Reactivity of mer-hydrido(2-mercaptobenzoyl)tris(trimethylphosphine)cobalt(iii) complex

Abstract

The reactivity of mer-hydrido(2-mercaptobenzoyl)tris(trimethylphosphine)cobalt(III) complex 1 was intensively studied. A series of sulfur-coordinated organocobalt complexes (2–8) were obtained through the reactions of 1 with RX (RX = HCl, C₂H₅Br and CH₃I), 2-(diphenylphosphanyl)phenol, 2-(diphenylphosphino)benzenethiol, and CO. The reaction of complex 1 with ethynyltrimethylsilane under 1 bar of CO afforded a penta-coordinate cobalt(I) complex 11via insertion reaction of CC bond of ethynyltrimethylsilane into Co–H bond and subsequent C,C-coupling reaction (reductive elimination). The formation mechanism of 11 was proposed and partly-experimentally verified. As an intermediate, the tetra-coordinate cobalt(I) complex 13 was isolated through the reaction of complex 1 with ethynyltrimethylsilane in the absence of CO. The crystal structures of complexes 2–4, 8 and 11 were determined by X-ray diffraction.