Syntheses and characterization of ammonium and tetraalkylammonium thiomolybdates and thiotungstates

Improved methods for the preparation of [NH4]2[MO2S2] and [NH4]2[MS4] are summarized and new syntheses of [NH4]2[MOS3] are reported (M = Mo, W). The facile conversion of the [NH4]+ salts to [Et4N]+ salts via reaction with aqueous [Et4N]OH is also described. Infrared and electronic spectral data for the thiometallates are summarized as an aid to future characterization.