Patent ID: 8067654

Claim:
A catalyst system for the selective trimerisation or tetramerisation of olefins comprising (a) a source of a Group 3 to 10 transition metal, (b) a ligand having the formula: R 1 R 2 X—Y—XR 3 R 4 wherein X is phosphorus, arsenic or antimony, Y is a bridging group having the formula: Z-(A)-D-R m wherein Z is methylene, 1,2-ethane, 1,2-phenylene, 1,3-propane, 1,2 catechol or nitrogen, A is a linear or cyclic hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl or substituted heterohydrocarbyl linking group wherein the number of atoms directly linking Z to D is 1, 2 or 3, D is N, P, As, O, S or Se, R is hydrogen, alkyl, hydrocarbyl, substituted hydrocarbyl, heteroalkyl, heterohydrocarbyl or substituted heterohydrocarbyl, and m is 1 or 2, R 1 , R 2 , R 3 , and R 4 are the same or different and represent hydrocarbyl or functionalized hydrocarbyl moieties with the proviso that if D is nitrogen, R is not a cyclic ether, and optionally (c) an activator.