Ethylene Polymerization on Chromocene Supported on Gamma-Al2o3 - an Ft-Ir Investigation

Interaction of chromocene (from the gaseous phase) with the isolated surface hydroxyl groups of γ-Al2O3 generates a quantitative hydrolysis reaction which leads to the formation of the coordinatively unsaturated Al3+CrCp surface species (A). Anchored mononuclear species A can react further with excess chromocene to give the polynuclear Al3+CrCp⋯CpCrCp species (B). Species A provide active sites for ethylene polymerization, in which chain initiation probably involves the formation of a metallocyclic structure.