The coordination chemistry of small sulfur-containing molecules: a personal perspective.

The sulfur oxides SO, SO₂ and SO₃, and thioformaldehyde H₂C=S and its oxides H₂C=SO and H₂C=SO₂ form stable coordination compounds with a range of transition metals. The complexes have a rich chemistry which differs markedly from that of the free ligands. Typical reactions involve electrophilic additions, nucleophilic additions and cycloadditions. The complexes can be used as synthons to incorporate these small molecules as building blocks into larger structures.