OLIGOMERISATION OF OLEFfNIC COMPOUNDS IN THE PRESENCE OF AN OLIGOMERISATION CATALYST, ANO A CATALYST ACTIVATOR INCLUDING A HALOGENATED ORGANIC GROUP

Technical Field

This invention relates to the oϋgomerisatioπ of olefinic compounds in the presence of an oligomerisation catalyst, and a catalyst activator including a haiogenated organic group.

Background Art

A number of different oligomerisation technologies are known to produce α-olefins. 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 ligands with both phosphorus and nitrogen heteroatoms, selectively catalyse the trimerisation of ethylene to 1-hexene.

Processes wherein transition metals and heteroatomic ligands are combined to form catalysts for trimerisation, tetramerisation, 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 ; US Complete Patent Application No. 1 1/130,106; WO 05/123884 A2 and WO 05/123633 A1.

The catalysts utilized in the abovementioned trimerisation, tetramerisation, oiigomerisation or polymerisation processes all include one or more catalyst activators to activate the catalyst. Such an activator is a compound that generates an active catalyst when the activator is combined with the catalyst.

Suitable activators include organoaluminium compounds, organoboron compounds, organic salts, such as methyl lithium and methyl magnesium bromide, inorganic acids and salts, such as tetrafluoroboric acid etherate, silver tetrafluoroborate, sodium hexafluoroantimonate and the like.

A common catalyst activator used in combination with Cr based catalysts for oligomeπsation of ofefiπic compounds is alkylaluminoxane, particularly methyialuminoxane (MAO). It is well known that MAO includes significant quantities of aikylaluminium in the form of trimethylalumiπium (TMA), and in effect the catalyst activator is a combination of TMA and MAO, The MAO may also be replaced with modified MAO (MMAO),

The use of fluoπnated boranes/borates as catalyst activators is also known. In J Organomet. Chem. 683 (2003) 200 triazacyclohexaπe CrCI ₃ complexes were activated with AiR ₃ and [PhN(Me) ₂ H] ⁺ [B(C ₆ F ₅ ) ₄ ] to give catalysts active for trimerisation of alpha-olefins. In J.Am. Chem. Soc, 126 (2004) 1304, Cr-based ethylene trimerisation catalysts were activated by treating Cr-aryl complexes with fluorinated aryl-boranes (BARF). IPCOM000031729D discloses the use of fluorinated borate and borane activators in combination with chromium based catalyst in the oiigomerisation of olefins.

In WO 99/64476, catalysts (especially Ziegler-Natta and metaiiocene poiymerisation catalysts) were activated by a combination of halogenated aryl containing Group13 metal or metalloid based Lewis acids and organo-Groupi 3 metal compounds,

Trityl tetrakis (pentafluorophenoxo) aluminate, [Ph ₃ C] ⁺ [AI(OC ₆ Fs) ₄ ] ^" , has been prepared and employed as a co-catalyst for ethylene and propylene polymerisation with metaiiocene complexes such as (C ₅ H ₅ ) ₂ ZrMe ₂ in Organometallics, 19 (2000) 1625 and Organometallics, 21 (2002) 3691. Angew. Chem. Int. Ed. 2004, 43, 2066 also discloses compounds such as [M(OC ₆ F ₅ J _n ] and [AI{OC(CF ₃ ) ₃ } ₄ ] ^" and the use of the latter as an activator for ethene and propene polymerisation with a Zr-alkyl complex in the presence of Al ₁ Bu ₃ J. Fluorine Chemistry 2001 , 112, 83 discloses the preparation of compounds such as [Ph ₃ C] ⁺ [AI{OC(CF ₃ ) ₃ } ₄ ]\

Journal of Organometallic Chemistry, 621 (2001 ), 184 discloses the use of [Me ₃ NH] ⁺ [B(OC ₆ Fs) ₄ ] ^" for polymerisation with iron catalysts including trideπtate ligands.

It has now been found that compounds of the present invention including at least one halogenated organic group bound to a group 3A or group 3B to 7B central atom by means of one or more binding atoms can be used as activators of oiigomerisation catalysts in oiigomerisation reactions. In some cases the productivity of the oligomeπsation catalysts was found to have been improved compared to when borane or borate activators are used, such as those detailed in IPCOM000031729D. Most surprisingly it also has been found

that different activators of this nature can influence the product selectivity of the oligomerisation catalysts. Furthermore, the relative high poiymer formation associated with borate activators, was at least reduced in at least some cases.

Disciosure of thejnvention

According to the present invention there is provided a process for producing an oligomeric product by the oligomerisation of at least one olefintc compound in the form of an olefin or a compound including a carbon to carbon double bond, by contacting the at least one olefSnic compound with the combination of an oligomerisation catalyst and a catalyst activator, which catalyst activator is a compound which includes at least one halogenated organic group which is bound to one or more binding atoms selected from the group consisting of a group 5A atom and a group 6A atom, which one or more binding atoms are in turn bound to a central atom selected from the group consisting of a group 3A atom, and a group 3B to 7B transition metal atom; and wherein the oligomerisation catalyst includes the combination of i) a source of a transition metal; and ii) a ligating compound of the formula

(R ¹ ) _m X ¹ (Y) X ² (R ² wherein: X ¹ and X ^a 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, and R ¹ being the same or different when m>1 , and R ² being the same or different when n>1.

In this specification a heterohydrocarbyl group is a univalent or multivalent organic compound which includes at least one heteroatom (that is not being H or C), and which organic compound binds with one or more other moieties through one or more carbon atoms of the organic compound and/or one or more heteroatoms

of the organic compound. Organohetery! groups and organyl groups (which include at least one heteroatom) are examples of heterohydrocarbyl groups.

In this specification a hydrocarbyl group is a univalent or multivalent group formed by removing one or more hydrogen atoms from a hydrocarbon.

Accordingly to another aspect of the present invention there is provided the use of a combination of a cataiyst activator and an oligomerisation catalyst in the oligomerisation of at least one olefinic compound in the form of an olefin or a compound including a carbon to carbon doubie bond by contacting the at least one olefinic compound with the oligomerisation catalyst, and the cataiyst activator, wherein the activator is a compound which includes at least one halogenated organic group which is bound to one or more binding atoms selected from the group consisting of a group 5A atom and a group 6A atom, which one or more binding atoms are in turn bound to a central atom selected from the group consisting of a group 3A atom, and a group 3B to 7B transition metal atom; and wherein oligomerisation catalyst includes a combination of i) a source of a transition metal; and ii) a ligating compound of the formula

wherein: X ¹ and X ² are independently selected from the group consisting of IM, 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, and R ¹ being the same or different when m>1 , and R ² being the same or different when n>1.

It has been found that the activator often provides good activity and even improved productivity compared to boranes and borates. Polymer formation has also been reduced in at least some cases. In comparison to the use of aluminoxanes as activator, the amount of activator required relative to catalyst has been reduced

in most cases. This has led to iower waste volumes (such as lower aluminium oxide in the product) and reduced activator cost. it has also been found that the activator influences the product selectivity specifically in respect of the molar ratio of trimer : tetramer formed.

Combination of catalyst and activator

The catalyst and activator may be combined prior to being contacted with the oiefinic compound. The catalyst and activator may react with each other to form a reaction product of the catalyst and the activator. The activator and catalyst may form part of the same compound. The said reaction product may be an ionic reaction product.

Activator

Preferably the activator is a Lewis acid.

As stated above the one or more binding atoms are bound to a central atom selected from the group consisting a group 3A atom, and a group 3B to 7B transition metal atom. The central transition metal atom is preferably selected from the group consisting of Nb, Ta, Y and La. Preferably the transition metal atom is Ta. Preferably the one or more binding atoms are bound to a central group 3A atom. Preferably the central group 3A atom is selected from the group consisting of Al and B, preferably it is Al.

The, or each binding atom is preferably an atom selected from the group consisting of O, N, P and S. Preferably it is O.

In one embodiment of the invention the activator may include oniy one or more halogenated organic groups bound to one or more binding atoms as set out above, which one or more binding atoms are groups bound to the central atom as set out above. !n an alternative embodiment of the invention the activator may also include one or more atoms or groups of atoms other than said one or more halogenated organic groups bound to said one ore more binding atoms.

The at least one halogenated organic group may be bound to each binding atom by means of a carbon atom and/or a non-carbon atom. The halogenated organic group may be a haiogenated hydrocarbyl group or a halogenated heterohycirocarbyl group. The halogenated organic group may be a halogenated organyl group or a halogenated organoheteryl group. Preferably it is a halogenated hydrocarbyl group.

In one embodiment of the invention the activator may be a compound of the formula, or the activator may include a moiety of the formula

wherein

M is selected from the group consisting of a group 3A atom, and a group 3B to 7B transition meta! atom; n is 1 or a larger integer; and

R is a halogenated organic group, R being the same or different when n is larger than 1.

The group 3B to 7B transition metal atom is preferably selected from the group consisting of Nb, Ta, Y and La. Preferably it is Ta. Preferably M is a group 3A atom. Preferably the group 3A atom is selected from the group consisting of Al and B, preferably it is Al.

R may be bound to each O by means of a carbon atom and/or a non-carbon atom. R may be a halogenated hydrocarbyl group, or a halogenated heterohydrocarbyl group or a halogenated organyl group, or a halogenated organoheteryl group.

in one embodiment of the invention the activator may be a compound of the formula

wherein M, R and n are as defined above. Alternatively the activator may be a compound which includes a moiety of the formula

wherein M, R and n are as defined above, and M is bound to at ieast one moiety Z which is not a

O \

OR or R

group as defined above. Preferably Z is a haiide or a hydrocarbyi group or heterohydrocarbyi group. Preferably Z is a haiide or an organoheteryl group. Preferably Z is -~O{R ¹⁰ ) ₂ wherein R ¹⁰ is a hydrocarbyi group, and R ¹⁰ being the same or different. R ¹⁰ may be aikyl and preferably it is ethyl. Alternatively Z may be haiide, preferably in the form of F. Alternatively, the activator may be a salt containing an anion which includes a moiety of the formula

preferably the anion is

wherein M, R and n are as defined above.

Preferably R is a halogenated hydrocarbyi group or a halogenated organyl group. The halogenated organy! group or halogenated hydrocarbyi group may comprise an organyl group or hydrocarbyi group wherein at least one hydrogen atom has be&n replaced with a halogen atom. Preferably all the hydrogen atoms of the organyl group or hydrocarbyi group are replaced with halogen atoms. Preferably all the halogen atoms are the same. Preferably the halogen atom is F,

The halogeπated organic group may be a monovalent or divalent halogenated hydrocarbyl group in the form of a hydrocarbyl group wherein at least one hydrogen atom has been replaced with a halogen atom. Preferably all the hydrogen atoms of the hydrocarbyl group are replaced with halogen atoms. Preferably all the halogen atoms are the same. Preferably the halogen atom is F. The halogenated hydrocarbyl group may comprise a halogenated acylic hydrocarbyl group or a halogenated cyclic hydrocarbyl group. The halogenated acycϋc hydrocarbyl group may comprise a halogenated alky!, preferably a halogenated branched alkyl, preferably halogenated isobutyl or tertiary-butyl. The halogenated cyclic hydrocarbyl group may comprise a halogenated aromatic compound, preferably a halogenated phenyl group.

In one embodiment of the invention the activator may be selected from the group consisting of a compound Al(OR) ₃ , a salt containing the anion

a compound including a moiety AI(OR) ₃ and a salt containing the anion [ra{OR) ₆ ] ^" wherein R is defined as above.

In one embodiment of the invention the activator may be selected from the group consisting of AI(OC ₆ F ₅ ) ₃ ;

X ⁺ [AI{OC(CF ₃ ) ₃ }4J-; X ⁺ [AI(OC ₆ Fs) ₄ ] ^" ; X ⁺ [AI(C _s F ₄ O ₂ ) ₂ j-; X ⁺ [AI{OC(CF ₃ ) ₂ C(CF ₃ ) _£ O} ₂ ]; X ⁺ [AIF{OC(CF ₃ ) ₃ } ₃ ];

X ⁺ [A! ₂ F{OC(CF ₃ ) ₃ } ₆ ]; (2}AI{OCH(C ₆ F ₅ ) ₂ } ₃ ; (Z)AI{OC(CF ₃ ) ₃ } ₃ and X ⁺ [Ta(OC ₆ Fs) ₆ ] ^" wherein X ⁺ is a cation including Ph ₃ C ⁺ , Me ₂ PhNH ⁺ and (Et ₂ O) ₂ H ⁺ ; and wherein Z is a moiety bound to Al which moiety Z is not an

O '

(OR) group or R O - group

where R is a haiogenated organic group.

The amount of activator used may be between 1-100 equivalents relative to the catalyst transition metal. Preferably it is iess than 5 equivalents relative to the catalyst transition metal, and most preferably between 1 -3 equivalents relative to the catalyst transition metal.

The activator may be prepared in situ, alternatively it may be preformed, in one embodiment of the invention the activator may be preformed from the co-activator as described herein below,

Co- Activator

The process may also include a co-activator which is a compound not falling within the definition of the activator. Preferably the co-activator includes no halogenated organic group which is bound to one or more binding atoms selected from the group consisting of a group 5A atom and a group 6A atom, which one or more binding atoms are in turn bound to a central atom selected from the group consisting of a group 3A atom, and a group 3B to 78 transition metal atom. Preferably the co-activator is a compound which includes at least one moiety selected from the group consisting of an organic group (preferably an organyl group), a haiogenated organic group (preferably a halogenated organyl group) and hydrogen; and the moiety being bound to an atom selected from the group consisting of a group 3A atom, a group 4A atom, and a metal atom, including an alkali metai atom and an alkaline earth metal atom.

Preferably the co-activator as set out above is an organoaluminium compound and/or an organoboron compound. Alternatively it may be an organic salt such as methyl lithium and/or methyl magnesium bromide.

Examples of suitable organoboron compounds are boroxines, triethylborane, tris(pentafluoropheny)borane, tributyl borane and the like.

Suitable organoaluminium compounds include compounds of the formula AI(R ⁹ ) ₃ (R ⁹ being the same or different), where each R ⁹ is independently an organyl group, a halogenated organyl group or a halide, with at ieast one of R ⁸ being an organyl group or a halogenated organyl group. Examples include trimethylaluminium (TMA), triethylaluminium (TEA), tri-isobutylaluminium (TIBA), tri-n-octylaluminium, methySaluminium dichloride, ethylaluminium dichloride, dimethylaluminium chloride, diethylaluminium chloride, aluminium isopropoxide, ethylaluminiumsesquichloride, methylaluminiumsesquichloride, and aluminoxanes.

Aluminoxanes are well known in the art as typically oligomeric 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. Mixtures of different aϊumϊnoxanes may also be used in the process.

The co-activator may comprise a compound of the formula

M ^' (R)π.

wherein M is selected from the group consisting of a group 3A atom, a group 4A atom and a metal atom, including an alkali metal atom and an alkaline earth metal atom; n is 1 or a larger integer; and

R is an organic group, R being the same or different when n is larger than 1.

Preferably M is selected from the group consisting of a group 3A atom, a group 4A atom, and a transition metal atom. Preferably the R group is bound to a group 3A atom. Preferably the group 3A atom is selected from the group consisting of Al and B, preferably it is Al.

The organic group R may be an organyl group, and preferably it comprises a hydrocarbyl group, preferably it comprises an alkyl group, preferably methyl, ethyl or a larger alkyi group.

in one embodiment of the invention the co-activator comprises AIR ₃ wherein R is an alkyi group.

The co-catalyst may be selected from the group consisting of trimethylaluminium (TMA); triethylaluminsum (TEA), tributylaluminium, tri-isobutylaiuminium (TIBA) and tri-n-octylaluminium.

it will be appreciated that TMA is relatively expensive and accordingly the use thereof may be wished to be avoided. It has been found that by using an activator as defined in the present invention in combination with a co-activator as defined above (but excluding TMA and MAO) the use of TMA can be avoided as a co- catalyst.

It is foreseen that a co-activator as defined hereinabove will usually be used in combination with an activator as defined above. However, it may be possible, by selecting a suitable source of transition metal (i) and/or a

[igating compound (ii), that the use of the co-activator may be avoided. It is believed (without being bound thereto} that a co-activator such as TMA is used to alkylate the catalyst formed by the combination of (i) and (ii) and that the activator then acts on alkyl abstracting agent of the alkylated catalyst to activate the said catalyst.

The amount of co-activator employed may be up to 1000 equivalents relative to the transition metal catalyst, but preferable is less than 600 equivalents. Preferably it is in the range between 30-300 equivalents relative to the transition metal catalyst.

In use where both an activator and a co-activator are used, the co-activator may be added first and the activator may be added subsequently.

Oliqomeric product

The oligomeric product may be an olefin, or a compound including an olefinic moiety. Preferably the oligomeric product includes an olefin, more preferably an olefin containing a single carbon-carbon double bond, and preferably it includes an α-olefin. 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 a mixture of hexene and octene, preferably a mixture of 1 -hexene and 1-octene.

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

Preferably the product contains at least 35% of the said olefin, preferably α-olefin, but it may be more than 40%, 50%, or even 60% by mass.

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

Oiiqomerisation

The oligomerisation process may comprise a trimerisation process, alternatively or additionally it may comprise a tetramerisation process.

The process may be oligomerisation 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 oϋgomerisation (preferably trimerisation and/or tetramerisation} 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 oiigomeric α-olefin. Preferably it comprises the trimerisation and/or tetramerisation of ethylene, preferably to 1-hexene and/or 1 -octene.

Olefinic compound to be oliqomerised

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-olefin 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 -pβntene, 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 and/or octene, preferably 1-hexene and/or 1-octene.

Catalyst

Source of transition metal (i)

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 ₁ 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)tricarbonyl chromium; chromium (ill) octanoate; chromium hexacarbonyl; chromium (III) acetylacetonate, chromium (III) naphthenate, chromium (111) 2-ethylhexaπoate. Preferably it is chromium trichloride tris-tetrahydrofuran or chromium (ill) acetylacetonate.

Liqatinq compound

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

An electron donor is defined as an entity that donates electrons used in chemical, including dative covalent, bond formation.

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

X ¹ and/or X ² may be independently phosphorus or phosphorus oxidised by S, Se, N or O. Preferably X ¹ and X ² are the same, and preferably both are P.

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 an n are not 0.

Preferably the ligating compound is a bidentate or tridentate ligand, preferably a bidentate ligand.

Preferably the ligating compound is of the formula

wherein Y is as defined above; 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 a hydrocarbyl group or a heterohydrocarbyl group.

Preferably X ¹ and X ² are independently selected from the group consisting of P, S and N, Preferably X ¹ and X ² are the same. Preferably both X ¹ and X ² are P.

One or more of R ³ to R ⁶ may be a substituted hydrocarbyl group or a substituted heterohydrocarbyi group, that is at least one substituent is bound to the hydrocarbyl group or the heterohydrocarbyl group. In this specification a substituent with reference to compounds bound to X ¹ and/or X ² is a moiety (excluding H) which is bound to a linear structure or a cyclic structure bound to X ¹ and/or X ² , but the substituent does not form part of the linear or cyclic structure. The linear or cyclic structure may be selected from the group consisting of a linear hydrocarbyi, a cyclic hydrocarbyi and a cyclic heterohydrocarbyl group. Linear hydrocarbyl may include ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyi, octeπyl, noπenyl, decenyl, ethynyϊ, propynyl, butynyl, pentynyl, hexynyl, heptynyl, octynyl, nonynyl and decynyi. Cyclic hydrocarbyl may include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyciononyl, cyclodecyl, cyclopentenyl, cyclohexeny!, cyclo-octeny!, phenyl, cyciopentadienyl, naphthaleneyi, norbornyl, adamaπtyl, pheπanthreneyj, anthraceneyl, phenaleneyj, tetrahydronaphthaleneyl, decaiinyl, indenyl and tetrahydroindenyl. Cyclic heterohydrocarbyl may include tetrahydrofuranyl, tetrahydrothiopheneyl, pyrrolideneyi, piperidineyl, pyrrolineyl, oxazolyl, thiazolyl, furanyl, thiopheneyl, pyrazoiinyl, pyrazolyl, imidazolyl, benzofuranyl, coumaraπyi and indolyl.

R ³ to R ⁶ may also be selected from a group of metallocenes such as a ferroceneyl, zirconoceneyl and titanoceπeyl group.

Preferably none of R ³ to R ⁶ are aromatic with a ring atom of the aromatic ring structure bound to either X ¹ or X ² and with a polar substituent as a non-πng atom bound to a ring atom of the aromatic ring structure adjacent to the ring atom bound to X ¹ or X ² .

!n this specification a polar substituent is a substituent with a permanent electric or induced dipole moment.

Preferably, if two or more of R ³ to R ⁶ are aromatic with a ring atom of the aromatic ring structure bound to either X ¹ and X ² not more than two of said aromatic R ³ to R ⁶ have a substituent as a non-ring atom bound to a ring atom of the aromatic ring structure adjacent to the ring atom bound to X ¹ or X ² .

In one embodiment of the invention R ³ to R ⁶ are the same or different and each is a hydrocarbyl group, or a heterohydrocarbyl group which contains no substituent or contains a non-polar substituent. Preferably each of R ³ to R ⁶ does not have any polar substituent. In one embodiment of the invention at least two of (but preferably all of) R ³ to R ⁶ are aromatic with a ring atom of the aromatic ring structure bound to X ¹ or X ² , but preferably not more than two of said aromatic R ³ to R ⁶ have a non-polar substituent other than H as a non- ring atom bound to a ring atom of the aromatic ring structure adjacent to the ring atom bound to X ¹ or X ² .

Preferably none of the aromatic R ³ to R ⁶ have a non-polar substituent as a non-ring atom bound to a ring atom of the aromatic ring structure adjacent to the ring atom bound to X ¹ or X ² . Preferably all of aromatic R ³ to R ⁶ are non-substituted aromatic compounds. R ³ to R ⁶ may be independently selected from the group consisting of a non-aromatic compound; an aromatic compound; and a heteroaromatic compound.

Preferably each of R ³ to R ⁶ is an aromatic or heteroaromatic compound, more preferably an aromatic compound (including a substituted aromatic compound). The aromatic compound (or substituted aromatic compound) may compπse phenyl or a substituted phenyl.

In this specification a non-polar substituent is a substituent without a permanent electric or induced dipole moment.

Examples of suitable non-polar substituents include, but are not limited to, methyl, ethyl, ethenyl, propyl, iso- propyl, cyclopropyl, propenyl, propynyl, butyl, sec-butyl, tertiary-butyl, cyclobutyl, butenyl, butynyl, pentyl, isopentyl, neopentyl, cyclopentyl, pentenyl, pentynyl, hexyi, sec-hexyl, cyclohexyl, 2-methylcyclohexyl, 2-

ethyicyclohexyl, 2-isopropyfcyclobexyl, cyciohexeπyl, hexenyi, hexynyl, octyl, cyclo-octyl, cyclo-octeπyl, decyl, benzyl, phenyl, tolyl, xylyl, o-methylphenyl, oethylpheπyl, oisopropylphenyl, o-f-butylphenyl, cumyl, mesityl, biphenyl, naphthyl, anthracenyl, and the like.

Any one of R ³ to R ⁶ may be independently linked to one or more of each other, or to Y to form a cyclic structure.

R ³ and R ⁴ may be the same and R ⁵ and R ⁶ may be the same. R ³ to R ⁶ may all be the same.

In another embodiment of the invention R ³ to R ⁶ are the same or different and each is a hydrocarbyl group, or a heterohydrocarbyi group, provided that at least one of R ³ to R ⁶ contains a polar substituent on a carbon atom, but not one of R ³ to R ^β contains a polar substituent on a carbon atom of R ³ to R ⁶ adjacent to a carbon atom bound to X ¹ or X ² . One or more or all of R ³ to R ⁶ may be independently selected from the group consisting of a substituted non-aromatic compound; a substituted aromatic compound; and a substituted heteroaromatic compound. Preferably each of R ³ to R ⁶ is a substituted aromatic or a substituted heteroaromatic compound, more preferably a substituted aromatic compound. The substituted aromatic compound may comprise a substituted phenyl. In one embodiment of the invention at least two of {but preferably all of) R ³ to R ⁶ are aromatic with a ring atom of the aromatic ring structure bound to X ¹ or X ² , but preferably not more than two of said aromatic R ³ to R ⁶ have a substituent as a non-ring atom bound to a ring atom of the aromatic ring structure adjacent to the ring atom bound to X ¹ or X ² .

Any polar substituent on one or more of R ³ , R ⁴ , R ⁵ and R ⁶ may be electron donating.

Suitable polar substituents may be a methoxy, ethoxy, isopropoxy, C ₃ -C ₂₀ alkoxy, phenoxy, methoxymethyl, methylthiomethyi, 1 ,3-oxazolyl, methoxymethoxy, hydroxyl, amino, pentafiuorophenoxy, tosyl, methylsulfanyi, trimethylsiloxy, dimethylamino, sulphate, nitro, halides or the like.

Y may be selected from the group consisting of an organic linking group such as a hydrocarbyl, substituted hydrocarbyi, heterohydrocarbyi and a substituted heterohydrocarbyt; an inorganic linking group such as a single atom link (that is X ¹ and X ² are bound to the same atom); methylene; dimethylmethylene; 1 ,2-ethane;

1 ,2-ethene; 1 ,1 -cyclopropane; 1 ,1-cyclobutane; 1 ,1-cyclohexane; 1 ,1 -cyclopentane; 1 ,2-cyclopeπtaπe; 1 ,2-

cyctohexaπe; 1 ,2-phenylene; 1 ,8-naphthyl; 9,10-phenanthrene; 4,5-phenaπthrene; 1 ,3-propane; 1 ,2- catechol, 1 ,2-diarylhydrazine and 1 ,2-dialkylhydrazine; -B(R ⁷ )-, -Si(R ⁷ J ₂ -, -P(R ⁷ )- and -N(R ⁷ )- where R ⁷ is hydrogen, a hydrocarby! or heterohydrocarbyi 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, aryioxy, substituted aryioxy, halogen, alkoxycarbonyl, carbonyioxy, alkoxy, aminocarbonyl, carbonylamino, diaikylamino, silyl groups or derivatives thereof, and aryl substituted with any of these substituents. Preferably R ⁷ may be a hydrocarbyl or a heterohydrocarbyi group. R ⁷ may be methyl, ethyl, propyl, isopropyl, cyclopropyi, ally!, butyl, tertiary-butyl, sec-butyi, cyclobutyl, pentyi, isopentyl, neopentyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclo-octyl, decyl, cyclodecyl, 1 ,5-dimetylheptyl, 2-πaphthylethyl, 1-naphthylmethyl, adamantylmethyi, adamaπtyl, 2-isopropylcyclohexyl, 2,6-dimethylcyclohβxyl, cyclododecyl, 2- methylcyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2-ethylcyciohexyl, 2-isopropylcyclohexy!, 2,6- dimethyl-cyclohexyl, exo-2-norbomanyl, isopinocamphenyl, dimethylamino, phthalimido, pyrrolyϊ, trimethyfsiiyl, dimethyj-tertiary-butyisilyl, 3-trimethoxylsilane-propyl, indanyl, cyclohexanemethyl, 2- methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 4-tertiary-butylphenyl, 4-nitrophenyl, (1 ,1 '- bis(cyclohexy!)-4,4'-methy!ene), 1 ,6-hexylene, 1-naphthyl, 2-naphthyl, N-morpholine, diphenyimethyl, 1 ,2- diphenyl-ethyl, phenylethyl, 2-methyiphenyl, 3-methylphenyl, 4-methySphenyl, 2,6-dimethyl-pheny!, 1 ,2,3,4- tetrahydronaphthyl, or a 2-octyl group.

In one embodiment of the invention Y may exclude (CH ₂ ) _x Z(CH ₂ ) _y , where Z is -P(R ⁸ )-, -N(R ⁸ )-, -As(R ³ )-, - Sb(R ³ )- or -S- and x and y are individually 1-15 and wherein R ⁸ is hydrogen or a halogen or a nitro group or a hydrocarbyi or a substituted hydrocarbyl group.

In another embodiment of the invention Y includes no heteroatom (that is an atom other than H or C) as a ring member of a heteroaromatic ring structure in the shortest link of Y between X ¹ and X ² . Y may Include at least one heteroatom (that is neither H or C) in the shortest link of Y between X ¹ and X ² and preferably said heteroatom is different to X ¹ and X ² . Preferably X ¹ and X ² are the same and said heteroatom is different to X ¹ and X ² , preferably said heteroatom is N.

Y may include a first atom bound to X ¹ and a different atom bound to X ² , such as the case where Y is 1 ,2 ethane. Preferably Y includes or is a single atom bound to both X ¹ and X ² .

Preferably the iigating compound is of the formula

with R ³ to R ⁷ as defined above.

Preferably each of R ³ to R ⁶ is an aikyl (preferably methyl, ethyl or tsopropyl) or aromatic (preferably phenyl or substituted phenyl).

Non limiting examples of the Iigating compound are (phenyl) ₂ PN(propyl)P(phenyl) ₂ ;

(phenyl)aPN{cyclopentyl)P(phenyl) ₂ ; (phenyl) ₂ PN(isopropyl)P(phenyl) ₂ ;

(phenyl) ₂ PN((4-f-butyl)-phenyl)P(phenyl) ₂ ;

(2-naphthyl) ₂ PN(methyl}P(phenyl) ₂ ;

(2-methylphenyl)(phenyl)PN(isopropy!)P(2-methylpheny!)(ph enyl); (ethyl)(phenyl}P-1 ,2-benzene-P(ethyl)(phenyl);

(4-methoxyphenyl) ₂ PN(isopropyl)P(phenyl) ₂ ;

(2-methoxyphenyr) ₂ P-1 ,2-benzene-P{2-methoxyphenyl) ₂ ;

The Iigating compound may include a polymeric moiety to render the reaction product of the source of transition metal and the said iigating compound to be soluble at higher temperatures and insoluble at lower temperatures e.g. 25 ⁰ 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 at., J. Am. Chem. Soc,

1987, 109, 177-179. In a similar vein these transition metal catalysts can also be immobilised by binding the

Iigating compound to silica, silica gel, polysiloxane or alumina backbone as, for example, demonstrated by C. Yuanyin era/., Chinese J. React. PoL, 1992, 1{2), 152-159 for immobilising platinum complexes.

The ligating compound may include multiple ligating units or derivatives thereof. Non-limiting examples of such ligands include dendrimeric ligands as well as ligands where the individual ligating units are coupled either via one or more of the R groups or via the linking group Y. More specific, but not limiting, examples of such ligands may include 1 ,2~di-{N(P(phenyl) ₂ ) ₂ )-benzene, 1 ,4-di-(N{P(pheπyl) ₂ ) ₂ )-benzene, N(CH ₂ CH ₂ N(P(phenyl) ₂ ) _£ } ₃ , 1 ,4-di-(P{phenyi)N(methyl)P(pheny!) ₂ )-benzene, 1 ,2-di-(N(P(p- methoxyphenyl) ₂ ) ₂ )-benzene, 1 ,4-di-{N(P(p-methoxyphenyl) ₂ } ₂ )-benzene, N(CH ₂ CH ₂ N(P(p- methoxyphenyl) ₂ ) ₂ ) ₃ and 1 ,4-di-{P(p-methoxyphenyl)N(methyl)P(p-methoxyphenyl) ₂ )-benzene.

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 oligomerisation catalyst may be prepared in situ, that is in the reaction mixture in which the oligomerisation reaction is to take place. Often the oligomerisation catalyst will be prepared in situ. Alternatively 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 metai to ligand compound molar ratio, from about 0.01 : 100 to 10 000 : 1 , preferably from about 0.1 : 1 to 10:1.

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

The oϋgomerisation 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, MgCI ₂ , zirconia, artificial hectorite or smectite clays such as Laponite™ RD or mixtures thereof, or on a polymer, for example polyethylene, polypropylene, polystyrene, or poly(aminostyrene). 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 oϋgomerisation catalyst. Sn some cases, the support materia! 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 oiefinic compound or mixture thereof to be oligomerised according to this invention can be introduced into the process in a continuous or batch fashion.

The oiefinic compound or mixture of oiefinic compounds may be contacted with the catalysts at a pressure of 1 barg or higher, preferably greater than 10 barg (1000 kPa), more preferably greater than 30 barg (3000 kPa). Preferred pressure ranges are from 10 to 300 barg (1000 to 3000 kPa), more preferably from 30 to 100 barg (3000 to 10000 kPa}.

The process may be carried out at temperatures from -100 ⁰ C to 250 °C. Temperatures in the range of 15- 150 ⁰ C are preferred. Particularly preferred temperatures range from 35-120 ⁰ 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 oiigomeric product is in a form that displays little or no solubility, and/or a two-phase liquid/iiquid 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, curnene, heptane, methylcyclohexane, methylcyclopentane, cyclohexane, ionic liquids as well as the product formed during the reaction in a liquid state and the like.

The reaction may be carried 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 oligomerisation 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 reactaπfs 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 another aspect of the present invention there is provided the combination of an oHgomerisation catalyst and a catalyst activator, which catalyst activator is a compound which includes at least one halogenated organic group which is bound to one or more binding atoms selected from the group consisting of a group 5A atom and a group 6A atom, which one or more binding atoms are in turn bound to a central atom selected from the group consisting of a group 3A atom, and a group 3B to 7B transition metal atom; and wherein the oligomerisation catalyst includes the combination of iii) a source of a transition metal; and iv) 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, and R' being the same or different when m>1 , and R ² being the same or different when n>1.

The invention will now be further described by means of the following non-limiting examples.

Examples

In the examples that follow, aiϊ manipulations were earned out under inert conditions, using standard Schlenk techniques. All solvents were dried and degassed via normal procedures. [Ph ₃ C][AI{OC(CF ₃ } ₃ } ₄ ] was prepared following the method described by Krossing et. a!., Journal of Fluorine Chemistry, 112 (2001 ), 83- 90. The ethylene used in the catalyst testing was supplied by BOC and was grade 3.0 unless otherwise stated.

Example 1. Preparation of {AI(OC ₆ F ₅ ) ₃ } ₂ A solution of 2M perfluorophenol (7.0 ml, 14 mmol) in toluene was added to a flask and a 1.9M solution of triethylaluminium (2.0 ml, 3.8 mmoi) was added dropwise. The solution was then heated to 60 ⁰ C for 4 hours and then allowed to cool. The solvent toluene was reduced under vacuum and 10 ml of petroleum spirits added. The resulting powder that formed was washed four times with petroleum spirits (5 ml) and dried under vacuum to afford a white powder. Yield: 1.694g (77%) Anal. Calcd. for (found) C ₁₈ F ₁₅ O ₃ AI: C 37.52 (37.34). ¹⁹ F NMR (282 MHz, DMSO-d ₆ ): -161.2, -162.1 , -162.8 (orthoF); -169.9 (meta-F); 179.0 (para-F). ¹³ C NMR (75 MHz, DMSO-d ₆ ): 143.0, 142.4, 139.2, 136.0, 132.8, 129.7 (CF). The molecular structure of the compound is shown in Figure 1.

Figure 1. Molecular structure of (AI(OC ₆ Fs) ₃ J ₂

Example 2. Preparation of [(Et ₂ O) ₂ H][AI(OC ₆ Fs) ₄ ]

At 0 ⁰ C a solution of perfjuorophenol (7.5 ml, 15 mrnoj) in 20 ml of diethylether was treated dropwise with 1.9M triethylalumiπium solution (1.7 mi, 3.2 mmol). After 2 hours at room temperature the solvent was removed under vacuum and the product washed twice with petroleum spirits to give a white powder. Yield: 1.641g (56%). Anal. CaIc. for (found) C ₃₂ H ₂₁ O ₆ F ₂₀ AI: C 42.31 (42.28), H 2.33 (2.47). ¹ H NMR (300 MHz, CDCI ₃ ): 5.60 (br, 1 H, H(OEt ₂ )); 4.39 (q, J=7Hz, 8H, OCH ₂ CH ₃ ); 1.55 (t, J=7Hz, 12H, OCH ₂ CW ₃ ). ¹⁹ F NMR (282 MHz, CDCI ₃ ): -163.7 (d, J=22Hz, ortho-F); -165.8 (t, J=22Hz, meta-F); -171.1 (t, J=22Hz, para-F). ¹³ C NMR (75 MHz, CDCI ₃ ): 142.0, 140.0, 138.8, 136.6 (CF); 71.9 (OCH ₂ ); 13.9 (OCH ₂ C ₃ ).

Example 3. Prepartion of (Et ₂ O)AI{OCH{C ₆ F ₅ ) ₂ } ₃ .

At 0 ⁰ C a solution of (C ₆ F ₅ ) ₂ C(H)OH (5.79 g, 15.9 mmol) in 15 ml of diethylether was treated dropwise with 1.9M AIEt ₃ . The addition of AIEt ₃ was continued portionwise until the starting alcohol was completely consumed by NMR analysis. The solvent was then removed under vacuum, the residue taken up in diethyiether, and the solvent removed again to yield a white powder. Yield: 5.743 g (91 %). Anal. Calcd. for C ₄₃ H ₁₃ O ₄ F ₃₀ (found): C 43.38 (44,14), H 1.10 (1.50). ¹ H NMR (300 MHz, CDCI ₃ ): 6.65 (s, 3H, OCH); 4.18 (q, J=7Hz, 4H, OCH ₂ CH ₃ ); 1.32 (t, J=7Hz, 6H, OCH ₂ CH ₃ ). ¹⁹ F NMR (282 MHz, CDCI ₃ ): -144.5 (orthoF); -155.2 (metø-F); -162.6 (para-F). ¹³ C NMR (75 MHz, CDCI ₃ ): 146.5, 143.2, 139.6, 136.2 (CF); 116.8 (ipso-Q; 69.6 (OCH ₂ CH ₃ ); 61.7 (OCH); 13.3 (OCH ₂ CH ₃ ). The molecular structure of the compound is shown in Figure 2.

Figure 2. Molecular structure of (Et ₂ O)Al[OCH(C ₆ F ₅ ) _S ] ₃

Example 4. Preparation of (Et ₂ O)Ai{OC{CF ₃ ) ₃ } ₃ .

A solution of 4 ml (29 mmol) of perfluoro-tert-butanoS in 10 ml of diethylether was cooled to 0°C and treated with a 1.9M solution of tπethylalumtrnum (3 ml, 5,7 mmol). After stirring ovemtght the solution was heated to 65°C for a further day. After cooling the solvent was removed under vacuum to give fine needies of colorless product Yield: 4.383g (95%) ¹ H NMR (300 MHz, CDCI ₃ ): 4.34 {q, J=7Hz, 4H, OCH ₂ CH ₃ ), 1.43 (t, J=7Hz, 6H, OCH ₂ CH ₃ ). ' ⁹ F NMR (282 MHz, CDCI ₃ ): -75.9 (CF ₃ ). The molecular structure of this compound is shown in Figure 3.

Figure 3. Molecular structure of (Et ₂ θ)Ai[OC(CF ₃ ) ₃ 3 ₃

Example 5. Ethylene oligomerisation with AI(OC ₆ F ₅ ) ₃ activator.

A 300ml stainless steel reactor equipped with mechanical stirring was heated to 120 ⁰ C and purged with ethylene Toluene (80 ml) was added, saturated with ethylene, and the reactor brought to 45°C. CrCI ₃ (thf) ₃ (30 ^~ moi) and Ph ₂ PNfPr)PPh ₂ (30 ^~ mol) were added to a Schienk flask under nitrogen and dissolved in 20 ml of toluene. To this solution was added 3 mmol of AIEt ₃ (100 equivalents relative to Cr), and the resulting mixture was added to the reactor followed by 40Zmol AI(OC ₆ F ₅ ) ₃ . The reactor was immediately charged with 40 bar of ethylene and the pressure kept constant throughout the reaction by the continuous addition of ethylene. After 30 minutes the ethylene supply was closed and the reactor cooled in an ice/water bath. Excess ethylene was bled and the reactor contents treated sequentially with 1000 ^" L of nonane (GC internal standard}, MeOH and 10% HCI. A sample of the organic phase was taken for GC-FID analysis while the

solid polyethylene produced was collected by filtration, washed with MeOH and dried at 100 ⁰ C. The total product mass was 4.124g. The product distribution is shown in Table 1.

Example 6. Ethylene oligomerisation with AI(OC ₆ Fs) ₃ activator. The same procedure as for example 5 was followed with the exception that 9mmol of AIEt ₃ was employed (300 equivalents relative to Cr). The total product mass was 3.655g. The product distribution is shown in Table 1.

Example 7. Ethylene oligomerisation with AI(OC ₆ F ₅ ) ₃ activator. The same procedure as for example 5 was followed with the exception that 3mmol of triisobutylaiuminium (TIBAL, 100 equivalents relative to Cr) was employed in place of AIEt ₃ . The total product mass was 1.556g. The product distribution is shown in Table 1.

Example 8. Ethylene oligomerisation with AI(OC ₆ Fg) ₃ activator. The same procedure as for example 5 was followed with the exception that 0.9mmol of ASEt ₃ was employed (30 equivalents relative to Cr). The total product mass was 9.067g. The product distribution is shown in Table 1.

Example 9. Ethylene oligomerisation with perfluorophenol (in-situ activator). CrCI ₃ (thf) ₃ (30umo!) and Ph ₂ PN( ¹ Pr)PPh ₂ (30GmOl) were added to a Schlenk flask under nitrogen and dissolved in 20 mi of toluene. This was treated with 90^mol of C ₆ F ₅ OH followed by 0.9 mmol (30 equivalents) of AIEt ₃ . The resulting solution was immediately added to the reactor (reactor conditions as detailed in example 5), and charged with 40 bar ethylene. After 30 minutes the contents were worked up as detailed in example 5. The total product mass was 5.319g. The product distribution is shown in Table 1.

Example 10. Comparative example of ethylene oligomerisation without phosphine ligand.

The same procedure as in example 9 was followed with the exception that Ph ₂ PN( ¹ Pr)PPh ₂ was omitted. The total product mass was 5.788g. The product distribution is shown in Table 1.

Example 11. Ethylene oligomerisation with [(Et ₂ O) ₂ H][Ai(OC ₆ Fs) ₄ ] activator.

The procedure of example 5 was followed with 101 mot CrCI ₃ (thf) ₃ , 12CmOl Ph ₂ PN{ ⁽ Pr}PPh ₂ , 1 mmol AIEt ₃ (100 equivalents), and 15Imol of [(Et ₂ O) ₂ H][At(OC ₆ Fs) ₄ ]. The total product mass was 0.873g. The product distribution is shown in Table 1.

Example 12, Ethylene oligomerisation with (Et, _? O)AI{OC{CF ₃ ) ₃ } ₃ activator.

The procedure of example 5 was followed with 20Cmol CrCI ₃ (thf) ₃ , 20lmol Ph ₂ PN( ¹ Pr)PPh ₂ , 2 mmol AIEt ₃ (100 equivalents), and 35πmol of (Et ₂ θ)AI[OC{CF ₃ ) ₃ ] ₃ . The total product mass was 4.26g. The product distribution is shown in Table 1.

Example 13. Ethylene oligomerisation with [Ph ₃ C][AI{OC(CF ₃ ) ₃ } ₄ ] activator.

A 30OmI stainless stee! reactor equipped with mechanical stirring was heated to 120 ⁰ C and purged with ethylene. Methylcyclohexane (80 ml) was added, saturated with ethylene, and the reactor brought to 65°C. Methylcycfohexane solutions of Cr(acac) ₃ (10ml of 1.OmM, lOZImol) and Ph ₂ PN( ¹ Pr)PPh ₂ (5ml of 2.5mM, 12.5CmOl) were added to a Schlenk flask under nitrogen and treated with 1.0 mmol Of AIEt ₃ (100 equivalents relative to Cr) . The resulting solution was added to the reactor followed by 15 ^{^} mol of [Ph ₃ C][AI{OC(CF ₃ ) ₃ } ₄ ]. The reactor was immediately charged with 40 bar of ethylene and the pressure kept constant throughout the reaction by the continuous addition of ethylene. After 60 minutes the ethylene supply was closed and the reactor cooled in an ice/water bath. Excess ethylene was bled and the reactor contents treated sequentially with 100O LL of nonane (GC internal standard), MeOH and 10% HCI. A sample of the organic phase was taken for GC-FtD analysis while the solid polyethylene produced was collected by filtration, washed with MeOH and dried at 100°C. The total product mass was 25.36g. The product distribution is shown in Table 1.

Example 14. Ethylene oligomerisation with IPh ₃ C][AI(OC(CF ₃ J ₃ J ₄ ] activator. The procedure of example 5 was followed with 30C:mol CrCI ₃ (thf) ₃ , 30,JmOl Ph ₂ PN( ¹ Pr)PPh ₂ , 0.9 mmol AIEt ₃ (30 equivalents), and 4OHmOl of [Ph ₃ C][At{OC(CF ₃ ) ₃ } ₄ ]. The reaction was continued for 1 hour. The total mass of product was 41.98g. The product distribution is shown in Table 1.

Example 15. Ethylene oligomerisation with [Ph ₃ CHAI(OC(CFs) ₃ J ₄ ] activator. The same procedure as in example 14 was followed with the exception that 3mmol of AIEt ₃ (100 equivalents) was employed. The totat mass of product was 52.62g. The product distribution is shown in Table 1.

Example 16, Ethylene oligomerisation with [Ph ₃ C][Al(OC(C F ₃ ) ₃ } ₄ ] activator.

The procedure of exampie 5 was followed with 101 mo! CrCI ₃ (thf) _3l 12 ^{^} mol Ph ₂ PN( ¹ Pr)PPh ₂ , 6 mmol AEt ₃ (600 equivalents}, and 12ImOi of [Ph ₃ C]EAi(OC(CF ₃ ) _S J ₄ ]. The total mass of product was 0.748g. The product distribution is shown in Table 1.

Example 17. Ethylene oligomerisation with [Ph ₃ C][AI{OC(CF ₃ ) ₃ } ₄ ] activator.

The procedure of example 5 was followed with IOlmol CrCϊ ₃ (thf) ₃ , I2 ^~ mol Ph ₂ PN( ¹ Pr)PPh ₂ , 3 mmol AEt ₃ (300 equivalents), and 15 ^{^} mol of [Ph ₃ C][AI(OC(CF ₃ J ₃ J ₄ ]. The reaction was continued for 1 hour. The total mass of product was 29.77g, The product distribution is shown in Table 1.

Example 18. Ethylene oligomerisation with [Ph ₃ C][AI(OC(CF ₃ ) _S j ₄ ] activator.

The same procedure as in example 17 was followed with the exception that 1mmoi of AIEt ₃ (100 equivalents) was employed. The total mass of product was 39.06g. The product distribution is shown in Table 1.

Example 19. Ethylene oligomerisation with [Ph ₃ C][AI{OC(CF ₃ ) ₃ J ₄ ] activator.

[CrCI ₃ ( Ph ₂ PN( ¹ Pr)PPh ₂ J] ₂ (IODmol of Cr) was added to a Schienk flask under nitrogen and suspended in 20 ml of toluene. This was treated with 1 mmol of AIEt ₃ (100 equivalents) to give a homogeneous solution. [Ph ₃ C][AI(OC(CFa) ₃ J ₄ ] (lOCmol) was added to the reactor (reactor conditions as detailed in example 5), followed by the Cr/PNP/AIEt ₃ solution, and the reactor was charged with 40 bar ethylene. After 30 minutes the contents were worked up as detailed in example 5. The total product mass was 8.65g. The product distribution is shown in Table 1.

Example 20. Ethylene oligomerisation with [Ph ₃ C][AI(OC(CF ₃ J ₃ J ₄ ] activator.

A 300ml stainless steel reactor equipped with mechanical stirring was heated to 120 ⁰ C and purged with ethylene. Methylcyclohexane (80 ml) was added, saturated with ethylene, and the reactor brought to 65°C.

CrC! ₃ (thf) ₃ (10Zmo!) and Ph ₂ PN( ¹ Pr)PPh ₂ (12ImOl) were added to a Schienk flask under nitrogen and dissolved in 5 ml of toluene. To this solution was added 1 mmol of AEt ₃ (100 equivalents relative to Cr). The resulting solution was added to the reactor followed by 15lmol of [Ph ₃ C][Aϊ(OC(CF ₃ ) ₃ J ₄ ]. The reactor was immediately charged with 40 bar of ethylene and the pressure kept constant throughout the reaction by the continuous addition of ethylene. After 60 minutes the ethylene supply was closed and the reactor cooled in an ice/water bath. Excess ethylene was bled and the reactor contents treated sequentially with 100OuL of

nonane (GC internal standard), MeOH and 10% HCI. A sample of the organic phase was taken for GC-FiD analysis while the solid polyethylene produced was collected by filtration, washed with MeOH and dried at 100 ⁰ C. The total product mass was 30.97g. The product distribution is shown in Table 1.

Example 21. Comparative example of ethylene oligomerisation with B(C ₆ F _S ) ₃ activator.

A 300ml stainless steel reactor equipped with mechanical stirring was heated to 120 ⁰ C and purged with ethylene. Toluene (80 ml) was added, saturated with ethylene, and the reactor brought to 45°C. CrCI ₃ (thf) ₃ (20rmo!) and Ph ₂ PN( ¹ Pr)PPh ₂ (20Z]mol) were added to a Schlenk flask under nitrogen and dissolved in 20 ml of toluene. To this solution was added 3 mmol of AIEt ₃ (100 equivalents relative to Cr), and the resulting mixture was added to the reactor followed by 30^mol B(C ₆ F ₅ J ₃ . The reactor was immediately charged with 50 bar of ethylene and the pressure kept constant throughout the reaction by the continuous addition of ethylene. After 30 minutes the ethylene supply was closed and the reactor cooled in an ice/water bath. Excess ethylene was bled and the reactor contents treated sequentially with 1000C L of nonane (GC internal standard), MeOH and 10% HCI. A sample of the organic phase was taken for GC-FID analysis while the solid polyethylene produced was collected by filtration, washed with MeOH and dried at 100°C. The total product mass was 0.611 g. The product distribution is shown in Table 1.

Example 22. Comparative ethylene oligomerisation with MMA0-3A activator

The same procedure as in example 20 was followed with the exception that 1 mmo! of MMAO-3A was employed as an activator in the place of AIEt ₃ and [Ph ₃ C][AI(OC(CFa) ₃ J ₄ ], and 40 bar of ethylene was fed. The total mass of product was 13.49g. The product distribution is shown in Table 1.

Example 23, Comparative ethylene oligomerisation with MMAO-3A activator.

The same procedure as in example 20 was foiiowed with the exception that 4.0mmol of MMAO-3A was employed as an activator in the place of AIEt ₃ and [Ph ₃ C][AKOC(CFa) ₃ I ₄ ], and 30 bar of ethylene was fed. The total mass of product was 37,39g. The product distribution is shown in Table 1.

Example 24. Preparation of Cr(CO) ₄ Ph ₂ PN( ¹ Pr)PPh ₂

Cr(CO) ₆ (1.54 g, 7.0 mmol) and Ph ₂ PN( ¹ Pr)PPh ₂ (2.99 g, 7.0 mmol) were dissolved in diglyme (60 ml) and heated to 170 ⁰ C for 2 hours during which time the solution turned yellow. The solution was cooled and methanol (40 ml) was added which precipitated a yellow solid. The solution was filtered and the solid was

washed with MeOH and dried in vacuo. Yield = 2.65 g (64 %). Anal. Calcd. for C ₃₁ H ₂₇ CrNO ₄ P ₂ (found): C 62.95 (62.94), H 4.60 (4.55), N 2.37 (2.31 ).

Example 25. Preparation of [Cr(CO) ₄ Ph ₂ PN{ ^F Pr)PPh ₂ ][Al{OC(CF ₃ ) ₃ }4] A dichloromethane (5 ml) solution of Ag[AI{OC(CF ₃ ) ₃ } ₄ ] (147 mg, 0.13 mmol) was added to a dichloromethane (5 ml) solution of Cr(CO) ₄ Ph ₂ PN( ¹ Pr)PPh ₂ (75 mg, 0.13mmol), The solution immediately darkened and after stirring for 1 hour the solution was filtered and the solid washed with dichloromethane (2 x 5 ml). The solvent was removed in vacuo from the combined organic fractions to leave a blue solid. Yield = 150 mg (74 %). Anal. Calcd. for C ₄₇ H ₂₇ AICrF ₃₆ NO ₈ P ₂ (found): C 36.22 (36.19), H 1.75 (1.73), N 0.90 (0.87).

Example 26. Ethylene oligomerisation with [Cr(CO) ₄ Ph ₂ PN( ¹ Pr)PPh ₂ ][AI(OC(CF ₃ ) _S l ₄ ]

A 300 ml glass Buchi reactor was heated to 120 ⁰ C and evacuated and back filled with nitrogen 3 times, Methylcyclohexane (40 ml) was added followed by a toluene (10 ml) solution of [Cr(CO) ₄ . Ph ₂ PN( ¹ Pr)PPh ₂ ][AI(OC(CFs) ₃ J ₄ ] (31 mg, 20 μmol). To the reactor AlEt ₃ (2 mmol, 100 equivalents relative to Cr) was added and the reactor was immediately charged with ethylene to a pressure of 8 bar. The solution was then irradiated with UV light from a High Pressure 100 Watt Mercury Vapor Short Arc lamp with a total intensity of 13 Wcm ^"1 for 10 minutes. The ethylene was siowly vented to a pressure of approximately 0.5 bar and the solution was then transferred to a 300ml stainless steel reactor equipped with mechanical stirring which had been heated to 120 ⁰ C, purged with ethylene, methylcyclohexane (50 m!) added and the reactor temperature brought to 60 ⁰ C. The reactor was immediately charged with 40 bar of ethylene and the pressure kept constant throughout the reaction by the continuous addition of ethylene. After 45 minutes the ethylene supply was closed and the reactor cooled in an ice/water bath. Excess ethylene was bied and the reactor contents treated sequentially with 1000'1'L of nonane (GC internal standard), MeOH and 10% HCL A sample of the organic phase was taken for GC-FID analysts while the solid polyethylene produced was collected by filtration, washed with MeOH and dried at 100 ⁰ C. The total product mass was 38.97 g. The product distribution is shown in Table 1.

Example 27. Ethylene oligomerisation with [Cr(CO) ₄ Ph ₂ pN{ ⁱ Pr)PPh ₂ 3[AI{OC(CF ₃ ) ₃ } ₄ ] A 300ml stainless steel reactor equipped with mechanical stirring was heated to 120 ⁰ C and purged with ethylene. Methylcyciohexane (90 ml) was added and the reactor brought to 60 ⁰ C. [Cr(CO) ₄ .

Ph ₂ PN( ¹ Pr)PPh ₂ ][Ai(OC(CFs) ₃ U] (8 nig, 5 μmol) was dissolved in toluene (10 cm ³ ) and Et ₃ AI (2 mmoi, 400 equivalents relative to Cr) was added. The resultant solution was added to the reactor and the reactor was immediately charged with 40 bar of ethylene and the pressure kept constant throughout the reaction by the continuous addition of ethylene. After 60 minutes the ethylene supply was closed and the reactor cooled in an ice/water bath. Excess ethylene was bled and the reactor contents treated sequentially with 100011 of nonane (GC internal standard), MeOH and 10% HCI. A sample of the organic phase was taken for GC-FID analysis while the solid polyethylene produced was collected by filtration, washed with MeOH and dried at 100 ⁰ C. The total product mass was 10.74 g. The product distribution is shown in Table 1.

Example 28. Ethylene oligomerisation with [Cr{CO) ₄ Ph _a PN('Pr)PPh ₂ ][AI{OC{CF ₃ ) ₃ } ₄ ]

A 300ml stainless steel reactor equipped with mechanical stirring was heated to 120°C and purged with ethylene. Methylcyclohexane (90 ml) was added and the reactor brought to 60 °C. Et ₃ AI (0.5 mmoi, 100 equivalents relative to Cr) followed by tri-/sobutyialuminium (1.5 mmoi, 300 equivalents relative to Cr) was added. [Cr(CO) ₄ Ph ₂ PN('Pr)PPh ₂ ][AS{OC(CF ₃ } ₃ } ₄ ] (8 mg, 5 μmol} was dissolved in toluene (10 cm ³ ) and the resultant solution was added to the reactor. The reactor was immediately charged with 40 bar of ethylene and the pressure kept constant throughout the reaction by the continuous addition of ethylene. After 60 minutes the ethylene supply was closed and the reactor cooled in an ice/water bath. Excess ethylene was bled and the reactor contents treated sequentially with 1 QQOClL of nonane (GC internal standard), MeOH and 10% HCI. A sample of the organic phase was taken for GC-FiD analysis while the solid polyethylene produced was collected by filtration, washed with MeOH and dried at 100 ^c C. The total product mass was 17.47g. The product distribution is shown in Table 1.

Example 29. Ethylene oligomerisation with [Ph ₃ C][AI(OC(CF ₃ ) _S ) ₄ ] activator.

The same procedure as in example 17 was followed with the exception that 1 mmoi of AIEt ₃ (100 equivalents) was employed and the ethylene source was Linde 4.5. The total mass of product was 65.31 g. The product distribution is shown in Table 1.

Example 30, Ethylene oligomerisation with [Cr(CO) ₄ Ph ₂ pN( ⁱ Pr)PPh ₂ ][AI{OC(CF ₃ ) ₃ } ₄ ]

The same procedure as in example 27 was followed with the exception that 1 mmol of AIEt ₃ (100 equivalents) was employed and the ethylene source was Linde 4.5. The total mass of product was 32.8g. The product distribution is shown in Table 1.

Example 31. Ethylene oligomerisatϊon with [Cr(CO) ₄ Ph ₂ PNePr)PPh ₂ ][AUOC(CF ₃ ) _J O ₄ ]

The same procedure as in example 27 was followed with the exception that 1 mmol of AIEt ₃ (200 equivalents} was employed and the ethylene source was Linde 4.5. The total mass of product was 36.4 g. The product distribution is shown in Table 1.

Example 32. Ethylene oligomerisation with [Ph ₃ C][Ta(OC ₆ Fs) ₆ ] activator.

The procedure of example 5 was followed with 10_mol CrCI ₃ (thf) ₃ , 12"mol Ph ₂ PN( ¹ Pr)PPh ₂ , 1 mmol AIEt ₃

(100 equivalents), and 20 ^{^} mol of [Ph ₃ C][Ta(OC ₆ Fs) ₆ ] The total product mass was 0.691 g. The product distribution is shown in Table 1.

Example 33. Ethylene oligomerisation with [Ph ₃ C][AIF(OC(CF ₃ ) _S ) ₃ ] activator.

The procedure of example 5 was followed with lOLJmol CrCI ₃ (thf) ₃ , 12Dmol Ph ₂ PN( ¹ Pr)PPh ₂ , 1 mmol AIEt ₃

(100 equivalents), and 15CmoI of [Ph ₃ C][AIF{OC(CF ₃ ) ₃ } ₃ ] The total product mass was 1.187g. The product distribution is shown in Table 1.

Example 34, Ethylene oligomerisation with [Ph ₃ C][AlaF{OC(CF ₃ ) ₃ } ₆ ] activator.

The procedure of example 5 was followed with IOIImol CrCI ₃ (thf) _3l 12^mol Ph ₂ PN( ¹ Pr)PPh ₂ , 1 mmol AIEt ₃

(100 equivalents), and IOUmol of [Ph ₃ C][AI ₂ F(OC(CF ₃ ) _S ) ₆ ]. The total product mass was 3.6Og. The product distribution is shown in Table 1 , while the ratio of C ₈ ZC ₆ is shown in Figure 4.

Example 35. Ethylene oligomerisation with [Ph ₃ C][AI ₂ F{OC(CF ₃ ) ₃ } ₆ ] activator.

The procedure of example 5 was followed with 101 mo! CrCI ₃ (thf) ₃ , 12_jmoi Ph ₂ PN( ¹ Pr)PPh ₂ , 1 mmol AiEt ₃

(100 equivalents), and 15Cmol of [Ph ₃ C][AI ₂ F(OC(CF ₃ ) _S ) ₆ ]. The total product mass was 6.66g. The product distribution ss shown in Table 1 , while the ratio of C ₈ ZC ₆ is shown in Figure 4.

Example 36. Ethylene oligomerisation with [Ph ₃ C][AI ₂ F(OC(C F ₃ ) ₃ } ₆ ] activator.

The procedure of example 5 was followed with IOImol CrCi ₃ (W) ₃ , 12 ^~ mol Ph ₂ PNfPr)PPh ₂ , 1 mmol AIEt ₃

(100 equivalents), and 20ImOi of [Ph ₃ C][Al ₂ F{OC(CF ₃ ) ₃ } ₆ ]. The total product mass was 7 14g. The product distribution is shown in Table 1 , while the ratio of C ₃ ZC ₆ is shown in Figure 4.

Example 37, Ethylene oligomerϊsation with [Ph ₃ C][AI ₂ F(OC(CF ₃ ) _S ) ₆ ] activator.

The procedure of example 5 was followed with lOϋmol CrCi ₃ {thf) _3l 12ImOl Ph ₂ PN( ¹ Pr)PPh ₂ , 1 mmol AIEt ₃ (100 equivalents), and 30Imol of [Ph ₃ C][AI ₂ F(OC(CF ₃ ) _S j ₆ ]. The total product mass was 27.62g. The product distribution is shown in Table 1 , while the ratio of C ₈ ZC ₆ is shown in Figure 4.

Table 1. Product distributions obtained in examples 5-19.

Percentages are ail mass%. 1-C ₆ and 1 -C ₈ refer to mass% selectivity within the total C ₆ and C ₈ fractions respectively.

Figure 4. Mass ratio of C ₈ / C ₆ as a function of amount of activator, corresponding to examples 34-37.

mass C8 / mass C6 as a function of amount [Ph3C][AI2F{OC(CF3)3}33

3.S ₁

³ I

1 -j 0.5 i

0 -

0 5 10 15 20 25 30 micromole AI2F{OC(CF3)3}3]

Example 38. Ethylene oligomerisation with [(EtHeX ₃ TAC)CrCi ₃ ], Et ₃ AI co-activator and [Ph ₃ C][AI{OC(CF ₃ ) ₃ }4] activator.

A 30OmL stainless steel reactor equipped with mechanical stirring was heated to 130°C under vacuum for 1 hour. After cooling under vacuum and back-filling with Ar, [Ph ₃ C][AI{OC(CF ₃ } ₃ } ₄ ] (30 μmoi) and

[(EtHeX ₃ TAC)CrCI ₃ ] [that is {tπs-N,N,N,-ethylhexyl)}1 ,3,5-tiazocyclohexane] (20 μmol) were added to the reactor as a solution in toluene (100 ml_) and the reactor brought to 40 ⁰ C. Et ₃ AI (2.0 mmol, 100 equivalents relative to Cr) was then added to the reactor and the vessel immediately charged with 2 bar of ethylene

(Linde 4.5 grade) and the pressure kept constant throughout the reaction by the continuous addition of ethylene. After 37 minutes the ethylene supply was closed and the reactor cooied in an ice/water bath.

Excess ethylene was bled and the reactor contents treated sequentially with 1000.7 L of nonane (GC internal standard), MeOH and 10% HCL A sample of the organic phase was taken for GC-FlD analysis while the

solid polyethylene produced was collected by filtration, washed with MeOH and dried at 100 ⁰ C. The total product mass was 13,87Og. The product distribution is shown in Table 2.

Example 39. Ethylene oligomerisatϊon with [(EtHeX ₃ TAC)CrCl ₃ ], Et ₃ AI co-activator and [Ph ₃ Cl[AI{OC(CF ₃ ) ₃ } ₄ ] activator,

A 30OmL stainless steel reactor equipped with mechanical stirring was heated to 130 ⁰ C under vacuum for 1 hour. After cooling under vacuum and back-filling with Ar, [Ph ₃ C][AI(OC(C F ₃ ) ₃ } ₄ ] (30 μmol) and [(EtHeX ₃ TAC)CrCI ₃ ] (20 μmol) were added to the reactor as a solution in toluene (100 mL) and the reactor brought to 50 ⁰ C. Et ₃ AI (2.0 mmol, 100 equivaients relative to Cr) was then added to the reactor and the vessel immediately charged with 5 bar of ethylene (Linde 4.5 grade) and the pressure kept constant throughout the reaction by the continuous addition of ethylene. After 17 minutes the ethylene supply was closed and the reactor cooled in an ice/water bath. Excess ethylene was bled and the reactor contents treated sequentially with 1000U L of nonane (GC internal standard), MeOH and 10% HCI. A sample of the organic phase was taken for GC-FID analysis while the solid polyethylene produced was collected by filtration, washed with MeOH and dried at 100 ⁰ C. The total product mass was 12,203g. The product distribution is shown in Table 2.

Example 40. Comparative ethylene oligomerisation with [(EtHeX ₃ TAC)CrCI ₃ ] and MAO activator.

A 30OmL stainless steel reactor equipped with mechanical stirring was heated to 130°C under vacuum for 1 hour. After cooling under vacuum and back-filling with Ar, toluene (90 mL) and MAO (4.0 mmol, 200 equivalents relative to Cr) was added to the reactor and the temperature maintained at 4O ⁰ C. In a schlenk

[(EtHeX ₃ TAC)CrCI ₃ ] (20 μmol) was dissolved in toluene (10 mL) and MAO (2.0 mmol, 100 equivalents relative to Cr) added. The resultant solution was added to the reactor and the vessel immediately charged with 2 bar of ethylene (Linde 4.5 grade) and the pressure kept constant throughout the reaction by the continuous addition of ethylene. After 36 minutes the ethylene supply was closed and the reactor cooled in an ice/water bath. Excess ethylene was bled and the reactor contents treated sequentially with 100OJL of nonane (GC internal standard), MeOH and 10% HCL A sample of the organic phase was taken for GC-FID analysis while the solid polyethylene produced was collected by filtration, washed with MeOH and dried at

100 ⁰ C. The total product mass was 9.941 g. The product distribution is shown in Table 2.

Example 41. Comparative ethylene oligomerisation with [(EtHeX ₃ TAC)CrCI ₃ ] and MMAO activator.

A 30OmL stainless steel reactor equipped with mechanicai stirring was heated to 13O ⁰ C under vacuum for 1 hour. After cooling under vacuum and back-fϋiing with Ar, toluene (90 ml.) and MMAO (4.0 mmol, 200 equivalents relative to Cr) was added to the reactor and the temperature maintained at 40 ⁰ C. In a schlenk [(EtHeX ₃ TAC)CrCI ₃ ] (20 μmol) was dissolved in toluene (10 ml) and MMAO (2.0 mmol, 100 equivalents relative to Cr) added. The resultant solution was added to the reactor and the vessel immediately charged with 5 bar of ethylene (Linde 4.5 grade) and the pressure kept constant throughout the reaction by the continuous addition of ethylene. After 36 minutes the ethylene supply was closed and the reactor cooled in an ice/water bath. Excess ethylene was bled and the reactor contents treated sequentially with 1000QL of nonane (GC internal standard), MeOH and 10% HCI. A sample of the organic phase was taken for GC-FID analysis while the solid polyethylene produced was collected by filtration, washed with MeOH and dried at 100 ⁰ C. The total product mass was 38.286g. The product distribution is shown in Table 2.

Table 2. Product distributions obtained in examples 38-41.

Percentages are all mass%. 1-C _e and 1-C ₈ refer to mass% selectivity within the total C ₆ and C ₈ fractions respectively.

Example 42. Ethylene oligomerisation with [{(Decyl-S-CH ₂ CH ₂ ) ₂ NH}CrCI ₃ ], Et ₃ AI co-activator and [Ph ₃ C3[AI{OC(CF ₃ ) ₃ } ₄ ] activator. A 30OmL stainless steel reactor equipped with mechanicai stirring was heated to 130 ⁰ C under vacuum for 1 hour. After cooling under vacuum and back-filling with Ar, [Ph ₃ C][AI{OC(CF ₃ ) ₃ } ₄ ] (30 μmol) and [{(Decyl-S- CH ₂ CH ₂ J ₂ NHJCrCI ₃ ] (20 μmol) were added to the reactor as a solution in toluene (100 mL} and the reactor brought to 85°C. Et ₃ AI (2.0 mmol, 100 equivalents relative to Cr) was then added to the reactor and the vessel immediately charged with 40 bar of ethylene (Linde 3.5 grade) and the pressure kept constant throughout the reaction by the continuous addition of ethylene. After 21 minutes the ethylene supply was closed and the reactor cooled in an ice/water bath. Excess ethylene was bled and the reactor contents

treated sequentially with 1000_L of πoπane (GC interna! standard), MeOH and 10% HCI. A sample of the organic phase was taken for GC-FlD analysis while the solid polyethylene produced was collected by filtration, washed with MeOH and dried at 100 ⁰ C. The total product mass was 4,317g. The product distribution is shown in Table 3.

Example 43. Comparative ethylene oligomerisation with [{(Decyl-S-CH ₂ CH ₂ ) ₂ NH}CrCI ₃ ] and MAO activator.

A 30OmL stainless steel reactor equipped with mechanical stirring was heated to 13O ⁰ C under vacuum for 1 hour. After cooling under vacuum and back-filling with Ar, [{(Decyl-S-CH ₂ CH ₂ ) ₂ NH}CrC! ₃ ] {44 μmol) was added to the reactor as a solution in toluene (100 mL) and the reactor brought to 100 ⁰ C. MAO (29.9 mmol, 680 equivalents relative to Cr) was then added to the reactor and the vessel immediately charged with 40 bar of ethylene (Linde 3.5 grade) and the pressure kept constant throughout the reaction by the continuous addition of ethylene. After 30 minutes the ethylene supply was closed and the reactor cooled in an ice/water bath. Excess ethylene was bled and the reactor contents treated sequentially with 1000_L of nonane (GC internal standard), MeOH and 10% HCI. A sample of the organic phase was taken for GC-FID analysis while the solid polyethylene produced was collected by filtration, washed with MeOH and dried at 100°C. The product distribution is shown in Table 3.

Table 3. Product distributions obtained in examples 42-43.

Percentages are all mass%. 1-C ₆ and 1-C ₈ refer to mass% selectivity within the total C ₆ and C ₈ fractions respectively.

Example 44. 1-hexene trimerisation with [(EtHeX ₃ TAC)CrCI ₃ ], Et ₃ AI co-activator and [Ph ₃ C][AI{OC(CF ₃ ) ₃ } ₄ ] activator. A 250 mL round bottom flask was dried in vacuo, back-filled with dry N ₂ and charged with [Ph ₃ C][AI(OC(CFa) ₃ J ₄ ] (0.0363g, 30 μππoi), [(EtHeX ₃ TAC)CrCI ₃ ] (0.0116g, 20 μmol), 1 -hexene (20 mL), nonane (1 mL, as GC standard) and toluene (20 mL). This solution was heated in an oil bath to 40 ⁰ C. Once a steady temperature had been achieved a solution of AIEt ₃ 1.9M in toluene {1.1 mi, 2mmol, 100 equivalents

relative to Cr) was added. Upon activation the brown/yellow solution became yellow over a few seconds. The solution was stirred at constant temperature for 2 hours.The reaction was quenched with methanol (2ml) and water (2ml). Samples (0.2ml) were taken from the reaction solution just prior to activation and after quenching. These were added to DCM {1.5ml} and analysed by GC-FID. The product distribution is shown in Table 4.

Example 45. Comparative 1-hexene trimerisatϊon with [(EtHeX ₃ TAC)CrCI ₃ ] and MMAO activator.

A 250 rnL round bottom flask was dried in vacuo, back-filled with dry N ₂ and charged with [(EtHeX ₃ TAC)CrCi ₃ ] (0.0116g, 20 μmol), 1-hexene (20 mL), nonane {1 ml_, as GC standard) and toluene (20 mL). This solution was heated in an oil bath to 40 ⁰ C. Once a steady temperature had been achieved a solution of MMAO 1.9M in heptanes (3.2ml, β.Ommol, 300 equivalents relative to Cr) was added. Upon activation the purple solution instantly became green. The solution was stirred at constant temperature for 2 hours.The reaction was quenched with methanol (2ml) and water (2ml). Samples (0.2ml) were taken from the reaction solution just prior to activation and after quenching. These were added to DCM (1.5ml) and analysed by GC-FID. The product distribution is shown in Table 4.

Table 4. Product distributions obtained in examples 44-45.

The above detailed examples reveal several advantages that can be achieved through the use of the activators and co-activators disclosed herein. Firstly, it is found that ethylene oiigomerisation with a combination of a Cr source, Ph ₂ PN( ¹ Pr)PPh ₂ , and an aikylaluminoxaπe such a MAO or MMAO normally furnishes an oligomeric mixture composed predominately of 1-hexene and 1 -octene, in which the amount of

1-octene is greater than the amount of 1-hexene. This is illustrated in comparative example 23, and further examples can be found in WO 04/056479 as well as Bollmann et. ai., J. Am. Chem. Soc, 126 (2004) 14712. Surprisingly however, examples 5-9 and 11-12 show that it is possible to produce an oligomer composed predominately of 1-hexene by replacing aluminoxane activators with the activators and co-activators disclosed herein. Furthermore, it can be concluded by considering ail examples, and as shown in Figure 4,

that control over the ratio of 1-hexene to 1-octene can be achieved through the choice of activator employed, the amount of activator employed, or the relative ratio of activator to co-activator.

A second advantage that can be acheived is a reduction in the total amount of aluminium that can be used while stiff maintaining acceptable productivity and selectivity. Comparative example 22 shows that when the amount of MMAO3A is reduced down to 100 equivalents relative to chromium, a lower productivity results and a large amount of polymer is formed. Comparison of example 22 with examples 15 and 18 shows that a higher productivity and lower polymer content can be acheived with similar total amounts of aluminium. As such, there is provided a means by which waste voiumes can be reduced. Furthermore, the co-activators that can be used in the present invention, such as triethylaiuminium, are generally substantially less expensive than aluminoxanes, and as such a lower activator cost is achievable for a given amount of oligomeric product.

Compared to the use of borane or borate activators, which also allow inexpensive co-activators such a triethylaiuminium to be employed, the activators disclosed herein are capable or much improved productivity. This is illustrated in comparative example 21 , and further examples can be found in IPCOM000031729D, which show that borane and borate activators lead to lower productivity for oligomer formation. Examples 14, 15, 17 and 18 show that greatly improved productivities can be acheived through the use of the activators disclosed herein,

Examples 26-28 illustrate that it is possible to use a system in which the source of transition metal, ligating compound, and activator are all constituents of a single chemical compound. Example 26 shows that such a system is also capable of producing acceptable productivity and low solids formation with reduced total amounts of aluminium.

Examples 29-30 compared to examples 18 and 27 respectively show that the productivity obtained from a particular catalyst system is dependent on the source of ethylene used.

Examples 38-39 further demonstrate the application of the activator to other catalyst systems, specificaiiy those employing tridentate ligands. More specifically a facially capping tridentate ligand. Jt can be seen by reference to the comparitive examples 40 and 41 that compared to MAO or MMAO activators a significant

reduction in the amount of aluminium utilised is achieved. Simultaneously a catalyst is generated with a higher activity per bar etheπe per gram Cr per hour. !t should be noted that in comparitive example 40 an ethene pressure of 5 bar (as opposed to 2 bar in examples 38 and 39) is required for the catalyst to function.

Examples 42 further demonstrates the application of the activator to other catalyst systems, specifically those employing tridentate ligands. More specifically a meridional-binding mode tridentate lϊgand. Example 43 shows a comparison with MMAO.

Examples 44 demonstrates the application of the activator in conjunction with catalyst systems for the oϋgomerisation of α-o!efins. Specfically the trimerisation of 1-hexene. Example 45 is a comparitive exampie with MMAO as activator.