New norbornene-based zirconocenes as self- immobilising precatalysts for ethylene polymerisation

One of the most original solutions to the problem of the industrial use of metallocenes is the development of auto-immobilizing catalysts, i.e. catalysts that contain an unsaturated bond that can be used as a comonomer in a prepolymerization step. In the framework of this kind of research, we report here the synthesis, characterization, immobilization and activity in ethylene polymerization of some new norbornene-bridged ansa-metallocenes. The obtained results show not only that these new immobilized catalysts are active in ethylene polymerization, but also that they are effectively incorporated into the polymeric chain.