CATALYSTS

摘要

A procatalyst complex for the polymerisation of olefins comprising a group III element or a group 3 to 8 transition metal n-bonded by an open n<5>-ligand at least two heteroatoms in the five atom n<5> chain and having an unsaturated ring fused to the first and second atoms of the n<5> chain and a further unsaturated ring fused to the fourth and fifth atoms of the n<5> chain, i.e. (IV) where (a) is an optionally substituted 5 to 12 membered ring; each X independently is C, N, P, B or Si, at least two X's being heteroatoms; a is 0 or 1; R is a C1-16 hydrocarbyl, a tri C1-8 hydrocarbylsilyl or a tri C1-8 hydrocarbylsiloxy group or a group RR where R is a 1 to 4 atom bridge and R is a group capable of o-bonding or n-bonding a transition metal; q is 1, 2 or 3; M is a group III element or a group 3 to 8 transition metal; L is a n-ligand; r is zero, 1 or 2; Z is a o-ligand; and s is zero or a positive integer having a value of up to 3.