The versatile chemistry of metallocene polymerisation catalysts: new developments in half-sandwich complexes and catalyst heterogenisation

Metallocene complexes of Group 4 metals are playing an increasingly important role in olefin polymerisation catalysis. This contribution surveys several aspects of the chemistry of metallocene catalysts that are being pursued in our laboratory at present, namely the application of half-sandwich complexes as catalysts for high-molecular weight elastomeric polypropene, unusual C–H activation reactions of zirconium half-sandwich complexes, the development of 14-electron borole complexes as neutral analogues of cationic [Cp 2 ZrR] + catalysts, and the heterogenisation of MAO-free zirconocene catalysts on borate-functionalised silica.