Polymerization process catalyzed by a bidentate bisphosphine-group VIII metal complex

A process for the polymerization of 1-olefins, comprising:

• (1) preparing a prepolymer-based catalyst by contacting one or more 1-olefins with a polymerization catalyst or catalyst system which includes the components:
• (a) a source of a Group VIII metal;
• (b) a bidentate phosphine ligand having the formula (R1)(R1)P—X—P(R1)(R1), where each R1 is independently a phenyl group or a substituted phenyl group with the proviso that at least one of the R1 groups is a phenyl group having at least one ortho substituent, and X is a bridging group of the structure —[N]x—[P]y—[N]—, where x and y are independently 0 or 1, or —C(R4)2— where each R4 may be the same or different and is hydrogen or a monovalent hydrocarbyl group, a substituted hydrocarbyl group or a hetero-hydrocarbyl group;
• and
• (c) optionally a promotor;
• and
• (2) contacting the prepolymer-based catalyst with one or more 1-olefins.

A process for the polymerization of olefins, consisting essentially of contacting a monomer selected from the group consisting of a hydrocarbon olefin, an olefin having a polar functionality and mixtures thereof under polymerization conditions with a polymerization catalyst or catalyst system which includes:

• (i) a compound of the formula (III)
• [(L)p(L1)qMm(Q)](An)(m-p)/n (III);
• and
• (ii) optionally a promoter,
• wherein M is a Group VIII metal in formal oxidation state m, each L is independently a monoanionic group or ligand, L1 is independently a neutral group or ligand, each A is independently a weakly coordinating or non-coordinating anion with a formal negative charge of n, p may have any value between 0 and m, q is an integer between 0 and 4 and Q is a bidentate phosphine ligand having the formula (R1)(R1)P—X—P(R1)(R1), where each R1 is independently a phenyl group or a substituted phenyl group with the proviso that at least one of the R1 groups is a phenyl group having at least one ortho substituent, and X is a bridging group of the structure —[N]x—[P]y—[N]—, where x and y are independently 0 or 1, or —C(R4)2— where each R4 may be the same or different and is hydrogen or a monovalent hydrocarbyl group, a substituted hydrocarbyl group or a hetero-hydrocarbyl group.