New dithiolate-bridged rhodium complexes

Abstract

Addition of a dithiol ligand HS(CH₂)_nSH (n= 2–4) to [{Rh(µ-OMe)(cod)}₂](cod = cycloocta-1,5-diene) afforded dithiolate-bridged complexes [{Rh₂[µ-S(CH₂)_nS](cod)₂}_x](x= 1 or 2). These diene complexes react with carbon monoxide to give the binuclear tetracarbonyl complexes [Rh₂{µ-S(CH₂)_nS}(CO)₄]. The crystal structures of [Rh₂{µ-S(CH₂)_nS}(cod)₂](n= 2 or 3) have been determined by X-ray diffraction methods. A study of the electronic structure of the complexes by analysis of the topology of the charge density shows that in spite of a zero formal bond order between the rhodium atoms a direct metal–metal interaction may be characterized.