Liquid-phase metal-centred autoxidation of styrene catalysed by rhodium species
Abstract
During the autoxidation of styrene, catalysed by [{RhCl(C2H4)2}2] at 110 °C in the presence of radical inhibitor, acetophenone and benzaldehyde arise by a path avoiding both radical chains and a Wacker cycle. Only about half of the oxygen and styrene consumed appear as measured products, and the nature of the side-reactions is unknown. The various activities of several rhodium(I) complexes suggest that co-ordination of both the styrene and oxygen to the metal is essential for reaction, and the co-ordination of each of these ligands to rhodium has been observed under conditions approaching those of reaction. The initial rate of acetophenone formation accords with the expression: Rate =