Model compounds for the active sites of oxo-transfer molybdoenzymes. Synthesis, structural characterization, and electrochemical properties of [NH 4 ] 2 [MoO 2 {O 2 CC(S)Ph 2 } 2 ]

[NH4]2[MoO2{O2CC(S)Ph2}2]middot;2H2O has been prepared and its crystal structure solved, providing the first example of a co-ordinatively saturated molybdenum complex which reacts readily and reversibly with organophosphines at room temperature in water or methanol; its variable-temperature 13C{1H} NMR spectra and electrochemical properties are presented.