Patent ID: 6927264

Claim:
A metal complex corresponding to the formula: where M is titanium, zirconium or hafnium in the +2, +3 or +4 formal oxidation state; R 1 independently each occurrence is hydrogen, hydrocarbyl, trihydrocarbylsilyl, trihydrocarbylsilylhydrocarbyl, germyl, halide, hydrocarbyloxy, hydrocarbylsiloxy, hydrocarbylsilylamino, di(hydrocarbyl)amino, hydrocarbyleneamino, di(hydrocarbyl)phosphino, hydrocarbylene-phosphino, hydrocarbylsulfido, halo-substituted hydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl, silyl-substituted hydrocarbyl, hydrocarbylsiloxy-substituted hydrocarbyl, hydrocarbylsilylamino-substituted hydrocarbyl, di(hydrocarbyl)amino-substituted hydrocarbyl, hydrocarbyleneamino-substituted hydrocarbyl, di(hydrocarbyl)phosphino-substituted hydrocarbyl, hydrocarbylenephosphino-substituted hydrocarbyl, or hydrocarbylsulfido-substituted hydrocarbyl, said R 1 group having up to 40 atoms not counting hydrogen atoms, and optionally two or more of the foregoing adjacent R 1 groups may together form a divalent derivative thereby forming a saturated or unsaturated fused ring; R 4 is hydrocarbyl, silyl, germyl, or halohydrocarbyl or up to 10 atoms other than hydrogen; Z is a divalent moiety lacking in delocalized π-electrons, or such a moiety comprising one σ-bond and a neutral two electron pair able to form a coordinate-covalent bond to M, said Z comprising boron, or a member of Group 14 of the Periodic Table of the Elements, and also comprising nitrogen, phosphorus, sulfur or oxygen; X is a monovalent anionic ligand group having up to 60 atoms exclusive of the class of ligands that are cyclic ligand groups bound to M through delocalized π-electrons; L independently each occurrence is a neutral ligating compound having up to 20 atoms; X′ is a divalent anionic ligand group having up to 60 atoms; x is 0, 1, 2, or 3; t is a number from 0 to 2, and x′ is 0 or 1.