ZA200504749B - Tetramerization of olefins - Google Patents

Description

T ETRAMERIZATION OF OLEFINS

Field of the invention:

This invention relates to an olefin tetramerisation process, a catalyst system for hl tetramerisation of olefins and the identification and use of ligand s for a catalyst system for tetrarmerisation of olefins.

Background of the invention

This invention defines a process and catalyst system that facilitates the production of 1-octene in higha selectivity, while avoiding the co-production of sign ificant quantities of butenes, other octene isomers, specific higher oligomers and polyethylene. The catalyst system =can also be used for the tetramerisation of other olefins, especially a (alpha) —olefins.

Despite the wel | known value of 1-octene, the art does not teach a commercially successful process for the tetramerisation of ethylene to produce 1-octene selectively. Corventional ethylene oligomerisation technologies pro«duce a range of a-olefins followirg either a Schulz-Flory or Poisson product distribution. By definition, these mathematical distributions limit the mass % of the tetramer that can be formed and make a dis tribution of products. In this regard, it is known frosm prior art (US patent 6,184,428) that a nickel catalyst comprising a chelating ligard, preferably 2- diphenyl phosph ino benzoic acid (DPPBA), a nickel precursor, preferably NiCl,.6H,0, and a catalyst activator, preferably sodium tetraphenylborate, catalyse the oligomerisation ©f ethylene to yield a mixture of linear olefins containing 1-octene.

The selectivity towards linear Cy a-olefins is claimed fo be 19%. Similarly the Shell

Higher Olefins Prrocess (SHOP process, US patents 3,676,523 and 33,635,937) using a similar catalysst system is reported to typically yield 11 mass % 1-octene in its . product mixture Chem Systems PERP reports 90-1, 93-6 and 94/95512). . Ziegler-type technologies based on trialkylaluminium catalysts, independently developed by Gulf Oil Chemicals Company (Chevron, e.g. DE patent 1,443,927) and

Ethyl Corporatior1 (BP/Amoco, e.g. US patent 3,906,053), are also cornmercially used to oligomerisex ethylene to mixtures of olefins that reportedly contain 13-25 mass % 1- octene (Chem Systems PERP reports 90-1, 93-6, and 94/95512).

The prior art also teaches that chromium-based catalysts containing heteroatomic ) ligands with both phosphorus and nitrogen heteroatoms selectively catalyse the trimerisation of ethylene to 1-hexene. Examples of such heter=oatomic ligands for * ethylene trimesrisation include bis(2-diethylphosphino-ethyl) amire (WO 03/053891, hereby fully incorporated herein by means of reference) as well as (o- methoxyphenwl),PN(methyl)P(o-methoxyphenyl), (WO 02/041 19, hereby fully incorporated herein by means of reference). Both these catalyst systems and processes are= very specific for the production of 1-hexene and ormly yield 1-octene as an impurity (typically less than 3 mass % of the product mixture as disclosed by WO 02/04119). The coordinating phosphorus hetero atoms in (o- methoxyphenysi),PN(methyl)P(o-methoxyphenyl), (WO 02/04119) are spaced apart by one nitrogen atom. It is believed that the nitrogen atom does not coordinate with the chromium , at least in the absence of an activator, and that without any further electron donating atoms on the ligand it is a bidentate system. Furthermore it is argued that thae polar, or electron donating substituents in the o rtho-position of the phenyl groups help form a tridentate system, which is generally b elieved to enhance selectivity towards 1-hexene formation (see Chem. Commun., 20«Q2, 858-859: “This has lead us to hypothesise that the potential for ortho-methoxyy/ groups to act as pendent donowrs and increase the coordinative saturation of the chromium centre is an important factor.”) WO 02/04119 (Example 16) teaches the production of octenes using a trimer-isation of olefins process and catalyst system. I n this instance, 1- butene was co-trimerised with two ethylene molecules to give 30% octenes.

However, the mature of these octenes was not disclosed and the applicant believes that they consi st of a mixture of linear and branched octenes.

The prior art teaches that high 1-octene selectivities cannot oe achieved since expansion of the generally accepted seven-membered metallacycle reaction intermediate for ethylene trimerisation (Chem. Commun., 1989, 674) to a nine- \ membered metallacyle is unlikely to occur (Organometallics, 2003, 22, 2564; Angew.

Chem. Int. Ed. , 2003, 42 (7), 808). It is argued that the nine-memmbered ring is the : least favoured medium-sized ring and should thus be disfavour-ed relative to the seven-member-ed ring (Organometallics, 2003, 22, 2564). In addition, it is also stated by the same authors that, “if a nine-membered ring formed, it woul d be more likely to grow to an elesven- or thirteen-membered ring. In other words, one would never expect much octene, but formation of some (li near) decene or dodecene would be more reasonable.”

Despite the teaching of the opposite, the applicant has now found a process for selectively producing a tetramerised olefin. “Whe applicant has further found that chromium-based catalysts containing mixed he teroatomic ligands with both nitrogen and phosphorus heteroatoms, without any polar substituents on the hydrocarbyl or heterohydrocarbyl groups on the phosphorus atom, can be used to selectively tetramerise ethylene to 1-octene often in excess of 70 mass% selectivity. This high 1-octene selectivity cannot be achieved via conventional one-step ethylene oligomerisation or trimerisation technologies whiich at most yield 25 mass% 1-octene.

Summary of the invention

This invention relates to a process for selectively producing tetrameric products.

This invention specifically relates to a processs for selectively producing tetrameric products such as 1-octene from olefins such as ethylene..

The invention relates to a process for select ively producing tetrametric products using a transition metal catalyst system containiekng a heteroatomic ligand.

According to a first aspect of the inventiom there is provided a process for tetramerisation of olefins wherein the product of the tetramerisation process is an olefin and makes up more than 30% of the product stream of the process.

According to a second aspect of the invention the tetramerisation process includes the step of contacting an olefinic feedstream with a catalyst system which includes a transition metal and a heteroatomic ligand and wherein the product of the tetramerisation process is an olefin and makes up more than 30% of the product stream of the process. [34

In this specification, % will be understood to be 2a mass %.

The term “tetramerisation” generally refers to the reaction of four, and preferably four identical, olefinic monomer units to yield a linear and/or branched olefin.

By heteroatomic is meant a ligand that contains at least two heteroatoms, which can be the same or different, where the heteroatoms may be selected from phosphorus, arsenic, antimony, sulphur, oxygen, bismuth, selenium or nitrogen. : The feedstream will be understood to include an olefin to be tetramerised and can be ] introduced into the process according to the invention in a continuous or batch fashion.

The product stream will be understood to include a tetramer, which tetramer is produced according to the invention in a continuous or batch fashion.

The feedstream may include an a-olefin and the product stream may include at least 30%, preferably at least 35%, of a tetramerrised o-olefin monomer.

The process may include a process for tetramerisation of a-olefins. Under the term a—olefins is meant all hydrocarbon compounds with terminal double bonds. This definition includes ethylene, propylene, 1-butene, isobutylene, 1-pentene, 1-hexene, 1-octene and the like.

The process may include a process for tetramerisation of a-olefins to selectively yield tetrameric a-olefin products.

The olefinic feedstream may include ethylene and the product stream may include at least 30% 1-octene. The process may be a process for tetramerisation of ethylene.

The invention allows the ligand, catalyst system and/or process conditions to be selected to give a product stream of more than 40%, 50%, 60% or 70% a-olefins. It may be preferable, depending on the further use of the product stream, to have such high selectivities of the a-olefin.

The olefinic feedstream may include ethylene and the (Cg + Cg) : (Cs + Cio ) ratio in [Ng the product stream may be more than 2.5:1.

The olefinic feedstream may include ethylene and the Cg : Cg ratio in the product stream is more than 1,

El

The ethylene may be contacted with the «catalyst system at a pressure of preferably greater than 10 barg, more preferably greater than 30 barg.

The heteroatomic ligand may be deseribed by the following general formula (R):A-B-C(R), where A and C are indeependently selected from a group which . comprises phosphorus, arsenic, antimony, oxygen, bismuth, sulphur, selenium, and nitrogen, and B is a linking group betwee A and C, and R is independently selected from any homo or hetero hydrocarbyl ggroup and n and m is determined by the respective valence and oxidation state of 2 and/or C.

A and/or C may be a potential electron donor for coordination with the transition metal.

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

The heteroatomic ligand may be described by the following general formula (R")(R?)A-B-C(R%)(R*) where A and C are independently selected from a group which comprises phosphorus, arsenic, antimonwy, bismuth and nitrogen and B is a linking group between A and C, and R', R%, R™ and R* are independently selected from hydrocarbyl or hetero hydrocarbyl or subostituted hydrocarbyl or substituted hetero hydrocarbyl groups.

The heteroatomic ligand may be desecribed by the following general formula (R"Y(R)A-B-C(R®)(R*) where A and C are independently selected from a group which comprises phosphorus, arsenic, antimonwy, bismuth and nitrogen and B is a linking group between A and C, and R', R24, R® and R* are independently non-aromatic or aromatic, including hetero aromatic, groups.

Any of the groups R', R?, R® and R* may- independently be linked to one or more of each other or to the linking group B to form a cyclic structure together with A and C, @ AandBorBandC. ’ Any substituents on one or more of R', RZ , R® and R* may be not electron donating.

Ss

R’, R% R® and R* may independently be non aromatic or aromatic, including hetero aromatic, groups and not all the groups R', RR? R® and R*, if aromatic, have a substituent on the atom adjacent to the atom bourd to A or C.

Each non electron donating substituent on one o r more of R', R?, R® and R* may be non-polar. IUPAC defines non-polar as an entity without a permanent electric dipole moment,

Suitable non-polar substituents may be a methyl, ethyl, propyl, butyl, isopropyl, isobutyl, tert-butyl, pentyl, hexyl, cyclopentyl, 2-methylcyciohexyl, cyclohexyl, cylopentadienyl, phenyl, bi-phenyl, naphthyl, tol yi, xylyl, mesityl, ethenyl, propenyl and benzyl group, or the like.

R", R?, R® and R* may be independently selected from a group comprising a benzyl, phenyl, tolyl, xylyl, mesityl, biphenyl, naphth-yl, anthracenyl, methoxy, ethoxy, phenoxy, tolyloxy, dimethylamino, diethylamiro, methylethylamino, thiophenyl, pyridyl, thioethyl, thiophenoxy, trimethylsilyl, dimethylhydrazyl, methyl, ethyl, ethenyl, propyl, butyl, propenyl, propynyl. cyclopertyl, cyclohexyl, ferrocenyl and tetrahydrofuranyl group. Preferably, R', R?, R® an-d R* may independently be selected from a group comprising a phenyl, tolyl, biphe nyl, naphthyl, thiophenyl and ethyl group.

B may be selected from any one of a group comprising: organic linking groups comprising a hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl and a substituted heterohydrocarbyl; inorganic linking ggroups comprising single atom links; ionic links; and a group comprising methylene, cdimethylmethylene, 1,2-ethane, 1,2- phenylene, 1,2-propane, 1,2-catechol, 1,2-dimesthylhydrazine, -B(R%)-, -Si(R%),-, -

P(R®)- and -N(R®)- where R® is hydrogen, a hydrocarbyl or substituted hydrocarbyl, a substituted heteroatom or a halogen. PreferabBy, B may be -N(R°)- and R® is a hydrocarbyl or a substituted hydrocarbyl group . R® may be hydrogen or may be selected from the groups consisting of alkyl, sutostituted alkyl, aryl, substituted aryl, » aryloxy, substituted aryloxy, halogen, nitro, allkoxycarbonyl, carbonyloxy, alkoxy, aminocarbonyl, carbonylamino, dialkylamino, silyl groups or derivatives thereof, and

B aryl substituted with any of these substituents. Preferably R® may be an isopropyl, a 1-cyclohexyl-ethyl, a 2-methyl-cyclohexyl or a 2-oectyl group.

B may be selected to be a single atom spacer. .A single atom linking spacer is defined as a substituted or non-substituted atom that is bound directly to A and C.

A and/or C may be independently oxidised by S, Se, NorO.

A and C may be independently phosphorus or phosgohorus oxidised by Sor Se orN or O.

The ligand may also contain multiple (R),A-B-C(R), units. Not limiting examples of such ligands include dendrimeric ligands as well as li gands where the individual units are coupled either via one or more of the R groups or via the linking group B . More specific, but not limiting, examples of such ligands may include 1,2-di- (N(P(phenyl),).)-benzene, 1,4-di-(N(P(phenyl),).)-benzene,

N(CH.CH,N(P(phenyl),).); and 1,4-di-(P(phenyl)N(methyl)P(phenyl),)-benzene.

The ligands can be prepared using procedures kno=wn to one skilled in the art and procedures disclosed in published literature. Examples of ligands are: (phenyl),PN(methyl)P(phenyl),, (phenyl)}.PN(pentyl)P(phenyl),, (phenyl),PN(phenyl)P(phenyl),, (phenyl),PN(p-methoxyphenyl)P(phenyl),, (phenyl),PN(p-'butylphenyl)P(phenyl),, (phenyl)2PN(«( CH;)3-N-morpholine)P(phenyl), (phenyl):PN(Si(CH;)s)P(phenyl),, (((phenyl),P),NCH,CH)N, (ethyl).PN(methyl)P(ethyl),, (ethyl).PN(isopropyl)P(phenyl),, (ethyl)(phenyl)PN(methyl)P(ethyl)(phenyl), (ethyl)( phenyl)PN(isopropyl)P(phenyl), (phenyl);,P(=Se)N(isopropyl)P(phenyl),, (phenyl ),PCH,CH,P(phenyl),, (o- ethylphenyl)(phenyl)PN(isopropyl)P(phenyl),, (o-rmethylphenyl),PN(isopropy!)P(o- methylphenyl)(phenyl) (pheny(),PN(benzy!)P(phenwl), (phenyl),PN(1-cyclohexyl- ethyl)P(phenyl),, (phenyl):PN[CH,CH,CH,Si(OMes)]P(phenyl),, (phenyl).PN(cyclohexyh)P(phenyl),, phenyl),PNJ(2-methylcyclohexyl)P(phenyl),, (phenyl), PN(allyl)P(phenyl),. (2-naphthyl),PN(rnethyl)P(2-naphthyl), (p- biphenyl),PN(methy!)P(p-biphenyl),. (p-methylphenyl B.PN(methyl)P(p-methylphenyl), (2-thiophenyl!);PN(methyl)P(2-thiophenyl),. (phenyl) PN(methy)N(methyl)P(phenyt),, (m-methylphenyl),PN(methyl)P(m-methylphenyl), , (>henyl).PN(isopropyl)P(phenyl),, and (phenyl),P(=S)N(isopropyl)P(phenyl),.

The catalyst system may include an activator and thee process may include the step of combining in any order a heteroatomic ligand with a transition metal precursor and an activator.

The process may include the steps of generating a heteroatomic coordination complex in situ from a transition metal precursor and a heteroatomic ligand. The process may } include the step of adding a pre-formed coordination complex, prepared using a heteroatomic ligand and a transition metal precursor, to a reaction mixture, or the . step of adding separately to the reactor, a heteroatomic ligand and a transition metal precursor such that a heteroatommic coordination complex of a transition metal is generated in situ. By generating a heteroatomic coordination complex in situ is meant that the complex is generated in the medium in which catalysis takes place.

Typically, the heteroatomic coordination complex is generated in situ. Typically, the transition metal precursor, and he teroatomic ligand are combined (both in situ and ex situ) to provide metal/ligand ratios from about 0.01:100 to 10 000:1, and preferably, from about 0.1:1 to 10:1.

The transition metal may be selected from any one of a group comprising chromium, molybdenum, tungsten, titanium, tantalum, vanadium and zirconium, preferably chromium.

The transition metal precursor which, upon mixing with the heteroatomic ligand and an activator, catalyses ethylene tetramerisation in accordance with the invention, may be a simple inorganic or organic salt, a co-ordination or organometallic complex and may be selected from any ore of a group comprising chromium trichloride tris- tetrahydrofuran complex, (benzene)tricarbonyt chromium, chromium (lil) octanoate, chromium (Ill) acetylacetonoate, chromium hexacarbonyl, and chromium (ll) 2- ethylhexanoate. The preferred transition metal precursors include chromium (ny acetylacetonoate and chromium (1 11) 2-ethylhexanoate.

The heteroatomic ligand can be modified to be attached to a polymer chain so that the resulting heteroatomic coordination complex of the transition metal is soluble at elevated temperatures, but becomes insoluble at 25°C. This approach would enable the recovery of the complex from the reaction mixture for reuse 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 complexes can also be - immobilised by binding the heteraatomic ligands to silica, silica gel, polysiloxane or alumina or the like backbone as, for example, demonstrated by C. Yuanyin et al.,

Chinese J. React. Pol., 1992, 1(2), 152-159 for immobilising platinum complexes.

The activator for use in th e process may in principle be any compound that generates an active catalyst when combined with the heteroatomic ligand and the transitior metal precursor. Mixturess of activators may also be used. Suitable compounds include organcaluminium compounds, organoboron compounds, organic salts, such i as methyllithium and met hylmagnesium bromide, inorganic acids and salts, such ass tetrafluoroboric acid ethe rate, silver tetrafluoroborate, sodium hexafluoroantimonate ) and the like.

Suitable organocaluminiurn compounds include compounds of the formula AIR; where each R is independently a C;-C,; alkyl, an oxygen containing moiety or a halide, and compounds such as LiAlH, and the like. Examples include trimethylaluminium (TMA), triethylaluminium (TEA), tri-isobutylaluminium (TIBA), tri-n— octylaluminium, methyslaluminium dichloride, ethylaluminium dichloride, dimethylaluminium chloride, diethylaluminium chloride, aluminium isopropoxide ., ethylaluminiumsesquichlo ride, methylaluminiumsesquichloride, and aluminoxanes._

Aluminoxanes are well kn own in the art as typically oligomeric compounds which cara be prepared by the controlled addition of water to an alkylaluminium compound, for example trimethylalumini um. Such compounds can be linear, cyclic, cages or mixtures thereof. Mixtures of different aluminoxanes may also be used in the= process.

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

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

The activator may be selected from alkylaluminoxanes such as methylaluminoxane= (MAO) and ethylaluminox ane (EAO) as well as modified alkylaluminoxanes such ass modified methylaluminoxane (MMAO). Modified methylaluminoxane (a commercial product from Akzo Nobel) contains modifier groups such as isobutyl or n-octyll * groups, in addition to methyl groups. - The transition metal and the aluminoxane may be combined in proportions to provide

Al/metal ratios from about 1:1 to 10 000:1, preferably from about 1:1 to 1000:1, ands more preferably from 1:1 to 300:1.

The proce=ss may include the step of adding to the catalyst sysstem a trialkylaluminium compound in amounts of between 0.01 to 1000 mol per mol of” alkylaluminoxane. ) it should Boe noted that aluminoxanes generally also contain -considerable quantities of the corresponding trialkylaluminium compounds used in their preparation. The . presence of these trialkylaluminium compounds in aluminoxames can be attributed to their incornplete hydrolysis with water. Any quantity of a trialk ylaluminium compound quoted in this disclosure is additional to alkylaluminium comp-ounds contained within the alumirmoxanes.

The processs may include the step of mixing the components of the catalyst system at any temperature between -20°C and 250°C in the presen ce of an olefin. The applicant has found that the presence of an olefin may stabilise the catalyst system.

The individual components of the catalyst system described herein may be combined simultaneously or sequentially in any order, and in the presence or absence of a solvent, ir order to give an active catalyst. The mixing of th e catalyst components can be co nducted at any temperature between -100°C and 2-50°C. The presence of an olefin during the mixing of the catalyst components generally provides a protective effect which may result in improved catalyst performance. The preferred temperature range may/ be between 20°C and 100°C.

The catalyst system, in accordance with the invention, or its @ndividual components, may also be immobilised by supporting it on a support material, for example, silica, alumina, MgCl,, zirconia or mixtures thereof, or on a goolymer, for example polyethyle ne, polypropylene, polystyrene, or poly(aminostyrenee). The catalyst can be formed in situ in the presence of the support material, or th e support can be pre- impregnated or premixed, simultaneously or sequentially, with one or more of the catalyst components. 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. The concept was, for example, “ successfully demonstrated with a chromium-based ethylene tr-imerisation catalyst by

T. Monoi and Y. Sasaki, J. Mol. Cat.A:Chem., 1987, 109, 17 7-179. In some cases, ’ the support can also act as a catalyst component, for example2 where such supports contain aluminoxane functionalities or where the support is capable of performing similar chemical functions as an aluminoxane, which is for i nstance the case with

IOLA™ (a commercial product from Grace Davison).

The reaction products as described herein, may be prepared using the disclosed

Catalyst system by a homogeneous liquid phase reactison in the presence or absence of an inert solvent, and/or by slurry reaction where th e catalyst system 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 i dominant medium, and/or gas phase reaction, using conventional equipment and contacting techniques.

T he process may also be carried out in an inert solvert. Any inert solvent that does rmot 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, methyicyclormexane, methylcyclopentane, cyclohexane, 1-hexene, 1-octene, ionic liquids and the Bike.

T he process may be carried out at pressures from atmospheric to 500 barg. Ethylene p ressures in the range of 10-70 barg are preferred. Particularly preferred pressures range from 30-50 barg.

The process may be carried out at temperatures from -100 °C to 250 °C.

Temperatures in the range of 15-130 °C are preferred. Particularly preferred temperatures range from 35-100°C.

Ir3 a preferred embodiment of the invention, the heteroatomic coordination complex amd reaction conditions are selected such that the yield of 1-octene from ethylene is gweater than 30 mass %, preferably greater than 35 mass %. In this regard yield rexfers to grams of 1-octene formed per 100g of total rea ction product formed.

Irm addition to 1-octene, the process may also yield diffe rent quantities of 1-butene, 1- hexene, methylcyclopentane, methylene cyclopesntane, propyicyclopentane, - propylene cyclopentane, specific higher oligomers andl polyethylene, depending on th e nature of the heteroatomic ligand and the reaction conditions. A number of these } products cannot be formed via conventional etFiwlene oligomerisation and tri merisation technologies in the yields observed in the peresent invention.

Although the catalyst, its individual components, reagents, solvents and reaction products are generally employed on a once-through basis, any of these materials can, and are indeed preferred to be recycled to some extent in order to minimise production costs. . The process may be carried out ire a plant which includes any type of reactor.

Examples of such reactors include, b ut are not limited to, batch reactors, semi-batch reactors and continuous reactors. The plant may include, in combination a) a reactor, 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, wherein the catalyst system may include a heterroatomic coordination complex of a transition metal precursor and an activator, as dlescribed herein.

In another embodiment of the process the reactor and a separator may be combined to facilitate the simultaneous formation of reaction products and separation of these compounds from the reactor. This process principle is commonly known as reactive distillation. When the catalyst systenn exhibits no solubility in the solvent or reaction products, and is fixed in the reactor so that it does not exit the reactor with the reactor product, solvent and unreacted olefin, the process principle is commonly known as catalytic distillation.

According to a further aspect of the invention, there is provided a catalyst system, as described above, for the tetramerisatiion of olefins. The catalyst system may include a heteroatomic ligand as described above and a transition metal. The catalyst system may also include an activator as described above.

The heteroatomic ligand is described by the following general formula (R):A-B-C(R)n where A and C are independently selected from a group which comprises phosphorus, arsenic, antirmony, oxygen, bismuth, sulphur, selenium, and nitrogen, and B is a linking group between A and C, and R is independently selected ” from any homo or hetero hydrocarbyl group and n and m is determined by the respective valence and oxidation state of A and/or C.

A and/or C may be a potential electron donor for coordination with the transition metal.

The heteroatomic ligand may be described by the following general formula (R')(R®)A-B-C(R*)(R*) where A and C are independently selected from a group which comprises phosphorus, arsenic, antimony, bismuth and nitrogen and B is a linkingy ) group between A and C, and R', R? R® and R* are independently selected from hydrocarbyl or hetero hydrocarbyl or substituted hydrocarbyl or substituted hetero _ hydrocarbyl groups.

The heteroatomic ligand may also be described by the following general formulaa (R"YRYA-B-C(R*)(R*) where A and C are independently selected from a group whicha comprises phosphorus, arsenic, arstimony, bismuth, and nitrogen and B is a linkings group between A and C, and R', RR? R® and R* are independently non-aromatic or aromatic, including hetero aromatic, groups.

Any of the groups R', R?, R® and RR* may independently be linked to one or more off each other or to the linking group B3 to form a cyclic structure together with A and C.

Aand BorBand C.

Any substituents on one or more of R', R% R®and R* may not be electron donating.

R', R?, R® and R* may be independently non aromatic or aromatic, including heteros aromatic, groups and not all the groups R', R%, R® and RY if aromatic, have aa substituent on the atom adjacent to the atom bound to A or C. It appears to the= applicant that single atom spacers having steric bulk promote the selectivity towardss 1-octene if ethylene is tetramerised, especially if there are no substituents on thes atom of the aromatic group adjacen t to the atom bound to A or C. Each non electrora donating substituent may be non polar. This also appears to promote selectivity~ towards 1-octene.

Suitable non-polar substituents may be a methyl, ethyl, propyl, butyl, isopropyl, isobutyl, tert-butyl, pentyl, hexyl, cyclopentyl, 2-methylcyclohexyl, cyclohexyl, cylopentadienyl, phenyl, bi-phenyl, naphthyl, tolyl, xylyl, mesityl, ethenyl, propenyE ; and benzyl group, or the like. ] R', R% R® and R* may independently be selected from a group comprising a benzyl, phenyl, tolyl, xylyl, mesityl, biphenyl, naphthyl, anthracenyl, methoxy, ethoxy, phenoxy, tolyloxy, dimethylamina, diethylamino, methylethylamino, thiophenyl, pyridyl, thioethyl, thiophenoxy, trimethylsilyl, dimethyihydrazyl, methyl, ethyl, ethenyl,

propyl, butyl, propenyl, propynyl, cyclopentyl, cyclohexyl, ferrocenyl and tetrahydrofura nyl group. Preferably, R', R? R® and R* may independently be selected from a group comprising a phenyl, tolyl, biphenyl, naphthyl, thiophenyl ard ethyl group.

B may be se lected from any one of a group comprising: organic linking groups : comprising a hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl and a substituted he-terohydrocarbyl; inorganic linking groups comprising single ato m links; ionic links; ane a group comprising methylene, dimethyimethylene, 1,2-etha ne, 1,2- phenylene, 1, 2-propane, 1,2-catechol, 1,2-dimethylhydrazine, -B(R%)-, -SiCR%),-, -

P(R®)- and -NCR°®)- where R® is hydrogen, a hydrocarbyl or substituted hydrocarbyl, a substituted he=teroatom or a halogen. Preferably, B may be -N(R%)- and R° is a hydrocarbyl ow a substituted hydrocarbyl group. R® may be hydrogen or amay be selected from the groups consisting of alkyl, substituted alkyl, aryl, substituted aryl, aryloxy, substituted aryloxy, halogen, nitro, alkoxycarbonyl, carbonyloxy, alkoxy, aminocarbonyB, carbonylamino, dialkylamino, silyl groups or derivatives thereof, and aryl substituted with any of these substituents. Preferably R® may be an isop ropyl, a 1-cyclohexylethhyl, a 2-methylcyclohexyl or a 2-octyl group.

B may be sele-cted to be a single atom spacer. The applicant has found that such a single atom s pacer between A and C generally increases the selectivity- of the tetramerisatior catalyst.

A and/or C ma y be independently oxidised by S, Se, N or O. A and C may preferably be independeratly phosphorus or phosphorus oxidised by S or Se or N or O.

The ligand may also contain multiple (R),A:B-C(R),, units. Not limiting examples of such ligands irclude ligands where the individual units are coupled either vias one or + more of the RR groups or via the linking group B. More specific, but not Nimiting, examples of such ligands may include 1,2-di-(N(P(phenyl),),)-benzene, 1,4-di- (N(P(phenyl),)=)-benzene, N(CH,CH,N(P(phenyl):).)s and 1,4-di- ’ (P(phenyl)N(m-ethyl)P(phenyl),)-benzene.

The ligand mmay be selected from any one or more of a group conmprising (phenyl).PN(m<ethyl)P(phenyl), (phenyl).PN(pentyl)P(p henyl), (phenyl)2PN(phenyl)P(phenyl),, (phenyl),PN(p-methoxyphenyl)P(p henyl), (phenyl),PN(p- ‘butylphenyl)P(phenyl),, (phenyl),PN((CH,);-N-morpholine)P(p henyl),

(phenyl),PN(SSi(CH,);)P(phenyl),, (((phenyl),P).NCH,CH,)N, (ethyl), PN(methyl)P(ethyl),, (ethyl),PN(isopropyl)P(phenyl),, (ethyl)(pheny1)PN(methyl)P(ethyl)(phenyl), (ethyl) (phenyl)PN(issopropyl)P(phenyl)s, ] (phenyl).P(=SSe)N(isopropyl)P(phenyl),, (phenyl),PCH,CH,P*(phenyl),, (o- ethylphenyl)(pheny!)PN(isopropy!)P(phenyl),, (o-methylphenyl ),PN(isopropyl)P(o- . methylphenyl )(phenyl), (phenyl),PN(benzyl)P(phenyl),, (pheny1),PN(1-cyclohexy!- ethyl)P(phenwl), (phenyl),PN[CH,CH,CH.S i(OMe;3)]P(phenyl),, (phenyl):PN(cyclohexyl)P(phenyl),, phenyl),PN(2-methylcyclohexyl)P(phenyl),, (phenyl).PN(allyl)P(phenyl),, (2-naphthyl),PN(methyl)P(2-naphthyl),, (p- biphenyl),PN(methyl)P(p-biphenyl),, (p-methylphenyl),PN(methyl)IP(p-methylphenyl),, (2-thiophenyl ),PN(methyl)P(2-thiophenyl),, (phenyl),PN(methyl)NE(methyl)P(phenyl),, (m-methylphenyl),PN(methyl)P(m-methylphenyl), = (phenyl),PN(iss opropyl)P(phenyl),, and (phenyl), P(=S)N(isopropyl)P(phenyl)..

The transitiom metal may be selected from any one of a group cormnprising chromium, molybdenum, tungsten, titanium, tantalum, vanadium and zirconium, preferably chromium.

The transitiom metal may be derived from a transition metal precursor selected from a simple inorganic or organic salt, a co-ordination or organometallic complex and may be selected from a group comprising chromium trichloride tris-tetrahydrofuran complex, (bexnzenejftricarbonyl chromium, chromium (Ill) octanoaate, chromium (11) acetylacetonoate, chromium hexacarbonyl, and chromium (Ill) 2-ethylhexanoate. The preferred tramsition metal precursors include chromium (Ill) acestylacetonoate and chromium (I11) 2-ethylhexanoate.

The transitiom metal precursor and heteroatomic ligand may have metal/ligand ratios from about 0. 01:100 to 10 000:1, preferably from about 0.1:1 to 10 :1.

The activator may in principle be any compound that generates an active catalyst when combined with the heteroatomic ligand and the transitiom metal precursor.

Mixtures of activators may also be used. Suitable cosmpounds include organoalumireium compounds, organoboron compounds, orgarmic salts, such as methyllithium and methylmagnesium bromide, inorganic acids and salts, such as tetrafluorobor-ic acid etherate, silver tetrafluoroborate, sodium hexxafluoroantimonate and the like.

The activator rmay be selected from alkylaluminoxanes such as methylalusminoxane - (MAO) and ethaylaluminoxane (EAO) as well as modified alkylaluminoxaness such as modified methylaluminoxane (MMAQ). Modified methylaluminoxane (a ccammercial product from .Akzo Nobel) contains modifier groups such as isobutyl or n-octyl groups, in addi tion to methyl groups. The transition metal and the aluminoxane may . be in such proportions relative to each other to provide Al/metal ratios from about 1:1 to 10 000:1, p referably from about 1:1 to 1000:1, and more preferably from 1:1 to 300:1.

The catalyst swstem may also include a trialkylaluminium compound in armounts of between 0.01 t=0 100 mol per mol of aluminoxane.

According to =a further aspect of the invention, there is provided a li gand, as described abowe, for a catalyst system, as described above, for the tetramewrisation of olefins.

The invention also extends to the identification and use of ligands suitable for use in a tetramerisation of olefins process or catalyst system.

EXAMPLES O F PERFORMING THE INVENTION

The invention will now be described with reference to the following non-limiting examples. The= individual components of the examples may conceivably b-e omitted or substituted and, although not necessarily ideal, the invention may concemivably still be performed and these components are not to be taken as essential to thee working of the inventiory.

In the exampless that follow all procedures were carried out under inert ceonditions, using pre-dried reagents. Chemicals were obtained from Sigma-Aldrich or Strem

Chemicals urless stated otherwise. All trialkylaluminium and alusminoxane compounds an.d solutions thereof were obtained from Crompton Gmbh, Akzzo Nobel and Albemarlle Corporation. In all the examples, the molar mmass of methylaluminox<ane (MAO) was taken to be 58.016 g/mol, corresponding to the (CHs- ’ Al-0) unit, in o-rder to calculate the molar quantities of MAO used in the preparation of the catalysts described in the examples below. Similarly the molar mass of ethylaluminoxa: ne (EAO) was taken as 72.042 g/mol, corresponding to the «CH3;CH,-

Al-O) building block, and that of modified methylaluminoxane prepared frorwn a 70:30 mixture of trimethylaluminium and tri-isobutylaluminium as 70.7 g/mol corresponding to the (Meg zisonBug s0-Al-O) unit. Ethylene oligomerisation products were analysed by GC-MS and GC-FID.

The mixed heteroatomic PNP ligands were made by reacting amines and phosphine chtorides R,PCl as described in (a) Ewart et al, J. €hem. Soc. 1964, 1643; (b)

Do ssett, S.J. et al, Chem. Commun., 2001, 8, 699: (cc) Balakrishna, M.S. et al, J.

Organomet. Chem. 1990, 390, 2, 203). The respective phosphine chlorides R,PCI we re prepared as described in literature (Casalnuovo, ALL. ef al, J. Am. Chem. Soc. 1994, 116, 22, 9869; Rajanbabu, T.V. et al, J. Org. Chem. 1997, 62, 17, 6012). The (phaenyl),PN(methyl)N(methyl)P(phenyl), ligand was pre=pared according to Slawin et al. (Slawin, AM.Z et al, J. Chem. Soc., Dalton Frans. 2002, 513). For the (phuenyl),PN(SiMe;)P(phenyl), ligand the preparation raethod of Schmidbaur et al. was used (Schmidbaur, H. et al, J.Organomet. Chem. 1984, 271, 173). The ligands (phwenyl),P(=E)N('propy!)P(phenyl), with E = S, Se were prepared as described in

Balakrishna, M.S. et al, Inorg. Chem. 1993, 32, 5676.

Example 1: Preparation of the (phenyl),PN(isopropyl )P(phenyl), ligand

Example 1a): Preparation of N,N-diisopropylphosphoramide dichloride

Diissopropylamine (70 ml, 0.50 mol) in toluene (80 nl) was added to a solution of PCI; (21.87 ml, 0.25 mol) in toluene (80 ml) at -10 “C. The mixture was stirred for two hours and then allowed to warm &o room temperature. The sol ution was stirred for a further hour after which it was filtered through a pad of celite. The product (35 g, 0.17 mol, 68 %) was obtained after removal of the solvent. *'P {H} NMR: 170 ppm

Example 1b) Preparation of phenyl-magnesium bromside

Magnesium turnings (9.11 g, 0.375 mol) were treated with 4-bromobenzene (7.90 mi, 75 mmol) in THF (100 ml). A vigorous reaction ensued which was cooled in an ice bath. Once the reaction had dissipated, the reaction mixture was heated under reflux for 2 hours yielding the Grignard reagent.

Example 1c) : Preparation of Bis(phenyl) phosphoruas chloride

The Grignard reagent was added to N,N-diisopropylphaosphoramide dichloride (6.64 ml, 36 mmol) in THF (100 ml) at 0 "C. After stirring at rosom temperature overnight the mixture was diluted with cyclohexane (200 ml) and dry HCI! gas was bubbled through the solution for 0.5 hours. After filtration of the precipitate, the solvent was removed to give a mixture of the phosphine chloride and bromid e in an 80% yield. This crude product was not isolated and all was used in the next steep.

Example 1d): Preparation of the (pheny!),PN(isopropavl)P(phenyl), ligand

To a solution of the crude Bis(phenyl) phosphorus chloride (28.8 mmol calculated from crude reaction mixture) in DCM (80 ml) and trietkylamine (15 ml) at 0 "C was added isopropylamine (1.11 ml ,13 mmol). The reactio n was stirred for 30 min after which the ice bath was removed. After stirring for a total of 14 hrs the solution was filtered to remove the triethylammonium salt formed. T he product was isolated after crystallisation in a 90 % yield. *'P {H} NMR: 49.0 ppm «broad singlet).

Example 2: Ethylene tetramerisation reaction using CrCl;(tetrahydrofuran),, (phenyl). PN(methyl)P(phenyl), and MAO

A solution of 29.0 mg of (phenyl),PN(methyl)P(pheny/l), (0.073 mmol) in 5 ml of toluene was added to a solution of 12.4 mg CrCla(tetrahydrofuran); (0.033 mmol) in ml toluene in a Schlenk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred toa 300 ml pressure reactor (autoclave) containing a mixture of toluene (80ml) and MAO (methylaluminoxane, 9.9 mmol) at 80°C. The pressure reactor was charged with ethyl ene after which the reactor temperature was controlled at 85°C, while the ethylene pressure was maintained at barg. Thorough mixing was ensured throughout by rmixing speeds of 1100 RPM’s using a gas entraining stirrer. The reaction was terminated after 60 minutes by discontinuing the ethylene feed to the reactor and coolizng the reactor to below 10°C.

After releasing the excess ethylene from the autoclavee, the liquid contained in the autoclave was quenched with ethanol followed by 1024 hydrochloric acid in water.

Nonane was added as an internal standard for the aralysis of the liquid phase by

GC-FID. A small sample of the organic layer was d ried 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°C and then weighed. The mass of total product was 31.86 g. The product distribution of this example is s ummarised in Table 1.

Example 3: Ethylene tetramerisation reaction using CrCl;(tetrahydrofuran)s, (phenyl),PN(methyl)P(phenyl), and MAO

A solution of 22.4 mg of (ph enyl),PN(methyl)P(phenyl), (0.056 mmol) in 5 mi of toluene was added to a solution of 12.4 mg CrCly(tetrahydrofuran); (0.033 mmol) in 15 mi toluene in a Schienk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred to a 300 ml pressure reactor (autoclave) containing a mixture of toluene (80ml) and MAO (methylaluminoxane, 9.9 mmol) at 80°C. The pressure reactor was charged with ethylene after which the reactor temperature was controlled at 85°C, while the ethylene pressure was maintained at 30 barg. The reaction was terminated after 60 min, and the procedure of Example 2 above was employed. The product mass was 28.76 g. The product distribution of this example is summarised in Table 1.

Example 4: Ethylene tetramerisation reaction using CrCls(tetrahydrofuran)s, (phenyl),PN(methyl)P(phenyl), and MAO

A solution of 26.3 mg of (phenyl),PN(methyl)P(phenyl), (0.066 mmol) in 3 ml of toluene was added to a solution of 12.4 mg CrCl,(tetrahydrofuran); (0.033 mmol) in 17 ml toluene in a Schlenk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred to a 300 ml pressure reactor (autoclave) containing a mixture of toluene (80ml) and MAO (methylaluminoxane, 9.9 mmol) at 60°C. The pressure reactor was charged with ethylene after which the reactor temperature was controlled at 65°C, while the ethylene pressure was maintained at 30 barg. The reaction was terminated after 60 min, and the procedure of Example 2 above was employed. The product mass was 47.23 g. The product distribution of this example is summarised in Table 1.

Example 5: Ethylene tetramer-isation reaction using CrCls(tetrahydrofuran),, (phenyl),PN(pentyl)P(phenyl); and MAO

A solution of 30.0 mg of (phenyl),PN(pentyl)P(phenyl), (0.074 mmol) in 10 ml of toluene was added to a solution of 12.4 mg CrCls(tetrahydrofuran); (0.033 mmol) in ml toluene in a Schlenk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred to a 300 ml pressure reactor (autoclave) containing a mixture of toluene (80ml) and MAO (methylaluminoxane, 10.6 mmol) at 60°C. The pressure reactor wvas charged with ethylene after which the reactor temperature was controlled at 65°C, while the ethylene pressure was maintained at 30 barg. The reaction was termirated after 60 min, and the procedure of Example 2 above was employed. The product mass was 74.84 g. The product distribution of €his example is summarised in Table 1.

Example 6: Ethylene tetramerissation reaction using CrCl;(tetrahydrofuran)s,, (phenyl),PN(benzyl)P(phenyl), mand MAO

A solution of 30.7 mg of (phenwl),PN(benzyl)P(phenyl), (0.065 mmol) in 10 mi of toluene was added to a solution of 12.4 mg CrCla(tetrahydrofuran); (0.033 mmol) in ml toluene in a Schlenk ves sel. The mixture was stirred for 5 min at ambient temperature and was then transferred to a 300 ml pressure reactor (autoclawe) containing a mixture of toluene (80ml) and MAO (methylaluminoxane, 10.6 mmol) at 60°C. The pressure reactor was charged with ethylene after which the reactor temperature was controlled at 65°C, while the ethylene pressure was maintained at 30 barg. The reaction was terminated after 180 min, and the procedure of Example 2 above was employed. The product mass was 22.08 g. The product distribution of this example is summarised in Table -1.

Example 7: Ethylene tetrameris ation reaction using CrCl;(tetrahydrofuran);, (phenyl), PN(phenyl)P(phenyl), and MAO

A solution of 34.9 mg of (phenyl),PN(phenyl)P(phenyl), (0.076 mmol) in 10 mi of toluene was added to a solution of 13.6 mg CrCls(tetrahydrofuran); (0.036 mmol) in 10 ml toluene in a Schlenk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred to a 300 ml pressure reactor (autoclawe) containing a mixture of toluene (80ml) and MAO (methylaluminoxane, 10.6 mmol) at 60°C. The pressure reactor was charged with ethylene after which the reactor temperature was controlled at 65°C, while the ethylene pressure was maintained at 30 barg. The reaction was terminated after 180 min, and the procedure of Example 2 above was employed. The product mass was 48.21 g. The product distribution of this example is summarised in Table 8. , : Example 8: Ethylene tetramerisation reaction using CrCls(tetrahydrofuran)s, (phenyl),PN(p-methoxy-phenyl) P(phenyl), and MAO ‘ A solution of 30.6 mg of (phenyi»2PN(p-methyoxyphenyl)P(phenyl), (0.062 mmol) in 10 ml of toluene was added to a solution of 12.4 mg CrCly(tetrahydrofuran)s (0.033 mmol) in 10 ml toluene in a Schalenk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred to a 300 ml pressure reactor

(autoclave) containing a mixture of toluene (80ml) and MAO (methaylaluminoxane, 10.6 mmol) at: 60°C. The pressure reactor was charged with ethylene after which the reactor tempesrature was controlled at 65°C, while the ethylene pressure was maintained at 30 barg. The reaction was terminated after 60 min, anc the procedure of Example 2 above was employed. The product mass was 7.01 «g. The product distribution of this example is summarised in Table 1.

Example 9: E thylene tetramerisation reaction using CrCl;(tetrahycirofuran);, (phenyl),PN(m-'butylphenyl)P(phenyl), and MAO

A solution of 229.3mg of (phenyl),PN(p-butylpheny!)P(phenyl), (0.062 mmol) in 10 ml of toluene wass added to a solution of 12.4 mg CrCls(tetrahydrofuran®; (0.033 mmol) in 10 ml tolue=ne in a Schlenk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred to a 300 ml pressure reactor (autoclave) containing a mnixture of toluene (80ml) and MAO (methylaluminoxane ,, 10.6 mmol) at 60°C. The pressure reactor was charged with ethylene after whi ch the reactor temperature vwsas controlled at 65°C, while the ethylene pressure wass maintained at barg. The reaction was terminated after 180 min, and the procedur-e of Example 2 above was employed. The product mass was 62.15 g. The product disstribution of this example is susmmarised in Table 1.

Example 10: Ethylene tetramerisation reaction using Cr(2-ethylhe xanoate)s, (phenylt),PN(axllyl)P(phenyl), and MAO

A solution of 27.6 mg of (phenyl),PN(allyl)P(phenyl), (0.066 mmol) in ‘M0 ml of toluene was added toe a solution of 22.8 mg Cr(2-ethylhexanoate); (0.033 rmmal) in 10 ml toluene in a Schlenk vessel. The mixture was stirred for 5 min at ambient temperature &and was then transferred to a 300 mi pressure reacstor (autoclave) containing a rmixture of toluene (80ml) and MAO (methylaluminoxane, 9.9 mmol) at 60°C. The pressure reactor was charged with ethylene after whi ch the reactor temperature was controlled at 65°C, while the ethylene pressure wass maintained at 30 barg. The @eaction was terminated after 30 min, and the procedur«e of Example 2 above was enmiployed. The product mass was 12.68 g. The product disstribution of this ’ example is susmmarised in Table 1.

Example 11: Ethylene tetramerisation reaction using Cr(acetylaces=tonoate);, (phenyl).PN[CCH,);Si(OMe);]P(phenyl), and MAO

A solution of 336.1 mg of (phenyl),PN[(CH,);Si(OMe);]P(phenyl), (0.0866 mmol) in 15 mi of toluene wvas added to a solution of 11.6 mg Cr(acetylacetonoate 7), (0.033 mmol)

in 10 ml toluene in a Schlenk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred to a 300 ml pressure reactor (autoclave) containirmg a mixture of toluene (75ml) and MAO (methylal uminoxane, 9.9 mmol) at 60°C. The pressure reactor was charged with ethylene after which the reactor temperature was controlled at 65°C, while the ethylene pressure was maintained at 30 barg. The reaction was terminated after 30 min, and the procedure of Example 2 above was employed. The product mass was 72.96 g. T he product distribution of this exarmple is summarised in Table 1.

Example 12: Ethylene tetramerisation reaction using Cr{acetylacetonoate)s, (phenyl) ;.PN[(CH,),-N-morpholine]P(phenyl), and MAO

A solutio n of 33.8 mg of (phenyl),PN[(CH.)s-N-morpholine]P (phenyl), (0.066 mmol) in ml of toluene was added to a solution of 11.5 mg Cr(acetylactonate); (0.033 mmol) ira 10 mi toluene in a Schlenk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred to a 300 ml pressure reactor (autoclave) containing a mixture of toluene (80ml) and MAC» (methylaluminoxane, 9.9 mmol) at 60°C. The pressure reactor was charged with ethylene after which the reactor temperature was controlled at 65°C, while the ethylene pressure was maintained at 30 barg. The reaction was terminated after 390 min, and the procedure of Exam ple 2 above was employed. The product mass weas 22.2 g. The product distribution of this example is summarised in Table 1.

Example 13: Ethylene tetramerisation reaction using CrCl(tetrahydrofuran),, (phenyl) 2PN(propyl)P(phenyl), and MAO

A solution of 26.1 mg of (phenyl).PN(‘propyl)P(phenyi), (0.061 mmol) in 10 mi of toluene was added to a solution of 11.6 mg CrCls(tetrahydwrofuran); (0.031 mmol) in 10 ml toluene in a Schlenk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred to a 300 ml pressure reactor (autoclave) containirag a mixture of toluene (80ml) and MAO (methylalu minoxane, 10.6 mmol) at 60°C. The pressure reactor was charged with ethylene after which the reactor temperature was controlled at 65°C, while the ethylene presssure was maintained at barg. The reaction was terminated after 180 min, and the procedure of Example 2 above was employed. The product mass was 56.44 g. The product distribution of this example is summarised in Table 1.

Examples 14: Ethylene tetramerisation reaction using CrCl;(tetrahydrofuran)s, (phenyl) =PN(propyl)P(phenyl), and MAO

A solution of 17.1 mg of (phenyl),PN(propyl)P(phe nyl), (0.04 mmol) in 10 ml of toluene was added to a solution of 7.5 mg CrCly(tetrahydrofuran), (0.02 mmol) in 10 ml toluene in a Schlenk vessel. The mixture was stirred for 5 min at ambient ) temperature and was then transferred to a 300 mel pressure reactor (autoclave) containing a mixture of toluene (80ml) and MAO (mexthylaluminoxane, 4.0 mmol) at ] 40°C. The pressure reactor was charged with ethmylene after which the reactor temperature was maintained at 43°C, while the ethylene pressure was kept at 45 barg. The reaction was terminated after 60 min, aned the procedure of Example 2 above was employed. The product mass was 39.98 g- The product distribution of this example is summarised in Table 1.

Example 15: Ethylene tetramerisation reaction usimg Cr(2-ethylhexanoate),, (phenyl),PN(‘propyl)P(phenyl), and MAO

A solution of 18.8 mg of (phenyl),PN(propyl)P(pheryl), (0.022 mmol} in 10 ml of toluene was added to a solution of 7.6 mg Cr(2-ethylmexanoate)s (0.011 mmol) in 10 ml toluene in a Schlenk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred to a 300 m | pressure reactor (autoclave) containing a mixture of toluene (80 mi) and MAO (mesthylaluminoxane, 3.3 mmol) at 40°C. The pressure reactor was charged with eth ylene after which the reactor temperature was controlled at 45°C, while the ethylere pressure was maintained at 45 barg. The reaction was terminated after 50 min, amd the procedure of Example 2 above was employed. The product mass was 64.71 g_ The product distribution of this example is summarised in Table 1.

Example 16: Ethylene tetramerisation reaction usirg Cr(acetylacetonoate),, (phenyl),PN('propyl)P(phenyl), and MAO

A solution of 28.2 mg of (phenyl),PN(’propyl)P(pherayl), (0.066 mmol) in 10 ml of toluene was added to a solution of 11.5 mg Cr(acetyla.cetonoate); (0.033 mmol) in 10 ml toluene in a Schlenk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred to a 300 m | pressure reactor (autoclave) containing a mixture of toluene (80 ml) and MAO (mesthylaluminoxane, 9.9 mmol) at ’ 40°C. The pressure reactor was charged with eth-ylene after which the reactor temperature was controlled at 45°C, while the ethylere pressure was maintained at ’ 45 barg. The reaction was terminated after 14 min, ard the procedure of Example 2 above was employed. The product mass was 75.80 g. The product distribution of this example is summarised in Table 1.

Example 17: Ethylene tetramerisation reraction using Cr(acetylacetonoate);, (phenyt),PN('propyl)P(phenyl), and EAC>/TMA

A solution of 28.2 mg of (phenyl),PN(/propyl)P(phenyl), (0.066 mmol) in 10 ml of toluene was added to a solution of 11.5 mg Cr(acetylacetonoate); (0.033 mmol) in 10 ml toluene in a Schlenk vessel. The muixture was stirred for 5 min at ambient temperature and was then transferred to a 300 ml pressure reactor (autoclave) containing a mixture of toluene (80 ml), EAQ (ethylaluminoxane, 33 mmol) and TMA (trimethylaluminum, 8.3 mmol) at 40°C. The pressure reactor was charged with ethylene after which the reactor temperature was controlled at 45°C, while the ethylene pressure was maintained at 45 arg. The reaction was terminated after 37 min, and the procedure of Example 2 abo ve was employed. The product mass was 29.03 g. The product distribution of this example is summarised in Table 1.

Example 18: Ethylene tetramerisation reraction using Cr(acetylacetonoate),, (phenyl),PN('propyl)P(phenyl), and MMAO

A solution of 17.1 mg of (phenyl),PN(‘propyl)P(phenyl), (0.04 mmol) in 10 ml of toluene was added to a solution of 7.0 mg Cr(acetylacetonoate); (0.02 mmol) in 10 ml toluene in a Schlenk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred to a 300 ml pressure reactor (autoclave) containing a mixture of toluene (80 ml) and MAO (modified methylaluminoxane, Akzo

Nobel MMAO-3A, 6.0 mmol) at 40°C. The pressure reactor was charged with ethylene after which the reactor temperature was controlled at 45°C, while the ethylene pressure was maintained at 45 brarg. The reaction was terminated after 15 min, and the procedure of Example 2 abo ve was employed. The product mass was 74.11 g. The product distribution of this example is summarised in Table 1.

Example 19: Ethylene tetramerisation reaction using Cr(acetylactonate)s, (pheny!),PN(’propyl)P(phenyl), and supported MAO

A solution of 28.2 mg of (phenyl),PN(lpropyl)P(phenyl), (0.066 mmol) in 10 ml of toluene was added to a solution of 11.5 m g Cr(); (0.033 mmol) in 10 ml toluene in a

Schlenk vessel. The mixture was stirred for 5 min at ambient temperature. 3.9 g : supported MAO (MAO on SiO, Crompton, containing 11.3 mmol MAO) was suspended in 30 mi of toluene and was thesn transferred to a 300 ml pressure reactor ‘ (autoclave) containing a mixture of toluenes (50 ml) and TMA (trimethylaluminum, 3.3 mmol) at 40°C. The catalyst solution was then added to the pressure reactor. The pressure reactor was charged with ethylen e after which the reactor temperature was controlled at 45°C, while the ethylene pressure was maintained at 45 barg. The reaction was terminated after 15 min, and the procedure of Example 2 above was employed. The product mass was 43.61 g. The product distribution of this example is summarizsed in Table 1.

Example 20: Ethylene tetramerisation reac-tion using Cr(acetylacetonoate);, (phenyl),PN(‘propyl)P(phenyl), and MAO

A solution of 18.8 mg of (phenyl),PN(propy-1)P(phenyl), (0.044 mmol) in 6.4 ml of cumene was added to a solution of 7.7 mg Cr(acetylacetonoate); (0.022 mmol) in 8 ml cumene in a Schlenk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred to a 1000 ml pressure reactor (autoclave) containing a mixture of cumene (180 ml) anced MAO (methylaluminoxane, 4.4 mmol, % solution in toluene) at 40°C. The presssure reactor was charged with ethylene after which the reactor temperature was controlled at 45°C, while the ethylene pressure was maintained at 45 barg. The reaction was terminated after 25 min, and the procedure of Example 2 above was empl oyed. The product mass was 118.78 g.

The product distribution of this example is summarised in Table 1.

Example 21: Ethylene tetramerisation reaction using Cr(acetylacetonoate)s, (phenyl),PN(‘propyl)P(phenyl), and MAO

A solution of 11.1 mg of (phenyl),PN(‘propy~I)P(phenyl); (0.026 mmol) in 10 mi of ethylbenzene was added to a solution of 7.0 rng Cr(acetylacetonoate); (0.02 mmol) in 10 ml ethylbenzene in a Schlenk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred to aa 300 ml pressure reactor (autoclave) containing a mixture of ethylbenzene (76 ml) and MAO (methylaluminoxane, 4.0 mmol, 7% solution in toluene) at 40°C. The pressure reactor was charged with ethylene after which the reactor temperature was controlled at 45°C, while the ethylene pressure was maintained at 45 bargy. The reaction was terminated after 10 min, and the procedure of Example 2 above was employed. The product mass was 70.6 g. The product distribution of this exampl € is summarised in Table 1.

Example 22: Ethylene tetramerisation reaction using Cr(acetylacetonoate),, (phenyl),PN(‘propyl)P(phenyl), and MAO

A solution of 5.8 mg of (phenyl),PN(propyl )P(phenyl), (0.014 mmol) in 10 ml of ) cyclohexane was added to a solution of 3.5 ng Cr(acetylacetonoate); (0.01 mmol) in 10 ml cyclohexane in a Schlenk vessel. The rmixture was stirred for 5 min at ambient temperature. This solution and a solution of MAO (methylaluminoxane, 2.0 mmol, 7% solution in toluene) was added via a burette to a 1000 ml pressure reactor

(autoclave) containing cyclohexa ne (170 ml) at 45°C and being pressurised at 40 bar.

After the addition, the ethylene pressure was maintained at 45 barg and the temperature controlled at 45°C. The reaction was terminated after 39 min, and the procedure of Example 2 above vwas employed. The product mass was 307.30 g. The product distribution of this example is summarized in Table 1.

Example 23: Ethylene tetramerisation reaction using Cr(acetylacetonoate), (phenyl),PN(‘propyl)P(phenyl)> and MAO

A solution of 11.6 mg of (pheruyl),PN('propyl)P(phenyl), (0.026 mmol) in 10 ml of cumene was added to a solutior of 7.4 mg Cr(acetylacetonoate); (0.02 mmol) in 10 ml cumene in a Schlenk vessel. The mixture was stirred for 5 min at ambient temperature. This solution and a solution of MAO (methylaluminoxane, 2.8 mmol, 7% solution in toluene) was added via a burette to a 1000 ml pressure reactor (autoclave) containing cumene (180 ml) at 45°C and being pressurised at 40 bar.

After the addition, the ethylerse pressure was maintained at 45 barg and the temperature controlled at 45°C. The reaction was terminated after 75 min, and the procedure of Example 2 above wvas employed. The product mass was 308.83 g. The product distribution of this example is summarised in Table 1.

Example 24: Ethylene tetramerrisation reaction using Cr(acetylacetonoate),, (2- naphthyl),PN(methyl)P(2-naphathyl), and MAO

A solution of 39.6 mg of (2-naphthyl),PN(methyl)P(2-naphthyl), (0.066 mmol) in 15 mi of toluene was added to a solution of 11.5 mg Cr(acetylacetonoate); (0.033 mmol) in ml toluene in a Schlenk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred to a 300 ml! pressure reactor (autoclave) containing a mixture of toluene (765ml) and MAO (methylaluminoxane, 9.9 mmol) at 60°C. The pressure reactor was charged with ethylene after which the reactor temperature was maintained at 65°C, while the ethylene pressure was kept at 30 barg. The reaction was terminated after 30 min, and the procedure of Example 2 above was employed. The product mass was 45.18 g. The product distribution of this example is summarised in Table 1.

Example 25: Ethylene tetrame risation reaction using Cr(acetylacetonoate)s, (p- biphenyl),PN(methyl)P(p-biphenyl), and MAO

A solution of 47.0 mg of (p-biphenyl),PN(methyl)P(p-biphenyl), (0.066 mmol) in 10 ml of toluene was added to a solution of 11.5 mg Cr(acetylacetonoate); (0.033 mmol) in 10 ml toluene in a Schlenk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred to a 300 ml pressure reactor (autoclave) containing a mixture of toluene (80ml) and MAO (methylaluminoxane, 9.9 mmol) at 60°C. The pressure reactor was charged with ethylene after which the reactor temperature was controlled at 65°C, while the ethylene pressure was maintained zat barg. The reaction was terminated after 30 min, and the procedure of Example 2 } above was employed. The product mass was 26.41 g. The product distribution of th is example is summarised in Tab le 1.

Example 26: Ethylene tetranmuerisation reaction using Cr(acetylacetonoate);, (ma- methylphenyl),PN(methyl)P(sm-methylphenyl), and MAO

A solution of 30.1 mg of (me-methylphenyl),PN(methyl)P(m-methylphenyl), (0.0656 mmol) in 15 ml of toluene was added to a solution of 11.5 mg Cr(acetylacetonoate ); (0.033 mmol) in 10 ml toluene in a Schienk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred to a 300 ml pressure reactor (autoclave) containing a mixture of toluene (75ml) and MAO (methylaluminoxane, 9.9 mmol) at 60°C. The pressure» reactor was charged with ethylene after which thme reactor temperature was controlled at 45°C, while the ethylene pressure weas maintained at 65 barg. The reaction was terminated after 30 min, and the procedure of Example 2 above was employed. The product mass was 52.34 g. The product distribution of this example is s ummarised in Table 1.

Example 27: Ethylene tetram erisation reaction using Cr(acetylacetonoate)s, (p— methylphenyl),PN(methyl)P(gp-methylphenyl). and MAO

A solution of 30.1 mg of (p-methylphenyl),PN(methyl)P(p-methylphenyl), (0.06 6 mmol) in 15 ml of toluene was added to a solution of 11.5 mg Cr(acetylacetonoate ); (0.033 mmol) in 10 mi toluene in a Schlenk vessel. The mixture was stirred for 5 min at ambient temperature and was then transferred to a 300 ml pressure reactor (autoclave) containing a mixtur-e of toluene (75mi) and MAO (methylaluminoxane, 9. 9 mmol) at 60°C. The pressures reactor was charged with ethylene after which th e reactor temperature was maint ained at 65°C, while the ethylene pressure was kept aat 45 barg. The reaction was terrminated after 15 min, and the procedure of Example 2 ' above was employed. The product mass was 80.59 g. The product distribution of this example is summarised in Table 1.

Example 28: Ethylene tetram erisation reaction using Cr(acetylacetonoate),, (0~ ethylphenyl)(Ph)PN(‘propyl)PPh, and MAO

Claims (85)

Claims

1. A process for tetramerisation of olefins wherein the product stream of the process contains more than 30% of the tetrameer olefin.

2. A process as claimed in Claim 1 which process includes the step of contacting an olefinic feedstream with a catalyst system containing a transition metal compound and a heteroatomic ligaand.

3. A process as claimed in Claim 1 or Claim 2, wherein the feedstream includes an o-olefin and the product stream imcludes at least 30% of a tetramerised a-olefin monomer.

4. A process as claimed in any one of claims 1 to 3, wherein the olefinic feedstream includes ethylene and the product strezam includes at least 30% 1- octene.

5. A process as claimed in any one of claims 1 to 3, wherein the olefinic feedstream includes ethylene and the product stream includes at least 40% 1- octene.

6. A process as claimed in any one of claims 1 to 3, wherein the olefinic feedstream includes ethylene and the product stream includes at least 50% 1- octene.

7. A process as claimed in any one of claims 1 to 3, wherein the olefinic feedstream includes ethylene and the product stream includes at least 60% 1- octene.

8. A process as claimed in any one of claims 1 to 3, wherein the olefinic feedstream includes ethylene and the product stream includes at least 70% 1- ) octene.

’ 9. A process as claimed in any one of claims 1 to 8, wherein the olefinic feedstream includes ethylene and wherein the (Cs + Cg) : (C4 + Cio ) ratio in the product stream is more than 2.5:1.

10. A process as claimed in any ones of claims 1 to 9, wherein the olefinic feedstream includes ethylene and whe rein the Cs : Cg ratio in the product stream is more than 1.

11. A process as claimed in any one of claims 4 to 10, wherein ethylene is ) contacted with the catalyst system at a pressure of more than 10 barg.

12. A process as claimed in any one of claims 1 to 11, wherein the heteroatomic ligand is described by the following general formula (R)sA-B-C(R)m where A and C are independently selected from a group which comprises phosphorus, arsenic, antimony, oxygen, bismuth, sulphur, selenium, and nitrogen, and B is a linki ng group between A and C, and the R’s are the same or different and each Ris independently selected from any homo or hetero hydrocarbyl group and mn and m for each R is independently determined by the respective valence an-d oxidation state of A and C.

13. A process as claimed in Claim “12, wherein A and/or C are potential electron donors for coordination with the transition metal.

14. A process as claimed in Claim 12 or Claim 13, wherein the heteroatomic ligand is described by the following general formula (RYR»A-B- C(R’)(R*) where A and C are independently selected from a group which comprises phosphorus, arsenic, antimory, bismuth and nitrogen and B is a linking group between A and C, and Re, R? R® and R* are independently selected from hydrocarbyl or hetero hydrocarbyl or substituted hydrocarbyl or substituted hetero hydrocarbyl groups.

15. A process as claimed in Claim 144, wherein the heteroatomic ligand is described by the following general formula (R"}R?)A-B-C(R*)(R*) where A and C are independently selected from a group which comprises phosphorus,

. arsenic, antimony, bismuth and nitrogen and Bis a linking group between A and C, and R, R? R® and R* are independently non-aromatic or aromatic, . including hetero aromatic, groups.

16. A process as claimed in Claim 12, wherein the ligand contains multiples of (R),A-B-C(R)n.

17. A process as claimed in Claim 15, wherein any substituents on one or more of R', R? R® and R* are not electron donating.

18. A process as claimed in any ore of claims 15 to 17, wherein R', R?, R® and R* are independently aromatic, including hetero aromatic, groups and not all the groups R', R? R® and R* haves a substituent on the atom adjacent to the atom bound to A or C.

19. A process as claimed in Claim 17 or Claim 18, wherein any non electron donating substituent is non polar.

20. A process as claimed in any one of claims 12 to 19, whereift B is selected from any one of a group comprising: organic linking groups comprising a hydrocarbyl, substituted” hydrocarbyl, heterohydrocarbyl and a substituted heterohydrocarbyl; inorganic linking groups comprising single atom links; ionic links; and a group cornprising methylene, dimethylmethylene, 1,2-ethane, 1,2-phenylene, 1,2-propare, 1,2-catechol, 1,2-dimethylhydrazine, -B(R%)-, -Si(R%)-, -P(R®)- and -N(R®)- wvhere R® is hydrogen, a hydrocarbyl or substituted hydrocarbyl, a substituted heteroatom or a halogen.

21. A process as claimed in any one of claims 12 to 20, wherein B is selected to be a single atom spacer.

22. A process as claimed in any one of claims 12 to 21, wherein B is selected to be -N(R?)-, wherein R® is hydrogen or selected from the groups consisting of alkyl, substituted alkyl, amyl, substituted aryl, aryloxy, substituted aryloxy, halogen, nitro, alkoxycarbonyl, carbonyloxy, alkoxy, aminocarbonyl, carbonylamino, dialkylamino, silyl gr oups or derivatives thereof, and aryl substituted with any of these substituemts. :

23. A process as claimed in any ome of claims 12 to 22, wherein A and/or C is independently oxidised by S, Se, N or O, where the valence of A and/or B C allows for such oxidation.

24, A process as claimed in any ome of claims 12 to 23, wherein A and C are independently phosphorus or phossphorus oxidised by S or Se or N or O.

25. A process as claimed ira any one of claims 14 to 22 and 24, wherein R', R%, R® and R* are independently selected from a group comprising a benzyl, phenyi, tolyl, xylyl, mesiityl, biphenyl, naphthyl, anthracenyl, methoxy, ethoxy, phenoxy, tolyloxy, dimethylamino, diethylamino, methylethylamino, thiophenyl, pyridyl, thioethyl, thiophenoxy, trimethylsilyl, dimethylhydrazyl, methyl, ethyl, ethenyl, propwl, butyl, propenyl, propynyl, cyclopentyl, cyclohexyl, ferroceny! and tetrahydrofuranyl group.

26. A process as claimed ir Claim 25, wherein R!, R?, R® and R* are independently selected from a group comprising a phenyl, tolyl, biphenyl, naphthyl, thiophenyl and ethyl group.

27. A process as claimed in any one of claims 1 to 22, 24 to 26 wherein the ligand is selected from any one of a group comprising (phenyl),PN(methyl)P(phenyl),, (phenyl),PN(pentyl)P(phenyl),, (phenyl);PN(phenyl)P(phenyl), (phenyl),PN(p-methoxyphenyl)P(phenyl),, (phenyl):,PN(p-"butylphenyl)P(phenyl),, (phenyl)oPN((CH)s-N-~ morpholine)P(phenyl),, (phenyl),PN(Si(CH3)s)P(phenyl),, (((phenyl),P),NCH,CH,)N (ethyl),PN(methyl)P(ethyl),, (ethyl),PN(isopropyl)P(phenyl),, (ethyt)(phenyl)PN(methyl)P(ethyl)(phenyl), (ethyl)(phenyl)PN(isopropyl)P(phenyl),, (phenyl!),P(=Se)N(isopropyl)P(phenyl),, (phenyl),PCH,CH,P(phenyl), (o- ethyiphenyl)(phenyl)PN(isopropy)P(phenyl), (o- methylphenyl).PN(isopropyl)P(o—methylphenyl)(phenyl) (phenyi),PN(benzyl)P(phenyl),, (phenyl),PN(1-cyclohexyl-ethyl)P(phenyt), (pheny!),PN[CH,CH,CH,Si(OMe 3)|P(phenyl),, (phenyl),PN(cyclohexyl)P(phenyi),, phenyl),PN(2- methylcyclohexyl)P(phenyl),, (phenyl),PN(allyl)P(phenyl),, (2- naphthyl),PN(methyl)P(2-naphth yi), (p-biphenyl),PN(methyl)P(p-biphenyl), (p-methylphenyl),PN(methyl)P(p—methylphenyl),, (2- ¢ thiophenyl),PN(methyl)P(2-thioplhenyt),, (phenyl),PN(methyl)N(methyl)P(pohenyl),, (m-methylphenyl),PN(methyl)P(m- - methylphenyt), i (phenyl),PN(isopropyl)P(phenyl),, and (phenyl),P(=S)N(isopropy!)P(phe=nyl),.

28. A process as claimed in any one of the claims 1 to 27, which process includes the step of combining in any order a heteroatomic ligand with a transition metal precursor and an activator.

29, A process as claimed in any one of claims 1 to 28, which process includes the step of adding a pre-formed coordination complex, prepared using the heteroatomic ligand and a transition metal precursor, to a reaction mixture containing an activator.

30. A process as claimed in Claim 28, which includes the step of generating a heteroatomic coordination co-mplex in situ from a transition metal precursor and a heteroatomic ligand.

31. A process as claimed in any one of the claims 2 to 30, wherein the transition metal is selected from any one= of a group comprising chromium, molybdenum, tungsten, titanium, tantalum _ vanadium and zirconium.

32. A process as claimed in any one of the claims 2 to 30, wherein the transition metal is chromium.

33. A process as claimed in any one of claims 28 to 30, wherein the transition metal precursor is selected from a group comprising of an inorganic salt, organic salt, a co-ordination complex and organometallic complex.

34. A process as claimed in Claim 33, wherein the transition metal precursor is selected from any one of a group comprising chromium trichloride tris-tetrahydrofuran complex, (benzene)tricarbonyl chromium, chromium (lll) octanoate, chromium «lll) acetylacetonoate, chromium hexacarbonyl and chromium (lil) 2-ethylhexanoate.

35. A process as claimed in any one of claims 28 to 34, wherein the transition metal is selected from a compplex selected from chromium (lll) acetylacetonoate and chromium (lif) 2-ethy*lhexanoate.

36. A process as claimed in any ones of claims 28 to 35, wherein the transition metal from a transition metal pre«cursor and heteroatomic ligand are combined to provide metalfligand ratios fromm about 0.01:100 to 10 000:1. 40 BN

37. A proccess as claimed in Claim 36, wherein the transition metal precursor anc} heteroatomic ligand are combined to provide metallliggand ratios from about 0.1:1 to 10:1.

38. A process as claimed in any one of claims 28 to 37, wherein the catalyst syste m includes an activator selected from any one of a gmoup consisting of osrganoaluminium compounds, organoboron compounds, org anic salts, such as methyilithium and methylmagnesium bromide, inorganic amcids and salts, suc h as tetrafluoroboric acid etherate, silver tetrafluoroborate and sodium hexaflLioroantimonate.

39. A proc-ess as claimed in any one of claims 28 to 38, wherein the activator is seleected from alkylaluminoxanes.

40. A processs as claimed in Claim 39, wherein the alkylaluminoxane, or mixtures themeof, is selected from a group which consists of methylaluminoxane (MAO), ethylaluminoxane (EAO) and modified alkylaluminoxa_nes (MMAO).

41. A processs as claimed in Claim 39 or Claim 40, wherein the transition metal and the aluminoxane are combined in proportions to provide Al/maetal ratios from abaoeut 1:1 to 10 000:1.

42. A proce=ss as claimed in Claim 41, wherein the transition metal and the aluminoxane are combined in proportions to provide Al/metal ratios fwom about 1:1 to 10800:1.

43. A processs as claimed in Claim 42, wherein the transition metal and the aluminoxane emre combined in proportions to provide Al/metal ratios fwom ’ about 1:1 to 30=0:1. v

44. A processs as claimed in any one of claims 39 to 43, which includes the step of adding to the catalyst system a trialkylaluminium compound in amounts of bet=ween 0.01 to 100 mol per mol of alkylaluminoxane.

45. A process as claimed in any one of claims 2 to 44, which includes the step of mixing the components of the catalyst system at any tempe rature between -20°C and 250°C in the presence of an olefin.

46. A process as claimed in Claim 45, wherein the temperature rarge is between 20°C and 100°C

47. A process as claimed in claims 1 to 46, wherein methylcyclope-ntane and methylene cyclopentane are formed as products and independently make up at least 1% of the product stream of the process.

A8. A tetramerisation catalyst system, which includes a transition metal and a heteroatormic ligand.

49. A catalyst system as claimed in Claim 48, wherein the heteroaatomic ligand is described by the following general fo rmula (R):A-B-C(R), where A and C are independently selected from a group =which comprises phosphorus, arsenic, antimony, oxygen, bismuth, su Iphur, selenium, and nitrogen, and B is a linking group between A and C, ard the R's are the same or different and each R is independently selected frorm any homo or hetero hydrocarbyl group and n and m for each R is indepenciently determined by the respective valence and oxidation state of A and C.

50. A catalyst system as claimed in Claim 49, wherein A and/or C are a potential electron donor for coordination with the transition metal.

51. A catalyst system as claimed in Claim 49 or Claim 50, wherein the heteroatomic ligand is described by the following general formula (R')(R=)A-B- C(R’)(R*) where A and C are independently selected from a group which comprises phosphorus, arsenic, antimony, bismuth and nitrogen and B3 is a linking group between A and C, and R', R%, R® and R* are independently , selected from hydrocarbyl or hetero hydrocarbyl or substituted hydrocarbyl or substituted hetero hydrocarbyl groups.

52. A catalyst system as claimed in Claim 51, wherein the heteroa-tomic ligand is described by the following general formula (R'Y(R*)A-B-C(RZ)(RY) where A and C are independently selected from a group which comprises phosphorus, arsenic, antimony, bismuth and nitrogen and B is a linking group between A and C, and R', R%, R® and R* are independently non-aromatic or aromatic, including hetero aromatic, groups.

53. A catalyst system as claimed in Claim 49, wherein the ligand contains multiples of (R),A-B-C(R)m.

54. A catalyst system as claimed in Claim 52 or Claim 53, wherein any substituents on one or more of R', R?, R® and R* are not electron donating.

55. A catalyst system as claimed in any one of claims 51 to 54, wherein R', R?, R* and R* are independently aromatic, including hetero aromatic, groups and not all the groups RR, R%, R® and R* have a substituent on the atom adjacent the to atom bound to A or C.

56. A catalyst system as claimed in Claim 54 or Claim 55, wherein any non electron donating substituen tis non polar.

57. A catalyst system as claismed in any one of claims 49 to 56, wherein B is selected from any one of a group comprising: organic linking groups comprising a hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl and a substituted heterohydrocarbyl; inorganic linking groups comprising single atom links; ionic links; and a group comprising methylene, dimethyimethylene, 1,2-ethane, 1,2-phenylene, 1,2-propane, 1,2-catechol, 1,2-dimethythydrazine, -B(R°), -Si(R%)-, -P(R°)- and -N (R®)- where R’ is hydrogen, a hydrocarbyl or substituted hydrocarbyl, a substituted heteroatom and a halogen.

58. A catalyst system as claiamed in any one of claims 49 to 57, wherein B is selected to be a single atom spoacer.

59. A catalyst system as clairmned in Claim 58, wherein B is selected to be - ’ N(R®)-, wherein R® is hydrogen or selected from the groups consisting of alkyl, substituted alkyl, aryl, substitute=d aryl, aryloxy, substituted aryloxy, halogen, ) nitro, alkoxycarbonyl, carbonyloxy, alkoxy, aminocarbonyl, carbonylamino, dialkylamino, silyl groups or deri vatives thereof, and aryl substituted with any of these substituents.

60. A catalyst system as claimed in any one of claims 49 to 59, wherein A and/or C is independently oxidised by S, Se, N or O where the valence of A and/or C allows for such oxidat ion.

61. A catalyst system as claimed in any one of claims 49 to 60, wherein A and C are independently phosphorus or phosphorus oxidised by S or Se or N or O.

62. A catalyst system as claimed in any one of claims 51 to 61, wherein R', R%, R® and R* are independently selected from a group comprising a benzyl, phenyl, tolyl, xylyl, messityl, biphenyl, naphthyl, anthracenyl, methoxy, ethoxy, phenoxy, tolyloxy, dirmethylamino, diethylamino, methylethylamino, thiophenyl, pyridyl, thioethyl, thiophenoxy, trimethylsilyl, dimethyihydrazyl, methyl, ethyl, ethenyl, propyl, butyl, propenyl, propynyl, cyclopentyl, cyclohexyl, ferrocenyl and tetra hydrofuranyl group.

63. A catalyst system as claimed in any one of claims 51 to 62, wherein R', R? R® and R* are indepesndently selected from a group comprising a phenyl, tolyl, biphenyl, naphthyl , thiophenyl and ethyl group.

64. A catalyst system as claimed in any one of claims 49 to 59, 61 to 63, wherein the ligand is selected from any one of a group comprising (phenyl),PN(methyl)P(pheny!),, (phenyl),PN(pentyl)P(phenyl),. (phenyl).PN(phenyl)P(phenyl),, (pheny!),PN(p-methoxyphenyl)P(phenyl), (phenyl):,PN(p-"butylpheny!)P(phenyl),, (phenyl),PN((CH,)s-N- morpholine)P(phenyl),, (phenyl),PN(Si(CHa);)P(phenyt),, (((phenyl)2P),NCH,CH2)N, (ethyl)}.PN(methyl)P(ethyt),, (ethyl):PN(isopropyl)P(phenyl)s, (ethyl)(phenyl)PN(methyl)P(ethy!)(phenyl), (ethyl)(phenyl)PN(isopropyl)P(p henyl),, (phenyl),P(=Se)N(isopropyl)P(phenyl),, (phenyl),PCH,CH;P(phenyl);, (o- ethylphenyl)(phenyl)PN(isoprop yl)P(phenyl),. (o- methylphenyl),PN(isopropyl)P(o-methylphenyl)(phenyl), (phenyl),PN(benzyl)P(phenyl),, (phenyl);PN(1-cyclohexyl-ethyl)P(phenyl), ) (phenyl),PN[CH,CH,CH,Si(OMe2;)]P(phenyl),, (phenyl),PN(cyclohexyl)P(phenwl),, phenyl),PN(2- methylcyclohexyl)P(phenyi),, (phenyl),PN(allyl)P(phenyl),, (2- naphthyl),PN(methyl)P(2-naphthyl), (p-biphenyl),PN(methyl)P(p-biphenyl),

(p-methylphenyl),PN(methyl)P(p-methylpheny-1), (2- thiophenyl),PN(methyl)P(2-thiophenyl), (phenyl),PN(methyl)N(methy!)P(phenyl),, (mm-methylphenyl).,PN(methyl)P(m- methylphenyl), , (phenyl),PN(issopropyl)P(phenyl), and (phenyl),P(=S)N(isopropyl)P(phenyl),.

65. A catalyst system as claimed in anys one of the claims 49 to 64, wherein the transition metal is selected from any one of a group comprising chromium, molybdenum, tungsten, titaniu:m, tantalum, vanadium and zirconium.

66. A catalyst system as claimed in any one of the claims 49 to 65, wherein the transition metal is chromium.

67. A catalyst system as claimed in Claim 66, wherein the transition metal is derived from a transition metal precursor seslected from a group comprising of an inorganic salt, organic salt, a co-ordinati on complex and organometallic complex.

68. A catalyst system as claimed in Claim #67, wherein the transition metal precursor is selected from a group comprissing chromium trichloride tris- tetrahydrofuran complex, (benzenejtricarboryl chromium, chromium (lll) octanoate, chromium (ill) acetylacetonoate, chromium hexacarbonyl, and chromium (11) 2-ethylhexanoate.

69. A catalyst system as claimed in any o ne of claims 48 to 68, wherein the transition metal is selected from a complex selected from chromium (iy acetylacetonoate and chromium (li) 2-ethylhex><anoate.

70. A catalyst system as claimed in claims 67 to 68 wherein the transition metal from a transition metal precursor a nd heteroatomic ligand have “ metal/ligand ratios from about 0.01:100 to 10 0=00:1. ’

71. A catalyst system as claimed in Claim 70, wherein the transition metal precursor and heteroatomic ligand are com_bined to provide metal/ligand ratios from about 0.1:1 to 10:1.

72. A catalyst system as claimed in ary one of the claims 48 to 71, which includes an activator.

73. A catalyst system as claimed in Claim 72, wherein the activator is selected from any one of a group consisti ng of arganoaluminium compounds, ) organoboron compounds, organic salts, such as methyllithium and methylmagnesium bromide, inorganic acids and salts, such as tetrafluoroboric acid etherate, silver tetrafluoroborate and sodium hexafluoroantimonate.

74. A catalyst system as claimed in Claim 72, wherein the activator is selected from alkylaluminoxanes.

75. A process as claimed in Claim 7-4, wherein the alkylaluminoxane, or mixtures thereof, is selected from group wshich consists of methylaluminoxane (MAO), ethylaluminoxane (EAO) and mod ified alkylaluminoxanes (MMAO).

76. A catalyst system as claimed in «Claim 74 or Claim 75, wherein the transition metal and the aluminoxane are in such proportions relative to each other to provide Al/metal ratios from about 1:1 to 10 000:1.

77. A catalyst system as claimed in Cl aim 76, wherein the transition metal and the aluminoxane are combined in proportions to provide Al/metal ratios from about 1:1 to 1000:1.

78. A process as claimed in Claim 77, wherein the transition metal and the aluminoxane are combined in proportions to provide Al/metal ratios from about 1:1 to 300:1.

79. A catalyst system as claimed in any one of claims 74 to 78, which includes a trialkylaluminium compound im amounts of between 0.01 to 100 mol per mol of aluminoxane.

80. Use of a tetramerisation catalyst system as claimed in any one of ’ claims 48 to 79 for the tetramerisation of alefins.

81. Use of a tetramerisation catalyst system as claimed in any one of claims 48 to 78 for the tetramerisation of e=thylene.

82. Use of a ligand for a tetramerisation process as claimed in any one of claims 1 to 47.

83. Use of a ligand for a tetramerisation catalyst system as claimed in any , one of claims 48 to 79.

84. An olefin tetramerisation process substantially ass described herein.

85. An olefin tetramerisation catalyst system substantially as described herein.