TRIANGULAR THIOCOMPLEXES OF MOLYBDENUM - REACTIONS WITH HALOGENS, HYDROHALOGEN ACIDS AND PHOSPHINES

The triangular (NH4)2Mo3S13·2H2O complex interacts with Cl2 and Br2 in CH3CN and with concentrated hydrohalogen acids HX (X = Cl, Br and I) retaining its Mo3(μ3-S)(μ-S2)34+ cluster fragment to produce the Mo3(μ3-S)(μ2-S2)3X62- complexes in high yields. IR and Raman spectra of the Mo3S7X62- complexes have been studied. Salts of Mo3S7X62- (X = Cl, Br) containing 92Mo, 100Mo and 34S isotopes and compounds with μ2-(32S-34S) ligands have been also synthesized. For Mo3S7Cl62-, an analysis of the normal vibrations has been performed. The Mo3S7X62- complexes (X = Cl, Br) interact with phosphines (PPh3 and dppe). The reactions proceed with elimination of the μ2-S2 sulfurs to form sulfides of the phosphines and the phosphine complexes Mo3S4X4·3PPh3 and Mo3S4X4·3dppe containing a Mo3S44+ cluster fragment. It has been shown, for the reaction of Mo3(μ3-34S)(μ2-32Se-34Sa)3Cl62- with PPh3, that it is the equatorial μ2-S2 sulfurs that are predominantly eliminated. © 1990.