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 importa nt role in olefin polymerisation catalysis. This contribution surveys sever al aspects of the chemistry of metallocene catalysts that are being pursued in our laboratory at present, namely the application of half-sandwich comp lexes as catalysts for high-molecular weight elastomeric polypropene, unusu al C-H activation reactions of zirconium half-sandwich complexes, the devel opment of 14-electron borole complexes as neutral analogues of cationic [Cp 2ZrR](+) catalysts, and the heterogenisation of MAO-free zirconocene cataly sts on borate-functionalised silica. (C) 1999 Elsevier Science B.V. All rig hts reserved.