Activation of CS2 and COS at a Rhodium(I) Germyl Complex: Generation of CS and Carbido Complexes

Abstract

Treatment of the germyl complex [Rh(GePh3)(PEt3)3] (1) with CS2 afforded the rhodium thiocarbonyl complex trans‐[Rh(SGePh3)(CS)(PEt3)2] (2) by phosphine dissociation and C–S bond activation. The analogous reaction with COS gave the structurally related carbonyl complex trans‐[Rh(SGePh3)(CO)(PEt3)2] (3). Low‐temperature NMR measurements revealed initial formation of the intermediates mer‐[Rh(GePh3)(η2‐CS2)(PEt3)3] (4) and mer‐[Rh(GePh3)(η2‐COS)(PEt3)3] (5). Reactions of 2 towards CO and HCl led to the replacement of the thiocarbonyl or germylthiolato ligand yielding complex 3 and trans‐[Rh(Cl)(CS)(PEt3)2] (6), respectively. The germylthiolato complex trans‐[Rh(SGePh3)(CS)(PEt3)2] (2) reacted with the boryl complex [Rh(Bpin)(PEt3)3] (7; pin = pinacolato) to afford the rhodium µ‐carbido complex trans,trans‐[{Rh(SBpin)(PEt3)2}(µ‐C){Rh(SGePh3)(PEt3)2}] (8). Complex 8 is not stable in solution and rearranges to form the symmetrical µ‐carbido complexes trans,trans‐[Rh2(µ‐C)(SGePh3)2(PEt3)4] (9) and trans,trans‐[Rh2(µ‐C)(SBpin)2(PEt3)4] (10). The molecular structures of 2 and 9 were determined by X‐ray crystallography.