Preparation of addition polymerization catalysts via Lewis acid mitigated metal center oxidation

DETAILED DESCRIPTION All reference to the Periodic Table of the Elements herein shall refer to the Periodic Table of the Elements, published and copyrighted by CRC Press, Inc.
, 1989.
Also, any reference to a Group or Groups shall be to the Group or Groups as reflected in this Periodic Table of the Elements using the IUPAC system for numbering groups.
The recitation "metalloid", as used herein, includes nonmetals such as boron, phosphorus and the like which exhibit semi-metallic characteristics.
Preferably M is titanium in the +4 oxidation state and M* is titanium in the +3 oxidation state.
L preferably is a monovalent anionic stabilizing ligand selected from the group consisting of: 1) covalently bonded hydrocarbyl, silyl, amido, phosphido, alkoxy, aryloxy, sulfido groups and mixtures thereof, said group being further substituted with an amine, phosphine, ether, or thioether containing substituent able to form a coordinate-covalent bond or chelating bond with M, said ligand having up to 50 nonhydrogen atoms, and 2) C.
sub.
3 -40 hydrocarbyl radicals comprising an ethylenic unsaturation able to form an .
eta.
3 bond with M.
The ligand moiety consisting of --Cp--Z--Y--, when present, is a dianionic ligand having the ionic charges residing formally on Cp and Y.
Such ligand causes the resulting complex to possess constrained geometry about the active metal catalyst site resulting in highly active Group 4 metal catalysts.
Constrained geometry complexes are further described in previously mentioned application Ser.
No.
545,402, filed Jul.
3, 1990, (equivalent to EP-A-416,815).
Highly preferred Group 4 metal complexes formed according to the present invention are monocyclopentadienyl metal complexes corresponding to the formula: ##STR1## wherein: M is titanium, L independently each occurrence is a covalently bonded hydrocarbyl group substituted with an amine, phosphine, ether, or thioether containing substituent able to form a coordinate-covalent bond or chelating bond with M, said ligand having up to 50 nonhydrogen atoms, or a C