Process for preparing addition polymerization catalysts via metal center oxidation

Claim 1

A process for the preparation of a catalyst useful for addition polymerizations corresponding to the formula: L ℓ MX n ⁺ A⁻, wherein: L independently each occurrence is an anionic or nonanionic ligand or ligand system; M is a metal of group 4-8 of the Periodic Table also having an oxidation state, M*, one less than the state of the metal in the catalyst; X independently each occurrence is hydride; halide; or a group selected from alkyl, alkenyl, silyl, germyl, aryl, and combinations thereof having up to 20 carbon, silicon or germanium atoms, and oxygen, halogen nitrogen, phosphorus and/or sulfur containing derivatives thereof; ℓ is an integer greater than or equal to 1; n is an integer greater than or equal to 1, and the sum of ℓ and n together is one less than the valence of M; and A⁻ is a monovalent, compatible, noncoordinating anion, the steps of the process comprising contacting under conditions to form the catalyst a reduced metal derivative corresponding to the formula: L ℓ M*X n , wherein L, ℓ, n, X, and M* are as previously defined with an oxidizing agent capable of oxidizing M* to form M and which in reduced form is noninterfering with the resulting catalyst, said oxidizing agent comprising a cationic oxidizer and a compatible noncoordinating anion, A⁻.