SR ^2d , -C(=S)OR ^2d , -C(=S)R ^2d or -SR ^2d , in particular from H, -R ^2d or -C(=0)R ^2d , with each R ^2d independently from any other R ^2d being a hydrogen or an unsubstituted or substituted C C ₄ alkyl,

X being a group described by a general formula -K _p -F|-K _q -, wherein

- F| is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)-, -0-C(=S)-, with I being 0 or 1 ,

K _p is a C _p -alkyl with p being 0, 1 , 2, 3 or 4,

K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, and wherein

- each R ¹ independently from any other R ¹ is -CF ₃ , -OCF ₃ , -SCF ₃ ,

-SOCF ₃ , -SO2CF ₃ or -CN, and wherein

- n of R ¹ _n is 0, 1 , 2, 3, 4 or 5,

with Y being a group described by a general formula -L _r -M _k -L _s , wherein

M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, with k being 0 or 1 ,

is a C _r -alkyl with r being 0, 1 , 2, 3 or 4,

L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, and with Z being a group described by a general formula -K _r -Fi-K _r , wherein

- Fj is -0-, -S-, -0-C(=0)-, -0-C(=S)-, -S-C(=0)- or NH-(C=0)- with i being 0 or 1 ,

K _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4,

K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4,

wherein the other one of R ^L and R ^R can be selected from H or -C _c -P,

- with P being -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ , -C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ , -OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

- with c being 0, 1 , 2, 3 or 4, and

- with each R ⁴ independently from any other R ⁴ being hydrogen or an unsubstituted or substituted C C ₄ alkyl, in particular an unsubstituted C C ₄ alkyl. In cases, in which q of K _q , t of K _t and s of L _s are not 0, K _q , K _t and L _s , are connected to the OM-moiety of the compound.

The term "substituted" refers to the addition of a substituent group to a parent compound.

"Substituent groups" can be protected or unprotected and can be added to one available site or to many available sites in a parent compound. Substituent groups may also be further substituted with other substituent groups and may be attached directly or by a linking group such as an alkyl, an amide or hydrocarbyl group to a parent compound. "Substituent groups" amenable herein include, without limitation, halogen, oxygen, nitrogen, sulphur, hydroxyl, alkyl, alkenyl, alkynyl, acyl (-C(0)R ^a ), carboxyl (-C(0)OR ^a ), aliphatic groups, alicyclic groups, alkoxy, substituted oxy (-OR ^a ), aryl, aralkyl, heterocyclic radical, heteroaryl, heteroarylalkyl, amino (-N(R ^b )(R ^c )), imino(=NR ^b ), amido(-C(0)N(R ^b )(R ^c ) or -N(R ^b )C(0)R ^a ), hydrazine derivates(-C(NH)NR ^a R ^b ), tetrazole(CN ₄ H ₂ ),azido (-N ₃ ), nitro (-N0 ₂ ), cyano (-CN), isocyano (-NC), cyanato (-OCN), isocyanato (-NCO), thiocyanato (-SCN); isothiocyanato (-NCS);

carbamido (-OC(0)N(R ^b )(R ^c ) or -N(R ^b )C(0)OR ^a ), thiol (-SR ^b ), sulfinyl (-S(0)R ^b ), sulfonyl (-S(0) ₂ R ^b ),sulfonamidyl (-S(0) ₂ N(R ^b )(R ^c ) or -N(R ^b )S(0) ₂ R ^b ) and fluorinated compounds -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ . Wherein each R ^a , R ^b and R ^c is, independently, Hor a further substituent group with a preferred list including without limitation, H, alkyl, alkenyl, alkynyl, aliphatic, alkoxy, acyl, aryl, heteroaryl, alicyclic, heterocyclic and heteroarylalkyl.

As used herein the term "alkyl," refers to a saturated straight or branched hydrocarbon moiety containing up to 10, particularly up to 4 carbon atoms. Examples of alkyl groups include, without limitation, methyl, ethyl, propyl, butyl, n-hexyl, octyl, decyl, iso-propyl, iso- butyl or tert-butyl and the like. Alkyl groups typically include from 1 to about 10 carbon atoms (C ₁ -C ₁₀ alkyl), particularly with from 1 to about 4 carbon atoms (CrC ₄ alkyl). The term

"cycloalkyi" refers to an interconnected alkyl group forming a ring structure. Alkyl or cycloalkyi groups as used herein may optionally include further substituent groups. If not defined otherwise, the term d-C ₄ alkyl refers to a straight or branched alkyl moiety (e.g. methyl, ethyl, propyl, butyl, iso-propyl, iso-butyl or tert-butyl). Examples for a substituted alkyl group (e.g. a substituted -CH ₃ or a substituted -CH ₂ CH ₃ ) may be -CHF ₂ or -CH ₂ CH ₂ F, thus, comprising additional fluorides as substituents.

As used herein the term "alkenyl," refers to a straight or branched hydrocarbon chain moiety containing up to 10 carbon atoms and having at least one carbon-carbon double bond.

Examples of alkenyl groups include, without limitation, ethenyl, propenyl, butenyl, 1 -methyl-2- buten-1 -yl, dienes such as 1 ,3-butadiene and the like. Alkenyl groups typically include from 2 to about 10 carbon atoms, more typically from 2 to about 4 carbon atoms. Alkenyl groups as used herein may optionally include further substituent groups. As used herein the term "alkynyl," refers to a straight or branched hydrocarbon moiety containing up to 10 carbon atoms and having at least one carbon-carbon triple bond.

Examples of alkynyl groups include, without limitation, ethynyl, 1 -propynyl, 1 -butynyl, and the like. Alkynyl groups typically include from 2 to about 10 carbon atoms, more typically from 2 to about 4 carbon atoms. Alkynyl groups as used herein may optionally include further substituent groups.

As used herein the term "alkoxy," refers to an oxygen-alkyl moiety, wherein the oxygen atom is used to attach the alkoxy group to a parent molecule. Examples of alkoxy groups include without limitation, methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, sec-butoxy, ie f-butoxy, n-pentoxy, neopentoxy, n-hexoxy and the like. The term "cycloalkoxy" refers to an interconnected alkoxy group forming a ring structure. Alkoxy or cycloalkoxy groups as used herein may optionally include further substituent groups. One example for a substituted alkoxy group (e.g. -OCH ₃ ) may be -OCF ₃ , thus, comprising three additional substituents (namely fluorides).

As used herein the term "aryl" refers to a hydrocarbon with alternating double and single bonds between the carbon atoms forming a ring structure (in the following an "aromatic hydrocarbon"). The term "heteroaryl" refers to aryl compounds in which at least one carbon atom is replaced with an oxygen, a nitrogen or asulphur atom. The aromatic hydrocarbon may be neutral or charged. Examples of aryl or hetero aryl groups are benzene, pyridine, pyrrole or cyclopenta-1 ,3-diene-anion. Aryl or hetero aryl groups as used herein may optionally include further substituent groups.

As used herein the term "organometallic compound" refers to a compound comprising at least one metal, in particular at least one transition metal (a metal selected from the group 3 to group 12 metals of the periodic table), as well as at least onemetal-carbon bond.

As used herein the term "metal sandwich compound" refers to a compound comprising a metal, in particular a transition metal, bound to two aryl or heteroaryl ligands (in the following "sandwich ligands") by a haptic covalent bound. It may comprise a cationic metal sandwich complex, e.g. cobaltocenium with a suitable counter anion such as iodide, chloride, bromide, fluoride, triflate, tetraborofluoride, hexafluorophosphate. The aryl or heteroarylligands may be unsubstituted or substituted.

As used herein the term "half metal sandwich compound" refers to a compound comprising a metal, in particular a transition metal, bound to just one aryl or heteroarylligand (sandwich ligand). The other ligand may comprise - without being limited to - alkyl, allyl, CN or CO, in particular CO.

As used herein the term "metal carbonyl compound" refers to a coordination complex of at least one transition metal with a carbon monoxide (CO) ligand. It may comprise a neutral, anionic or cationic complex. The carbon monoxide ligand may be bond terminally to a single metal atom or may be bridging to two or more metal atoms. The complex may be

homoeleptic (containing only carbon monoxide ligands) or heteroeleptic.

As used herein the term "metallocene" refers to a metal sandwich compound comprising an aryl or heteroarylfive ring ligand (in the following "cp-ligand" or "hetero cp-ligand").

Compounds comprising the general formula A:

According to one alternative of the first aspect of the invention at least one of R ^L and R ^R is selected from the group comprising the general formula A,

- with X being a group described by a general formula -K _p -F|-K _q -, wherein

- F| is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)- or -0-C(=S)-, with I being 0 or 1 ,

K _p is a C _p -alkyl with p being 0, 1 , 2, 3 or 4,

K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, and wherein

- each R ¹ independently from any other R ¹ is -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN, and

- n of R ¹ _n is 0, 1 , 2, 3, 4 or 5,

- wherein the other one of R ^L and R ^R can be selected from H or -C _c -P,

- with P being -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ , -C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ ,

-S0 ₂ CF ₃ or -CN,

- with c being 0, 1 , 2, 3 or 4, and

- with each R ⁴ independently from any other R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, the other one of R ^L and R ^R is selected from H or -C _c -P, with P being - H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular P being -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and with R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein F| is -NH-(C=0)- or -O- with I being 1 , p of K _p being 0, K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and wherein each R ¹ independently from any other R ¹ is -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN, with n of R ¹ _n being 0, 1 , 2, 3, 4 or 5.

In some embodiments, n of R ¹ _n is 1 or 2, and each R ¹ independently from any other R ¹ is -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN. In some embodiments, n of R ¹ _n is 2 and each R ¹ independently from any other R ¹ is -CN, -CF ₃ , -OCF ₃ . In some embodiments, n of R ¹ _n is 2 and each R ¹ independently from any other R ¹ is -CN or -CF ₃ .

In some embodiments, n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety. In some embodiments, n of R ¹ _n is 2, each R ¹ independently from any other R ¹ is -CN, -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ . In some embodiments, n of R ¹ _n is 2, each R ¹ independently from any other R ¹ is -CN or -CF ₃ and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety. In some embodiments, n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety.

In some embodiments, n of R ¹ _n is 1 and R ¹ is -CN, -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ . In some embodiments, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ , in particular R ¹ is -SCF ₃ .

In some embodiments, n of R ¹ _n is 1 , R ¹ is -CN, -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ and R ¹ is in para position to the attachment position of the benzene moiety. In some

embodiments, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ and R ¹ is in para position to the attachment position of the benzene moiety. In some embodiments, n of R ¹ _n is 1 , R ¹ is - SCF ₃ and R ¹ is in para position to the attachment position of the benzene moiety.

In some embodiments, F| is -NH-(C=0)- or -O- with I being 1. In some embodiments, F| is - NH-(C=0)- or -O- with I being 1 , q of K _q is 0 and p of K _p is 0. In some embodiments, F| is - NH-(C=0)- or -O- with I being 1 , p of K _p is 0 and K _q is a d-alkyl.

In some embodiments, at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by the general formula -K _p -F _r K _q -, wherein F| is -NH-(C=0)- or -O- with I being 1 , p of K _p being 0, K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and wherein each R ¹ independently from any other R ¹ is -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN, with n of R ¹ _n being 1 or 2.

In some embodiments, F, is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)- or -0-C(=S)-, in particular -NH-(C=0)- or -0-, with I being 1 , and

- n of R ¹ _n is 1 or 2, n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

- n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety.

In some embodiments, F, is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)-, -0-C(=S)-, in particular -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, K _q is a d- or C ₂ -alkyl, in particular a Ci-alkyl, and

- n of R ¹ _n is 1 or 2,

n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

- n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety.

In some embodiments, at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein

- F| is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)- or -0-C(=S)-, with I being 0 or 1 ,

K _p is a C _p -alkyl with p being 0, 1 , 2, 3 or 4, K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, and wherein

- each R ¹ independently from any other R ¹ is -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN, and n of R ¹ _n is 0, 1 , 2, 3, 4 or 5,

and the other one of R ^L and R ^R is selected from H or -C _c -P,

- with P being -H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ ,

with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or CrC ₄ alkyl.

In some embodiments, at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein F| is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-,

-C(=S)0-, -0-C(=0)- or -0-C(=S)-, in particular -NH-(C=0)- or -O-, with I being 1 , K _p is a C _p - alkyl with p being 0, 1 , 2, 3 or 4, K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, and

n of R ¹ _n is 1 or 2,

n of R ¹ _n is 2,

- n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 1 ,

- n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety, and wherein

the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, -(HC=N)OR ⁴ , -OR ⁴ , - CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , - (HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or C C ₄ alkyl.

In some embodiments, at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein F| is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, - C(=S)0-, -0-C(=0)- or -0-C(=S)-, in particular -NH-(C=0)- or -0-, with I being 1 , p of K _p is 0, K _q is a C or C ₂ -alkyl, in particular a Ci-alkyl, and n of R ¹ _n is 1 or 2,

n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

- n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta

position to the attachment position of the benzene moiety, n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety, and wherein

the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, -(HC=N)OR ⁴ , -OR ⁴ , - CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , - (HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or C C ₄ alkyl.

In some embodiments, at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein F| is -NH-(C=0)- or -0-, with I being 1 , p of K _p is 0, K _q is a Ci-alkyl, and

n of R ¹ _n is 1 or 2,

- n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety,

- n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety, and wherein

the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -OR ⁴ and R ⁴ being hydrogen or d-C ₄ alkyl, in particular hydrogen. In some embodiments, R ^L and R ^R are both selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein

- F| is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)- or -0-C(=S)-, with I being 0 or 1 ,

- K _p is a C _p -alkyl with p being 0, 1 , 2, 3 or 4,

K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, and wherein

- each R ¹ independently from any other R ¹ is -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN, and n of R ¹ _n is 0, 1 , 2, 3, 4 or 5.

In some embodiments, R ^L and R ^R are both selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein F| is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)- or -0-C(=S)-, in particular -NH-(C=0)- or -0-, with I being 1 , p of K _p is 0, K _q is a C or C ₂ -alkyl, in particular a Ci-alkyl, and each R ¹ independently from any other R ¹ is -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN, and n of R ¹ _n is 0, 1 , 2, 3, 4 or 5, n of R ¹ _n is 1 or 2. In some embodiments, R ^L and R ^R are both selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein F| is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)- or -0-C(=S)-, in particular -NH-(C=0)- or -0-, with I being 1 , p of K _p is 0, K _q is a C or C ₂ -alkyl, in particular a Ci-alkyl, and

- n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety,

- n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety.

In some embodiments, at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F _r K _q -, wherein F| is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, - C(=S)0- or -0-C(=0)-, -0-C(=S)-, in particular -NH-(C=0)- or -0-, with I being 1 , p of K _p is 0, K _q is a C or C ₂ -alkyl, in particular a Ci-alkyl, and

n of R ¹ _n is 1 or 2,

n of R ¹ _n is 2,

- n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety, and

the other one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein F| is -0-, -NH, -NHC(=0)- , -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)-, -O- C(=S)-, in particular -NH-(C=0)- or -0-, with I being 1 , p of K _p is 0, K _q is a d- or C ₂ -alkyl, in particular a Ci-alkyl, and

n of R ¹ _n is 1 ,

- n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety.

In some embodiments, at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein F| is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, - C(=S)0-, -0-C(=0)-, -0-C(=S)-, in particular -NH-(C=0)- or -O-, with I being 0 or 1 ,

K _p is a C _p -alkyl with p being 0, 1 , 2, 3 or 4, in particular p being 0,

- K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and wherein

each R ¹ independently from any other R ¹ is -C(=0)OR ² , -C(=0)NR ² ₂ , -C(=0)SR ² , -C(=S)OR ² -C(NH)NR ² 2, -CN ₄ H ₂ , -NR ² ₂ , -C(=0)R ² , -C(=S)R ² , -OR ² , -SR ² , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

- with each R ² independently from any other R ² being hydrogen, CH ₃ , C ₂ H ₅ ,

C ₃ H ₇ or C ₄ H _9, in particular with each R ² being hydrogen, and

the other one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein F| is -0-, -NH, -NHC(=0)- , -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)-, -O- C(=S)-, in particular -NH-(C=0)- or -0-, with I being 0 or 1 ,

K _p is a C _p -alkyl with p being 0, 1 , 2, 3 or 4, in particular p being 0,

K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and wherein - each R ¹ independently from any other R ¹ is -C(=0)OR ² , -C(=0)NR ² ₂ , -C(=0)SR ² ,

-C(=S)OR ² -C(NH)NR ² 2, -CN ₄ H ₂ , -NR ² ₂ , -C(=0)R ² , -C(=S)R ² , -OR ² , -SR ² , -CF ₃ , -OCF3, -SCF3, -SOCF3, -SO2CF3, -CN, -NO2, -F, -CI, -Br or -I, in particular -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -SO2CF ₃ or -CN,

with each R ² independently from any other R ² being hydrogen, CH ₃ , C ₂ H ₅ , C ₃ H ₇ or C ₄ H _9, in particular with each R ² being hydrogen.

In some embodiments, R ^L and R ^R are identical and selected from the group comprising the general formula A, wherein X, K _p , F|, K _q , R ¹ _n , n and R ² have the same meaning as defined in the previously described embodiments.

Compounds comprising the general formula B:

According to an alternative of the first aspect of the invention at least one of R ^L and R ^R is selected from the group comprising the general formula B,

with Y being a group described by a general formula, -L _r -M _k -L _s , wherein

M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, with k being 0 or 1 ,

is a C _r -alkyl with r being 0, 1 , 2, 3 or 4,

L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, and

R ^A being selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ^2a , -NR ^2a ₂ or

-R ^2a , with R ^2a being a hydrogen or d-C ₄ alkyl,

wherein the other one of R ^L and R ^R can be selected from H or -C _c -P,

- with P being -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ , -C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular H, -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN, with c being 0, 1 , 2, 3 or 4, and

with each R ⁴ independently from any other R ⁴ being hydrogen or d-C ₄ alkyl. In some embodiments, the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular P being -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and with R ⁴ being hydrogen or CrC ₄ alkyl.

In some embodiments, M _k is -C(=0)- with k being 1 , r of L _r is 0 and L _s is Ci-alkyl with s being 1 . In some embodiments, M _k is -C(=0)- with k being 1 , r of L _r is 0 and s of L _s is 0. In some embodiments, k is 0. In some embodiments, k is 0, r of L _r is 0 and s of L _s is 0. In some embodiments, k is 0, r of L _r is 0 and L _s is Ci-alkyl with s being 1 .

In some embodiments, at least one of R ^L and R ^R is selected from the group comprising the general formula B, with Y being a group described by a general formula -L _r -M _k -L _s , wherein r of is 0, and

M _k is -(C=0)- with k being 1 or k is 0,

L _s is a Cs-alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , or

s of L _s being 0.

In some embodiments, at least one of R ^L and R ^R is selected from the group comprising the general formula B,

with Y being a group described by a general formula -L _r -M _k -L _s , wherein M _k is

-C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, with I being 0 or 1 , L _r is a C _r -alkyl with r being 0,

1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, and

- with R ^A being selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ^2a , -NR ^2a ₂ or -R ^2a , with R ^2a being a hydrogen or d-C ₄ alkyl, and

the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular P being -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and with R ⁴ being hydrogen or Ci-C ₄ alkyl.

In some embodiments, at least one of R ^L and R ^R is selected from the group comprising the general formula B, with R ^A being selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ^2a , -NR ^2a ₂ or -R ^2a , with R ^2a being a hydrogen or C C ₄ alkyl, and the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular P being -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and with R ⁴ being hydrogen or d-C ₄ alkyl, and with Y being a group described by the general formula -L _r -M _k -L _s , wherein

M _k is -(C=0)- with k being 1 , r of L _r is 0, and L _s is a Ci-alkyl with s being 1 , or

k is 0, r of L _r is 0, and L _s is a Ci-alkyl with s being 1 , or k is 0, r of is 0, and s of L _s is 0.

In some embodiments, R ^L and R ^R are both selected from the group comprising the general formula B, with Y being a group described by the general formula, -L _r -M _k -L _s , wherein M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, in particular -C(=0)-, with k being 0 or 1 , L _r is a C _r - alkyl with r being 0, 1 , 2, 3 or 4 and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, with R ^A being selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ^2a , -NR ^2a ₂ or -R ^2a , with R ^2a being a hydrogen or CrC ₄ alkyl.

In some embodiments, R ^L and R ^R are both selected from the group comprising the general formula B, with Y being a group described by a general formula -L _r -M _k -L _s , with k being 0, r of being 0 and L _s being a Ci-alkyl with s being 1 . In some embodiments, R ^L and R ^R are both selected from the group comprising the general formula B, with Y being a group described by a general formula -L _r -M _k -L _s , with k being 0, r of L _r being 0 and s of L _s being 0.

In some embodiments, R ^L and R ^R are both selected from the group comprising the general formula B, with R ^A being selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ^2a , -NR ^2a ₂ or -R ^2a , with R ^2a being a hydrogen or d-C ₄ alkyl, and with Y being a group described by the general formula -L _r -M _k -L _s , wherein

M _k is -(C=0)- with k being 1 , r of L _r is 0, and L _s is a Ci-alkyl with s being 1 , or k is 0, r of is 0, and L _s is a Ci-alkyl with s being 1 , or

k is 0, r of is 0, and s of L _s is 0.

In some embodiments, R ^L and R ^R are identical and selected from the group comprising the general formula B, wherein Y, L _r , M _k , L _s , R ^A and R ^2a have the same meaning as defined in the previously described embodiments.

Compounds comprising the general formula C:

According to a further alternative of the first aspect of the invention at least one of R ^L and R ^R is selected from the group comprising the general formula C,

- with Z being a group described by a general formula -K _r -Fi-K _r , wherein

Fi is -0-, -S-, -0-C(=0)-, -0-C(=S)-, -S-C(=0)- or NH-(C=0)- with i being 0 or 1 ,

K _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4,

- K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, and - with R being H, -R , -C(=0)R , -C(=0)OR , -C(=0)NR ₂ , -C(=0)SR , -C(=S)OR or -C(=S)R ^2b , in particular being H, R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or C1-C4 alkyl,

wherein the other one of R ^L and R ^R can be selected from H or -C _c -P,

- with P being -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ , -C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-l , in particular H, -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

with c being 0, 1 , 2, 3 or 4, and

- with each R ⁴ independently from any other R ⁴ being hydrogen or C1-C4 alkyl.

In some embodiments, the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular P being -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and with R ⁴ being hydrogen or C1-C4 alkyl.

In some embodiments, i is 0. In some embodiments, i is 0, r of K _r is 0 and t of K _t is 0. In some embodiments, i is 0, r of K _r is 0 and t of K _t is Ci-alkyl.

In some embodiments, at least one of R ^L and R ^R is selected from the group comprising the general formula C, with Z being a group described by the general formula -K _r -Fi-K _r , wherein i is 0, r of K _r is 0, and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, in particular t being 0 or 1 . In some embodiments, R ^L and R ^R are selected from the group comprising the general formula C,

with Z being a group described by the general formula -K _r -Fi-K _r , wherein F, is -0-, -S-, -0-C(=0)-, -0-C(=S)-, -S-C(=0)- or NH-(C=0)- with i being 0 or 1 , K _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, and

- with R ^B being H, -R ^2b , -C(=0)R ^2b , -C(=0)OR ^2b , -C(=0)NR ^2b ₂ , -C(=0)SR ^2b , -C(=S)OR ^2b or -C(=S)R ^2b , in particular H, R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or C1-C4 alkyl, and

with the other one of R ^L and R ^R being selected from H or -C _c -P, with P being

-H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular P being -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and with

R ⁴ being hydrogen or C1-C4 alkyl.

In some embodiments, at least one of R ^L and R ^R is selected from the group comprising the general formula C, with Z being a group described by the general formula -K _r -Fi-K _r , wherein i of Fi, r of K _r , t of K _t are 0, and R ^B is H, -R ^2b , -C(=0)R ^2b , -C(=0)OR ^2b , -C(=0)NR ^2b ₂ , -C(=0)SR , -C(=S)OFT or -C(=S)R , in particular H, -R or -C(=0)R , with each R independently from any other R ^2b being a hydrogen or C1-C4 alkyl.

In some embodiments, at least one of R ^L and R ^R is selected from the group comprising the general formula C, with Z being a group described by the general formula -K _r -Fi-K _r , wherein i of Fi, r of K _r , t of K _t are 0, and R ^B is H, -R ^2b , -C(=0)R ^2b , -C(=0)OR ^2b , -C(=0)NR ^2b ₂ ,

-C(=0)SR ^2b , -C(=S)OR ^2b or -C(=S)R ^2b , in particular H, -R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or C1-C4 alkyl, and with the other one of R ^L and R ^R being selected from H or -C _c -P, with P being -H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -SO2CF ₃ , -CN, -NO2, -F, -CI, -Br or -I, in particular P being H, -OR ⁴ ,

-(HC=N)OR ⁴ or -SCF ₃ , and with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or C C ₄ alkyl.

In some embodiments, at least one of R ^L and R ^R is selected from the group comprising the general formula C, with Z being a group described by the general formula -K _r -Fi-K _r , wherein i of Fi, r of K _r , t of K _t are 0, and R ^B is H, -R ^2b , -C(=0)R ^2b , -C(=0)OR ^2b , -C(=0)NR ^2b ₂ ,

-C(=0)SR ^2b , -C(=S)OR ^2b or -C(=S)R ^2b , in particular H, R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or C1-C4 alkyl and the other one of R ^L and R ^R is selected from H or -SCF ₃ .

In some embodiments, R ^L and R ^R are both selected from the group comprising the general formula C, with Z being a group described by the general formula -K _r -Fi-K _r , wherein F, is -0-, -S-, -0-C(=0)-, -0-C(=S)-, -S-C(=0)- or NH-(C=0)- with i being 0 or 1 , K _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4.

In some embodiments, R ^L and R ^R are both selected from the group comprising the general formula C, with Z being a group described by the general formula -K _r -Fi-K _r , wherein F, is -0-, -S-, -0-C(=0)-, -0-C(=S)-, -S-C(=0)- or NH-(C=0)- with i being 0 or 1 , K _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, and R ^B is H, -R ^2b ,

-C(=0)R ^2b , -C(=0)OR ^2b , -C(=0)NR ^2b ₂ , -C(=0)SR ^2b , -C(=S)OR ^2b or -C(=S)R ^2b , in particular H, R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or C1-C4 alkyl and the other one of R ^L and R ^R is selected from H or -SCF ₃ .

In some embodiments, R ^L and R ^R are both selected from the group comprising the general formula C, with Z being a group described by a general formula -K _r -Fi-K _r , wherein I of F, and r of K _r are 0 and K _t is a Ci-alkyl with t being 1 .

In some embodiments, R ^L and R ^R are both selected from the group comprising the general formula C, with Z being a group described by a general formula -K _r -Fi-K _r , wherein I of F, and r of K _r are 0 and K _t is a d-alkyl with t being 1 , and R ^B is H, -R ^2b , -C(=0)R ^2b , -C(=0)OR ^2b , -C(=0)NR ^2b ₂ , -C(=0)SR ^2b , -C(=S)OR ^2b or -C(=S)R ^2b , in particular H, R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or C1-C4 alkyl and the other one of R ^L and R ^R is selected from H or -SCF ₃ . In some embodiments, R ^L and R ^R are both selected from the group comprising the general formula C, with Z being a group described by a general formula -K _r -Fi-K _r , wherein I of F, and r of K _r and K _t are 0.

In some embodiments, R ^L and R ^R are both selected from the group comprising the general formula C, with Z being a group described by a general formula -K _r -Fi-K _r , wherein I of F, and r of K _r and K _t are 0, and R ^B is H, -R ^2b , -C(=0)R ^2b , -C(=0)OR ^2b , -C(=0)NR ^2b ₂ , -C(=0)SR ^2b , -C(=S)OR ^2b or -C(=S)R ^2b , in particular H, R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or CrC ₄ alkyl and the other one of R ^L and R ^R is selected from H or -SCF ₃

In some embodiments, R ^L and R ^R are identical and selected from the group comprising the general formula C, wherein Z, K _r , F,, K _t , R ^B and R ^2b have the same meaning as defined in the previously described embodiments.

Compounds comprising the general formula D:

According to another alternative of the first aspect of the invention at least one of R ^L and R ^R is selected from the group comprising the general formula D,

- with Y being a group described by a general formula, -L _r -M _k -L _s , wherein

M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, with k being 0 or 1 ,

is a C _r -alkyl with r being 0, 1 , 2, 3 or 4,

- L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, and

- with each R ^D being selected independently from any other R ^D from H, R ^2d , -C(=0)R ^2d , -C(=0)OR ^2d , -C(=0)NR ^2d ₂ , -C(=0)SR ^2d , -C(=S)OR ^2d , -C(=S)R ^2d or-SR ^2d , in particular from H, -R ^2d or -C(=0)R ^2d , with each R ^2d independently from any other R ^2d being a hydrogen or C1-C4 alkyl,

wherein the other one of R ^L and R ^R can be selected from H or -C _c -P,

- with P being -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ , -C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-l, in particular H, -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

- with c being 0, 1 , 2, 3 or 4, and with each R ⁴ independently from any other R ⁴ being hydrogen or C1-C4 alkyl.

In some embodiments, the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular P being -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and with R ⁴ being hydrogen or C1-C4 alkyl.

In some embodiments, M _k is -C(=0)- with k being 1 . In some embodiments, M _k is -C(=0)- with k being 1 , r of L _r is 0 and s of L _s is Ci-alkyl

In some embodiments, k is 0. In some embodiments, k is 0, r of L _r is 0 and s of L _s is 0. In some embodiments, k is 0, r of L _r is 0 and s of L _s is Ci-alkyl.

In some embodiments, at least one of R ^L and R ^R is selected from the group comprising the general formula D, with Y being a group described by a general formula -L _r -M _k -L _s , wherein r of is 0, and

M _k is -(C=0)- with k being 1 or k is 0,

L _s is a Cs-alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 .

In some embodiments, at least one of R ^L and R ^R is selected from the group comprising the general formula D,

with Y being a group described by the general formula -L _r -M _k -L _s , wherein M _k is

-C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, with k of M _K being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, and,

- with each R ^D being selected independently from any other R ^D from H, -R ^2d , -C(=0)R ^2d , -C(=0)OR ^2d , -C(=0)NR ^2d ₂ , -C(=0)SR ^2d , -C(=S)OR ^2d , -C(=S)R ^2d or -SR ^2d , in particular from H, -R ^2d or -C(=0)R ^2d , with each R ^2d independently from any other R ^2d being a hydrogen or C1-C4 alkyl, and

with the other one of R ^L and R ^R being selected from H or -C _c -P, with P being

-H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or

-I, in particular P being -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and with R ⁴ being hydrogen or C1-C4 alkyl.

In some embodiments, at least one of R ^L and R ^R is selected from the group comprising the general formula D, with k of M _k and r of L _r being 0, and L _s being a Ci-alkyl with s being 1 , or M _k being -(C=0)- with k being 1 , r of L _r being 0, and L _s being a Ci-alkyl with s being 1 ,

with each R ^D being selected independently from any other R ^D from H, -R ^2d , -C(=0)R ^2d , -C(=0)OR ^2d , -C(=0)NR ^2d ₂ , -C(=0)SR ^2d , -C(=S)OR ^2d , -C(=S)R ^2d or -SR ^2d , in particular from H, -R ^2d or -C(=0)R ^2d , with each R ^2d independently from any other R ^2d being a hydrogen or C1-C4 alkyl, and with the other one of R ^L and R ^R being selected from H or -C _c -P, with P being -H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular P being -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and with R ⁴ being hydrogen or CrC ₄ alkyl.

In some embodiments, R ^L and R ^R are both selected from the group comprising the general formula D, with Y being a group described by a general formula, -L _r -M _k -L _s , wherein M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, particular -C(=0)-, with k being 0 or 1 , L _r is a C _r - alkyl with r being 0, 1 , 2, 3 or 4 and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4.

In some embodiments, R ^L and R ^R are both selected from the group comprising the general formula D, with Y being a group described by a general formula, -L _r -M _k -L _s , wherein M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, particular -C(=0)-, with k being 0 or 1 , L _r is a C _r - alkyl with r being 0, 1 , 2, 3 or 4 and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, with each R ^D being selected independently from any other R ^D from H, R ^2d , -C(=0)R ^2d , -C(=0)OR ^2d , -C(=0)NR ^2d ₂ , -C(=0)SR ^2d , -C(=S)OR ^2d , -C(=S)R ^2d or-SR ^2d , in particular from H, -R ^2d or -C(=0)R ^2d , with each R ^2d independently from any other R ^2d being a hydrogen or d-C ₄ alkyl.

In some embodiments, R ^L and R ^R are both selected from the group comprising the general formula D, with Y being a group described by a general formula, -L _r -M _k -L _s , with k of M _k and r of being 0, and L _s being a Ci-alkyl with s being 1 , or M _k being -(C=0)- with k being 1 , r of L _r being 0, and L _s being a Ci-alkyl with s being 1 .

In some embodiments, R ^L and R ^R are both selected from the group comprising the general formula D, with each R ^D being selected independently from any other R ^D from H, R ^2d , - C(=0)R ^2d , -C(=0)OR ^2d , -C(=0)NR ^2d ₂ , -C(=0)SR ^2d , -C(=S)OR ^2d , -C(=S)R ^2d or-SR ^2d , in particular from H, -R ^2d or -C(=0)R ^2d , with each R ^2d independently from any other R ^2d being a hydrogen or d-C ₄ alkyl, and with Y being a group described by a general formula -L _r -M _k -L _s , wherein

k of M _k and r of L _r being 0, and L _s being a Ci-alkyl with s being 1 , or

M _k is -(C=0)- with k being 1 , r of L _r being 0, and L _s being a Ci-alkyl with s being 1 .

In some embodiments, R ^L and R ^R are identical and selected from the group comprising the general formula D, wherein Y, L _r , M _k , L _s , R ^D and R ^2d have the same meaning as defined in the previously described embodiments.

In some embodiments, OM is a metal sandwich complex, wherein each of the two sandwich ligands is selected independently from a five-membered or six-membered aryl group or a five-membered or six-membered heteroaryl group. In some embodiments, OM is a metal sandwich complex, wherein both sandwich ligands are the same and are selectedfrom a five- membered or six-membered aryl group or a five-membered or six-membered heteroaryl group. In some embodiments, OM is a metal sandwich complex, wherein at least one of the two ligands is selected from a five-membered or six-membered aryl group, wherein the other is selected from a five-membered or six-membered heteroaryl group. In some embodiments, OM is a substituted or unsubstituted metallocene, wherein each of two ligands is selected independently from a five-membered aryl group (cp-ligand) or a five-membered heteroaryl group (hetero cp-ligand). The metal sandwich complex may be connected to the parent molecule by any atom of one of the two sandwich ligands Furthermore or additionally, it may comprise a cationic metal sandwich complex, e.g. cobaltocenium with a suitable counter anion such as iodide, chloride bromide, fluoride, triflate, tetrafluoroborate or

hexafluorophosphate.

Compounds comprising an OM of the general formula (2a):

In some embodiments, OM is a metal sandwich complex of the general formula (2a),

wherein M is a metal selected from Fe, Ru, Co, Ni, Cr, Os or Mn, and

T is C or N, and

z of R _z ^u is 0, 1 , 2 or 3, in particular z of R _z ^u is 0 or 1 , and

y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular y of R _y ^L is 0, 1 or 2, and

R _z ^u is a C1-C1 ₀ alkyl, in particular a C1-C4 alkyl, and

- R _y ^L is selected from -OCF ₃ , -CN, -CF ₃ , -SCN, F, CI, Br, l,-SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -OR ⁵ or -R ⁵ ,

with R ⁵ being hydrogen, C1-C1 ₀ alkyl, in particular C1-C4 alkyl, or C1-C4 alkyl substituted with C1-C4 alkoxy.

In some embodiments, M of the general formula 2a is Fe, Ru or Co. In some embodiments, M of the general formula 2a is Fe or Ru. In some embodiments, M of the general formula 2a is Fe.

In some embodiments, T is C.

In some embodiments, M of the general formula 2a is Fe and T is C. In some embodiments, T is C, and z of R _z is 0, 1 , 2 or 3, R _z is a C-i-C-io alkyl, in particular a C1-C4 alkyl, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, and R _y ^L is selected from -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -OR ⁵ or -R ⁵ , with R ⁵ being hydrogen, C1-C1 ₀ alkyl, in particular C1-C4 alkyl, or C1-C4 alkyl substituted with C1-C4 alkoxy.

In some embodiments, T is C, and z of R _z ^u is 0 or 1 , R _z ^u is a C1-C1 ₀ alkyl, in particular a C C ₄ alkyl, y of R _y ^L is 0, 1 or 2, and R _y ^L is selected from -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -OR ⁵ or -R ⁵ , with R ⁵ being hydrogen, C1-C1 ₀ alkyl, in particular C1-C4 alkyl, or C1-C4 alkyl substituted with C1-C4 alkoxy.

In some embodiments, M of the general formula 2a is a metal selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is Fe or Ru, further in particular M is Fe, T is C or N, wherein R ^u is a C1-C1 ₀ alkyl, in particular a C1-C4 alkyl and R ^L is selected from -SCF ₃ , -SOCF ₃ , -SO2CF ₃ , -OR ⁵ or -R ⁵ , with R ⁵ being hydrogen, C1-C1 ₀ alkyl, in particular C C ₄ alkyl, or C1-C4 alkyl substituted with C1-C4 alkoxy, and

- z of R _z ^u is 1 , y of R _y ^L is 0,

- z of R _z ^u is 1 , y of R _y ^L is 1 ,

- z of R _z ^u is 1 , y of R _y ^L is 2,

- z of R _z ^u is 0, y of R _y ^L is 1 , or

- z of R _z ^u is 0, y of R _y ^L is 2.

In some embodiments, M of the general formula 2a is a metal selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is Fe or Ru, further in particular M is Fe, T is C or N, wherein R ^u is a C1-C1 ₀ alkyl, in particular a C1-C4 alkyl and R ^L is selected from -SCF ₃ , - SOCF ₃ , -SO2CF ₃ , -OR ⁵ or -R ⁵ , with R ⁵ being hydrogen, C1-C1 ₀ alkyl, in particular C C ₄ alkyl, or C1-C4 alkyl substituted with C1-C4 alkoxy, and z of R _z ^u is 0, y of R _y ^L is 0,

In some embodiments, T is N, z of R _z ^u is 0 and y of R _y ^L is 0. In some embodiments, T is N, z of R _z ^u is 0, y of R _y ^L is 0, and M of the general formula 2a is selected from the group of Fe, Ru or Co, in particular M is Fe or Ru, further in particular M is Fe.

In some embodiments, T is C, z of R _z ^u is 0 and y of R _y ^L is 0. In some embodiments, T is C, z of R _z ^u is 0, y of R _y ^L is 0, and M of the general formula 2a is selected from the group of Fe, Ru or Co, in particular M is Fe or Ru, further in particular M is Fe.

In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein

- F| is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, - C(=0)0-, -C(=S)0-, -0-C(=0)-, -0-C(=S)-, in particular -NH-(C=0)- or -O-, with I being 1 , K _p is a Cp-alkyl with p being 0, 1 , 2, 3 or 4, K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4,

F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , or

F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 1 , and each R ¹ independently from any other R ¹ is -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN, with n of R ¹ _n being 0, 1 , 2, 3, 4 or 5,

- wherein the other one of R ^L and R ^R can be selected from H or -C _c -P, with P being

- -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ ,

-C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,

-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-l, in particular -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ ,

-S0 ₂ CF ₃ or -CN,

- with c being 0, 1 , 2, 3 or 4, and

- with each R ⁴ independently from any other R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F _r K _q -, wherein F| is -NH-(C=0)- or -O- with I being 1 , p of Kp is 0, and K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and

n of R ¹ _n is 1 or 2,

n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

- n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta

position to the attachment position of the benzene moiety, n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety,

- wherein the other one of R ^L and R ^R can be selected from H or -C _c -P, with P being

- -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ ,

-C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,

-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-I, in particular -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ ,

-S0 ₂ CF ₃ or -CN,

- with c being 0, 1 , 2, 3 or 4, and

- with each R ⁴ independently from any other R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and

- n of R ¹ _n is 1 or 2,

n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

- n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety,

wherein the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, - (HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or CrC ₄ alkyl.

In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by the general formula -K _p -F|-K _q -, wherein F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and

- n of R ¹ _n is 1 or 2,

n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

- n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety, and wherein

the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -OR ⁴ and R ⁴ being hydrogen or d-C ₄ alkyl, in particular hydrogen.

In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by the general formula -K _p -F _r K _q -, wherein F| is -0-, -NH, -NHC(=0)-, -NHC(=S)-, - C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)- or -0-C(=S)-, in particular -NH-(C=0)- or -0-, with I being 1 , p of K _p is 0, K _q is a C or C ₂ -alkyl, in particular a Ci-alkyl, and

n of R ¹ _n is 1 or 2, n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety, and

the other one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by the general formula -K _p -F|-K _q -, wherein F| is -0-, -NH, - NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -O- C(=0)- or -0-C(=S)-, in particular -NH-(C=0)- or -0-, with I being 1 , p of K _p is 0, K _q is a C or C ₂ -alkyl, in particular a Ci-alkyl, and

n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety.

In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F _r K _q -, wherein F| is -0-, -NH, -NHC(=0)-, -NHC(=S)-, - C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)-, -0-C(=S)-, in particular -NH-(C=0)- or -0-, with I being 0 or 1 ,

- Kp is a Cp-alkyl with p being 0, 1 , 2, 3 or 4, in particular p being 0,

K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and wherein

each R ¹ independently from any other R ¹ is -C(=0)OR ² , -C(=0)NR ² ₂ , -C(=0)SR ² , -C(=S)OR ² -C(NH)NR ² 2, -CN ₄ H ₂ , -NR ² ₂ , -C(=0)R ² , -C(=S)R ² , -OR ² , -SR ² , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

- with each R ² independently from any other R ² being hydrogen, CH ₃ , C ₂ H ₅ , C ₃ H ₇ or C ₄ H _9, in particular with each R ² being hydrogen, and the other one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by the general formula -K _p -F|-K _q -, wherein F| is -0-, -NH, - NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -O- C(=0)-, -0-C(=S)-, in particular -NH-(C=0)- or -0-, with I being 0 or 1 ,

- K _p is a Cp-alkyl with p being 0, 1 , 2, 3 or 4, in particular p being 0,

K _q is a Cq-alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and wherein

each R ¹ independently from any other R ¹ is -C(=0)OR ² , -C(=0)NR ² ₂ , -C(=0)SR ² , -C(=S)OR ² -C(NH)NR ² 2, -CN ₄ H ₂ , -NR ² ₂ , -C(=0)R ² , -C(=S)R ² , -OR ² , -SR ² , -CF ₃ , -OCF3, -SCF3, -SOCF3, -SO2CF3, -CN, -NO2, -F, -CI, -Br or -I , , in particular -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -SO2CF ₃ or -CN,

with each R ² independently from any other R ² being hydrogen, CH ₃ , C ₂ H ₅ , C ₃ H ₇ or C ₄ H _9, in particular with each R ² being hydrogen.

In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, wherein R ^L and R ^R are identical and selected from the group comprising the general formula A, wherein X, K _p , F|, K _q , R ¹ _n , n and R ² have the same meaning as defined in the previously described embodiments.

In some embodiments, M of the general formula 2a is Fe, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by the general formula -K _p - F|-K _q -, wherein

- F| is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -

C(=0)0-, -C(=S)0-, -0-C(=0)- or -0-C(=S)-, in particular -NH-(C=0)- or -O-, with I being

1 , Kp is a Cp-alkyl with p being 0, 1 , 2, 3 or 4, K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4,

F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 0, 1 ,

2, 3 or 4, in particular q being 1 , or

- F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 1 , and each R ¹ independently from any other R ¹ is -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or - CN, with n of R ¹ _n being 0, 1 , 2, 3, 4 or 5

- wherein the other one of R ^L and R ^R can be selected from H or -C _c -P, with P being - -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ , -C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,

-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-I, in particular -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ ,

-S0 ₂ CF ₃ or -CN,

- with c being 0, 1 , 2, 3 or 4, and

- with each R ⁴ independently from any other R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, M of the general formula 2a is Fe, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by the general formula -K _p - F|-K _q -, wherein F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and

n of R ¹ _n is 1 or 2,

- n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety,

- n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety,

- wherein the other one of R ^L and R ^R can be selected from H or -C _c -P, with P being

- -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ ,

-C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,

-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-l, in particular -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ ,

-S0 ₂ CF ₃ or -CN,

- with c being 0, 1 , 2, 3 or 4, and

- with each R ⁴ independently from any other R ⁴ being hydrogen or d-C ₄ alkyl. In some embodiments, M of the general formula 2a is Fe, T is C, z of R _z is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by the general formula -K _p - F|-K _q -, wherein F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and

n of R ¹ _n is 1 or 2,

n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, - n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety,

wherein the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, - (HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or CrC ₄ alkyl.

In some embodiments, M of the general formula 2a is Fe, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p - F|-K _q -, wherein F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and

n of R ¹ _n is 1 or 2,

- n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety, n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, - n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety, and wherein

the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -OR ⁴ and R ⁴ being hydrogen or CrC ₄ alkyl, in particular hydrogen.

In some embodiments, M of the general formula 2a is Fe, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p - Fi-Kq-, wherein F, is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)-, -0-C(=S)-, in particular -NH-(C=0)- or -O-, with I being 1 , p of K _p is 0, K _q is a d- or C ₂ -alkyl, in particular a Ci-alkyl, and

n of R ¹ _n is 1 or 2,

n of R ¹ _n is 2,

- n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety, and

the other one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein F| is -0-, -NH, -NHC(=0)- , -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)- or -0-C(=S)-, in particular -NH-(C=0)- or -0-, with I being 1 , p of K _p is 0, K _q is a C or C ₂ -alkyl, in particular a Ci-alkyl, and

n of R ¹ _n is 1 ,

- n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety.

In some embodiments, M of the general formula 2a is Fe, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p - Fi-Kq-, wherein F, is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, - C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)- or -0-C(=S)-, in particular -NH-(C=0)- or -O-, with I being 0 or 1 ,

- K _p is a Cp-alkyl with p being 0, 1 , 2, 3 or 4, in particular p being 0,

K _q is a Cq-alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and wherein

each R ¹ independently from any other R ¹ is -C(=0)OR ² , -C(=0)NR ² ₂ , -C(=0)SR ² , -C(=S)OR ² -C(NH)NR ² 2, -CN ₄ H ₂ , -NR ² ₂ , -C(=0)R ² , -C(=S)R ² , -OR ² , -SR ² , -CF ₃ , -OCF3, -SCF3, -SOCF3, -SO2CF3, -CN, -NO2, -F, -CI, -Br or -I , in particular -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -SO2CF ₃ or -CN,

- with each R ² independently from any other R ² being hydrogen, CH ₃ , C ₂ H ₅ , C ₃ H ₇ or C ₄ H _9, in particular with each R ² being hydrogen, and

the other one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by the general formula -K _p -F|-K _q -, wherein F| is -0-, -NH, - NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -O- C(=0)- or -0-C(=S)-, in particular -NH-(C=0)- or -0-, with I being 0 or 1 ,

Kp is a Cp-alkyl with p being 0, 1 , 2, 3 or 4, in particular p being 0,

K _q is a Cq-alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and wherein

each R ¹ independently from any other R ¹ is -C(=0)OR ² , -C(=0)NR ² ₂ , -C(=0)SR ² , -C(=S)OR ² -C(NH)NR ² 2, -CN ₄ H ₂ , -NR ² ₂ , -C(=0)R ² , -C(=S)R ² , -OR ² , -SR ² , -CF ₃ ,

-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I , in particular -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

with each R ² independently from any other R ² being hydrogen, CH ₃ , C ₂ H ₅ , C ₃ H ₇ or C ₄ H _9, in particular with each R ² being hydrogen.

In some embodiments, M of the general formula 2a is Fe, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, wherein R ^L and R ^R are identical and selected from the group comprising the general formula A, wherein X, K _p , F|, K _q , R ¹ _n , n and R ² have the same meaning as defined in the previously described embodiments. In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula B, with Y being a group described by a general formula, -L _r -M _k -L _s , wherein

M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 ,

k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , or,

k is 0, r of is 0, and s of L _s is 0,

and R ^A is selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ^2a , -NR ^2a ₂ or R ^2a , with R ^2a being a hydrogen or CrC ₄ alkyl,

- wherein the other one of R ^L and R ^R can be selected from H or -C _c -P, with P being

- -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ ,

-C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,

-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-l, in particular -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ ,

-S0 ₂ CF ₃ or -CN,

- with c being 0, 1 , 2, 3 or 4, and

- with each R ⁴ independently from any other R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula B, with Y being a group described by the general formula, -L _r -M _k -L _s , wherein

- M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 , k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , or,

k is 0, r of is 0, and s of L _s is 0,

and R ^A is selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ^2a , -NR ^2a ₂ or R ^2a , with R ^2a being a hydrogen or CrC ₄ alkyl, wherein the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and R ^L and R ^R are selected from the group comprising the general formula B, with Y being a group described by a general formula, -L _r -M _k -L _s , wherein

- M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 ,

k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , or,

k is 0, r of is 0, and s of L _s is 0,

and R ^A is selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ^2a , -NR ^2a ₂ or R ^2a , with R ^2a being a hydrogen or d-C ₄ alkyl.

In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, wherein R ^L and R ^R are identical and selected from the group comprising the general formula B, wherein Y, L _r , M _k , l_s, R ^A and R ^2a have the same meaning as defined in the previously described

embodiments.

In some embodiments, M of the general formula 2a is Fe, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula B, with Y being a group described by a general formula, -L _r - M _k -L _s , wherein

M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

- M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 ,

k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , or,

k is 0, r of is 0, and s of L _s is 0,

and R ^A is selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ^2a , -NR ^2a ₂ or R ^2a , with R ^2a being a hydrogen or CrC ₄ alkyl, wherein the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, M of the general formula 2a is Fe, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and R ^L and R ^R are both selected from the group comprising the general formula B, with Y being a group described by a general formula -L _r - M _k -L _s , wherein

- M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 ,

k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , or,

k is 0, r of is 0, and s of L _s is 0,

and R ^A is selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ^2a , -NR ^2a ₂ or R ^2a , with R ^2a being a hydrogen or d-C ₄ alkyl.

In some embodiments, M of the general formula 2a is Fe, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, wherein R ^L and R ^R are identical and selected from the group comprising the general formula B, wherein Y, L _r , M _k , L _s , R ^A and R ^2a have the same meaning as defined in the previously described embodiments. In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula C, with Z being a group described by the general formula -K _r -Fi-K _r , wherein

- Fj is -0-, -S-, -0-C(=0)-, -0-C(=S)-, -S-C(=0)- or NH-(C=0)- with i being 0 or 1 , K _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, i of Fi is 0, r of K _r is 0 and t of K _s is 0, or

- i of Fi is 0, r of K _r is 0 and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, in particular s being 1 ,

and R ^B being H, -R ^2b , -C(=0)R ^2b , -C(=0)OR ^2b , -C(=0)NR ^2b ₂ , -C(=0)SR ^2b , -C(=S)OR ^2b or - C(=S)R ^2b , in particular from H , R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or CrC ₄ alkyl,

wherein the other one of R ^L and R ^R can be selected from H or -C _c -P,

- with P being -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ , -C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-l , in particular H, -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

- with c being 0, 1 , 2, 3 or 4, and

with each R ⁴ independently from any other R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula C, with Z being a group described by a general formula -K _r -Fi-K _r , wherein

- Fi is -0-, -S-, -0-C(=0)-, -0-C(=S)-, -S-C(=0)- or NH-(C=0)- with i being 0 or 1 , K _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4,

- i of Fi is 0, r of K _r is 0 and t of K _s is 0, or

i of Fi is 0, r of K _r is 0 and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, in particular s being 1 ,

and R ^B being H, -R ^2b , -C(=0)R ^2b , -C(=0)OR ^2b , -C(=0)NR ^2b ₂ , -C(=0)SR ^2b , -C(=S)OR ^2b or - C(=S)R ^2b , in particular from H , R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or C1-C4 alkyl, wherein the other one of R ^L and R ^R is selected from H or -Cc-P, with P being -H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF3, -S0 ₂ CF ₃ , -CN, - N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or C1-C4 alkyl.

In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and R ^L and R ^R are both selected from the group comprising the general formula C, with Z being a group described by the general formula -K _r -Fi-K _r , wherein

- Fj is -0-, -S-, -0-C(=0)-, -0-C(=S)-, -S-C(=0)- or NH-(C=0)- with i being 0 or 1 , K _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, i of Fj is 0, r of K _r is 0 and t of K _s is 0, or

i of Fj is 0, r of K _r is 0 and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, in particular s being 1 ,

and R ^B being H, -R ^2b , -C(=0)R ^2b , -C(=0)OR ^2b , -C(=0)NR ^2b ₂ , -C(=0)SR ^2b , -C(=S)OR ^2b or - C(=S)R ^2b , in particular from H, R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or C1-C4 alkyl.

In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru,, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, wherein R ^L and R ^R are identical and selected from the group comprising the general formula C, wherein Z, K _r , Fj, K _t , R ^B and R ^2a have the same meaning as defined in the previously described embodiments. In some embodiments, M of the general formula 2a is Fe, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula C, with Z being a group described by a general formula -Kr- Fi-Kr, wherein

- Fj is -0-, -S-, -0-C(=0)-, -0-C(=S)-, -S-C(=0)- or NH-(C=0)- with i being 0 or 1 , K _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, i of Fj is 0, r of K _r is 0 and t of K _s is 0, or

i of Fj is 0, r of K _r is 0 and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, in particular s being 1 , and R being H, -R , -C(=0)R , -C(=0)OR , -C(=0)NR ₂ , -C(=0)SR , -C(=S)OR or - C(=S)R ^2b , in particular from H, R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or C1-C4 alkyl,

wherein the other one of R ^L and R ^R can be selected from H or -C _c -P,

- with P being -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ , -C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-l, in particular H, -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

with c being 0, 1 , 2, 3 or 4, and

- with each R ⁴ independently from any other R ⁴ being hydrogen or C1-C4 alkyl.

In some embodiments, M of the general formula 2a is Fe, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula C, with Z being a group described by a general formula -K _r - Fj-Kr, wherein

- Fj is -0-, -S-, -0-C(=0)-, -0-C(=S)-, -S-C(=0)- or NH-(C=0)- with i being 0 or 1 , K _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, i of Fj is 0, r of K _r is 0 and t of K _s is 0, or

i of Fj is 0, r of K _r is 0 and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, in particular s being 1 ,

and R ^B being H, -R ^2b , -C(=0)R ^2b , -C(=0)OR ^2b , -C(=0)NR ^2b ₂ , -C(=0)SR ^2b , -C(=S)OR ^2b or - C(=S)R ^2b , in particular from H, R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or C1-C4 alkyl, wherein the other one of R ^L and R ^R is selected from H or -Cc-P, with P being -H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, - N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or C1-C4 alkyl.

In some embodiments, M of the general formula 2a is Fe, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and R ^L and R ^R are both selected from the group

comprising the general formula C, with Z being a group described by the general formula -K _r - Fi-Kr, wherein

- Fj is -0-, -S-, -0-C(=0)-, -0-C(=S)-, -S-C(=0)- or NH-(C=0)- with i being 0 or 1 , K _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, i of Fj is 0, r of K _r is 0 and t of K _s is 0, or i of Fj is 0, r of K _r is 0 and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, in particular s being 1 ,

and R ^B being H, -R ^2b , -C(=0)R ^2b , -C(=0)OR ^2b , -C(=0)NR ^2b ₂ , -C(=0)SR ^2b , -C(=S)OR ^2b or - C(=S)R ^2b , in particular from H, R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or CrC ₄ alkyl.

In some embodiments, M of the general formula 2a is Fe, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, wherein R ^L and R ^R are identical and selected from the group comprising the general formula C, wherein Z, K _r , F,, K _t , R ^B and R ^2a have the same meaning as defined in the previously described embodiments.

In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula D, with Y being a group described by a general formula, -L _r -M _k -L _s , wherein

M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 , or

k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , and each R ^D being selected independently from any other R ^D from H, R ^2d , -C(=0)R ^2d , -C(=0)OR ^2d , -C(=0)NR ^2d ₂ , -C(=0)SR ^2d , -C(=S)OR ^2d , -C(=S)R ^2d or-SR ^2d , in particular from H, -R ^2d or -C(=0)R ^2d , with each R ^2d independently from any other R ^2d being a hydrogen or d-C ₄ alkyl,

wherein the other one of R ^L and R ^R can be selected from H or -C _c -P,

- with P being -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ , -C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-l, in particular H, -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

with c being 0, 1 , 2, 3 or 4, and

with each R ⁴ independently from any other R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula D, with Y being a group described by a general formula, -L _r -M _k -L _s , wherein

- M _k is -C(=0)-, -C(=0)0-, -C(=S)-, -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 , or

k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , and each R ^D being selected independently from any other R ^D from H, R ^2d , -C(=0)R ^2d ,

-C(=0)OR ^2d , -C(=0)NR ^2d ₂ , -C(=0)SR ^2d , -C(=S)OR ^2d , -C(=S)R ^2d or-SR ^2d , in particular from H, -R ^2d or -C(=0)R ^2d , with each R ^2d independently from any other R ^2d being a hydrogen or CrC ₄ alkyl, wherein the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, - (HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and R ^L and R ^R are selected from the group comprising the general formula D, with Y being a group described by a general formula, -L _r -M _k -L _s , wherein

M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

- M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 , or

k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , and each R ^D being selected independently from any other R ^D from H, R ^2d , -C(=0)R ^2d , -C(=0)OR ^2d , -C(=0)NR ^2d ₂ , -C(=0)SR ^2d , -C(=S)OR ^2d , -C(=S)R ^2d or-SR ^2d , in particular from H, -R ^2d or -C(=0)R ^2d , with each R ^2d independently from any other R ^2d being a hydrogen or C C ₄ alkyl.

In some embodiments, M of the general formula 2a is selected from the group of Fe, Ru, Co, Ni, Cr, Os or Mn, in particular M is selected from Fe, Ru or Co, further in particular M is Fe or Ru,, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, wherein R ^L and R ^R are identical and selected from the group comprising the general formula D, wherein Y, L _r , M _k , l_s, R ^A and R ^2a have the same meaning as defined in the previously described

embodiments.

In some embodiments, M of the general formula 2a is Fe, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula D, with Y being a group described by a general formula -L _r - M _k -L _s , wherein

- M _k is -C(=0)-, -C(=0)0-, -C(=S)-, -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 , or

k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , and each R ^D being selected independently from any other R ^D from H, R ^2d , -C(=0)R ^2d ,

-C(=0)OR ^2d , -C(=0)NR ^2d ₂ , -C(=0)SR ^2d , -C(=S)OR ^2d , -C(=S)R ^2d or-SR ^2d , in particular from H, -R ^2d or -C(=0)R ^2d , with each R ^2d independently from any other R ^2d being a hydrogen or CrC ₄ alkyl,

wherein the other one of R ^L and R ^R can be selected from H or -C _c -P,

- with P being -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ , -C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-l, in particular H, -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

with c being 0, 1 , 2, 3 or 4, and

- with each R ⁴ independently from any other R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, M of the general formula 2a is Fe, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and at least one of R ^L and R ^R is selected from the group comprising the general formula D, with Y being a group described by a general formula -L _r - M _k -L _s , wherein

M _k is -C(=0)-, -C(=0)0-, -C(=S)-, -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 , or k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , and each R ^D being selected independently from any other R ^D from H, R ^2d , -C(=0)R ^2d , -C(=0)OR ^2d , -C(=0)NR ^2d ₂ , -C(=0)SR ^2d , -C(=S)OR ^2d , -C(=S)R ^2d or-SR ^2d , in particular from H, -R ^2d or -C(=0)R ^2d , with each R ^2d independently from any other R ^2d being a hydrogen or CrC ₄ alkyl, wherein the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, - (HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, M of the general formula 2a is Fe, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, and R ^L and R ^R are selected from the group comprising the general formula B, with Y being a group described by a general formula -L _r -M _k -L _s , wherein

M _k is -C(=0)-, -C(=0)0-, -C(=S)-, -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

- M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 , or

k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , and R ^A being selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ^2a , -NR ^2a ₂ or R ^2a , with R ^2a being a hydrogen or d-C ₄ alkyl.

In some embodiments, M of the general formula 2a is Fe, T is C, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0, y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular R _y ^L is 0, R _y ^L and R _z ^u have the same meaning as defined above, wherein R ^L and R ^R are identical and selected from the group comprising the general formula D, wherein Y, L _r , M _k , L _s , R ^D and R ^2d have the same meaning as defined in the previously described embodiments.

Examples are:

The last compound may comprise a counter anion CA selected from , CI ^" , Br ^" , F ^" , BF ₄ ^" , CF ₃ SO ₃ ^" (OTf) or PF ₆ ^" .

In some embodiments, OM is a metal sandwich complex of the general formula (2a'),

wherein M is a metal selected from Fe, Ru, Co, Ni, Cr, Os or Mn, and

T is C or N, and

z of R _z ^u is 0, 1 , 2 or 3, in particular z of R _z ^u is 0 or 1 , and

y of R _y ^L is 0, 1 , 2, 3, 4 or 5, in particular y of R _y ^L is 0, 1 or 2, and

R _z ^u is a C1-C10 alkyl, in particular a C C ₄ alkyl, and

- R _y ^L is selected from -OCF ₃ , -CN, -CF ₃ , -SCN, F, CI, Br, I -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -OR ⁵ or -R ⁵ ,

with R ⁵ being hydrogen, C1-C10 alkyl, in particular d-C ₄ alkyl, or d-C ₄ alkyl substituted with d-C ₄ alkoxy.

Reference is made to the previously described embodiments concerning the use of a metal sandwich complex of the general formula (2a). The same embodiments concerning in particular R ^L and R ^R , are possible with said metal sandwich complex of the general formula (2a'). The same applies to a half metal sandwich complex of the general formula (2b), as discussed below.

The metal sandwich complex of the general formula (2a) in the above mentioned

embodiments may be neutral or cationic species, particularly the metal sandwich complex with M being Co may be in the cationic form comprising a counter anion CA selected from , CI ^" , Br , F, BF ₄ ^" , CF ₃ S0 ₃ ^~ (OTf) or PF ₆ \

Compounds comprising an OM of the general formula (2b):

In some embodiments, OM is a half metal sandwich complex of the general formula (2b),

(2b)

wherein M is a metal selected from Mn, Re or Tc, and z of R _z ^u is 0, 1 , 2 or 3, in particular z of R _z ^u is 0 or 1 , with R _z ^u being C-I-C-IO alkyl, in particular d-C ₄ alkyl

In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C1-C1 ₀ alkyl, in particular a Ci-C ₄ alkyl, and at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p - F|-K _q -, wherein

- F| is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, - C(=0)0-, -C(=S)0-, -0-C(=0)- or -0-C(=S)-, in particular -NH-(C=0)- or -O-, with I being 1 , K _p is a Cp-alkyl with p being 0, 1 , 2, 3 or 4, K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4,

F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , or

F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 1 , and each R ¹ independently from any other R ¹ is -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or - CN, with n of R ¹ _n being 0, 1 , 2, 3, 4 or 5,

wherein the other one of R ^L and R ^R can be selected from H or -C _c -P,

- with P being -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ , -C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-l, in particular H, -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

with c being 0, 1 , 2, 3 or 4, and

with each R ⁴ independently from any other R ⁴ being hydrogen or d-C ₄ alkyl. In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C1-C10 alkyl, in particular a C1-C4 alkyl, and at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by the general formula -K _p - F|-K _q -, wherein F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and

n of R ¹ _n is 1 or 2,

n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, - n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety,

- wherein the other one of R ^L and R ^R can be selected from H or -C _c -P, with P being

- -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ ,

-C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,

-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-I, in particular -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ ,

-S0 ₂ CF ₃ or -CN,

- with c being 0, 1 , 2, 3 or 4, and

- with each R ⁴ independently from any other R ⁴ being hydrogen or C1-C4 alkyl.

In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C1-C10 alkyl, in particular a C1-C4 alkyl, and at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p - F|-K _q -, wherein F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and

n of R ¹ _n is 1 or 2, n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

- n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety,

wherein the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, - (HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or CrC ₄ alkyl.

In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C ₁ -C ₁₀ alkyl, in particular a C C ₄ alkyl, and at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p - F|-K _q -, wherein F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and

n of R ¹ _n is 1 or 2,

n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, - n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety, and wherein

the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -OR ⁴ and R ⁴ being hydrogen or C1-C4 alkyl, in particular hydrogen.

In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C1-C1 ₀ alkyl, in particular a C1-C4 alkyl, at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p - Fi-Kq-, wherein F, is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, - C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)-, -0-C(=S)-, in particular -NH-(C=0)- or -0-, with I being 1 p of K _p is 0, K _q is a d- or C ₂ -alkyl, in particular a Ci-alkyl, and

n of R ¹ _n is 1 or 2,

n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety, and

the other one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein F| is -0-, -NH, -NHC(=0)- , -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)-, -O- C(=S)-, in particular -NH-(C=0)- or -0-, with I being 1 , p of K _p is 0, K _q is a C or C ₂ -alkyl, in particular a Ci-alkyl, and

n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, - n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety.

In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C Ci ₀ alkyl, in particular a C1-C4 alkyl, at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p - F|-K _q -, wherein F, is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, - C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)- or -0-C(=S)-, in particular -NH-(C=0)- or -O-, with I being 0 or 1 ,

K _p is a Cp-alkyl with p being 0, 1 , 2, 3 or 4, in particular p being 0,

K _q is a Cq-alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and wherein - each R ¹ independently from any other R ¹ is -C(=0)OR ² , -C(=0)NR ² ₂ , -C(=0)SR ² ,

-C(=S)OR ² -C(NH)NR ² 2, -CN ₄ H ₂ , -NR ² ₂ , -C(=0)R ² , -C(=S)R ² , -OR ² , -SR ² , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

- with each R ² independently from any other R ² being hydrogen, CH ₃ , C ₂ H ₅ , C ₃ H ₇ or C4H _9, in particular with each R ² being hydrogen, and

the other one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein F| is -0-, -NH, -NHC(=0)- , -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)-, -O- C(=S)-, in particular -NH-(C=0)- or -0-, with I being 0 or 1 ,

- Kp is a Cp-alkyl with p being 0, 1 , 2, 3 or 4, in particular p being 0,

K _q is a Cq-alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and wherein

each R ¹ independently from any other R ¹ is -C(=0)OR ² , -C(=0)NR ² ₂ , -C(=0)SR ² , -C(=S)OR ² -C(NH)NR ² 2, -CN ₄ H ₂ , -NR ² ₂ , -C(=0)R ² , -C(=S)R ² , -OR ² , -SR ² , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

with each R ² independently from any other R ² being hydrogen, CH ₃ , C ₂ H ₅ , C ₃ H ₇ or C4H _9, in particular with each R ² being hydrogen.

In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C1-C1 ₀ alkyi, in particular a C1-C4 alkyi, wherein R ^L and R ^R are identical and selected from the group comprising the general formula A, wherein X, K _p , F|, K _q , R ¹ _n , n and R ² have the same meaning as defined in the previously described embodiments.

In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C1-C1 ₀ alkyi, in particular a C1-C4 alkyi, and at least one of R ^L and R ^R is selected from the group comprising the general formula B, with Y being a group described by the general formula, -L _r - M _k -L _s , wherein

M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 ,

k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , or,

- k is 0, r of L _r is 0, and s of L _s is 0,

and R ^A being selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ^2a , -NR ^2a ₂ or R ^2a , with R ^2a being a hydrogen or CrC ₄ alkyl,

- wherein the other one of R ^L and R ^R can be selected from H or -C _c -P, with P being

- -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ ,

-C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,

-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-I, in particular -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ ,

-S0 ₂ CF ₃ or -CN,

- with c being 0, 1 , 2, 3 or 4, and

- with each R ⁴ independently from any other R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C ₁ -C ₁ 0 alkyl, in particular a C C ₄ alkyl, and at least one of R ^L and R ^R is selected from the group comprising the general formula B, with Y being a group described by a general formula, -L _r - M _k -L _s , wherein

M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 ,

- k is 0, r of L _r is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , or,

k is 0, r of is 0, and s of L _s is 0,

and R ^A being selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ^2a , -NR ^2a ₂ or R ^2a , with R ^2a being a hydrogen or d-C ₄ alkyl, wherein the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or d-C ₄ alkyl. In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C1-C1 ₀ alkyi, in particular a C1-C4 alkyi, and R ^L and R ^R are selected from the group comprising the general formula B, with Y being a group described by a general formula, -L _r -M _k -L _s , wherein - M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 ,

k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , or,

k is 0, r of is 0, and s of L _s is 0,

and R ^A being selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ^2a , -NR ^2a ₂ or R ^2a , with R ^2a being a hydrogen or C1-C4 alkyi.

In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C1-C1 ₀ alkyi, in particular a C1-C4 alkyi, wherein R ^L and R ^R are identical and selected from the group comprising the general formula B, wherein Y, L _r , M _k , L _s , R ^A and R ^2a have the same meaning as defined in the previously described embodiments.

In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C Ci ₀ alkyi, in particular a C1-C4 alkyi, and at least one of R ^L and R ^R is selected from the group comprising the general formula C, with Z being a group described by a general formula -K _r - Fi-Kr, wherein

- Fi is -0-, -S-, -0-C(=0)-, -0-C(=S)-, -S-C(=0)- or NH-(C=0)- with i being 0 or 1 , K _r is a C _r -alkyi with r being 0, 1 , 2, 3 or 4, and K _t is a C _t -alkyi with t being 0, 1 , 2, 3 or 4, i of Fi is 0, r of K _r is 0 and t of K _s is 0, or

i of Fi is 0, r of K _r is 0 and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, in particular s being 1 ,

and R ^B being H, -R ^2b , -C(=0)R ^2b , -C(=0)OR ^2b , -C(=0)NR ^2b ₂ , -C(=0)SR ^2b , -C(=S)OR ^2b or - C(=S)R ^2b , in particular from H, R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or C1-C4 alkyi,

wherein the other one of R ^L and R ^R can be selected from H or -C _c -P, - with P being -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ , -C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF _3! -OCF _3! -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-l, in particular H, -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

- with c being 0, 1 , 2, 3 or 4, and

with each R ⁴ independently from any other R ⁴ being hydrogen or Ci-C ₄ alkyi.

In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C1-C1 ₀ alkyi, in particular a C1-C4 alkyi, and at least one of R ^L and R ^R is selected from the group comprising the general formula C, with Z being a group described by a general formula -K _r - Fj-Kr, wherein

- Fi is -0-, -S-, -0-C(=0)-, -0-C(=S)-, -S-C(=0)- or NH-(C=0)- with i being 0 or 1 , K _r is a C _r - alkyl with r being 0, 1 , 2, 3 or 4, and K _t is a C _t -alkyi with t being 0, 1 , 2, 3 or 4,

- i of Fi is 0, r of K _r is 0 and t of K _s is 0, or

- i of Fi is 0, r of K _r is 0 and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, in particular s being 1 , and R ^B being H, -R ^2b , -C(=0)R ^2b , -C(=0)OR ^2b , -C(=0)NR ^2b ₂ , -C(=0)SR ^2b , -C(=S)OR ^2b or - C(=S)R ^2b , in particular from H, R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or C1-C4 alkyi, wherein the other one of R ^L and R ^R is selected from H or -Cc-P, with P being -H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, - N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or C1-C4 alkyi.

In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C1-C1 ₀ alkyi, in particular a C1-C4 alkyi, and R ^L and R ^R are both selected from the group comprising the general formula C, with Z being a group described by a general formula -K _r -Fi-K _r , wherein

- Fi is -0-, -S-, -0-C(=0)-, -0-C(=S)-, -S-C(=0)- or NH-(C=0)- with i being 0 or 1 , K _r is a C _r - alkyl with r being 0, 1 , 2, 3 or 4, and K _t is a C _t -alkyi with t being 0, 1 , 2, 3 or 4,

- i of Fi is 0, r of K _r is 0 and t of K _s is 0, or

- i of Fi is 0, r of K _r is 0 and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, in particular s being 1 , and R ^B being H, -R ^2b , -C(=0)R ^2b , -C(=0)OR ^2b , -C(=0)NR ^2b ₂ , -C(=0)SR ^2b , -C(=S)OR ^2b or - C(=S)R ^2b , in particular from H, R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or C1-C4 alkyi. In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C1-C10 alkyi, in particular a C1-C4 alkyi, wherein R ^L and R ^R are identical and selected from the group comprising the general formula C, wherein Z, K _r , F,, K _t , R ^B and R ^2a have the same meaning as defined in the previously described embodiments.

In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C1-C10 alkyi, in particular a C1-C4 alkyi, and at least one of R ^L and R ^R is selected from the group comprising the general formula D, with Y being a group described by a general formula, -L _r - M _k -L _s , wherein

M _k is -C(=0)-, -C(=0)0-, -C(=S)-, -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 , or

- k is 0, r of L _r is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , and each R ^D being selected independently from any other R ^D from H, R ^2d , -C(=0)R ^2d , -C(=0)OR ^2d , -C(=0)NR ^2d ₂ , -C(=0)SR ^2d , -C(=S)OR ^2d , -C(=S)R ^2d or-SR ^2d , in particular from H, -R ^2d or -C(=0)R ^2d , with each R ^2d independently from any other R ^2d being a hydrogen or C1-C4 alkyi,

wherein the other one of R ^L and R ^R can be selected from H or -C _c -P,

- with P being -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ , -C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-l, in particular H, -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

- with c being 0, 1 , 2, 3 or 4, and

with each R ⁴ independently from any other R ⁴ being hydrogen or C1-C4 alkyi.

In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C1-C10 alkyi, in particular a C1-C4 alkyi, and at least one of R ^L and R ^R is selected from the group comprising the general formula D, with Y being a group described by a general formula, -L _r - M _k -L _s , wherein

M _k is -C(=0)-, -C(=0)0-, -C(=S)-, -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 , or

k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , and each R ^D being selected independently from any other R ^D from H, R ^2d , -C(=0)R ^2d , -C(=0)OR ^2d , -C(=0)NR ^2d ₂ , -C(=0)SR ^2d , -C(=S)OR ^2d , -C(=S)R ^2d or-SR ^2d , in particular from H, -R ^2d or -C(=0)R ^2d , with each R ^2d independently from any other R ^2d being a hydrogen or CrC ₄ alkyi, wherein the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, - (HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or C1-C4 alkyi.

In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C1-C1 ₀ alkyi, in particular a C1-C4 alkyi, and R ^L and R ^R are both selected from the group comprising the general formula D, with Y being a group described by a general formula, -L _r -M _k -L _s , wherein

M _k is -C(=0)-, -C(=0)0-, -C(=S)-, -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 , or

- k is 0, r of L _r is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , and each R ^D being selected independently from any other R ^D from H, R ^2d , -C(=0)R ^2d , -C(=0)OR ^2d , -C(=0)NR ^2d ₂ , -C(=0)SR ^2d , -C(=S)OR ^2d , -C(=S)R ^2d or-SR ^2d , in particular from H, -R ^2d or -C(=0)R ^2d , with each R ^2d independently from any other R ^2d being a hydrogen or C1-C4 alkyi.

In some embodiments, M of the general formula 2b is selected from the group of Mn, Re or Tc, z of R _z ^u is 0, 1 , 2 or 3, in particular R _z ^u is 0 or 1 , more particularly R _z ^u is 0, R _z ^u is a C1-C1 ₀ alkyi, in particular a C1-C4 alkyi, wherein R ^L and R ^R are identical and selected from the group comprising the general formula D, wherein Y, L _r , M _k , L _s , R ^A and R ^2a have the same meaning as defined in the previously described embodiments.

The half metal sandwich complex of the general formula (2b) in the above mentioned embodiments may be neutral or cationic species, particularly the half metal sandwich complex with M being Co may be in the cationic form comprising a counter anion CA selected from I ^" , CI ^" , Br ^" , F ^" , BF ₄ ^" , CF ₃ S0 ₃ ^" (OTf) or PF ₆ ^" . An example is:

Compounds comprising an OM of the general formula (2c):

In some embodiments, OM comprises the general formula (2c),

C02(CO)6

(2c).

In some embodiments, OM comprises the general formula 2c, and at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein

- F| is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, - C(=0)0-, -C(=S)0-, -0-C(=0)-, -0-C(=S)-, in particular -NH-(C=0)- or -O-, with I being

1 , K _p is a C _p -alkyl with p being 0, 1 , 2, 3 or 4, K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4,

F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 0, 1 ,

2, 3 or 4, in particular q being 1 , or

F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 1 , and each R ¹ independently from any other R ¹ is -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or - CN, with n of R ¹ _n being 0, 1 , 2, 3, 4 or 5,

- wherein the other one of R ^L and R ^R can be selected from H or -C _c -P, with P being

- -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ ,

-C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,

-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-I, in particular -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ ,

-S0 ₂ CF ₃ or -CN,

- with c being 0, 1 , 2, 3 or 4, and

- with each R ⁴ independently from any other R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, OM comprises the general formula 2c, and at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and

n of R ¹ _n is 1 or 2,

n of R ¹ _n is 2,

- n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 1 ,

- n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety,

- wherein the other one of R ^L and R ^R can be selected from H or -C _c -P, with P being

- -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ ,

-C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,

-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-I, in particular -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or - CN,

- with c being 0, 1 , 2, 3 or 4, and

- with each R ⁴ independently from any other R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, OM comprises the general formula 2c, and at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and

n of R ¹ _n is 1 or 2,

n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety, n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

- n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety,

wherein the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, - (HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or CrC ₄ alkyl.

In some embodiments, OM comprises the general formula 2c, and at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein F| is -NH-(C=0)- or -O- with I being 1 , p of K _p is 0, and K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and

- n of R ¹ _n is 1 or 2,

n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta position to the attachment position of the benzene moiety,

n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

- n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety, and wherein

the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -OR ⁴ and R ⁴ being hydrogen or d-C ₄ alkyl, in particular hydrogen.

In some embodiments, OM comprises the general formula 2c, at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F _r K _q -, wherein F, is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, - C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)-, -0-C(=S)-, in particular -NH- (C=0)- or -0-, p of K _p is 0, K _q is a C or C ₂ -alkyl, in particular a Ci-alkyl, with I being 1 , and n of R ¹ _n is 1 or 2,

n of R ¹ _n is 2,

n of R ¹ _n is 2 and one of the two R ¹ is in ortho and the other R ¹ is in meta position to the attachment position of the benzene moiety,

- n of R ¹ _n is 2 and one of the two R ¹ is -CF ₃ in ortho and the other R ¹ is -CN in meta

position to the attachment position of the benzene moiety, and

the other one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein F| is -0-, -NH, -NHC(=0)- , -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)-, -O- C(=S)-, in particular -NH-(C=0)- or -0-, p of K _p is 0, K _q is a d- or C ₂ -alkyl, in particular a C alkyl, with I being 1 n of R ¹ _n is 1 ,

n of R ¹ _n is 1 and R ¹ is in para position to the attachment position of the benzene moiety, n of R ¹ _n is 1 and R ¹ is -SCF ₃ , -SOCF ₃ or -S0 ₂ CF ₃ in para position to the attachment position of the benzene moiety, or

n of R ¹ _n is 1 and R ¹ is -SCF ₃ in para position to the attachment position of the benzene moiety.

In some embodiments, OM comprises the general formula 2c, at least one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F _r K _q -, wherein F, is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, - C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)-, -0-C(=S)-, in particular -NH- (C=0)- or -0-, with I being 0 or 1 ,

Kp is a Cp-alkyl with p being 0, 1 , 2, 3 or 4, in particular p being 0,

K _q is a Cq-alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and wherein - each R ¹ independently from any other R ¹ is -C(=0)OR ² , -C(=0)NR ² ₂ , -C(=0)SR ² ,

-C(=S)OR ² -C(NH)NR ² 2, -CN ₄ H ₂ , -NR ² ₂ , -C(=0)R ² , -C(=S)R ² , -OR ² , -SR ² , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I , in particular -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

- with each R ² independently from any other R ² being hydrogen, CH ₃ , C ₂ H ₅ , C ₃ H ₇ or C ₄ H _9, in particular with each R ² being hydrogen, and

the other one of R ^L and R ^R is selected from the group comprising the general formula A, with X being a group described by a general formula -K _p -F|-K _q -, wherein F| is -0-, -NH, -NHC(=0)- , -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)-, -O- C(=S)-, in particular -NH-(C=0)- or -0-, with I being 0 or 1 ,

K _p is a C _p -alkyl with p being 0, 1 , 2, 3 or 4, in particular p being 0,

K _q is a C _q -alkyl with q being 0, 1 , 2, 3 or 4, in particular q being 1 , and wherein - each R ¹ independently from any other R ¹ is -C(=0)OR ² , -C(=0)NR ² ₂ , -C(=0)SR ² ,

-C(=S)OR ² -C(NH)NR ² 2, -CN ₄ H ₂ , -NR ² ₂ , -C(=0)R ² , -C(=S)R ² , -OR ² , -SR ² , -CF ₃ , -OCF3, -SCF3, -SOCF3, -SO2CF3, -CN, -NO2, -F, -CI, -Br or -I, in particular -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -SO2CF ₃ or -CN

with each R ² independently from any other R ² being hydrogen, CH ₃ , C ₂ H ₅ , C ₃ H ₇ or C ₄ H _9, in particular with each R ² being hydrogen.

In some embodiments, OM comprises the general formula 2c, wherein R ^L and R ^R are identical and selected from the group comprising the general formula A, wherein X, K _p , F|, K _q , R ¹ _n , n and R ² have the same meaning as defined in the previously described embodiments.

In some embodiments, OM comprises the general formula 2c, and at least one of R ^L and R ^R is selected from the group comprising the general formula B, with Y being a group described by a general formula, -L _r -M _k -L _s , wherein

- M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

- M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 ,

- k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , or,

- k is 0, r of is 0, and s of L _s is 0,

and R ^A being selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ^2a , -NR ^2a ₂ or R ^2a , with R ^2a being a hydrogen or d-C ₄ alkyl,

- wherein the other one of R ^L and R ^R can be selected from H or -C _c -P, with P being

- -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ ,

-C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,

-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-I, in particular -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ ,

-S0 ₂ CF ₃ or -CN,

- with c being 0, 1 , 2, 3 or 4, and

- with each R ⁴ independently from any other R ⁴ being hydrogen or d-C ₄ alkyl. In some embodiments, OM comprises the general formula 2c, and at least one of R ^L and R ^R is selected from the group comprising the general formula B, with Y being a group described by a general formula, -L _r -M _k -L _s , wherein

- M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

- M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 ,

- k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , or,

- k is 0, r of is 0, and s of L _s is 0,

and R ^A being selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ^2a , -NR ^2a ₂ or R ^2a , with R ^2a being a hydrogen or CrC ₄ alkyl, wherein the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, OM comprises the general formula 2c, and R ^L and R ^R are selected from the group comprising the general formula B, with Y being a group described by a general formula, -L _r -M _k -L _s , wherein

- M _k is -C(=0)-, -C(=0)0-, -C(=S)- or -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

- M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 ,

- k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , or,

- k is 0, r of is 0, and s of L _s is 0,

and R ^A being selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ^2a , -NR ^2a ₂ or R ^2a , with R ^2a being a hydrogen or C C ₄ alkyl.

In some embodiments, OM comprises the general formula 2c, wherein R ^L and R ^R are identical and selected from the group comprising the general formula B, wherein Y, L _r , M _k , L _s , R ^A and R ^2a have the same meaning as defined in the previously described embodiments.

In some embodiments, OM comprises the general formula 2c, and at least one of R ^L and R ^R is selected from the group comprising the general formula C, with Z being a group described by a general formula -K _r -Fi-K _r , wherein

- Fi is -0-, -S-, -0-C(=0)-, -0-C(=S)-, -S-C(=0)- or NH-(C=0)- with i being 0 or 1 , K _r is a Cr - alkyl with r being 0, 1 , 2, 3 or 4, and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, - i of Fj is 0, r of K _r is 0 and t of K _s is 0, or

- i of Fj is 0, r of K _r is 0 and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, in particular s being 1 , and R ^B being H, -R ^2b , -C(=0)R ^2b , -C(=0)OR ^2b , -C(=0)NR ^2b ₂ , -C(=0)SR ^2b , -C(=S)OR ^2b or - C(=S)R ^2b , in particular from H, R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or CrC ₄ alkyl,

wherein the other one of R ^L and R ^R can be selected from H or -C _c -P,

- with P being -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ , -C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-l, in particular H, -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

with c being 0, 1 , 2, 3 or 4, and

with each R ⁴ independently from any other R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, OM comprises the general formula 2c, and at least one of R ^L and R ^R is selected from the group comprising the general formula C, with Z being a group described by a general formula -K _r -Fi-K _r , wherein

- Fj is -0-, -S-, -0-C(=0)-, -0-C(=S)-, -S-C(=0)- or NH-(C=0)- with i being 0 or 1 , K _r is a C _r - alkyl with r being 0, 1 , 2, 3 or 4, and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4,

- i of Fj is 0, r of K _r is 0 and t of K _s is 0, or

- i of Fj is 0, r of K _r is 0 and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, in particular s being 1 , and R ^B being H, -R ^2b , -C(=0)R ^2b , -C(=0)OR ^2b , -C(=0)NR ^2b ₂ , -C(=0)SR ^2b , -C(=S)OR ^2b or - C(=S)R ^2b , in particular from H, R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or d-C ₄ alkyl, wherein the other one of R ^L and R ^R is selected from H or -Cc-P, with P being -H, -(HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, - N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or d-C ₄ alkyl.

In some embodiments, OM comprises the general formula 2c, and R ^L and R ^R are selected from the group comprising the general formula C, with Z being a group described by a general formula -K _r -Fi-K _r , wherein

- Fj is -0-, -S-, -0-C(=0)-, -0-C(=S)-, -S-C(=0)- or NH-(C=0)- with i being 0 or 1 , K _r is a C _r - alkyl with r being 0, 1 , 2, 3 or 4, and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4,

- i of Fj is 0, r of K _r is 0 and t of K _s is 0, or

- i of Fj is 0, r of K _r is 0 and K _t is a C _t -alkyl with t being 0, 1 , 2, 3 or 4, in particular s being 1 , and R being H, -R , -C(=0)R , -C(=0)OR , -C(=0)NR ₂ , -C(=0)SR , -C(=S)OR or - C(=S)R ^2b , in particular from H, R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or C ₁ -C4 alkyl.

In some embodiments, OM comprises the general formula 2c, wherein R ^L and R ^R are identical and selected from the group comprising the general formula C, wherein Z, K _r , F,, K _t , R ^B and R ^2a have the same meaning as defined in the previously described embodiments.

In some embodiments, OM comprises the general formula 2c, and at least one of R ^L and R ^R is selected from the group comprising the general formula D, with Y being a group described by a general formula, -L _r -M _k -L _s , wherein

- M _k is -C(=0)-, -C(=0)0-, -C(=S)-, -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 , or

k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , and each R ^D being selected independently from any other R ^D from H, R ^2d , -C(=0)R ^2d ,

-C(=0)OR ^2d , -C(=0)NR ^2d ₂ , -C(=0)SR ^2d , -C(=S)OR ^2d , -C(=S)R ^2d or-SR ^2d , in particular from H, -R ^2d or -C(=0)R ^2d , with each R ^2d independently from any other R ^2d being a hydrogen or C ₁ -C4 alkyl,

wherein the other one of R ^L and R ^R can be selected from H or -C _c -P,

- with P being -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ , -C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-l, in particular H, -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

with c being 0, 1 , 2, 3 or 4, and

- with each R ⁴ independently from any other R ⁴ being hydrogen or C ₁ -C4 alkyl.

In some embodiments, OM comprises the general formula 2c, and at least one of R ^L and R ^R is selected from the group comprising the general formula D, with Y being a group described by a general formula, -L _r -M _k -L _s , wherein

M _k is -C(=0)-, -C(=0)0-, -C(=S)-, -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 , or

k is 0, r of is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , and each R ^D being selected independently from any other R ^D from H, R ^2d , -C(=0)R ^2d , -C(=0)OR ^2d , -C(=0)NR ^2d ₂ , -C(=0)SR ^2d , -C(=S)OR ^2d , -C(=S)R ^2d or-SR ^2d , in particular from H, -R ^2d or -C(=0)R ^2d , with each R ^2d independently from any other R ^2d being a hydrogen or C1-C4 alkyl, wherein the other one of R ^L and R ^R is selected from H or -C _c -P, with P being -H, - (HC=N)OR ⁴ , -OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or -I, in particular from -OR ⁴ , -(HC=N)OR ⁴ or -SCF ₃ , with c being 0, 1 , 2, 3 or 4, and R ⁴ being hydrogen or C1-C4 alkyl.

In some embodiments, OM comprises the general formula 2c, and R ^L and R ^R are selected from the group comprising the general formula D, with Y being a group described by a general formula, -L _r -M _k -L _s , wherein

M _k is -C(=0)-, -C(=0)0-, -C(=S)-, -C(=S)0-, with k being 0 or 1 , L _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4, L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4,

M _k is -C(=0)- with k being 1 , r of L _r is 0, and L _s is a C ₃ -alkyl with q being 0, 1 , 2, 3 or 4, in particular s being 1 , or

- k is 0, r of L _r is 0, and L _s is a C ₃ -alkyl with s being 0, 1 , 2, 3 or 4, in particular s being 1 , and each R ^D being selected independently from any other R ^D from H, R ^2d , -C(=0)R ^2d , -C(=0)OR ^2d , -C(=0)NR ^2d ₂ , -C(=0)SR ^2d , -C(=S)OR ^2d , -C(=S)R ^2d or-SR ^2d , in particular from H, -R ^2d or -C(=0)R ^2d , with each R ^2d independently from any other R ^2d being a hydrogen or C1-C4 alkyl.

In some embodiments, OM comprises the general formula 2c, wherein R ^L and R ^R are identical and selected from the group comprising the general formula D, wherein Y, L _r , M _k , L _s , R ^A and R ^2a have the same meaning as defined in the previously described embodiments.

An example is

Particular embodiments of this aspect of the invention are: a. 3- (Ferrocenyloxy)-4-(trifluoromethyl)benzonitrile

(compound 1 ) b. -ferrocenyl-4-((trifluoromethyl)thio)benzamide

(compound 2) c. -(2-hvdroxymethyl)ferrocenyl)-4-((trifluoromethyl)thio)benza mide

(compound 3) d. Dicobalthexacarbonyl 4-methyl-N-prop-2-vnyl-benzamide

(compound 4) e. Dicobalthexacarbonyl N-(4-hvdroxybut-2-vnyl)-4-methyl-benzamide

(compound 5)

N-(2-((5-cvano-2-(trifluoromethyl)phenoxy)methyl)ferrocen yl)-4- ((trifluoromethyl)thio)benzamide

(compound 6) g. Dicobalthexacarbonyl-N-(4-(5-cvano-2-(trifluoromethyl)phenox y)but-2-en-1 -yl)-4- ((trifluoromethyl)thio)benzamide

(compound 7)

h. Λ/,Λ - (((oxybis(methylene))bis(2J -ferrocenyl))bis(methylene))bis(4- ((trifluoromethyl)thio) ferroceneamide

(compound 8)

te f-butyl 1 -(ferrocenyloxy)-2-cvanopropan-2-ylcarbamate

(compound 9)

j. N-(2-cvano-1 -hvdroxypropan-2-yl)ferroceneamide

(compound 10)

k. /V-(2-cvano-1 -hvdroxypropan-2-yl)-2-(trifluoromethylthio)ferrocenamide

(compound 1 1 )

I. 2-amino-3-(ferrocenyloxy)-2-methylpropanenitrile

(compound 12) m. N-(2-cvano-1 -hvdroxypropan-2-yl)ruthenoceneamide

Compound (41 )

According to a second aspect of the invention provided herein are intermediates of organometallic compounds characterized by a general formula (3),

R-

(3)

wherein at least one of R ^L and R ^R is selected from

in particular from with R ^A being selected from -R ^2a , -OR ^2a , -NR ^2a ₂ or -SR ^2a , in particular from -OR ^2a , -NR ^2a ₂ or -R ^2a , with each R ^2a independently from any other R ^2a being a hydrogen or CrC ₄ alkyl,

with R ^B being selected from H, -R ^2b , -C(=0)R ^2b , -C(=0)OR ^2b , -C(=0)NR ^2b ₂ , -C(=0)SR ^2b , -C(=S)OR ^2b or -C(=S)R ^2b , in particular from H, R ^2b or -C(=0)R ^2b , with each R ^2b independently from any other R ^2b being a hydrogen or d-C ₄ alkyl,

with each R ^D being selected independently from any other R ^D from H, R ^2d , -C(=0)R ^2d , -C(=0)OR ^2d , -C(=0)NR ^2d ₂ , -C(=0)SR ^2d , -C(=S)OR ^2d , -C(=S)R ^2d or -SR ^2d , in particular from H, -R ^2d or -C(=0)R ^2d , with each R ^2d independently from any other R ^2d being a hydrogen or d-C ₄ alkyl, - with X being a group described by a general formula -K _p -F|-K _q -, wherein

- F| is -0-, -NH, -NHC(=0)-, -NHC(=S)-, -C(=0)NH-, -C(=S)NH-, -(C=0)-, -C(=S)-, -C(=0)0-, -C(=S)0-, -0-C(=0)-, -0-C(=S)-, with I being 0 or 1 ,

- K _p is a Cp-alkyl with p being 0, 1 , 2, 3 or 4,

- K _q is a Cq-alkyl with q being 0, 1 , 2, 3 or 4, and wherein

each R ¹ independently from any other R ¹ is -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -SO2CF ₃ or -CN, and wherein

n of R ¹ _n is 0, 1 , 2, 3, 4 or 5,

- with Y being a group described by a general formula -L _r -M _k -L _s , wherein

- M _k is -C(=0)-, -C(=0)0-, -C(=S)- or-C(=S)0-, with k being 0 or 1 ,

- is a Cr-alkyl with r being 0, 1 , 2, 3 or 4,

- L _s is a Cs-alkyl with s being 0, 1 , 2, 3 or 4, and

- with Z being a group described by a general formula -K _r -Fi-K _r , wherein

- Fj is -0-, -S-, -0-C(=0)-, -0-C(=S)-, -S-C(=0)- or NH-(C=0)- with i being 0 or 1 ,

- K _r is a C _r -alkyl with r being 0, 1 , 2, 3 or 4,

- K _t is a Ct-alkyl with t being 0, 1 , 2, 3 or 4,

wherein the other one of R ^L and R ^R can be selected from H or -C _c -P,

- with P being -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ , -C(NH)NR ⁴ 2, -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ ₂ , -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ ,-OCF ₃ , -S(0) ₂ R ⁴ , -S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -NO2, -F, -CI, -Br or-l, in particular H, -OR ⁴ , -(HC=N)OR ⁴ , -CF ₃ , -OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

- with c being 0, 1 , 2, 3 or 4, and

- with each R ⁴ independently from any other R ⁴ being hydrogen or d-C ₄ alkyl.

Concerning specified embodiments reference is made too the description of the first aspect of the invention. In particular the same embodiments with respect to the general formulas A, B, C or D may be applied for the intermediates of the second aspect of the invention. Particular embodiments of this aspect of the invention are:

a. N-[4-(2,5-dimethylphenoxy)but-2-vnyll-4-methyl-benzamide

(compound13)

b. N-(4-hvdroxybut-2-vnyl)-4-methyl-benzamide

(compound14) -methyl-N-prop-2-vnyl-benzamide

(compound15)

The compounds of the general formula (1 ) or (3) can also be obtained in the form of their hydrates and/or also can include other solvents used for example for the crystallization of compounds present in the solid form. Depending on the method and/or the reaction conditions, compounds of the general formula (1 ) or (3) can be obtained in the free form or in the form of salts.

The compounds of the general formula (1 ) or (3) may be present as optical isomers or as mixtures thereof. The invention relates both to the pure isomers and all possible isomeric mixtures and is hereinafter understood as doing so, even if stereochemical details are not specifically mentioned in every case. Isomeric, in particular enantiomeric, mixtures of compounds of the general formula (1 ) or (3), which are obtainable by the process or any other way, may be separated in known manner - on the basis of the physical-chemical differences of their components - into pure isomers, in particular enantiomers, for example by fractional crystallisation, distillation and/or chromatography, in particular by preparative HPLC using a chiral HPLC column.

According to the invention, apart from separation of corresponding isomer mixtures, generally known methods of diastereoselective or enantioselective synthesis can also be applied to obtain pure diastereoisomers or enantiomers, e.g. by carrying out the method described hereinafter and using educts with correspondingly suitable stereochemistry. It is advantageous to isolate or synthesise the biologically more active isomer, provided that the individual compounds have different biological activities.

A third aspect of the invention is the process for the preparation of the compounds described by the general formula (1 ) or (3).

A reaction pathway for compounds comprising at least one moiety of the general formula A is depicted in scheme 1 :

16 17 18

Scheme 1 :

Compounds 16 and 17 comprising the substituents R _y ^L , R _z ^u , T, R ¹ _n , K _p , K _q and M as defined above, are known compounds, which can be purchased or may be synthesized by known procedures or may be prepared analogously to known compounds. These compounds may be particularly synthesized by an adapted procedure described in the experimental section with respect to comparable compounds. Qi and Q ₂ are functional groups, which can undergo a coupling reaction with each other yielding a F| moiety, as defined above. Thus, the reaction yields a compound comprising a substituent with the general formula A.

For example, Qi is NH ₂ and Q ₂ is -C(=0)CI and the reaction takes place in the presence of NEt ₃ , yielding -C(=0)-NH- moiety (F,) (see Gasser et ai, J. Organomet. Chem. 2010, 695, 249-255). Optionally, Q ₂ is OH and the reaction takes place in the presence of HATU (0-(7- azabenzotriazol - 1 - yl) - Λ/,Λ/,Λ/',Λ/' - tetramethyluronium-hexafluorophosphate), DIPEA (N,N- Diisopropylethylamine) in /V,/V-dimethylformamid (comparable to the procedure of Patra et al. (Organometallics, 2010, 29, 4312-4319)). In some embodiments, the OH group may be exchanged to the leaving group CI according to a procedure described by Lorkowski et al. (VIII. Preparation of monomeric and polymeric ferrocenylene oxadiazoles, J. Prakt. Chem. 1967, 35, 149-58, by Witte et al. {Organometallics 1999, 18, 4147-4155) or by Cormode et al. {Dalton Trans. 2010, 39, 6532-6541 ).

Furthermore, Qi may be OH and Q ₂ is a leaving group such as CI or F, in particular a leaving group as described in WO2005/044784 A1 , and the reaction takes place in the presence of NaH, yielding -O- moiety (F|).

The ferrocene moiety may comprise a further substituent (eg. SCF ₃ or -O-alkyl), which takes no part in the coupling reaction. Furthermore, the ferrocene moiety may comprise another functional group Qi suitable for a coupling reaction. Thus, two moieties of the general formula A may be introduced on the ferrocene moiety by a subsequent reaction. Similar procedures may be applied in order to achieve other F| moieties.

Such procedures are known procedures or may be prepared analogously to known procedures, in particular analogous to the procedures described in the experimental section.

Furthermore, compounds comprising an OM moiety according to the general formula (2a') may be produced analogously to an adapted procedure as described further below concerning compound 8.

The same applies for an OM moiety according to the general formula (2b).

A similar pathway is applied for an OM moiety according to the general formula (2c) using compound 16' instead of compound 16, yielding the respective intermediate.

(compound 16')

Compound 16' is a known compound, which can be purchased or may be synthesized by known procedures or may be prepared analogously to known compounds. These

compounds may be particularly synthesized by an adapted procedure described in the experimental section with respect to comparable compounds. Compound 16' may comprise a further substituent (eg. -O-alkyl instead of the H moiety), which takes no part in the coupling reaction or another functional group Qi suitable for a coupling reaction (see experimental section). Thus, two moieties of the general formula A may be introduced by a subsequent reaction. Similar procedures may be applied in order to achieve other F| moieties. Subsequently the intermediate is then reacted with Co ₂ (CO) ₈ according to an adapted synthetic method employed by Gasser ei al. (Inorg. Chem. 2009, 48, 3157-3166) yielding a compound comprising an OM moiety according to the general formula (2c).

A reaction pathway for compounds comprising at least one moiety of the general formula B is depicted in scheme 2:

Scheme 2: Compounds 19 and 20 comprising the substituents R _y ^L , R _z ^u , T, R ^A , L _s , L _r and M as defined above, are known compounds, which can be purchased or may be synthesized by known procedures or may be prepared analogously to known compounds (see e.g. Gasser et al., J. Organomet. Chem. 2007, 692, 3835-3840; Patra et al., J. Med. Chem. 2012, 55, 8790-8798; Apreutesei et al., Appl. Organomet. Chem. 2005, 19, 1022-1037 ; Bonini et al., Eur. J. Org. Chem. 2002, 543-550; Routaboul et al., J. Organomet. Chem. 2001 , 637, 364- 371 ). These compounds may be particularly synthesized by an adapted procedure described in the experimental section with respect to comparable compounds.

U is H, -C(=0)-Q, -C(=0)0-Q, -C(=S)-Q or-C(=S)0-Q, wherein Q is a leaving group or H. U can undergo a coupling reaction with the N-moiety of compound 19 yielding a M _k moiety, as defined above. Thus, the reaction yields a compound comprising the general formula B. Optionally a L _r -alkyl group may be introduced between the functional group and Q (e.g. - C(=0)-L _r -Q). In this case, U may be -L _r -Q.

For example, U is H and the reaction takes place in the presence of K ₂ C0 ₃ , 18-crown-6, Acetonitrile, yielding -O- moiety (M _k ) (see Gasser et al., J. Organomet. Chem. 2007, 692, 3835-3840 and Gasser et al., J. Med. Chem. 2012, 55, 8790-8798).

In another embodiment, U can be -C(=0)-Q with Q being OH or a leaving group. The reaction proceeds according to an adapted procedure of Gasser et al. {J. Med. Chem. 2012, 55, 8790-8798). Q may be CI and the reaction takes place in the presence of NEt ₃ . Optionally Q is OH and the reaction takes place in the presence of HATU (0-(7- azabenzotriazol - 1 - yl) - Ν,Ν,Ν',Ν' - tetramethyluronium-hexafluorophosphate), DIPEA (Λ/,/V-Diisopropylethylamine) in Λ/,/V-dimethylformamid (comparable to the procedure of Patra et al. (Organometallics, 2010, 29, 4312-4319). In some embodiments, the OH group may be exchanged to the leaving group CI as discussed previously.

The ferrocene moiety may comprise a further substituent (eg. SCF ₃ or -O-alkyl), which takes no part in the coupling reaction. Furthermore, the ferrocene moiety may comprise another functional group N-moiety suitable for a coupling reaction. Thus, two moieties of the general formula B may be introduced on the ferrocene moiety by a subsequent reaction.

Similar procedures may be applied in order to introduce substituents of the general formula D. Furthermore, compounds comprising an OM moiety according to the general formula (2a') may be produced analogously to an adapted procedure as described further below concerning compound 8. The same applies for an OM moiety according to the general formula (2b).

A comparable pathway is applied for an OM moiety according to the general formula (2c), which is depicted in scheme 2' and shows the pathway to the respective intermediates.

25 36

20

Scheme 2': Compounds 25 and 20 comprising the substituents R _y ^L , R _z ^u , T, R ^A , Y and M as defined above, are known compounds, which can be purchased or may be synthesized by known procedures or may be prepared analogously to known compounds. These

compounds may be particularly synthesized by an adapted procedure described in the experimental section with respect to comparable compounds.

Q is a leaving group, in particular a leaving group as described in Gauvry et al.

(WO2005/044784 A1 ). The reaction proceeds also according to an adapted procedure of Gauvry et al. (WO2005/044784 A1 ) yielding compound 26. Subsequently the intermediate 26 is then reacted with Co ₂ (CO) ₈ according to an adapted synthetic method employed by

Gasser et al. (Inorg. Chem. 2009, 48, 3157-3166) yielding a compound comprising an OM moiety according to the general formula (2c).

Compound 25 may comprise a further substituent (eg. -O-alkyl instead of the H moiety), which takes no part in the coupling reaction (see experimental section) or another functional group Qi suitable for a coupling reaction (see experimental section). Thus, two moieties of the general formula B may be introduced by a subsequent reaction. Subsequently the intermediate is then reacted with Co ₂ (CO) ₈ according to an adapted synthetic method employed by Gasser et al. (Inorg. Chem. 2009, 48, 3157-3166) yielding a compound comprising an OM moiety according to the general formula (2c). Similar procedures may be applied in order to introduce substituents of the general formula D.

A reaction pathway for compounds comprising at least one moiety of the general formula C is depicted in scheme 3:

22 23 24

Scheme 3: Compounds 22 and 23 comprising the substituents R _y ^L , R _z ^u , T, R ^B , Z and M as defined above, are known compounds, which can be purchased or may be synthesized by known procedures or may be prepared analogously to known compounds These compounds may be particularly synthesized by an adapted procedure described in the experimental section with respect to comparable compounds.

The 2-amino-2-hydroxymethylproprionitrile derivative 23 may be produced according to an adapted procedure according to Gauvry et al. (WO2005/044784 A1 ). Compound 22 was reacted with one equivalent of compound 23 yielding compound 24 according to an adapted procedure from Gasser ei a/. (J. Organomet. Chem. 2010, 695, 249-255). In some embodiments, Q is CI and the reaction takes place in the presence of NEt ₃ . In some embodiments, Q is OH and the reaction takes place in the presence of HATU (0-(7- azabenzotriazol - 1 - yl) - Λ/,Λ/,Λ/',Λ/' - tetramethyluronium-hexafluorophosphate), DIPEA (N,N- Diisopropylethylamine) in /V,/V-dimethylformamid (comparable to the procedure of Patra et al. (Organometallics, 2010, 29, 4312-4319)). In some embodiments, the OH group is exchanged to the leaving group CI according to a procedure described by Lorkowski et al. (VIII.

Preparation of monomeric and polymeric ferrocenylene oxadiazoles, J. Prakt. Chem. 1967, 35, 149-58, by Witte et al. {Organometallics 1999, 18, 4147-4155) or by Cormode et al.

{Dalton Trans. 2010, 39, 6532-6541 ).

The ferrocene moiety may comprise a further substituent (eg. SCF ₃ or -O-alkyl), which takes no part in the coupling reaction. Furthermore, the ferrocene moiety may comprise another functional group _Z-C(=0)-Q suitable for a coupling reaction. Thus, two moieties of the general formula C may be introduced on the ferrocene moiety by a subsequent reaction. Furthermore, compounds comprising an OM moiety according to the general formula (2a') may be produced analogously to an adapted procedure as described further below concerning compound 8. The same applies for an OM moiety according to the general formula (2b).

Metal sandwich complex of the general formula (2a) or (2a') and half metal sandwich complex of the general formula (2b) follow a similar pathway as the above mentioned reactions depicted in scheme 1 and scheme 2, which are easily adaptable for a person skilled in the art. In particular an adaption may be based on publication of Wolter-Steingrube et. al. ("Synthesis and Molecular Structures of Monosubstituted Pentamethylcobaltocenium Cations", Eur. J. Inorg. Chem. 2014, 41 15-4122, DOI:10.1002/ejic.201402443; see also Vanicek et al., Organometallics 2014, 33, 1152-1156, dx.doi.org/10.1021/om401 120h

E. Fourie et al., Journal of Organometallic Chemistry 754 (2014) 80e87, dx.doi.org/10.1016/ j.jorganchem.2013.12.027).

A similar pathway is applied for an OM moiety according to the general formula (2c) using compound 22' instead of compound 22, yielding the respective intermediate.

(compound 22')

Compound 22' is a known compound, which can be purchased or may be synthesized by known procedures or may be prepared analogously to known compounds. These compounds may be particularly synthesized by an adapted procedure described in the experimental section with respect to comparable compounds. Compound 22' may comprise a further substituent (eg. -O-alkyl instead of the H moiety), which takes no part in the coupling reaction or another functional group -Z-C(=0)-Q suitable for a coupling reaction (see experimental section). Thus, two moieties of the general formula C may be introduced by a subsequent reaction. Subsequently the intermediate is then reacted with Co ₂ (CO) ₈ according to an adapted synthetic method employed by Gasser et al. (Inorg. Chem. 2009, 48, 3157-3166) yielding a compound comprising an OM moiety according to the general formula (2c).

According to a fourth aspect of the invention, the compounds defined as the first and second aspect of the invention are provided for use in a method for treatment of disease.

Furthermore, a compound according to the general formula (4),

OM

(4)

wherein OM is an organometallic compound independently selected from the group of an unsubstituted or substituted metal sandwich compound, an unsubstituted or substituted half metal sandwich compound or a metal carbonyl compound, in particular OM is an organometallic compound according to the general formula (2a), (2a'), (2b), (2b'), or (2c), wherein R ^LL and R ^RR can be selected independently from each other form H or

-C _c -P, with P being

- -H, -OR ⁴ , -0-C(=0)R ⁴ , -C(=0)OR ⁴ , -C(=0)NR ⁴ ₂ , -C(=0)SR ⁴ , -C(=S)OR ⁴ , -C(NH)NR ⁴ ₂ , -(HC=N)OR ⁴ , -CN ₄ H ₂ , -NR ⁴ 2, -C(=0)R ⁴ , -C(=S)R ⁴ , -SR ⁴ , -CF ₃ , -OCF ₃ , -S(0) ₂ R ⁴ ,

-S(0) ₂ OR ⁴ , -S(0) ₂ NR ⁴ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ , -CN, -N0 ₂ , -F, -CI, -Br or-l, in particular -(HC=N)OR ⁴ , -CF ₃ ,-OCF ₃ , -SCF ₃ , -SOCF ₃ , -S0 ₂ CF ₃ or -CN,

- with c being 0, 1 , 2, 3 or 4, and

- with each R ⁴ independently from any other R ⁴ being hydrogen or d-C ₄ alkyl

for use in a method of treatment of disease is provided. Particular embodiments are compounds 1 to 15 and 41 and a. 2-(N,N-dimethylaminomethylferrocene)carboxaldehvde

(compound 27)

2-(acetoxymethylferrocene)carboxaldehvde

(compound 28)

2-(hvdroxymethlv)ferrocenecarboxaldehvdeoxime

(compound 29)

-(hvdroxymethyl)ferrocenylmethylamine

(compound 30)

e. 2-(Hvdroxymethylferrocene)carboxaldehvde

(compound 31 )

f. 2-(Hvdroxymethyl)ruthenocenecarboxaldehvde oxime

4-Hydroxybut-2-vn-1 -yl methanesulfonate

H O OMs

33 (compound 33) h. 4-Aminobut-2-yn-1 -ol

H O N H ₂

34

(compound 34)

Chlorocarbonyl ferrocene

(compound 35)

j. 2-(Acetoxymethylruthenocene)carboxaldehyde

(compound 36) k. Thiocyanatoferrocene

(compound 37)

I. Trifluoromethylthioferrocene

-SCF ₃

Fe

(compound 38) m. Thiocyanatoruthenocene

^SCN

^>

Ru

^> (compound 39)

n. 1 '-Thiocvanatoiodoruthenocene (compound 40)

Pharmaceutically acceptable salts of the compounds provided herein are deemed to be encompassed by the scope of the present invention.

According to one aspect of the invention, a pharmaceutical composition for preventing or treating helminth infection, particularly infection by tapeworms (cestodes), flukes

(trematodes) and roundworms (nematodes), in particularspecies of Haemonchus,

Trichstrongylus, Teladorsagia, Cooperia, Oesophagostomum and/or Chabertia, tapeworm infection, schistosomiasis, ascariasis, dracunculiasis, elephantiasis, enterobiasis, filariasis, hookworm infection, onchocerciasis, trichinosis and/or trichuriasis is provided, comprising a compound according to the above aspect or embodiments of the invention.

Pharmaceutical compositions for enteral administration, such as nasal, buccal, rectal or, especially, oral administration, and for parenteral administration, such as dermal (spot-on), intradermal, subcutaneous, intravenous, intrahepatic or intramuscular administration, may be used. The pharmaceutical compositions comprise approximately 1 % to approximately 95% active ingredient, preferably from approximately 20% to approximately 90% active ingredient.

According to one aspect of the invention, a dosage form for preventing or treating helminth infection, particularly infection by particularly tapeworms (cestodes), flukes (trematodes) and roundworms (nematodes), tapeworm infection, schistosomiasis, ascariasis, dracunculiasis, elephantiasis, enterobiasis, filariasis, hookworm infection, onchocerciasis, trichinosis and/or trichuriasis is provided, comprising a compound according to the above aspect or

embodiments of the invention. Dosage forms may be for administration via various routes, including nasal, buccal, rectal, transdermal or oral administration, or as an inhalation formulation or suppository. Alternatively, dosage forms may be for parenteral administration, such as intravenous, intrahepatic, or especially subcutaneous, or intramuscular injection forms. Optionally, a pharmaceutically acceptable carrier and/or excipient may be present.

According to one aspect of the invention, a method for manufacture of a medicamentfor preventing or treating helminth infection, particularly infection by particularly tapeworms (cestodes), flukes (trematodes) and roundworms (nematodes), tapeworm infection, schistosomiasis, ascariasis, dracunculiasis, elephantiasis, enterobiasis, filariasis, hookworm infection, onchocerciasis, trichinosis and/or trichuriasisis provided, comprising the use of a compound according to the above aspect or embodiments of the invention. Medicaments according to the invention are manufactured by methods known in the art, especially by conventional mixing, coating, granulating, dissolving or lyophilizing.

According to one aspect of the invention, a method for preventing or treating helminth infection, particularly the indications mentioned previously, is provided, comprising the administration of a compound according to the above aspects or embodiments of the invention to a patient in need thereof.

The treatment may be for prophylactic or therapeutic purposes. For administration, a compound according to the above aspect of the invention is preferably provided in the form of a pharmaceutical preparation comprising the compound in chemically pure form and optionally a pharmaceutically acceptable carrier and optionally adjuvants. The compound is used in an amount effective against helminth infection. The dosage of the compound depends upon the species, the patient age, weight, and individual condition, the individual pharmacokinetic data, mode of administration, and whether the administration is for prophylactic or therapeutic purposes. The daily dose administered ranges from

approximately 1 μg kg to approximately 1000 mg/kg, preferably from approximately 1 μg to approximately 100 μg, of the active agent according to the invention.

Wherever reference is made herein to an embodiment of the invention, and such

embodiment only refers to one feature of the invention, it is intended that such embodiment may be combined with any other embodiment referring to a different feature. For example, every embodiment that defines OM may be combined with every embodiment that defines R ¹ , F| or K _p or others as defined above to characterize a group of compounds of the invention or a single compound of the invention with different properties.

The invention is further characterized, without limitations, by the following examples and figure, from with further features, advantages or embodiments can be derived. The examples and figures do not limit but illustrate the invention.

Short description of the Figures:

Fig.1 shows the effect of compound 10 on a H. contortus worm suspension (the number of dead or immobile worms after an incubation of 24 h is displayed);

Fig. 2 shows the effect of compound 15 on a H. contortus worm suspension (the number of dead or immobile worms after an incubation of 24 h is displayed).

General Methods

Materials: All chemicals were of reagent grade quality or better, obtained from commercial suppliers and used without further purification. Solvents were used as received or dried over 4 A and 3A molecular sieves. THF and Et ₂ 0 were freshly distilled under N ₂ by employing standard procedures. ¹ All syntheses were carried out using standard Schlenk techniques. Instrumentation and methods: ¹ H- and ¹³ C-NMR spectra were recorded in deuterated solvents on a Bruker DRX 400 orAV2 500at 30°C. The chemical shifts8, are reported in ppm. The residual solvent peaks have been used as internal reference. The abbreviations for the peak multiplicities are as follows: s (singlet), d (doublet), dd (doublet of doublet), t (triplet), q (quartet), m (multiplet) and br (broad). Infrared spectra were recorded on a PerkinElmer spectrum BX TF-IR spectrometer and KBr presslings were used for solids. Signal intensities are abbreviated w (weak), m (medium), s (strong) and br (broad). ESI mass spectra were recorded on a Bruker Esquire 6000 or on a Bruker maxis QTOF-MS instrument

(BrukerDaltonics GmbH, Bremen, Germany). The LC-MS spectra were measured on an Acquity™ from Waters system equipped with a PDA detector and an auto sampler using an Agilent Zorbax 300SB-C18 analytical column (5.0 μηη particle size, 100 A pore size, 150 ^χ 3.0 mm) or an Macherey - Nagel 100 - 5 C18 (3.5 μηη particle size, 300 A pore size, 150 ^χ 3.0 mm). This LC was coupled to an Esquire HCT from Bruker (Bremen, Germany) for the MS measurements. The LC run (flow rate: 0.3 mL min-1 ) was performed with a linear gradient of A (distilled water containing 0.1 % v/v formic acid) and B (acetonitrile (Sigma-

Aldrich HPLC-grade), t = 0 min, 5% B; t = 3 min, 5% B; t = 17 min, 100% B; t = 20 min, 100% B; t = 25 min, 5% B. High-resolution ESI mass spectra were recorded on a Bruker maxis QTOF-MS instrument (BrukerDaltonics GmbH, Bremen, Germany). The samples (around 0.5 mg) were dissolved in 0.5 mL of MeCN/H ₂ 0 1 :1 + 0.1 % HCOOH. The solution was then diluted 10:1 and analysed via continuous flow injection at 3 μΙ min ^"1 . The mass spectrometer was operated in the positive electrospray ionization mode at 4000 V capillary voltage, -500 V endplate offset, with a N ₂ nebulizer pressure of 0.4 bar and dry gas flow of 4.0 l/min at 180°C. MS acquisitions were performed in the full scan mode in the mass range from m/z 100 to 2000 at 20Ό00 resolution and 1 scan per second. Masses were calibrated with a 2 mmol/l solution of sodium formate over m/z 158 to 1450 mass range with an accuracy below 2 ppm.

Cell Culture: Human cervical carcinoma cells (HeLa) were cultured in DMEM (Gibco) supplemented with 5% fetal calf serum (FCS, Gibco), 100 U/ml penicillin, 100 μg/ml streptomycin at 37°C and 5% C0 ₂ . The normal human fetal lung fibroblast MRC-5 cell line was maintained in F-10 medium (Gibco) supplemented with 10% FCS (Gibco), 200mmol/l L-Glutamine, 100 U/ml penicillin, and 100 μg/ml streptomycin at 37°C and 5%

C02.Toestablish the anticancer potential of the compounds they were tested in one cell line, namely HeLa by a fluorometric cell viability assay using Resazurin (Promocell GmbH).

Compounds showing cytotoxicity were then tested on normal MRC-5 cells. 1 day before treatment, cells were plated in triplicates in 96-well plates at a density of 4 x 10 ³ cells/well in 100μΙ for HeLa and 7 x 10 ³ cells/well for MRC-5 cells. Cells were treated with increasing concentrations of the compounds for 2 days. After 2 days, medium and drug were removed and 100 ml fresh medium containing Resazurin (0.2 mg/ml final concentration) were added. After 4h of incubation at 37°C, the highly red fluorescent dye resorufin's fluorescence was quantified at 590nm emission with 540nm excitation wavelength in the SpectraMax M5 microplate Reader.

C. elegans movement inhibition assay: Asynchronous N2 C. elegans worms (Bristol) were maintained on nematode growth medium (NGM) agar, seeded with a lawn on OP50 £ coli as a food-source, according to standard protocol (Maintenance of C. elegans; Stiernagle, T., Ed.; WormBook, 2006.). Worms were harvested from NGM plates by washing with M9 buffer (42 mmol/l Na ₂ HP0 ₄ , 22 mmol/l KH ₂ P0 ₄ , 86 mmol/INaCI and 1 mmol/l MgS0 ₄ ), aspiration and collection in a 10 mL tube (Falcon). The average number of worms in 5 μΙ_ of this suspension was calculated by transferring 4 x 5 μΙ_ aliquots to a glass slide (Menzel Glaser), and worms were enumerated under a compound microscope (Olympus CH30). To adjust the suspension to contain 1 worm per μΙ_, M9 buffer was either added or removed after pelleting worms at 600 xg for 30 sec.

Dilution of test compounds, Zolvix (monepantel) and DMSO for working stock solutions and 96 well plate set-up for liquid screen: A volume of 70 μΙ_ of M9 buffer was added to each well in a 96-well plate, using a multichannel pipettor. A volume of 20 μΙ_ of worm suspension was added to each well using a single-channel pipettor, with a trimmed pipette tip (increased aperture to minimize damage to worms). The worm suspension was resuspended by flicking after every three wells to maintain consistency. The compounds were stored at 4 °C, and diluted in dimethyl sulfoxide (DMSO) to achieve a 100 mmol/l concentration 1 hr prior to addition to assay. These stock solutions were diluted further in DMSO to create a series of 20 mmol/l, 2 mmol/l, 0.02 mmol/l and 0.002 mmol/l which were subsequently diluted 1 :20 in M9 buffer to create 1 mmol/l, 0.1 mmol/l, 1 μπποΙ/Ι and 0.1 μπποΙ/Ι (all 5% (v/v) DMSO). 10 μΙ_ of each concentration was added to wells in duplicate to achieve final concentrations of 100 μηιοΙ/Ι, 10 μπποΙ/Ι, 100 nmol/l and 10 nmol/l in 100 μΙ_ (0.5% DMSO). A Zolvix

(monepantel) dilution series was simultaneously created following the same dilution schema, and used as a positive οοηίΓθΙ;10μΙ_ of 10 % DMSO was added to achieve 1 % DMSO vehicle control. 10 μΙ_ M9 was added to negative control wells (see Figure 1 ). Plates were incubated at room temperature (22-24 °C) overnight at 20 °C.

Quantitative worm mobility scoring: Immobile worms were counted as a percentage of total worms in each well using an Olympus SZ30 dissecting microscope. The immobile fraction was subtracted from the total, and this remainder was divided by the total to give a percentage of live worms per well. Descriptive and inferential statistics were deferred until further replicates are performed. In vitro experiments can be conducted by testing compounds in a larval development assay. To do this, sheep are infected with infective third-stage larvae (L3) of species of

Haemonchus, Trichstrongylus, Teladorsagia, Cooperia, Oesophagostomum or Chabertia. Faeces from these sheep are collected and used for experiments; -100 g of faeces are crushed homogenized and suspended in -1000 ml of sugar solution (specific gravity 1.2), put through a 'tea strainer' sieve, and the large undigested food material in the sieve discarded. The sugar solution is then placed into a flat dish and strips of plastic overhead transparency film placed on the surface. The plastic is left for at least 45 minutes to allow the eggs to stick and then removed carefully. The eggs are collected by washing them from the plastic film, with water, into a 50 ml centrifuge tube. The water containing egg suspension eggs is put through a 40 mm sieve to remove further plant material and then centrifuged at 1 ,000 x g for 10 minutes. The supernatant is checked for eggs and then discarded as the majority of eggs are at the bottom of the tube. These eggs are collected in 1 ml of water and diluted to -200 eggs/20 ml.

1 . Each compound is tested at five concentrations: 100, 50, 25, 12.5 and 6.25 mmol/l (i.e. serial 2-fold dilutions starting from 100 mmol/l). Dilutions of each compound (10 ml in total) are performed in 1 .5 ml microcentrifuge tubes, 1 ml of molten agar added, the tube vortexed and the agar aliquoted (150 ml) into the wells of a 96-well microtitre plate.

2. DMSO is used in a number of wells as solvent-only controls (negative controls) whilst cydectinis used as a positive control. Concentrations of cydectin used for positive controls for the compound re-testing are: 6.25, 12.5, 25, 50 and 100 mmol/l.

3. -100 eggs (20 ml) are then added to each well.

4. Plates are then incubated overnight at 27° C.

5. Plates are checked the following morning and afternoon to ensure that most eggs had hatched. Any compounds that appeared to have an ovicidal effect are noted.

6. Following hatching of most eggs, 15 ml of nutritive medium is added to feed the larvae.

Nutritive medium is prepared as follows: 1 g of yeast extract is added to 90 ml of 0.85% physiological saline and autoclaved for 20 mins at 121 ° C. Three millilitres of 10 x Earle's balanced salt solution is added to 27 ml of yeast extract solution and the pH of the solution adjusted to 5.4-5.6 by the addition of bicarbonate.

7. Following 7 days additional incubation, the numbers of L3 larvae that had developed in each well is determined.

In vivo experiments can be conducted in sheep monospecifically infected with these parasites (i.e. species of Haemonchus, Trichstrongylus, Teladorsagia, Cooperia,

Oesophagostomum or Chabertia). EN DO PARASITES

Activity in vitro against Dirofilaria immitis (Pi) (filarial nematodes).

Freshly harvested and cleaned microfilariae from blood from donor animals are used (dogs for Di).The microfilariae are then distributed in formatted microplates containing the test substances to be evaluated for antiparasitic activity. Each compound is tested by serial dilution in order to determine its minimum effective dose (MED). The plates are incubated for 48 hours at 26 °C and 60% relative humidity (RH). Motility of microfilariae is then recorded to identify possible nematocidal activity. Efficacy is expressed in percent reduced motility as compared to the control and standards.

Activity in vitro against Haemonchus contortus & Trichostrongylus colubriformis (Gastrointestinal nematodes).

Freshly harvested and cleaned nematode eggs are used to seed a suitably formatted microplate containing the test substances to be evaluated for antiparasitic activity. Each compound is tested by serial dilution in order to determine its MED. The test compounds are diluted in nutritive medium allowing the full development of eggs through to 3rd instar larvae. The plates are incubated for 6 days at 28°C and 60% relative humidity (RH). Egg-hatching and ensuing larval development are recorded to identify a possible nematocidal activity.

Efficacy is expressed in percent reduced egg hatch, reduced development of L3, or paralysis & death of larvae of all stages.

Examples of synthetic pathways

Synthesis of 3- (Ferrocenyloxy)-4-(trifluoromethyl)benzonitrile (compound 1 ) and N- ferrocenyl-4-((trifluoromethyl)thio)benzamide (compound 2).

The proposed synthetic pathway is depicted in Scheme 4.

Scheme 4: (a); NaH, 3-fluoro-4-(trifluoromethyl)benzonitrile, THF, overnight, 0°C→r.t, 16%; (b) NEt ₃ , 4-(trifluoromethylthio)benzoyl chloride, THF, 16 h, r.t., 32%.

Example 2:

Synthesis of N-(2-hydroxymethyl)ferrocenyl)-4-((trifluoromethyl)thio)benz amide (compound 3) The proposed synthetic pathway is depicted in Scheme 5.

30

Scheme 5: (a) ί-BuLi, DMF, Et ₂ 0, 0.35 min, r.t., 98%; (b) acetic anhydride, reflux, 2 h, 74%; (c) NaOH, hydroxylamine chlorhydrate, EtOH, reflux, 3 h, 78%; (d) LiAIH ₄ , THF, overnight, r.t., 51 %; (e) NEt ₃ , 4-(trifluoromethylthio)benzoyl chloride, THF, overnight, r.t., 40%, (f) NaH, 3-fluoro-4-(trifluoromethyl)benzonitrile, THF, overnight, 0°C→r.t, 79%.

Compound 8 is producible with the same reaction. The compounds 6 and 8 can be separate by column chromatography.

Example 3: Synthesis of ie f-butyl 1 -(ferrocenyloxy)-2-cyanopropan-2-ylcarbamate (compound 9)

The proposed synthetic pathway is depicted in Scheme 6.

Scheme 6: (a) Boc ₂ 0, THF, reflux, overnight, 68%; (b) K ₂ C0 ₃ , 18-crown-6, Acetonitrile, reflux, 60 h, 19%.

Example 4: Synthesis of N-[4-(2,5-dimethylphenoxy)but-2-ynyl]-4-methyl-benzamide (compound 13) and N-(4-hydroxybut-2-ynyl)-4-methyl-benzamide (compound 14).

The proposed synthetic pathway is depicted in Scheme 7.

Scheme 7: (a) methansulfonyl chloride, NEt ₃ , THF, overnight, 0°C→r.t, 26%; (b) Ammonium hydroxide, 1 h, r.t, 80%; (c) 1 M solution of NaHC0 ₃ , 4-(trifluoromethylthio)benzoyl chloride, Ethyl acetate, 2 h, r.t.; (d) 3-fluoro-4-(trifluoromethyl)benzonitrile, THF, overnight, 0°C→r.t; (e) Co ₂ (CO) ₈ , THF, 5 h, r.t., >98%. Instead of the mesylate a chloride might be used with an adapted procedure.

Compound 4, 5 and 15 are producible with a similar method.

Syntheses and Characterization

3- (Ferrocenyloxy)-4-(trifluoromethyl)benzonitrile (1 )

15

Ferrocenemethanol (0.19 g, 0.46 mmol) was dissolved in dry THF (40 mL). The solution was cooled with an ice bath to 0°C. Then NaH (16.8 mg, 0.7 mmol) were added and the reaction mixture was stirred for half an hour at 0°C. 3-fluoro-4-(trifluoromethyl)benzonitrile (0.096 g, 0.51 mmol) was added and the reaction mixture was allowed to warm to

room temperature. The yellow reaction mixture was stirred overnight at room temperature. After stirring the mixture overnight, additional 3-fluoro-4-(trifluoromethyl) benzonitrile (0.198 g, 1.02 mmol) was added. The reaction was stirred for an additional 24 h at room temperature and then quenched with H ₂ 0 (1 mL). The organic layer was evaporated under reduced pressure. The remaining residue was redissolved in CH ₂ CI ₂ (20 mL) and was washed with H ₂ 0 (5 mL) and brine (2 x 10 mL). The combined aqueous phases were extracted with CH ₂ CI ₂ (10 mL). The combined organic phases were dried over MgS0 ₄ , filtered and the solvent was evaporated under reduced pressure. The crude product was purified by column chromatography on silica with hexane:ethyl acetate (15:1 ) as the eluent (R _f = 0.42) to afford 3-(ferrocenyloxy)-4-(trifluoromethyl)benzonitrile (1 ) as a bright yellow solid. Yield: 16%. Elemental Analysis: calcd. for Ci ₉ H ₁₄ F ₃ NOFe = C, 59.25; H, 3.66; N, 3.64. Found = C, 59.07; H, 3.57; N, 3.51. ESI-MS: m/z (%) = 385.05 ([M] ⁺ , 100.

N-ferrocenyl-4-((trifluoromethyl)thio)benzamide (2)

Ferrocenylmethylamine(0.050 g, 0.232 mmol) was dissolved in dry THF (10 mL). NEt ₃ (65 μΙ, 0.46 mmol) and 4-(trifluoromethylthio)benzoyl chloride (44 μΙ, 0.255 mmol) were then added to the solution. The reaction mixture was then stirred for 16 h at room temperature. The solvent was evaporated under reduced pressure. The remaining residue was redissolved in CH ₂ CI ₂ (5 mL) and extracted with H ₂ 0 (1 x 5 mL) and brine (1 x 5 mL). The organic phase was diluted with Et0 ₂ (5 mL) and again extracted with H ₂ 0 (5 mL). The organic phase was dried over MgS0 ₄ , filtered and the solvent was evaporated under reduced pressure. The crude product was purified by column chromatography on silica with hexane:ethyl acetate (8:1 ) as the eluent (R _f = 0.17) to afford N-ferrocenyl-4-((trifluoromethyl) thio)benzamide (2) as a yellow oil. Yield: 32%. HR ESI-MS:cald. for Ci ₉ H ₁₆ F ₃ FeNNaO ([M+Na] ⁺ ) m/z (%) = 442.01539, found m/z (%) = 442.01463.

N-(2-h ydroxymeth yQferrocen yl)-4-((trifluorometh yl)thio)benzamide (3) 2-(Hydroxymethyl)ferrocenylmethylamine (30, 0.402 g, 1 .640 mmol) was dissolved in dry THF (100 mL). NEt ₃ (479 μΙ, 3.44 mmol) and 4-(trifluoromethylthio) benzoyl chloride (309 μΙ, 1.80 mmol) were then added to the solution. The reaction mixture was then stirred overnight at room temperature. More NEt ₃ (174 μΙ, 1 .72 mmol) and 4-(trifluoromethylthio)benzoyl chloride (154 μΙ, 0.90 mmol) were then added to the reaction mixture which was stirred for another 3 h at room temperature. A 1 M aqueous solution of NaOH (20 mL) was added and the reaction mixture became immediately transparent. The reaction mixture was stirred for another 3 h at room

temperature. After adding brine (10 mL) and H ₂ 0 (10 mL) to the reaction mixture, the solution was extracted with Et ₂ 0 (3 x 50 mL). The combined organic layers were dried over MgS0 ₄ , filtered and the solvent was evaporated under reduced pressure. /V-(2-hydroxymethyl) ferrocenyl)-4-((trifluoromethyl)thio)benzamide (3) precipitated by addition of ether as a yellow solid after 12 h at 4°C in 40% yield. HR ESI-MS: cald. for C ₂₀ H ₁₈ F ₃ FeNO ₂ S (M ⁺ ) m/z (%) = 449.03513 , found m/z (%) = 449.03543. Co- N-(prop-2-vn-1-yl)-4-((trifluoromethyl)thio)benzamide (4) de 0

solution was then added dropwise to the colorless N-(prop-2-yn-1 -yl)-4-((trifluoromethyl) thio)benzamide-solution. The reaction was stirred at room temperature and protected from light for 1 h. The solvent was evaporated under reduced pressure and the crude product was purified by a short silica plug with hexane:ethyl acetate (4:1 ) as the eluent (Rf = 0.79 (hexane :ethyl acetate (7:3))) to afford 4 as a reddish crystalline solid. Yield: 82%. Elemental Analysis: calcd. for Ci ₇ H ₈ N0 ₇ F ₃ SCo2 = C, 37.45; H, 1 .48; N, 2.57. Found = C, 37.51 ; H, 1 .45; N , 2.46. Co- N-(4-hvdroxybut-2-vn-1-yl)-4-((trifluoromethyl)thio)benzamid e (5)

N-(4-hydroxybut-2-yn-1 -yl)-4-((trifluoromethyl)thio) benzamide (0.097 g, 0.34 mmol) was dissolved in dry and degassed THF (10 ml_). Meanwhile, Co ₂ (CO) ₈ (0.127 g, 0.370 mmol) was dissolved as well in dry and degassed THF (5 ml_). The reddish- Co ₂ (CO) ₈ solution was then added dropwise to the colorless N-(4-hydroxybut-2-yn-1 -yl)-4- ((trifluoromethyl)thio)benzamide-solution. The reaction was stirred at room temperature and protected from light for 1 h. The solvent was evaporated under reduced pressure and the crude product was purified by a short silica plug with hexane:ethyl acetate (5: 1 ) as the eluent (Rf = 0.44 (hexane:ethyl acetate (3: 1 ))) to afford 5as a reddish crystalline solid. Yield: 23%. Elemental Analysis: calcd. for Ci ₈ H ₁₀ NO ₈ F ₃ SCo ₂ = C, 37.59; H, 1 .75; N, 2.44. Found = C, 37.51 ; H , 1 .45; N, 2.46.

N-(2-((5-cvano-2-(trifluoromethyl)phenoxy)methyl)ferrocenyl) -4- ((trifluoromethyl)thio)benzamide (6)

/V-(2-hydroxymethyl)ferrocenyl)-4-((trifluoromethyl)thio) benzamide (3, 0.080 g, 0.178 mmol) and 3-fluoro-4- (trifluoromethyl)benzonitrile (0.034 g, 0.178 mmol) were dissolved in dry THF (40 ml_). NaH (4.7 mg, 1 .9 mmol)

was added after having cooled the solution down to 0°C. The yellow reaction mixture was stirred overnight at room temperature. After stirring the mixture for 24 h, additional NaH (9.4 mg, 3.8 mmol) and 3-fluoro-4-(trifluoromethyl) benzonitrile (0.068 g, 0.356 mmol) were added to the reaction mixture. After 2 h, the yellow solution turned reddish and additional NaH (9.4 mg, 3.8 mmol) and 3-fluoro-4-(trifluoro- methyl)benzonitrile (0.068 g, 0.356 mmol) were again added to the reaction mixture. The reaction was stirred for an additional 2 h at room temperature and then quenched with H ₂ 0 (2 mL) and brine (6 ml_). The aqueous layer was extracted with ethyl acetate (3 x 20 ml_). The combined organic layers were dried over MgS0 ₄ , filtered and the solvent was evaporated under reduced pressure. The crude product was purified by column

chromatography on silica with hexane:ethyl acetate (7:3) as the eluent (R _f = 0.60). The contaminated purified product was washed with pentane to afford /V-(2-((5-cyano-2- (trifluoromethyl)phenoxy)methyl)ferrocenyl)-4-((trifluoromet hyl)thio)benzamide(6) as a bright yellow solid. Yield: 79%. HR ESI-MS: cald. for C ₂ 8H ₂ oF ₆ FeN ₂ 0 ₂ S (M ⁺ ) m/z (%) = 618.0491 1 , found m/z (%) = 618.04936. cald. for C ₂₈ H ₂₀ F ₆ FeN ₂ NaO ₂ S ([M+Na] ⁺ ) m/z (%) = 641.03877, found m/z (%) = 641.03913.

Dicobalthexacarbonyl-N-(4-(5-cvano-2-(trifluoromethyl)phenox y)but-2-en-1-yl)-4- ((trifluoromethyl)thio)benzamide (7)

/V-(4-(5-cyano-2-(trifluoromethyl)phenoxy)but-2-yn-1 - yl)-4-((trifluoromethyl)thio)benzamide (2e, 0.016 g, 0.035 mmol) was dissolved in dry and degassed THF

(2.3 mL) and added to a solution of Co ₂ (CO) ₈ (14.0

mg, 0.04 mmol) in dry and degassed THF (2 mL). After several minutes, the reaction mixture colour changed from bright yellow to reddish. The solution was then evaporated after having been stirred for 5 h at room temperature. The crude product was purified by column chromatography on silica with hexane:ethyl acetate (7:3) as the eluent (R _f = 0.70) to give dicobalthexacarbonyl-/V-(4-(5-cyano-2-(trifluoromethyl) phenoxy)but-2-en-1 -yl)-4-((trifluoromethyl)thio)benzamide (7) as a red oil. Yield: >98%. With further purification and washing with pentane a red crystalline solid, was obtained. Yield:

90%. HR ESI-MS: cald. for C ₂₆ H ₁₂ Co ₂ F ₆ N ₂ Na0 ₈ S ([M+Na] ⁺ ) m/z (%) = 766.87710, found m/z (%) = 766.87748.

N,N'-(((oxybis(methylene))bis(2,1 -ferrocenylene))bis(methylene))bis(4-((trifluoromethyl) thio)ferroceneamide) (8)

2-(Hydroxymethyl)ferrocenylmethylamine (0.200 g, 0,816 mmol) was dissolved in dry THF (18 mL). NEt ₃ (124 μΙ, 0.89 mmol) and 4-(trifluoromethylthio)benzoyl chloride (150 μΙ, 0.89 mmol) were then added to the yellow solution. The reaction mixture was stirred overnight at room temperature. Additional NEt ₃ (124 μΙ, 0.89 mmol) and 4-(trifluoromethylthio)benzoyl chloride (150 μΙ, 0.89 mmol) were added after 24 h to the reaction mixture. After the addition the reaction was further stirred overnight at room temperature. A 1 M aqueous solution of NaOH (20 mL) was added and the reaction mixture became immediately transparent. The reaction mixture was stirred for another 2 h at room temperature. After adding brine (10 mL) and H ₂ 0 (10 mL) to the reaction mixture, the solution was extracted with Et ₂ 0 (3 x 50 mL). The combined organic layers were dried over MgS0 ₄ , filtered and the solvent was

evaporated under reduced pressure. The crude product was purified by column

chromatography on silica with CH ₂ CI#:MeOH (50:1 ) as the eluent (Rf = 0.80) to give 8 as a yellow solid. Yield: 7%.

N-(2-cyano-1 -hvdroxypropan-2-yl)ferroceneamide(10):

Chlorocarbonyl ferrocene 35 (0.162 g, 0.652 mmol) and 2-amino-2 hydroxymethylproprionitrile - producible according to Gauvry et al. (WO2005/044784 A1 ) - (0.065 g, 0.652 mmol) were dissolved in dry

THF (15 mL). Triethylamine (453 μί, 3.26 mmol) was added to the

solution and the reaction mixture was stirred overnight at room temperature. The solvent was evaporated under reduced pressure and the crude product was purified by column chromatography on silica with hexane:ethyl acetate (7:1 →0:1) as the eluent (R _f = 0.07). The contaminated product was washed with dichloromethane to give /V-(2-cyano-1 -hydroxypropan-2-yl)ferroceneamide 10 as a pure orange solid. Yield: 29%. HR ESI-MS: cald. for Ci ₅ H ₁₆ FeN ₂ 0 ₂ (M ⁺ ) m/z (%) = 312.05508, found m/z (%) = 312.05557.

N-(4-(5-cvano-2-(trifluoromethyl)phenoxy)but-2-vn-1-yl)-4 -((trifluorom

(13)

25

Crude /V-(4-hydroxybut-2-yn-1 -yl)-4-((trifluoromethyl)thio) benzamide (14, 0.060 g, 0.207 mmol) and 3-fluoro-4- (trifluoromethyl)benzonitrile (0.039 g, 0.208 mmol) were

dissolved in dry THF (7 mL). After cooling the reaction solution to 0°C, Nal (9.6 mg, 0.40 mmol) was added. The reaction mixture was stirred overnight at room temperature and then quenched with H ₂ 0 (5 mL) and brine (15 mL). The aqueous layer was extracted with ethyl acetate (3 x 10 mL) and the combined organic layers were washed with brine, dried over MgS0 ₄ , filtered and the solvent was evaporated under reduced pressure. The crude product was purified by column chromatography on silica with hexane:ethyl acetate (7:3) as the eluent (R _f = 0.26) to give /V-(4-(5-cyano-2-(trifluoromethyl) phenoxy)but-2-yn-1 -yl)-4-((trifluoromethyl)thio)benzamide (13) as a white solid. Yield: 46 %. HR ESI-MS: cald. for C ₂₀ H ₁₂ CF ₆ N ₂ NaO ₂ S ([M+Na]+) m/z (%) = 481.04195, found m/z (%) = 481 .04159.

N-(4-hvdroxybut-2-vn-1-yl)-4-((trifluoromethyl)thio)benzamid e (14)

4-Aminobut-2-yn-1 -ol (34, 100 mg, 1.17 mmol) was dissolved in dry ethyl acetate (1 .35 mL) and a 1 M aqueous solution of sodium bicarbonate (1.35 mL). 4-(trifluoro- methylthio)benzoyl chloride (180 μΙ, 1.07 mmol) was then added to the reaction mixture. After stirring the reaction at room temperature for 2 h, water (2 mL) and ethyl acetate (2 mL) were added to the reaction mixture, which was further stirred for 5 min. The organic layer was extracted with brine (3 x 20 mL) and the combined aqueous layers were washed with ethyl acetate (1 x 40 mL). The combined organic layers were dried over MgS0 ₄ , filtered and the solvent was evaporated under reduced pressure. The crude product was used without further purification for the next reaction step. Alternatively, 4- Aminobut-2-yn-1 -ol (0.197 g, 1 .91 mmol) was dissolved in dry CH ₂ CI ₂ (15 mL). To this colorless reaction solution one equivalent of NEt3 (200 μ\-, 1 .47 mmol) was added and the reaction was allowed to stir at room temperature for 10 min. To this solution 4- (trifluoromethylthio)benzoyl chloride (240 μ\-, 1.47 mmol) was added dropwise and a second equivalent of NEt ₃ (240 μ\-, 1.47 mmol). The reaction mixture was stirred at room

temperature for 1 h. The solvent was evaporated under reduced pressure and the crude residual product was purified by column chromatography on silica using

dichloromethane/methanol (50:1 ) as the eluent (Rf = 0.1 ) to afford 14 as a colorless solid. Yield: 35%. Elemental Analysis: calcd. for Ci ₂ H ₁₀ F ₃ NO ₂ S = C, 49.82; H, 3.48; N, 4.84. Found = C, 49.63; H, 3.40; N, 4.71.

N-(prop-2-vn-1-yl)-4-((trifluoromethyl)thio)benzamide (15) Prop-2-yn-1 -amine (120 μ\-, 1.82 mmol) was dissolved in dry CH ₂ CI ₂ (15 mL). To this colorless solution, 4-(trifluoro- methylthio)benzoyl chloride (200 μ\-, 1 .21 mmol) was

added, which lead immediately to the formation of a colorless precipitate. To this cloudy reaction suspension NEt ₃ (510 μΐ, 3.64 mmol) was added and the reaction became transparent again. After stirring for 30 min at room temperature, the solvent was evaporated under reduced pressure. The crude product was redissolved in CH ₂ CI ₂ (5 mL) and washed with H ₂ 0 (2 mL) and brine (2 mL). The organic layer was dried with MgS0 ₄ , filtered and the solvent was evaporated under reduced pressure. The crude product was purified by a short silica plug with CH2CI2 as the eluent (Rf = 0.44 (CH ₂ CI ₂ :MeOI-l (10:1 ))) to afford 15 as a colorless crystalline solid. Yield: 63%. Elemental Analysis: calcd. for CnH ₈ NOF ₃ S = C, 50.96; H, 3.1 1 ; N, 5.40. Found = C, 50.73; H, 3.21 ; N, 5.33.

2-(N,N-dimethylaminomethylferrocene)carboxaldehyde (27)

2-(/V,/V-dimethylaminomethylferrocene)carboxaldehyde (27) was prepared following the procedure reported by Picart-Goethgheluck et al (Picart-Goetgheluck, S.; Delacroix, O.; Maciejewski, L; Brocard, J. Synthesis 2000, 2000, 1421 ).The spectroscopic data matched those reported by Picart-Goethgheluck et al.

2-(acetoxymethylferrocene)carboxaldehvde (28)

The synthesis of 2-(acetoxymethylferrocene)carboxaldehyde (28) is an adapted procedure from Ralambomanana et al. (Andrianina Ralambomanana, D.; Razafimahefa-Ramilison, D.; Rakotohova,

A. C; Maugein, J.; PEIinski, L. Bioorg. Med. Chem. 2008, 16, 9546). A brown viscose mixture of 2-(/V,/V-dimethylaminomethyl- ferrocene) carboxaldehyde (27, 1 .50 g, 5.53 mmol) and acetic anhydride (1.74 mL) was stirred at 100°C for approximately 2 h under a nitrogen atmosphere. The reaction mixture was then cooled to room temperature before CH ₂ CI ₂ (70 mL) was added. The organic layer was washed with a 0.5M aqueous solution of sodium hydroxide (3 x 30 mL). The combined aqueous layers were then extracted with CH ₂ CI ₂ (50 mL). The combined organic layers were dried over MgS0 ₄ and the solvent was evaporated under reduced pressure. The residual brown oil was purified by column chromatography on silica with hexane:ethyl acetate (3:1 ) as the eluent (R _f = 0.28) to give 2-(acetoxymethylferrocene)carboxaldehyde (28) as a brown oil. Yield: 74%. The spectroscopic data matched those reported by Ralambomanana et al.

2-(hvdroxymethlv)ferrocenecarboxaldehvdeoxime (29) The synthesis of 2-(hydroxymethly)ferrocenecarboxaldehydeoxime (28) is an adapted procedure from Gnoatto et al.{ Gnoatto, S. C. B.; Dassonville-Klimpt, A.; Da Nascimento, S.; Galera, P.;

Boumediene, K.; Gosmann, G.; Sonnet, P.; Moslemi, S. Eur. J. Med. Chem. 2008, 43, 1865). A mixture of 2-(acetoxymethyl-ferrocene)carboxaldehyde (28,0.210 g, 0.734 mmol), NaOH (188 mg) and hydroxylamine chlorhydrate (1 12 mg, 1.62 mmol) was dissolved in dry ethanol (8 mL) and refluxed for 3 h. The reaction mixture was allowed to cool down to room temperature, quenched with water (8 mL) and stirred for a further hour at room temperature. The solution was extracted with CH ₂ CI ₂ (10 x 25 mL). The combined organic layers were dried over MgS0 ₄ and the solvent was evaporated under reduced pressure. The crude product was purified by column chromatography on silica with hexane:ethyl acetate (2: 1→ 1 :1 ) as the eluent (R _f = 0.25) to give 2- (hydroxymethly)ferrocenecarboxaldehydeoxime (29) as an orange oil. Yield: 78%. HR ESI- MS: calcd. for Ci ₂ H ₁₃ FeN0 ₂ (M ⁺ ) m/z (%) = 259.02868, found m/z (%) = 259.02902.

2-(hvdroxymethyl)ferrocenylmethylamine or (2-(aminomethyl)phenyl)methanol (30)

5

The synthesis of 2-(hydroxymethyl)ferrocenylmethylamine(30) is an adapted procedure from Beer ei a/. (Beer, P. D.; Smith , D. K. J. C em. Soc, Dalton Trans.1998, 417). 2-(Hydroxymethly) ferrocenecarboxaldehydeoxime (29, 0.074 g, 0.286 mmol) was dissolved in dry THF (2.3 mL) and an excess of lithium aluminium hydride (49.3 mg, 1 .30 mmol) was carefully added portionwise. The mixture was stirred overnight at room

temperature. The following day, dry THF (1 mL) and LiAIH ₄ (21 .2 mg, 0.56 mmol) were added in intervals of one hour to the reaction mixture. The reaction solution was further stirred at room temperature for 2 h. The reaction mixture was then quenched with H ₂ 0 (1 .5 mL) and the solvent was removed in vacuo. The residue was dissolved in CH ₂ CI ₂ (10 mL) and the organic layer was extracted with a 1 M NaOH aqueous solution (15 mL). The aqueous layer was then washed with CH ₂ CI ₂ (4 x 50 mL). The combined organic layers were dried over MgS0 ₄ , filtered and the solvent was evaporated under reduced pressure. The crude product was purified by column chromatography on silica with methanokammonia solution (95:5) as the eluent (R _f = 0.4) to give 2-(hydroxymethyl)ferrocenylmethylamine (30) as a yellow oil. Yield: 51 %.H R ESI-MS: cald. for Ci ₂ H ₁₆ FeNO ([M+H] ⁺ ) m/z (%) = 246.05741 , found m/z (%) = 246.05758.

2-(Hvdroxymethylferrocene)carboxaldehvde (31 )

2-(Hydroxymethylferrocene)carboxaldehyde was prepared following the procedure reported by Ralambomanana et al. (Andrianina

Ralambomanana, D.; Razafimahefa-Ramilison, D.; Rakotohova, A. C; Maugein, J.; PEIinski, L. Bioorg. Med. Chem. 2008, 16, 9546).

2-(Hvdroxymethyl)ruthenocenecarboxaldehvde oxime (32)

2-(Acetoxymethylruthenocene)carboxaldehyde (0.100 g, 0.30 mmol), NaOH (0.08 g, 2.0 mmol) and hydroxylamine

hydrochloride (0.045 g, 0.64 mmol) were dissolved in anhydrous ethanol (5 mL). The mixture was stirred for 30 min until the greater part of the solid was dissolved. The solution was then refluxed for 3 h. After allowing the reaction mixture to reach room temperature, the cloudy yellow mixture was quenched with H ₂ 0 (20 mL). The reaction was further stirred for 75 min. The mixture was then extracted with dichloromethane (5x 25ml_). The combined organic phases were dried over Na ₂ S0 ₄ , filtered and the solvent was removed in vacuo. The residual brown solid was purified by column chromatography on silica with hexane:ethylacetate (2:1 ) as eluent (Rf = 0.30) to give 32 as a dark yellow solid. Yield = 72 %. Elemental Analysis: calcd. for

Ci ₂ H ₁₃ N0 ₂ Ru = C, 47.36; H, 4.31 ; N, 4.60. Found = C, 47.51 ; H, 4.37; N, 4.48.

4-Hydroxybut-2-vn- 1-yl methanesulfonate (33)

To a solution of but-2-yne-1 ,4-diol (5.0 g, 58 mmol)in dry THF (68 mL), methansulfonyl chloride (4.48 mL, 58.0 mmol)

10 and triethylamine (8.08 mL, 58 mmol) were added dropwise under stirring at 0°C. The reaction mixture was stirred overnight at room temperature. The solvent was evaporated under reduced pressure and the crude product purified by column chromatography on silica with dichloromethane:methanol (97:3) as the eluent (R _f = 0.2) to give 4-hydroxybut-2-yn-1 -yl methanesulfonate (33) as a colourless oil. Yield: 26%. The spectroscopic data matched those reported by Daher et al. (Daher, R.; Therisod, M. ACS Med. C em. Lett. 2010, 1, 101 -104.)

4-Aminobut-2-yn-1 -ol (34)

Although 4-aminobut-2-yn-1 -ol (34) is already known in the

HO ^NH ₂ literature, a different experimental procedure was carried out

34

20 (Lukinaviius, G.; Lapiene, V.; Stasevskij, Z.; Dalhoff, C; Weinhold, E.; Klimasauskas, S. J. Am. Chem. Soc. 2007, 129, 2758-2759). A solution of 4-hydroxybut- 2-yn-1 -yl methanesulfonate (33, 0.773 g, 4.71 mmol) and ammonium hydroxide (1 1.7 mL) was stirred for 1 h at room temperature. The solvent was evaporated at reduced pressure and the residue was treated with Dowex 1 x 8 R ₃ N ⁺ CI ^" , which was prewashed first with methanol, then water and finally with a 4% aqueous solution of NaOH. The filtrate was freeze-dried with to give 4-aminobut-2-yn-1 -ol (34) as a yellowish solid. Yield: 80%. The spectroscopic data of this compound matched those reported by Lukinaviiusei a/. HR ESI- MS: cald. for C ₂ oH ₁₂ CF ₆ N ₂ Na0 ₂ S ([M+Na] ⁺ ) m/z (%) = 481.04195, found m/z (%) =

481 .04159.

Chlorocarbonyl ferrocene (35): The synthesis of chlorocarbonyl ferrocene 35 was adapted from a procedure of Cormode et al. ((Cormode, D. P.; Evans, A. J.; Davis, J. J.; Beer, P. D. Dalton Trans.2010, 39, 6532)). After suspending ferrocenecarboxylic acid producible according to Witte, P.; Lai, T. K.; Waymouth, R. M.

OrganometallicsWdd, 18, 4147 - (462 mg, 2.01 mmol) in dry CH ₂ CI ₂ (23 mL), oxalyl chloride (1 100 μ\-, 13.64 mmol) in dry CH ₂ CI ₂ (10 mL) was added dropwise to the reaction mixture whereby the orange suspension turned dark red. The reaction mixture was refluxed for 2 h and then stirred overnight at room temperature. The solvent was then removed under vacuum. The product was not purified and used immediately for the next synthetic step.

2-(Acetoxymethylruthenocene)carboxaldehvde (36)

2-(/V,/V-dimethylaminomethylruthenocene)carboxaldehyde (0.983 g,

3.10 mmol) was dissolved in acetic anhydride (1 .2 mL, 12.71 mmol). The solution was heated to 100°C for 10 h. After allowing the reaction mixture to reach room temperature, the reaction mixture was diluted with CH ₂ CI ₂ (50 mL) and the organic layer was washed with 0.5M aqueous solution of NaOH (3x 50 mL). The organic phase was extracted and the combined organic phases were dried over Na ₂ S0 ₄ , filtered and the solvent was removed in vacuo. The crude yellow product was purified by flash column chromatography using silica with ethylacetate as eluent (R _f = 0.70) to give 36 as a yellow solid. Yield: 71 %. Elemental Analysis: calcd. for Ci ₄ H ₁₄ 0 ₃ Ru = C, 50.75; H, 4.26. Found = C, 50.88; H, 4.21.

Trifluoromethylthioferrocene (38)

Thiocyanatoferrocene (0.05 g, 0.21 mmol) was dissolved in dry THF (50 SCF3 mL), then degassed for 30 min and cooled to -10 °C. An excess of 20 trifluoromethyltrimethylsilane (0.47 mL, 3.15 mmol) was then added to this yellow reaction solution. The temperature of the reaction mixture was maintained at -10 °C, while a catalytic amount of

tetrabutylammoniumfluoride solution (1 M in THF, 0.09 mL, 0.09 mmol) was added dropwise to the solution containing trifluoromethyltrimethylsilane and 1 over a period of 10 min. The reaction solution was further stirred for 5 min and then directly filtered through a silica plug. The product was further eluted from the plug by dichloromethane. Based on the observed volatility of 3 at low pressure and elevated temperature, the solution was dried by a gentle stream of N ₂ gas to obtain the orange oily product 3. Yield: 0.054 g (90%, 0.19 mmol). Elemental Analysis calcd. For CnH ₉ F ₃ SFe: C, 46.18; H, 3.17. Found: C, 46.36; H, 3.34. HR EI-MS of 3: calcd. for CnH ₉ F ₃ FeS (M+) m/z (%) = 285.97210. Found m/z (%) = 285.97213.

Thiocvanatoruthenocene (39) and 1 ,1 '-Thiocvanatoiodoruthenocene (40)

(compound 40) A mixture of monoiodoruthenocene (0.17 g, 0.47 mmol) and diiodoruthenocene ( 0.06 g, 0.12 mmol) was refluxed in dry acetonitrile (40 mL) with an excess of sodium thiocyanate (0.39 g, 4.83 mmol) and a catalytic amount of Cu ₂ 0 (0.01 g, 0.07 mmol) for 64 h. The reaction was then allowed to reach room temperature, filtered, and evaporated in vacuo. The crude colorless solid was purified by column chromatography on silica using hexane:ethyl acetate (30:1 ) as eluent. Thiocyanatoruthenocene 39 (Rf = 0.24, hexane:ethylacetate (25:1 )) was obtained as colorless solid. Yield: 0.12 g (89%, 0.42 mmol). 1 ,1 '-thiocyanatoiodoruthenocene 40 (Rf = 0.15, hexane:ethylacetate (25:1 )) could also be isolated as colorless solids. Elemental Analysis compound 39: calcd. for CnHgNRuS: C, 45.82; H, 3.15; N, 4.86. Found: C, 45.65; H, 3.07; N, 4.69. Elemental Analysis compound 40: calcd. for CnH ₈ NIRuS: C, 31.89; H, 1.95; N, 3.38. Found: C, 31 .28; H, 1.92; N, 3.13.

N-(2-cyano-1 -hydroxypropan-2-yl)ruthenoceneamide (41 )

^^^^ Chlorcarbonyl ruthenocene (1 .67 g, 6.96 mmol) and 2-amino-2-

I hydroxymethylproprionitrlie (1 .05 g, 10.5 mmol) were dissolved in dry THF (50 mL) and NEt ₃ (6.8 mL, 50 mmol) was slowly added and the mixture was stirred at room temperature for 16 h. The solvent was removed in vacuo and the yellow residue was purified by column chromatography on silica., /V-(2-cyano- 1 -hydroxypropan-2-yl)ruthenocenamide 4a' was eluted with ethyl acetate:hexane (1 :7 -> 7:1 ) (R _f = 0.05 in 1 :7 ethyl acetate:hexane) obtaining a crude product. The crude product was dissolved in boiling acetonitrile and recrystallized at -4°C for 4 days. Yield = 31 %, Elemental Analysis: calcd. for Ci ₅ H ₁₆ 02N ₂ Ru = C, 50.41 ; H, 4.51 ; N, 7.84. Found = C, 50.85; H, 4.44; N, 7.41 .

Cytotoxicity and Nematocidal Studies:

The toxicity towards human cervical cancer HeLa was investigated using the fluorometric cell viability assay (Resazurin) (Ahmed, S. A.; Gogal, R. M. J.; Walsh, J. E. J. Immunol. Methods 1994, 170, 21 1 -224). For compounds which were found to be toxic towards HeLa cells, their cytotoxicity towards the human lung fibroblasts MRC-5 was also tested (see table 1 ).

C. elegans is widely used as a tool in the pharmaceutical and biotechnology industry to test the efficacy of compounds against nematodes and other organisms (cf. Divergence, Inc. - now aquired fromthe Montsanto Company), which has the major advantage that the modes/mechanisms of action and associated phenotypes can be fully characterised as well as resistance development assessed. Given that C. elegans and socioeconomic strongylid nematodes belong to clade V of the phylum Nematoda (Blaxter et al., 1998 - Nature), there is a high likelihood that drug action will be effective/effected in strongylid nematodes.

Table 1 :shows the toxicity towards human cervical cancer HeLa and towards the human lung fibroblasts MRC-5 using the fluorometric cell viability assay.

Table 2 comprises information concerning the effect of compound 1 on C. elegans and H. contortus. Interestingly, it was demonstrated that the mobility of the C. elegans worms was reduced at a concentration of 50 μΜ indicating a good nematocidal action of the respective compounds.

Table 2 shows the effect of compound 1 on C. elegans and H. contortus.

The activity against Haemontus Contortus, Dirofilaria immitis and Trychostronaylus colubriformis was tested and the results are shown in table 3.

Compound 37 76% - 56%

Compound 38 0% 31 % 0%

Compound 39 0% 66% 0%

Compound 40 90% 98% 55%

Compound 41 0% - 0%

Table 3:shows the activity against Haemontus Contortus, Dirofilaria immitis and

Trychostrongylus colubriformis

As can be seen in Table 3, interesting EC values could be obtained, especially on compounds 2, 4, 10, 37 an 40, which had efficacies up tp 90% at a dosage of 10 mg/mL against Haemonchus contortus. Importantly, some of the compounds, namely 2, 7, 39 and 40 have a really high efficacy (up to 98%) at a dosage of 10 mg/mg and showed an interesting selectivity within the examined parasites.