Structural and functional analogue of the active site of polysulfide reductase from Wolinella succinogenes

Synthesis of PPh4]2Mo(SPh)2(S2C2(CN)2)2] (2) from PPh4]2MoO(S2C2(CN)2)2] (1) has been achieved to mimic the postulated Mo(S)6] core of polysulfide reductase with two thiolates and two bis(ene-dithiolate) ligands. Compound 2 reacts with polysulfide to yield H2S, modeling the function of polysulfide reductase. The facile conversion of 2 back to 1 in moist solvent suggests that the interconversion of the MoIV = O] and MoIV - X] (X = O-Ser, S-Cys, Se-Cys) moieties might occur in the DMSO reductase class of enzymes under appropriate hydrophobic/hydrophilic conditions.