Abstract: The invention relates to a polymerization catalyst system comprising a catalytic complex formed by activating a transition metal compound which comprises a metal selected from group 3 through 10 of the periodic table, preferably from group 4, 5, or 6 of the periodic table, and a group 13, 15, or 16 heterocyclic fused cyclopentadienide ligand. In one embodiment the inventive transition metal compound is represented by the [L]mM[A]n(S)o wherein M is a transition metal selected from groups 3 through 10 of the periodic table, and at least one of L is group 13, 15, or 16 heterocyclic fused cyclopentadienide ligand. Also disclosed is a polymerization process utilizing the catalyst systems of the invention. Ethylene polymerizations or copolymerizations with dimethyl (&eegr;5-pentamethylcyclopentadienyl)(1-azaindenyl) zirconium and bis(5-methyl-cyclopenta[b]thiophene) zirconium dichloride, activated by tris(pentafluorophenyl) boron and methylalumoxane, respectively, are illustrated.

Abstract: This invention relates to single site catalyst systems comprising activated bimetallocyclic transition metal compounds, and the use of these catalyst systems for the polymerization of ethylenically and acetylenically unsaturated monomers. The bimetallocyclic compounds comprise two metal atoms, selected from the group consisting of Group 4 or Group 5 metal atoms, connected through two covalent bridging links so as to form a cyclic compound having delocalized bonding in the cyclic structure. The exemplary bimetallocyclic compound bis-M-(trimethylsilyl-methylidyne) tetrakis-(trimethylsilylmethyl) ditantalum activated with alumoxane and borate compounds is shown to be useful for preparing ethylene polymers having M.sub.n of at least 267,000 and MWD of about 2.3.

Abstract: A polymerization process for olefinically or acetylenically unsaturated monomers is disclosed. The process comprises contacting the one or more of the monomers with a suitable ionic catalyst system in the presence of a long-chain, linear alkyl ligand-containing organo aluminum compound. Preferred ionic catalysts are derived from 1) bridged hafnium compounds, 2) silicon bridged monocyclopentadienyl titanium compounds and 3) unbridged, bulky Group 15 containing, bulky monocyclopentadienyl titanium compounds, and a non-coordinating anion precursor compound. A class of preferred anion precursors consists of hydrated salts comprising a Group 1 or 2 cation and a non-coordinating anion. Using the preferred ionic catalysts high temperature processes, e.g., at or above 90.degree. C. can be conducted to prepare polyolefins, particularly ethylene copolymers, of both high molecular weight and high comonomer content.

Abstract: A polymerization process for olefinically or acetylenically unsaturated monomers is disclosed. The process comprises contacting the one or more of the monomers with a suitable ionic catalyst system in the presence of a long-chain, linear alkyl ligand-containing organo aluminum compound. Preferred ionic catalysts are derived from 1) bridged hafnium compounds, 2) silicon bridged monocyclopentadienyl titanium compounds and 3) unbridged, bulky Group 15 containing, bulky monocyclopentadienyl titanium compounds, and a non-coordinating anion precursor compound. A class of preferred anion precursors consists of hydrated salts comprising a Group 1 or 2 cation and a non-coordinating anion. Using the preferred ionic catalysts high temperature processes, e.g., at or above 90.degree. C. can be conducted to prepare polyolefins, particularly ethylene copolymers, of both high molecular weight and high comonomer content.