Abstract: A process for forming tactic polymers employing at least one olefin polymerization catalyst comprising a non-racemic mixture of the R- and S-enantiomers of a metal complex containing at least one asymmetrically substituted (chiral) carbon atom, and a chain shuttling agent, a polar aprotic organic compound, or both a chain shuttling agent and a polar aprotic organic compound.

Abstract: A process for forming a high molecular weight, multi-block copolymer comprising two or more chemically distinguishable segments or blocks, the process comprising polymerizing one or more olefin monomers in the presence of a chain shuttling agent and a catalyst composition comprising two or more olefin polymerization catalysts capable of preparing polymers having differing chemical or physical properties under equivalent polymerization conditions, or a catalyst composition comprising at least one olefin polymerization catalyst containing multiple active catalyst sites capable of preparing polymers having differing chemical or physical properties

Abstract: Hafnium complexes of heterocyclic organic imidazol-2-yl ligands containing internal orthometallation and their use as components of olefin polymerization catalyst compositions, especially supported catalyst compositions, are disclosed.

Abstract: Hafnium complexes of carbazolyl substituted imidazol ligands and their use as components of olefin polymerization catalyst compositions are disclosed.

Abstract: Hafnium complexes of heterocyclic organic ligands containing internal orthometallation and their use as components of olefin polymerization catalysts, especially for gas-phase olefin polymerizations, are disclosed.

Abstract: Hafnium complexes of heterocyclic organic ligands having improved solubility in aliphatic hydrocarbon solvents and their use as components of olefin polymerization catalysts as well as novel syntheses of component parts thereof are disclosed.

Abstract: Group 4 metal complexes comprising a polyvalent, heteroaryl donor ligand and their use as components of olefin polymerization catalysts, especially suited for preparing propylene/ethylene copolymer products having high isotacticity and low molecular weight, are disclosed.

Abstract: A process for polymerization of addition polymerizable monomers with a catalyst composition comprising a Group 4 or 5 metal bis(silane)amido complex corresponding to the formula: where the various substituents are as defined in claim 1.

Abstract: A process for polymerization of addition polymerizable monomers with a catalyst composition comprising a Group 4 or 5 metal bis(silane)amido complex corresponding to the formula: 1