Preparation of monocyclopentadienyl metal complexes by nucleophilic substitution of bis(cyclopentadienyl) metal complexes

摘要

Bridged monocyclopentadienyl derivatives of a Group 4 metal are prepared by contacting a corresponding bis(cyclopentadienyl) metal complex with an alkali metal derivative or alkaline earth metal derivative of a hydrocarbyl ligand R, which is optionally substituted with one or more amino, phosphino, ether, thioether, or silyl groups. The bis(cyclopentadienyl) Group 4 metal complexes can be prepared by contacting a compound corresponding to one of the formulas (Cp).sub.3 MQ. sub.n X.sub.t, (Cp).sub.2 MQ.sub.n X.sub.t+1, or CpMQ.sub.n X.sub.t+2 and a dianionic salt compound corresponding to the formula: (L.sup.+x).sub.y (Cp*-Z-Y).sup.-2 or ((LX').sup.+x).sub.y (Cp*-Z-Y).sup.-2. An addition polymerization catalyst comprising a bis(cyclopentadienyl) Group 4 metal complex and an activating cocatalyst, and an addition polymerization process using such a catalyst.