OLIGOMERISATION CATALYST WITH PENDANT DONOR GROUPS

Technical Field

This invention relates to the oligomerisation of olefinic compounds in the presence of an oligomeπsation catalyst which includes a ligating compound wherein at least one electron donating group thereon is linked through a linking moiety to a hetero atom of the ligating compound The invention also relates to such an oligomerisation catalyst

Background Art

A number of different oligomerisation technologies are known to produce α-olefιns Some of these processes, including the Shell Higher Olefins Process and Ziegler-type technologies, have been summarized in WO 04/056479 A1 The same document also discloses that the prior art (e g WO 03/053891 and WO 02/04119) teaches that chromium based catalysts containing heteroaromatic hgands with both phosphorus and nitrogen hetero atoms, selectively catalyse the trimerisation of ethylene to 1 - hexene

Processes wherein transition metals and heteroatomic hgands are combined to form catalysts for trimerisation, tetrameπsation, oligomerisation and polymerisation of olefinic compounds have also been described in different patent applications such as WO 03/053890 A1 , WO 03/053891 , WO 04/056479 A1 ,

WO 04/056477 A1 , WO 04/056480 A1 , WO 04/056478 A1 , South African provisional patent application number 2004/3805, South African provisional patent application number 2004/4839, South African provisional patent application number 2004/4841 , and UK provisional patent application no 0520085 2, and US provisional patent application number 60/760,928

It has now been found that when an olefinic compound is oligomensed in the presence of an oligomerisation catalyst which includes a ligating compound wherein at least one electron donating group thereon is linked through a linking moiety to a hetero atom of the ligating compound, the selectivity of the process is influenced, for example to provide a high selectivity towards a trimerised product instead of a tetramerised product Good selectivity towards linear alpha olefin products was also achieved This is illustrated by comparing example 3 to comparative example 1

Organometallics 2002, 21 , 5122 - 5135 discloses titanium based catalysts for the trimerisation of ethylene to 1 -hexene The cyclopentadienyl hgands disclosed include pendant arene groups thereon which bind to the titanium However the disclosed hgands do not have electron donating groups linked through a linking moiety to a hetero atom of the ligand and are very different to the ligands of the present invention

Journal of Organometalhc Chemistry 690 (2005) 713-721 discloses chromium complexes of tridentate imine hgands I and amine hgands Il

I Il

In each case Y was an electron donating heteroatomic (that is containing an atom other than H and C) group such as PPh ₂ , SMe or OMe, and Z was also a heteroatomic (that is containing a compound other than H or C) group such as PPh ₂ , SEt, C ₅ H ₄ N, NMe ₂ , OMe or SMe In the chromium complexes formed with these ligands, the hetero atoms in Y and Z, as well as N in the hgands I and Il formed bonds with the chromium atom

Most surprising it has now been found that a heteroatomic group in the form of Y in ligands I and Il is not required to provide an effective trimeπsation catalyst The omission of such a Y group in such and similar ligands has the advantage that in at least some cases it may lead to high selectivities to 1-hexene and/or alpha olefinic compounds and/or, high reaction rates and/or good catalyst stability

Disclosure of the Invention

According to the present invention there is provided a process for producing an ohgomeπc product by the oligomerisation of at least one olefinic compound by contacting the at least one olefinic compound with an oligomeπsation catalyst which includes the combination of ι) a source of a transition metal, and n) a ligating compound of the formula

(R ¹ ) _m X ¹ (Y) X ² (R ² ) _n

wherein X ¹ and X ² are independently an atom selected from the group consisting of N,

P, As, Sb, Bi, O, S and Se or said atom oxidized by S, Se, N or O, where the valence of X ¹ and/or X ² allows for such oxidation,

Y is a linking group between X ¹ and X ² , m and n are independently 0, 1 or a larger integer, and R ¹ and R ² are independently selected from the group consisting of hydrogen, a hydrocarbyl group, a heterohydrocarbyl group, and an organoheteryl group, R ¹ being the same or different when m>1 , R ² being the same or different when n>1 , and at least one R ¹ or R ² is a moiety of formula

(L)(D)

wherein L is a linking moiety between X ¹ or X ² and D, and

D is an electron donating moiety which includes at least one multiple bond between adjacent atoms which multiple bond renders D capable of bonding with the transition metal in the source of transition metal, provided that when D is a moiety

derived from an aromatic compound with a ring atom of the aromatic compound bound to L, D has no electron donating moiety that is bound to a ring atom of the aromatic compound adjacent to the ring atom bound to L, and that is in the form of a heterohydrocarbyl group, a heterohydrocarbylene group, a heterohydrocarbylidene group, or an organoheteryl group that is capable of bonding by a coordinate covalent bond to the transition metal in the source of transition metal

An electron donating moiety is defined in this specification as a moiety that donates electrons used in chemical bond, including coordinate covalent bond, formation

In this specification the following further definitions also apply

a hydrocarbyl group is a univalent group formed by removing one hydrogen atom from a hydrocarbon,

a hydrocarbylene group is a divalent group formed by removing two hydrogen atoms from the same or different carbon atoms in a hydrocarbon, the resultant free valencies of which are not engaged in a double bond,

a hydrocarbylidene group is a divalent group formed by removing two hydrogen atoms from the same carbon atom of a hydrocarbon, the resultant free valencies of which are engaged in a double bond,

a heterohydrocarbyl group is a univalent group formed by removing one hydrogen atom from a heterohydrocarbon, that is a hydrocarbon compound which includes at least one hetero atom (that is, not being H or C), and which group binds with other moieties through the resultant free valency on that carbon atom,

a heterohydrocarbylene group is a divalent group formed by removing two hydrogen atoms from the same or different carbon atoms in a heterohydrocarbon, the free valencies of which are not engaged in a double bond and which group binds with other moieties through the resultant free valencies on that or those carbon atoms,

a heterohydrocarbylidene group is a divalent group formed by removing two hydrogen atoms from the same carbon atom of a heterohydrocarbon, the free valencies of which are engaged in a double bond,

an organoheteryl group is a univalent group containing carbon atoms and at least one hetero atom, and which has its free valence at an atom other than carbon, and

olefinic compound is an olefin or a compound including a carbon to carbon double bond, and olefinic moiety has corresponding meaning

Oliqomeric product

The oligomenc product may be an olefin, or a compound including an olefinic moiety Preferably the oligomeπc product includes an olefin, more preferably an olefin containing a single carbon-carbon double bond, and preferably it includes an α-olefιn The olefin product may include hexene, preferably 1 -hexene, alternatively or additionally it includes octene, preferably 1-octene In a preferred embodiment of the invention the olefinic product includes hexene, preferably 1 -hexene

In one preferred embodiment of the invention the oligomerisation process is a selective process to produce an oligomeπc product containing more than 30% by mass of total product of a single olefin product The olefin product may be hexene, preferably 1 -hexene

Preferably the product contains at least 35% of the said olefin, preferably α-olefιn, but it may be more than 40%, 50%, 60% or even 80% and 90% by mass Preferably the product contains less than 30% and even less than 10% by mass of another olefin

The olefin being present in more than 30% by mass of the total product may comprise more than 80%, preferably more than 90%, preferably more than 95% by mass of an α-olefιn

The olefinic product may be branched, but preferably it is non-branched

Oliαomeπsation

Preferably the oligomerisation process comprises a trimerisation process

The process may be oligomeπsation of two or more different olefinic compounds to produce an oligomer containing the reaction product of the two or more different olefinic compounds Preferably however, the oligomerisation (preferably trimerisation) comprises the oligomerisation of a single monomer olefinic compound

In one preferred embodiment of the invention the oligomerisation process is oligomerisation of a single α- olefin to produce an oligomenc α-olefιn Preferably it comprises the trimerisation of ethylene, preferably to 1 -hexene

Olefinic compound to be oliqomeπsed

The olefinic compound may comprise a single olefinic compound or a mixture of olefinic compounds In one embodiment of the invention it may comprise a single olefin

The olefin may include multiple carbon-carbon double bonds, but preferably it comprises a single carbon- carbon double bond The olefin may comprise an α-olefιn with 2 to 30 carbon atoms, preferably 2 to 10

carbon atoms The olefinic compound may be selected from the group consisting of ethylene, propene, 1 - butene, 1 -pentene, 1 -hexene, 1 -heptene, and 1 -octene, 1 -nonene, 1-decene, 3-methyl-1 -butene, 3- methyl-1 -pentene, 4-methyl-1 -pentene, styrene, p-methyl styrene, 1 -dodecene or combinations thereof Preferably it comprises ethylene or propene, preferably ethylene The ethylene may be used to produce hexene, preferably 1-hexene

Oliqomeπsation Catalyst Activator

In a preferred embodiment of the invention the catalyst also includes one or more activators Such an activator may be a compound that generates an active catalyst when the activator is combined with the source of transition metal and the ligating compound

Suitable activators include aluminium compounds, boron compounds, organic salts, such as methyl lithium and methyl magnesium bromide, inorganic acids and salts, such a tetrafluorobonc acid etherate, silver tetrafluoroborate, sodium hexafluoroantimonate and the like

Suitable aluminium compounds include compounds of the formula AI(R ⁹ ) ₃ (R ⁹ being the same or different), where each R ⁹ is independently a C ₁ -C12 alkyl, an oxygen containing moiety or a halide, aluminoxanes, and compounds such as L1AIH ₄ and the like Aluminoxanes are well known in the art as typically oligomeπc compounds which can be prepared by the controlled addition of water to an alkylaluminium compound, for example trimethylaluminium Such compounds can be linear, cyclic, cages or mixtures thereof Examples of suitable aluminium compounds in the form of organoaluminium activators include tnmethylaluminium (TMA), triethylaluminium (TEA), tri-isobutylaluminium (TIBA), tri-n-octylaluminium, methylaluminium dichloride, ethylaluminium dischloπde, dimethylaluminium chloride, diethylaluminium chloride, aluminium isopropoxide, ethylaluminiumsesquichloride, methylaluminiumsesquichloπde, methylaluminoxane (MAO), ethylaluminoxane (EAO), isobuthylaluminoxane (iBuAO), modified alkylaluminoxanes such as modified methylaluminoxane (MMAO) and mixture thereof

Examples of suitable boron compounds are boroxines, NaBHU, tπethylborane, trιs(pentafluorophenyl)borane, trityl tetrakιs(pentafluorophenyl) borate, dimethylanilinium tetrakιs(pentafluorophenyl)borate, tπbutyl borate and the like

The activator may be a compound as described in UK Provisional Patent Application No 0520085 2 which is incorporated herein by reference

The activator may also be or contain a compound that acts as a reducing or oxidizing agent, such as sodium or zinc metal and the like, or hydrogen or oxygen and the like

The activator may be selected from alkylaluminoxanes such as methylaluminoxane (MAO), high stability methylaluminoxane (MAO HS), modified alkylaluminoxanes such as modified methylaluminoxane (MMAO) MMAO is described later in this specification

The transition metal source and the aluminoxane may be combined in proportions to provide Al/transition metal molar ratios from about 1 1 to 10 000 1 , preferably from about 1 1 to 1500 1 , and more preferably from i 1 to 1000 1

The oligomerisation process may also include the step of the continuous addition of the activator, including a reducing (such as hydrogen (H ₂ )) or oxidizing agent, to a solution containing the transition metal source

It should be noted that aluminoxanes generally also contain considerable quantities of the corresponding trialkylaluminium compounds used in their preparation The presence of these trialkylaluminium compounds in aluminoxanes can be attributed to their incomplete hydrolysis with water

It has been found that modified methylaluminoxane (MMAO) is especially suitable as an activator which may result in improved activity and stability of the catalyst

MMAO is methyl aluminoxane wherein one or more, but not all methyl groups have been replaced by one or more non-methyl moieties Preferably the non-methyl moiety is an organyl, preferably a hydrocarbyl or a heterohydrocarbyl Preferably it is an alkyl, preferably isobutyl or n-octyl

Source of transition metal

Preferably the source of transition metal as set out in (i) above is a source of a Group 4B to 6B transition metal Preferably it is a source of Cr, Ti, V, Ta or Zr, more preferably Cr, Ti, V or Ta Preferably it is a source of either Cr, Ta or Ti Most preferably it is a source of Cr

The source of the Group 4B to 6B transition metal may be an inorganic salt, an organic salt, a coordination compound or an organometallic complex

Preferably the source of transition metal is a source of chromium and preferably it is selected from the group consisting of chromium trichloride tris-tetrahydrofuran, (benzene)tπcarbonyl chromium, chromium (III) octanoate, chromium (III) hexaonate, chromium hexacarbonyl, chromium (III) acetylacetonate, chromium (III) naphthenate, chromium (III) 2-ethylhexanoate Preferably it is chromium (III) acetylacetonate

Liαatinα compound

As stated above at least one R ¹ or R ² is a moiety of the formula

(L)(D)

wherein L is a linking moiety between X ¹ or X ² and D, and

D is an electron donating moiety which includes at least one multiple bond between adjacent atoms which multiple bond renders D capable of bonding with the transition metal in the source of transition metal, provided that when D is a moiety derived from an aromatic compound with a ring atom of the

aromatic compound bound to L, D has no electron donating moiety that is bound to a ring atom of the aromatic compound adjacent to the ring atom bound to L, and that is in the form of a heterocarbyl group, a heterohydrocarbylene group, a heterohydrocarbylidene group, or an organoheteryl group that is capable of bonding by a coordinate covalent bond to the transition metal in the source of transition metal

Preferably D is an electron donating moiety capable of bonding with the transition metal by a coordinate covalent bond

Preferably, when D is an aromatic compound with a ring atom of the aromatic compound bound to L, D has no electron donating moiety in any form capable of bonding by a coordinate covalent bond to the transition metal bound to a ring atom of the aromatic compound adjacent to the ring atom bound to L

Preferably D is an electron donating moiety in the form of a hydrocarbyl moiety or a heterohydrocarbyl moiety which includes at least one multiple bond between adjacent atoms, preferably adjacent carbon atoms, wherein at least one such multiple bond renders D capable of bonding by a coordinate covalent bond to the transition metal Preferably D is a hydrocarbyl moiety

D may be an aromatic or heteroaromatic moiety D may include a moiety (including a hydrocarbyl or heterohydrocarbyl) other than H bound to a ring atom defined by D D may include one or more electron donating moieties Preferably D has no such electron donating moiety, preferably no moiety other than H, as a non-ring atom bound to a ring atom defined by D Preferably D is an aromatic moiety

In one embodiment of the invention D may comprise phenyl, or a substituted phenyl wherein one or more moieties other than H are bound as a non-ring atom to a ring atom of D

Preferably D is an aromatic or heteroaromatic moiety selected from the group consisting of phenyl, naphthyl, 7-(1 ,2,3,4-tetrahydronaphthyl), anthracenyl, phenanthrenyl, phenalenyl, 3-pyrιdyl, 3-thιopeneyl, 7-benzofuranyl, 7-(2H-1 -benzopyranyl), 7-quιnolιnyl and 6-benzιsoxazolyl

L is preferably bound to a single atom of D, preferably to a single ring atom of D where D is an aromatic or a heteroaromatic moiety Preferably L is bound to D by means of a single bond Preferably L is bound to an atom (preferably a carbon atom) of D which atom of D is linked to another atom of D (preferably a carbon atom) by means of a multiple bond Preferably L is bound to a ring atom of D where D is an aromatic or a heteroaromatic moiety

L may be bound to X ¹ or X ² by means of a single bond or a double bond

Preferably L is aliphatic and preferably L includes no multiple bonds between atoms in the L moiety Preferably L includes not more than 3 carbon atoms, and all the carbon atoms of L may be sp ³ carbon atoms Preferably L is a hydrocarbon moiety In one embodiment of the invention L may include one or more carbon atoms where all carbon atoms only have saturated bonds, and preferably L is -CH ₂ - Alternatively L may comprise one or more carbon atoms with unsaturated bonds, and L may be =CH-

L may be selected from -CH ₂ -, -CH=, -CH ₂ -CH ₂ -, -CH=CH-, -CH ₂ -CH ₂ -CH ₂ -, -CH=CH-CH ₂ -, -CH ₂ - CH=CH-, -CH(CHs)-CH ₂ -CH ₂ -, -CH ₂ -CH(CHs)-CH ₂ -, -CH ₂ -CH ₂ -CH(CH ₃ )- and -CH ₂ -C(CHs) ₂ -CH ₂ -

Combined (L)(D) may be a moiety selected from benzyl, ethyl-phenyl, propyl-phenyl, methyl-naphthyl, ethyl-naphthyl, propyl-naphthyl, methyl-anthracenyl, methyl-phenanthrenyl, methyl-phenalenyl, methyl-3- (pyπdyl), methyl-3-(thιopeneyl), methyl-7-(benzofuranyl), methyl-7-(2H-1-benzopyranyl), methyl-7- (quinolmyl) and methyl-6-(benzιsoxazolyl)

Y may be selected from the group consisting of an organic linking group such as a hydrocarbylene, substituted hydrocarbylene, heterohydrocarbylene and a substituted heterohydrocarbylene, an inorganic linking group comprising either a single- or two-atom linker spacer, and a group comprising methylene, dimethylmethylene, ethylene, ethene-1 ,2-dιyl, propane-1 ,2-dιyl, propane-1 ,3-dιyl, cyclopropane-1 ,1-dιyl, cyclopropane- 1 ,2-dιyl, cyclobutane-1 ,2-dιyl, cyclopentane-1 ,2-dιyl, cyclohexane-1 ,2-dιyl, cyclohexane- 1 ,1 -dιyl, 1 ,2-phenylene, naphthalene-1 ,8-dιyl, phenanthrene-9,10-dιyl, phenanthrene-4,5-dιyl, 1 ,2- catecholate, 1 ,2-dιarylhydrazιne-1 ,2-dιyl (-N(Ar)-N(Ar)-) where Ar is an aryl group, 1 ,2-dιalkyIhydrazιne- 1 ,2-dιyl (-N(AIk)-N(AIk)-) where AIk is an alkyl group, -B(R ⁷ )-, -Sι(R ⁷ ) ₂ -, -P(R ⁷ )- and -N(R ⁷ )- where R ⁷ is hydrogen, a hydrocarbyl or heterocarbyl or halogen Preferably, Y may be -N(R ⁷ )- and R ⁷ may be selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, aryloxy, substituted aryloxy, halogen, alkoxycarbonyl, carbonyloxy, alkoxy, aminocarbonyl, carbonylamino, dialkylamino, silyl groups or derivatives thereof, and aryl substituted with any of these substituents Preferably R ⁷ may be a hydrocarbyl or a heterohydrocarbyl or an organoheteryl group R ⁷ may be methyl, ethyl, propyl, isopropyl, cyclopropyl, allyl, butyl, tertiary-butyl, sec-butyl, cyclobutyl, pentyl, isopentyl, 1 ,2-dιmethylpropyl (3-methyl- 2-butyl), 1 ,2,2-trιmethylpropyl (WS-3,3-dιmethyl-2-butyl), 1 -(1-methylcyclopropyl)-ethyl, neopentyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclo-octyl, decyl, cyclodecyl, 1 ,5-dιmetylheptyl, 2-naphthylethyl, 1 - naphthylmethyl, adamantylmethyl, 1 -adamantyl, 2-adamantyl, 2-ιsopropylcyclohexyl, 2,6- dimethylcyclohexyl, cyclododecyl, 2-methylcyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2- ethylcyclohexyl, 2-ιsopropylcyclohexyl, 2,6-dιmethyl-cyclohexyl, exo-2-norbornanyl, isopinocamphenyl, dimethylamino, phthalimido, pyrrolyl, trimethylsilyl, dimethyl-tertiary-butylsilyl, 3-trιmethoxylsιlane-propyl, indanyl, cyclohexanemethyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 4-tertιary- butylphenyl, 4-nιtrophenyl, (1 ,1'-bιs(cyclohexyl)-4,4'-methylene), 1 ,6-hexylene, 1 -naphthyl, 2-naphthyl, N- morpholine, diphenylmethyl, 1 ,2-dιphenyl-ethyl, phenylethyl, 2-methylphenyl, 3-methylphenyl, 4- methylphenyl, 2,6-dιmethyl-phenyl, 1 ,2,3,4-tetrahydronaphthyl, or a 2-octyl group

Preferably Y includes at least two, and preferably only two atoms in the shortest link between X ¹ and X ² The said two atoms may form part of a cyclic structure, alternatively they form part of an acyclic structure

In one embodiment of the invention Y is a moiety of formula

- Y ¹ - Y ² -

wherein Y ¹ and Y ² are independently CR ₂ ¹⁹ or AR ²⁰ , wherein R ¹⁹ and R ²⁰ are independently hydrogen, a hydrocarbyl group or a heterocyclocarbyl group, and A is selected from the group consisting of N, P, As, Sb and Bi Preferably A is N It will be appreciated that in CR ₂ ¹⁹ , R ¹⁹ can be the same or different

Preferably R ¹⁹ and R ²⁰ are independently H or a hydrocarbyl group, preferably an alkyl

Preferably Y ¹ and Y ² are the same In one embodiment of the invention Y may be

R ²¹ R ²¹ — CH ₂ -CH ₂ - or — N— N—

wherein each R ²¹ is independently a hydrocarbyl group, preferably an alkyl group

In an alternative embodiment of the invention Y may comprise a moiety derived from a cyclic compound wherein two atoms of the cyclic ring structure are bond to X ¹ and X ² respectively The moiety derived from a cyclic compound may compnse a moiety derived from a cyclic organic compound which may include at least one heteroatom (that is an atom other than H and C) Preferably the cyclic compound comprises an aromatic compound or a heteroaromatic compound Preferably it comprises an aromatic compound and in one embodiment, adjacent carbon ring atoms are bound to X ¹ and X ² respectively Preferably Y comprises a moiety derived from a monocyclic aromatic compound, preferably a benzene ring with adjacent πng atoms bound to X ¹ and X ² respectively

X ¹ and/or X ² may be a potential electron donor for coordination with the transition metal referred to in (ι)

X ¹ and/or X ² , may be independently oxidised by S, Se, N or O

It will be appreciated that m and n are dependent on factors such as the valence and oxidation state of X ¹ and X ² , bond formation of Y with X ¹ and X ² respectively, and bond formation of R ¹ and R ² with X ¹ and X ² respectively Preferably both m and n are not O

In one embodiment of the invention the ligating compound may be of the formula

wherein Y is a linking group between X ¹ and X ² , X ¹ and X ² are independently selected from the group consisting of N, P, As, Sb and Bi, and R ³ to R ⁶ are each independently hydrogen, a hydrocarbyl group or a heterohydrocarbyl group and at least one of R ³ to R ⁶ is a moiety of formula

(L)(D)

wherein L is a linking moiety between X ¹ or X ² and D, and

D is an electron donating moiety which includes at least one multiple bond between adjacent atoms which multiple bond renders D capable of bonding with the transition metal in the source of transition metal,

provided that when D is an aromatic compound with a ring atom of the aromatic compound bound to L, D has no electron donating moiety that is bound to a πng atom of the aromatic compound adjacent to the ring atom bound to L and that is in the form of a heterohydrocarbyl group, a heterohydrocarbylene group, a heterohydrocarbylidene group, or an organoheteryl group that is capable of bonding by a coordinate covalent bond to the transition metal in the source of transition metal

Any of R ³ to R ⁶ which is not a moiety of formula (L)(D) may be an aromatic or heteroaromatic moiety The aromatic or heteroaromatic moiety may include one or more substituents other than H on one or more aromatic carbon atoms, but preferably no such substituents are provided

Preferably at least two, preferably all of R ³ to R ⁶ are moieties of formula (L)(D) as defined above Preferably L and D are as defined above

Preferably X ¹ or X ² are the same and preferably both are P

Preferably Y is as defined above and preferably Y is a moiety of formula

-Y ¹ -Y ² - as defined above

In an alternative embodiment of the invention the ligating compound may be of formula

\

^ X ⁱ - Y - X* = (L)(D) R ¹¹

or

)

wherein Y is as defined above, (L)(D) is as defined above, X ¹ or X ² are independently selected from the group consisting of N, P, As, Sb and Bi, R ¹⁰ to R ¹² are each independently hydrogen, a hydrocarbyl group or a heterohydrocarbyl group

Preferably R ¹² is hydrogen

Preferably Y is as defined above

Preferably X ¹ and X ² are different Preferably X ² is N and preferably X ¹ is P

Preferably = (L)D is =CH _V - and - (L)(D) is benzyl

R ¹⁰ and R ¹¹ may each be a hydrocarbyl or heterohydrocarbyl moiety Preferably each of R ³ to R ⁶ , R ¹⁰ and R ¹¹ is an aromatic or heteroaromatic moiety, more preferably an aromatic moiety The aromatic or heteroaromatic moiety may include one or more substituents other than H on one or more aromatic carbon atoms, but preferably no such substituents are provided The aromatic moiety may comprise phenyl or a substituted phenyl

Non-limiting examples of the ligating compound are (benzyl) ₂ PN(methyl)N(methyl)P(benzyl) ₂ ,

(benzyl) ₂ PN(ethyl)N(ethyl)P(benzyl) ₂ ,

(benzyl) ₂ PN(/-propyl)N(/-propyl)P(benzyl) ₂ ,

(benzyl) ₂ PN(methyl)N(ethyl)P(benzyl) ₂ ,

(benzyl) ₂ PN(methyl)N(;-propyl)P(benzyl) ₂ , (benzyl) ₂ PN(methyl)N(f-butyl)P(benzyl) _2l

(benzyl) ₂ PCH ₂ N(/-propyl)P(benzyl) ₂ ,

(allyl) ₂ PN(ethyl)N(ethyl)P(allyl) ₂ ,

(phenyl) ₂ P-C ₂ H ₄ -N=C(H)-phenyl,

(phenyl) ₂ P-C ₂ H ₄ -N(H)-CH ₂ -phenyl, (benzyl)(phenyl)PN(ethyl)N(ethyl)P(benzyl)(phenyl),

(benzyl)(phenyl)PN(ethyl)N(ethyl)P(phenyl) ₂ ,

(benzyl)(phenyl)PN(ethyl)N(ethyl)P(benzyl) _{2 >}

(ethyl-phenyl) ₂ PN(ethyl)N(ethyl)P(ethyl-phenyl) ₂ ,

(propyl-phenyl) ₂ PN(ethyl)N(ethyl)P(propyl-phenyl) ₂ , (methyl-naphthyl) ₂ PN(ethyl)N(ethyl)P(methyl-naphthyl) ₂ ,

(ethyl-naphthyl) ₂ PN(ethyl)N(ethyl)P(ethyl-naphthyl) ₂ ,

(benzyl) ₂ PN(ιsopropyl)P(benzyl) ₂ ,

(benzyl) ₂ PN(methyl)P(benzyl) ₂ ,

(benzyl) ₂ PN(ethyl)P(benzyl) ₂ , (benzyl) ₂ PN(1 ,2-dιmethylpropyl)P(benzyl) ₂ ,

(benzyl) ₂ P-ethene- 1 ,2-dιyl-P(benzyl) ₂ ,

(benzyl) ₂ P-ethylene-P(benzyl) ₂ ,

(benzyl) ₂ P-1 ,2-phenylene-P(benzyl) ₂

The ligating compound may include a polymeric moiety to render the reaction product of the source of transition metal and the said ligating compound to be soluble at higher temperatures and insoluble at lower temperatures e g 25 ^S C This approach may enable the recovery of the complex from the reaction mixture for re-use and has been used for other catalyst as described by D E Bergbreiter et al , J Am Chem Soc , 1987, 109, 177-179 In a similar vein these transition metal catalysts can also be immobilised by binding the ligating compound to silica, silica gel, polysiloxane or alumina backbone as, for example, demonstrated by C Yuanyin et al , Chinese J React Pol , 1992, 1(2), 152-159 for immobilising platinum complexes

The ligating compound may include multiple ligating units or derivatives thereof

The ligating compounds may be prepared using procedures known to one skilled in the art and procedures forming part of the state of the art

The oligomensation catalyst may be prepared in situ, that is in the reaction mixture in which the oligomensation reaction is to take place Typically the oligomensation catalyst will be prepared in situ However it is foreseen that the catalyst may be pre-formed or partly pre-formed

The source of transition metal and ligating compound may be combined (in situ or ex situ) to provide any suitable molar ratio, preferably a transition metal to ligand compound molar ratio, from about 0 01 100 to 10 000 1 , preferably from about 0 1 1 to 10 1

During catalyst preparation, the transition metal may be present in a range from 0 01 micromol to 200 mmol/l, preferably from 1 micromol to 15 mmol/l

The process may also include combining one or more different sources of transition metal with one or more different ligating compounds

The oligomensation catalyst or its individual components, in accordance with the invention, may also be immobilised by supporting it on a support material, for example, silica, alumina, MgCb, zirconia, artificial hectorite or smectite clays such as Laponite™ RD or mixtures thereof, or on a polymer, for example polyethylene, polypropylene, polystyrene, or poly(amιnostyrene) The catalyst can be formed in situ in the presence of the support material, or the support can be pre-impregnated or premixed, simultaneously or sequentially, with one or more of the catalyst components or the oligomensation catalyst In some cases, the support material can also act as a component of the activator This approach would also facilitate the recovery of the catalyst from the reaction mixture for reuse

Process

The olefinic compound or mixture thereof to be oligomensed according to this invention can be introduced into the process in a continuous or batch fashion

The olefinic compound or mixture of olefinic compounds may be contacted with the catalysts at a pressure of 100 kPa or higher, preferably greater than 1000 kPa, more preferably greater than 3000 kPa Preferred pressure ranges are from 1000 to 30 000 kPa, more preferably from 3000 to 10 000 kPa

The process may be carried out at temperatures from -100 ⁰ C to 250 ⁰ C Temperatures in the range of 15- 150 ⁰ C are preferred Particularly preferred temperatures range from 35-120 ^a C

The reaction products derived from the reaction as described herein, may be prepared using the disclosed catalysts by a homogeneous liquid phase reaction in the presence or absence of an inert solvent, and/or by slurry reaction where the catalysts and the oligomeric product is in a form that displays little or no solubility, and/or a two-phase liquid/liquid reaction, and/or a bulk phase reaction in which neat reagent

and/or product olefins serve as the dominant medium, and/or gas phase reaction, using conventional equipment and contacting techniques

The reaction may also be carried out in an inert solvent Any inert solvent that does not react with the activator can be used These inert solvents may include any saturated aliphatic and unsaturated aliphatic and aromatic hydrocarbon and halogenated hydrocarbon Typical solvents include, but are not limited to, benzene, toluene, xylene, cumene, heptane, methylcyclohexane, methylcyclopentane, cyclohexane, lsopar C, lsopar E, lsopar H, Norpar, as well as the product formed during the reaction in a liquid state and the like

The reaction may be earned out in a plant which includes reactor types known in the art Examples of such reactors include, but are not limited to, batch reactors, semi-batch reactors and continuous reactors The plant may include, in combination a) a stirred or fluidised bed reactor system, b) at least one inlet line into this reactor for olefin reactant and the catalyst system, c) effluent lines from this reactor for oligomeπsation reaction products, and d) at least one separator to separate the desired oligomerisation reaction products which may include a recycle loop for solvents and/or reactants and/or products which may also serve as temperature control mechanism

According to another aspect of the present invention there is provided an oligomerisation product prepared by a process substantially as described hereinabove

According to yet another aspect of the present invention there is provided an oligomerisation catalyst which includes the combination of ι) a source of a transition metal, and ιι) a ligating compound of the formula

(R ¹ ) _m X ¹ (Y) X ² (R ² ) _n

wherein X ¹ and X ² are independently selected from the group consisting of N, P, As, Sb, Bi, O, S and Se,

Y is a linking group between X ¹ and X ² , m and n are independently 0, 1 or a larger integer, and

R ¹ and R ² are independently hydrogen, a hydrocarbyl group or a heterohydrocarbyl group, R ¹ being the same or different when m>1 , R ² being the same or different when n>1 , and at least one R ¹ or R ² is a moiety of formula

(L)(D)

wherein L is a linking moiety between X ¹ or X ² and D, and

D is an electron donating moiety which includes at least one multiple bond between adjacent atoms which multiple bond renders D capable of bonding with the transition metal in the source of transition metal, provided that when D is a moiety derived from an aromatic compound with a ring atom of the

aromatic compound bound to L, D has no electron donating moiety that is bound to a ring atom of the aromatic compound adjacent to the ring atom bound to L, and that is in the form of a heterohydrocarbyl group, a heterohydrocarbylene group, a heterohydrocarbylidene group, or an organoheteryl group that is capable of bonding by a coordinate covalent bond to the transition metal in the source of transition metal .

The catalyst may also further include an activator as set out above.

The catalyst may comprise a trimerisation catalyst.

Examples of the invention

The invention will now be further described by means of the following non-limiting comparative examples and examples according to the invention in which the ligands set out below are used and which demonstrate the shift of selectivity to hexene brought about by the invention:

Ligand 1 Ligand 2

Liga Liga R2 = phenyl Liga R2 = benzyl Liga R2 = CH ₂ CH ₂ phenyl Liga Liga

Ligand 3 Ligand 4

Ligand 3a: R1 = phenyl Ligand 4a: R1 = cyclohexyl Ligand 3b: R1 = benzyl Ligand 4b: R1 = phenyl

Ligand 5

Ph ₂ P N=N

Ligand 5a: R 1 = isobutyl Ligand 5b: R1 = phenyl

Synthesis of ligands

All ligands were prepared by procedures similar to those reported in literature References include, amongst others Slawm, A M Z, Wainwπght, M and Woollins, J D ₁ J Chem Soc , Dalton Trans 2002, 513-519, Blann, K , Bollmann, A , Dixon, J T , et al Chem Commun , 2005, 620-621 , Dennett, J N L , Gillon, A L , Pringle, P G et al Organometallics, 2004, 23, 6077 - 6079, Doherty, S , Knight, J G , Scanlan, T H el al, Journal of Organometallic Chemistry, 2002, 650, 231

Comparative Example 1 (relative to Example 2)

Ethylene oligomerisation reaction using Cr(acetylacetonate) ₃ , (phenyl) ₂ PN(methyl)N(methyl)P(phenyl) ₂ (Ligand 1a) and MMA0-3A in methylcyclohexane at 60 ^a C/4500 kPa

A solution of 1 07 mg of (phenyl) ₂ PN(methyl)N(methyl)P(phenyl) ₂ (2 5 μmol) in 1 0 ml of methylcyclohexane was added to a solution of 0 88 mg chromιum(acetylacetonate) ₃ (2,5 μmol) in 1 0 ml of methylcyclohexane in a Schlenk tube MMAO-3A (modified methylalummoxane, 2 4 mmol) was added to this solution This mixture was then transferred to a 450 ml pressure reactor (autoclave) containing of methylcyclohexane (100 ml) at 55 ⁹ C The autoclave was charged with ethylene after which the reactor temperature was controlled at 60 ^a C, while the ethylene pressure was maintained at 4500 kPa The reaction was terminated after 38 mm, by discontinuing the ethylene feed to the reactor and cooling the reactor to below 20 ³ C After releasing the excess ethylene from the autoclave, the liquid contained in the autoclave was quenched with ethanol followed by 10% hydrochloric acid in water Nonane was added as an internal standard for the analysis of the liquid phase by GC-FID A small sample of the organic layer was dried over anhydrous sodium sulfate and then analysed by GC-FID The remainder of the organic layer was filtered to isolate the solid products These solid products were dried overnight in an oven at 100 ^S C and then weighed The total product mass was 116 46 g The product distribution of this example is summarised in Table 1

Example 2

Ethylene oligomerisation reaction using Cr(acetylacetonate) ₃ ,

(benzyl) ₂ PN(methyl)N(methyl)P(benzyl) ₂ (Ligand 1b) and MMA0-3A in cyclohexane at 60 ^s C/5000 kPa

A solution of 1 36 mg of (benzyl) ₂ PN(methyl)N(methyl)P(benzyl) ₂ (2 8 μmol) in 5 ml of cyclohexane was added to a solution of 0 9 mg Cr(acetylacetonate)3 (2 5 μmol) in 5 ml cyclohexane in a Schlenk tube MMAO-3A (modified methylalummoxane, 2 4 mmol) was added and the mixture was immediately transferred to a 300 ml pressure reactor (autoclave) containing cyclohexane (90 ml) at 55 ^fi C The autoclave was charged with ethylene after which the reactor temperature was controlled at 60 ⁰ C, while the ethylene pressure was maintained at 5000 kPa The reaction was terminated after 30 mm and the work-up procedure of Example 1 above was employed The total product mass was 11 35 g The product distribution of this example is summarised in Table 1

Comparative Example 3 (relative to Example 4 and Example 5)

Ethylene oligomerisation reaction using Cr(acetylacetonate) ₃ , (phenyl) ₂ PN(ethyl)N(ethyl)P(phenyl) ₂ (Ligand 1c) and MMAO-3 in methylcyclohexane at 60 ^s C/4500 kPa

A solution of 1 14 mg of (phenyl) ₂ PN(ethyl)N(ethyl)P(phenyl) ₂ (2 5 μmol) in 1 0 ml of methylcyclohexane was added to a solution of 0 88 mg chromιum(acetylacetonate) ₃ (2,5 μmol) in 1 0 ml of methylcyclohexane in a Schlenk tube MMAO-3A (modified methylalummoxane, 2 4 mmol) was added to this solution This

mixture was then transferred to a 450 ml pressure reactor (autoclave) at 55 ⁰ C containing methylcyclohexane (100 ml) The autoclave was charged with ethylene after which the reactor temperature was controlled at 60 ³ C, while the ethylene pressure was maintained at 4500 kPa The reaction was terminated after 18 mm and the work-up procedure of Example 1 above was employed The total product mass was 152 37 g The product distribution of this example is summarised in Table 1

Example 4

Ethylene oligomerisation reaction using Cr(acety1acetonate) ₃ , (benzyl) ₂ PN(ethyl)N(ethy1)P(benzyl) ₂

(Ligand 1d) and MMA0-3A in cyclohexane at 60 ⁹ C/5000 kPa A solution of 1 43 mg of (benzyI) ₂ PN(ethyl)N(ethyl)P(benzyl) ₂ (2 8 μmol) in 5 ml of cyclohexane was added to a solution of 0 9 mg Cr(acetylacetonate) ₃ (2 5 μmol) in 5 ml cyclohexane in a Schlenk tube MMA0-3A (modified methylaluminoxane, 2 4 mmol) was added and the mixture was immediately transferred to a 300 ml pressure reactor (autoclave) containing cyclohexane (90 ml) at 55 ³ C The autoclave was charged with ethylene after which the reactor temperature was controlled at 60 ^s C, while the ethylene pressure was maintained at 5000 kPa The reaction was terminated after 30 mm by discontinuing the ethylene feed to the reactor and the work-up procedure of Example 1 above was employed. The total product mass was 37 76g The product distribution of this example is summarised in Table 1

Example 5 Ethylene oligomerisation reaction using Cr(acetylacetonate) ₃ , (allyl) ₂ PN(ethyl)N(ethyl)P(allyl) ₂ (Ligand 1e) and MMA0-3A in methylcyclohexane at 60 ^s C/5000 kPa

A solution of 1 56 mg of (allyl) ₂ PN(ethyl)N(ethyl)P(allyl) ₂ (5 0 μmol) in 2 0 ml of methylcyclohexane was added to a solution of 1 76 mg chromium(acetylacetonate) ₃ (5 0 μmol) in 2 0 ml of methylcyclohexane in a Schlenk tube MMAO-3A (modified methylaluminoxane, 4 8 mmol) was added to this solution This mixture was then transferred to a 300 ml pressure reactor (autoclave) containing a 90 ml of methylcyclohexane at 55 ³ C The autoclave was charged with ethylene after which the reactor temperature was controlled at 60 ^e C, while the ethylene pressure was maintained at 5000 kPa The reaction was terminated after 30 mm and the work-up procedure of Example 1 above was employed The total product mass was 15 05 g The product distribution of this example is summarised in Table 1

Comparative Example 6 (relative to Examples 7 and 8)

Ethylene oligomerisation reaction using Cr(acety!acetonate) ₃ , (phenyl) ₂ PN(isopropyl)P(phenyl) ₂

(ligand 2a) and MMAO-3A in methylcyclohexane at 60 ^s C/4500 kPa

A solution of 1 07 mg of (phenyl) ₂ PN(ιsopropyl)P(phenyl) ₂ (2 5 μmol) in 1 ml of methylcyclohexane was added to a solution of 0 88 mg Cr(acetylacetonate) ₃ (2 5 μmol) in 1 ml methylcyclohexane in a Schlenk tube MMAO-3A (modified methylaluminoxane, 2 4 mmol) was added and the mixture was immediately transferred to a 300 ml pressure reactor (autoclave) containing methylcyclohexane (100 ml) at 55 ³ C The autoclave was charged with ethylene after which the reactor temperature was controlled at 60 ³ C, while the ethylene pressure was maintained at 4500 kPa The reaction was terminated after 23 mm and the work-up procedure of Example 1 above was employed The total product mass was 66 13 g The product distribution of this example is summarised in Table 2

Example 7

Ethylene oligomerisation reaction using Cr(acetylacetonate) ₃ , (benzyl) ₂ PN(isopropyl)P(benzyl) ₂ (ligand 2b) and MMAO-3A in methylcyclohexane at 60 ⁹ C/4500 kPa

A solution of 4 84 mg of (benzyl) ₂ PN(ιsopropyl)P(benzyl) ₂ (10 μmol) in 4 ml of methylcyclohexane was added to a solution of 1 76 mg Cr(acetylacetonate) ₃ (5 μmol) in 2 ml methylcyclohexane in a Schlenk tube MMAO-3A (modified methylaluminoxane, 4 8 mmol) was added and the mixture was immediately transferred to a 300 ml pressure reactor (autoclave) at 55 ^B C containing 90 ml of methylcyclohexane The autoclave was charged with ethylene after which the reactor temperature was controlled at 60 ⁹ C, while the ethylene pressure was maintained at 4500 kPa The reaction was terminated after 20 mm and the work-up procedure of Example 1 above was employed The total product mass was 51 02 g The product distribution of this example is summarised in Table 2

Example 8

Ethylene oligomerisation reaction using Cr(acetylacetonate) ₃ ,

(phenyl) ₂ PN(isopropyl)P(pheny1)(CH ₂ CH ₂ phenyl) (ligand 2c) and MMA0-3A in methylcyclohexane at 60 ⁹ CMSOO kPa

A solution of 4 98 mg of (phenyl) ₂ PN(ιsopropyl)P(phenyl)(CH ₂ CH ₂ phenyl) (10 μmol) in 4 ml of methylcyclohexane was added to a solution of 1 76 mg Cr(acetylacetonate) ₃ (5 μmol) in 2 ml methylcyclohexane in a Schlenk tube MMAO-3A (modified methylaluminoxane, 48 mmol) was added and the mixture was immediately transferred to a 300 ml pressure reactor (autoclave) containing 90 ml of methylcyclohexane at 55 ⁹ C The autoclave was charged with ethylene after which the reactor temperature was controlled at 60 ⁸ C, while the ethylene pressure was maintained at 4500 kPa The reaction was terminated after 15 mm and the work-up procedure of Example 1 above was employed The total product mass was 1 39 g The product distribution of this example is summarised in Table 2

Comparative Example 9 (relative to Example 10)

Preparation of the complex {[(phenyl) ₂ P-1 ,2-phenylene-P(phenyl) ₂ ]CrCI ₃ }2 (Ligand 3a-CrCI ₃ ) The complex {[(phenyl) ₂ P-1 ,2-phenylene-P(phenyl)2]CrCl ₃ } ₂ was prepared according to the synthetic procedure used for the preparation of [(phenyl) ₂ P) ₂ N(phenyl)CrCl3] ₂ as described in J Am Chem Soc 2004, 126, 14712

Ethylene oligomerisation reaction using the complex {[(phenyl) ₂ P-1 ,2-phenylene-P(phenyl) ₂ ]CrCI ₃ } ₂ and MMA0-3A in cyclohexane at 80 ^s C/5000 kPa

MMAO-3A (modified methylaluminoxane, 1 2 mmol) was added to a suspension of 1 51 mg of the complex {[(phenyl) ₂ P-1 ,2-phenylene-P(phenyl) ₂ ]CrCl ₃ } ₂ (1 25 μmol) and the mixture was immediately transferred to a 300 ml pressure reactor (autoclave) containing cyclohexane (90 ml) at 75 ^S C The autoclave was charged with ethylene after which the reactor temperature was controlled at 80 ^s C, while the ethylene pressure was maintained at 5000 kPa The reaction was terminated after 8 5 mm and the workup procedure of Example 1 above was employed The total product mass was 63 53g The product distribution of this example is summarised in Table 3

Example 10 Preparation of the complex {[(benzyl) ₂ P-1 ,2-phenylene-P(benzyl)2]CrCl3}2 (Ligand 3D-CrCb)

The complex {[(benzyl) ₂ P-1 ,2-phenylene-P(benzyl) ₂ ]CrCl ₃ } ₂ was prepared according to the synthetic procedure used for the preparation of [(phenyl) ₂ P)2N(phenyl)CrCI ₃ ] ₂ as described in J Am Chem Soc 2004, 126, 14712

Ethylene oligomerisation reaction using the complex {[(benzyl)2P-1 ,2-phenylene-P(benzyl) ₂ ]CrCI ₃ } ₂ and MMAO-3A in methylcyclohexane at 60 ^s C/5000 kPa

MMAO-3A (modified methylaluminoxane, 1 92 mmol) was added to a suspension of 2 64 mg of the complex {[(benzyl) ₂ P-1 ,2-phenylene-P(benzyl) ₂ ]CrCl ₃ } ₂ (2 μmol) and the mixture was immediately transferred to a 300 ml pressure reactor (autoclave) containing methylcyclohexane (90 ml) at 55 ^S C The autoclave was charged with ethylene after which the reactor temperature was controlled at 60 ^a C, while the ethylene pressure was maintained at 5000 kPa The reaction was terminated after 12 mm and the work-up procedure of Example 1 above was employed The total product mass was 50 83g The product distribution of this example is summarised in Table 3

Comparative Example 11 (relative to Example 12)

Preparation of the complex [(phenyl)2P-1,2-phenylene-N=C(H)-cyclohexyl]CrCI ₃ (Ligand 4a-CrCI ₃ ) The complex [(phenyl) ₂ P-1 ,2-phenylene-N=C(H)-cyclohexyl]CrCI ₃ was prepared according to the synthetic procedure used for the preparation of [(phenyl) ₂ P) ₂ N(phenyl)CrCl ₃ ] ₂ as descπbed in J Am Chem Soc 2004, 126, 14712

Ethylene oligomerisation reaction using the complex [(phenyl) ₂ P-1,2-phenylene-N=C(H)- cyclohexyl]CrCI ₃ and MMAO-3A in methylcyclohexane at 60 ⁹ C/4500 kPa

A suspension of 2 65 mg of [(phenyl) ₂ P-1 ,2-phenylene-N=C(H)-cyclohexyl]CrCI ₃ (5 μmol) in 2 ml of methylcyclohexane was stirred overnight in a Schlenk tube MMAO-3A (modified methylaluminoxane, 4 8 mmol) was added and the solution was transferred to a 300 ml pressure reactor (autoclave) containing methylcyclohexane (90 ml) at 55 °C The autoclave was charged with ethylene after which the reactor temperature was controlled at 60 ^S C, while the ethylene pressure was maintained at 4500 kPa The reaction was terminated after 20 mm and the work-up procedure of Example 1 above was employed The total product mass was 0 69 g The product distribution of this example is summarised in Table 4

Example 12

Preparation of the complex [(phenyl) ₂ P-1 ,2-phenylene-N=C(H)-phenyl]CrCI ₃ (Ligand 4b-CrCI ₃ )

The complex [(phenyl) ₂ P(1 ,2-phenylene)NC(H)-phenyl]CrCI ₃ was prepared from Cr(THF) ₃ CI ₃ and the ligand according to the synthetic procedure used for the preparation of [(phenyl)l ₂ P) ₂ N(phenyl)CrCl ₃ ] ₂ as described in J Am Chem Soc 2004, 126, 14712

Ethylene oligomerisation reaction using the complex [(phenyl) ₂ P-1 ,2-phenylene-N=C(H)- phenyl]CrCI ₃ and MMAO-3A in methylcyclohexane at 60 ^s C/4500 kPa A suspension of 2 62 mg of [(phenyl) ₂ P-1 ,2-phenylene-N=C(H)-phenyl]CrCI ₃ (5 μmol) in 2 ml of methylcyclohexane was stirred overnight in a Schlenk tube MMAO-3A (modified methylaluminoxane, 4 8 mmol) was added and the solution was transferred to a 300 ml pressure reactor (autoclave) containing methylcyclohexane (90 ml) at 55 ² C The autoclave was charged with ethylene after which the reactor temperature was controlled at 60 ⁸ C, while the ethylene pressure was maintained at 4500 kPa The reaction was terminated after 15 mm and the work-up procedure of Example 1 above was employed The total product mass was 241 g The product distribution of this example is summarised in Table 4

Comparative Example 13 (relative to Example 14)

Preparation of the complex {[(phenyl) ₂ P-ethylene-N=C(H)-isobutyl]CrCl ₃ } ₂ (Ligand Sa-CrCI ₃ )

The complex {[(phenyl) ₂ P-ethylene-N=C(H)-isobutyl]CrCI ₃ }2 was prepared from Cr(THF) ₃ CI ₃ and the ligand according to the synthetic procedure used for the preparation of [(phenyl) ₂ P) ₂ N(phenyl)CrCl ₃ ] ₂ as described in J. Am. Chem. Soc. 2004, 126, 14712.

Ethylene oligomerisation reaction using the complex {[(phenyl) ₂ P-ethylene-N=C(H)-isobutyl]CrCI ₃ } ₂ and MMA0-3A in methylcyclohexane at 60 ^S C/5000 kPa

A suspension of 8.88 mg of {[(phenyl) ₂ P-ethylene-N=C(H)-isobutyl]CrCI ₃ } ₂ (20 μmol) in 10 ml of methylcyclohexane was transferred to a 300 ml pressure reactor (autoclave) containing methylcyclohexane (90 ml) and MMAO-3A (modified methylaluminoxane, 9.6 mmol) at 55 ⁰ C. The autoclave was charged with ethylene after which the reactor temperature was controlled at 60 ⁹ C, while the ethylene pressure was maintained at 5000 kPa. The reaction was terminated after 60 min and the work-up procedure of Example 1 above was employed. The product distribution of this example is summarised in Table 4.

Example 14

Preparation of the complex {[(phenyl) ₂ P-ethylene-N=C(H)-phenyl]CrCl3}2 (Ligand Sb-CrCI ₃ )

The complex {[(phenyl) ₂ P-ethylene-N=C(H)-phenyl]CrCI ₃ } ₂ was prepared from Cr(THF) ₃ CI ₃ and the ligand according to the synthetic procedure used for the preparation of [(phenyl) ₂ P) ₂ N(phenyl)CrCI ₃ ] ₂ as described in J. Am. Chem. Soc. 2004, 126(45), 14712.

Ethylene oligomerisation reaction using the complex {[(phenyl) ₂ P-ethylene-N=C(H)-phenyl]CrCI ₃ } ₂ and MMA0-3A in methylcyclohexane at 60 ⁹ C/5000 kPa

A suspension of 9.27 mg of {[(phenyl) ₂ P-ethylene-N=C(H)-phenyl]CrCI ₃ } ₂ (20 μmol) in 10 ml of methylcyclohexane was transferred to a 300 ml pressure reactor (autoclave) containing a mixture of methylcyclohexane (90 ml) and MMAO-3A (modified methylaluminoxane, 9.6 mmol) at 55 ⁰ C. The autoclave was charged with ethylene after which the reactor temperature was controlled at 60 ^S C, while the ethylene pressure was maintained at 5000 kPa. The reaction was terminated after 60 min and the work-up procedure of Example 1 above was employed. The total product mass was 12.2 g. The product distribution of this example is summarised in Table 4.

Table 1 :

K*

O

Table 2

Table 3

Table 4