ATRP of Methacrylates Catalysed by Homo-and Heterobimetallic Ruthenium Complexes

摘要

The catalytic activity of a series of ruthenium-based homo_and heterobimetallic complexes was determined by investigating the atom transfer radical polymerisation of methyl methacrylate. The complexes under investigation were [(arene)Ru(μ-Cl)_3RuCl(C_2H_4)-(L)] (L = PCy_3 or a N-heterocyclic carbene ligand), [(p-cymene)-Ru(μ- Cl)_3RuCl(=C=CHR)(PCy_3)] (R = Ph or t-Bu), and [RuCl_2- (p-cymene){PCy_2(CH_2)_2(η~5-C_5H_4)TiX_2(η~5-C_5H_5)}] (X = Cl, F, and OBz). The catalytic activity of a variety of related [(p_cymene)-ClRu(μ-Cl)_2Ru(O^N)(=CHPh)] complexes (O^N is a Schiff base ligand) is also reported. The results clearly demonstrate that the ligands strongly affect the ability of the resulting ruthenium complexes to favour the occurrence of a well-behaved ATRP.