The reactions of sulphur dioxide with the coordinatively unsaturated complexes [MCl(C₆H₄Me-4)(CO)(PPH₃)₂] (M = Ru, Os), and the role of the adduct [OsCl(C₆H₄Me-4)(CO)(PPh₃)₂(SO₂)]

Abstract

The 16-electron p-tolyl complexes [MCl(C6H4Me-4)(CO)(PPh3)2] (M = Os (1a), Ru (1b)) react with liquid sulphur dioxide, SO2, to give the adduct [OsCl(C6H4Me-4)(CO)(PPh3)2(SO2)] (2a) and the S-sulphinate complex [RuCl2{S(O)2C6H4Me-4)}(CO)(PPh3)2] (3b) respectively. The adduct 2a slowly undergoes conversion in solution into the S-sulphinate [OsCl{S(O)2C6H4Me-4)}(CO)(PPh3)2] (3a), a process which is retarded by high concentrations of SO2. The S-sulphinate complexes 3 react with carbon monoxide to give the O-sulphinates [MCl{OS(O)C6H4Me-4)}(CO)2(PPh3)2] (M = Os (5a), Ru (5b)). It is suggested that the formation of 2a represents a diversion rather than an intermediate in the insertion process leading to 3a. Show more