('S4')2-=2,2'-(ETHYLENEDITHIO)BIS(THIOPHENOLATE) - TRANSITION-METAL COMPLEXES WITH SULFUR-CONTAINING LIGANDS .64. PROOF OF STRONG S-H ... S BRIDGES IN [RU(SH2)(PPH3)('S4')].THF, THE 1ST H2S COMPLEX CHARACTERIZED BY X-RAY CRYSTALLOGRAPHY

What are the properties of H2S complexes of transition metals? These reactive compounds probably play an important role in many geochemical and biological processes, although they have not been completely characterized. An X-ray structural analysis has now been carried out on the ruthenium complex 1. THF, ('S4')2- = 2,2'-(ethylenedithio)-bis(thiophenolate). Surprisingly, the H2S ligand was found to be stabilized by strong S-H ... S bridges. On exposure to air, 1 is rapidly oxidized to the mu-S2 complex 2 [Eq. (a)].