Syntheses and reactivities of hydrosulfido- or sulfido-bridged heterobimetallic complexes containing Group 6 and Group 9 metals

Abstract

Reactions of [Cp2M(SH)2] (M = Mo 1, W 2) with one equiv of [IrH2(PPh3)2(Me2CO)2][PF6] in acetone at room temperature under 1 atm of H2 afforded the hydrosulfido–hydrido complexes [Cp2M(μ-SH)2IrH2(PPh3)2][PF6] (M = Mo 4, W 5), whereas those of 1 and 2 with [RhH2(PPh3)2(Me2CO)(EtOH)][PF6] 6 resulted in the formation of [Cp2Mo(μ-SH)2Rh(PPh3)2][PF6] 7 and [Cp2W(μ-S)2Rh(PPh3)2][PF6] 8. X-Ray analyses have been undertaken to clarify the detailed structure of [Cp2Mo(μ-SH)2IrH2(PPh3)2][BPh4] derived from 4 along with 7 and 8. Bimetallic complexes 4, 5, 7, and 8 catalysed the hydrogenation of alkynes such as 1-octyne and tert-butyl propiolate at room temperature under 1 atm of H2, yielding 1-octene and tert-butyl acrylate as the major products, respectively. In both reactions, the Mo–Rh complex 7 showed the highest catalytic activity, although even the reactions using 7 are much slower than those catalyzed by the mononuclear Rh complex 6.