Patent ID: 7569646

Claim:
A compound having the general formula: wherein M is Zr, Hf or Ti; (C 5 H 5-x R x ) is a cyclopentadienyl ring which is substituted with from zero to five substituent groups R, x is 0, 1, 2, 3, 4 or 5 denoting the degree of substitution, and each substituent group R 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 is replaced by a halogen atom, C 1 -C 20 hydrocarbyl-substituted metalloid radicals wherein the metalloid is selected from the group IV A of the Periodic Table of Elements, and halogen radicals, or (C 5 H 5-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-1 ) is a heteroatom ligand in which J is an element with a coordination number of three from Group V-A of the Periodic Table of Elements, each R′ is, independently, a radical selected from a group consisting of C 1 -C 20 hydrocarbyl radicals, substituted C 1 -C 20 hydrocarbyl radicals where one or more hydrogen atoms is replaced by a halogen radical, and z is the coordination number of the element J; each Q is, independently, selected from the group consisting of halogen, hydride or C 1 -C 20 hydrocarbyl, provided that Q is different from (C 5 H 5-x R x ); L is a neutral Lewis base where “w” is a number greater than 0 and up to 3; M′ has the same meaning as M; and Q′ has the same meaning as Q.