Patent ID: 7163907

Claim:
A catalyst system for the production of polyolefins comprising: (A) a Group IV B transition metal component represented by one of the two general formulae wherein M is Zr, Hf or Ti and is in its highest formal oxidation state (+4, d 0 complex); (C 5 H 5-y-x R x ) is a cyclopentadienyl ring which is substituted with from zero to five radical R groups, “x” is 0, 1, 2, 3, 4 or 5 denoting the degree of substitution, and each substituent R group is, independently, a radical selected from the group consisting of C 1 –C 20 hydrocarbyl radicals, substituted C 1 –C 20 hydrocarbyl radicals wherein one or more hydrogen atoms are replaced by a halogen atom, C 1 –C 20 hydrocarbyl-substituted metalloid radicals wherein the metalloid is selected from the group consisting of germanium and silicon, and halogen radicals; or (C 5 H 5-y-x R x ) is a cyclopentadienyl ring in which two adjacent R groups are joined forming a C 4 –C 20 ring to give a saturated or unsaturated polycyclic cyclopentadienyl ligand; (JR′ z-l-y ) is a heteroatom ligand in which J is an element with a coordination number of three from Group V-A or an element with a coordination number of two from Group VI-A of the Periodic Table of Elements, each R′ is, independently, a radical selected from the group consisting of C 1 –C 20 hydrocarbyl radicals and substituted C 1 –C 20 hydrocarbyl radicals, wherein one or more hydrogen atoms is replaced by a halogen atom, and “z” is the coordination number of the element J; each Q is independently, hydride, C 1 –C 20 hydrocarbyl radicals, substituted hydrocarbyl radicals wherein one or more hydrogen atoms is replaced by an electron withdrawing group, or C 1 –C 20 hydrocarbyl-substituted metalloid radicals wherein the metalloid is selected from the group consisting of germanium and silicon, provided that Q is not a substituted or unsubstituted cyclopentadienyl ring, or both Q together may be an alkylidene, olefin, acetylene or a cyclometallated hydrocarbyl; “y” is 0 or 1; when “y” is 1, T is a covalent bridging group containing a Group IV-A or V-A element; L is a neutral Lewis base; and “w” is a number from 0 to 3; wherein M′ has the same meaning as M and Q′ has the same meaning as Q; and (B) an activator compound comprising (1) a cation; and (2) a compatible noncoordinating anion.