Synthesis, spectroscopic characterization and structural studies of dimethylsulfoxide and dimethylformamide adducts of bis(μ-sulfido)bis[{O,O-dialkyldithiophosphato}oxomolybdenum(V)] complexes. Crystal structures of Mo2O2(Φ-S2)[S2P(OEt)2]2·Me2SO, Mo2O2(Φ-

Dimethylsulfoxide and dimethylformamide adducts of bis(μ-sulfido)bis[{O,O-dialkyldithiophosphato}oxomolybdenum(V)] of the type Mo2O2(Φ-S2)[S2P(OR)2]2·L (R=Me, Et and i-Pr; L=Me2SO and Me2NCHO) were prepared by the dropwise addition of a benzene solution of dimethylsulfoxide or dimethylformamide in excess to a 1:2 benzene–n-hexane solution of bis(μ-sulfido)bis[{O,O-dialkyldithiophosphato}oxomolybdenum(V)]. The compounds, Mo2O2(Φ-S2)[S2P(OR)2]2·L, were characterized by elemental analysis, IR, and 1H and 31P NMR spectroscopy. The crystal structures of Mo2O2(Φ-S2)[S2P(OEt)2]2·Me2SO, Mo2O2(Φ-S2)[S2P{O(i-Pr)}2]2·Me2SO and Mo2O2(Φ-S2)[S2P{O(i-Pr)}2]2·NC5H5 were determined. Mo2O2(Φ-S2)[S2P(OEt)2]2·Me2SO crystallizes in the space group P21/n, with cell parameters a=15.319(3) Å, b=8.750(2) Å, c=20.322(4) Å, β=108.55(3)°, V=2582.5(9) Å−3, Z=4, R=0.0277 and Rw=0.0329. Mo2O2(Φ-S2)[S2P{O(i-Pr)}2]2·Me2SO crystallizes in the space group C2/c, with cell parameters a=29.848(6) Å, b=8.566(2) Å, c=12.328(3) Å, β=110.03(3)°, V=2961.2(10) Å−3, Z=4, R=0.0272 and Rw=0.0299. Mo2O2(Φ-S2)[S2P{O(i-Pr)}2]2·NC5H5 crystallizes in the space group P21/n, with cell parameters a=9.210(2) Å, b=28.859(6) Å, c=12.421(3) Å, β=109.01(3)°, V=3121.5(11) Å−3, Z=4, R=0.0643 and Rw=0.1022. If the Mo–Mo interaction is ignored, the immediate environment about one of the Mo atoms in all three compounds is essentially a distorted octahedral with a very long MoO or MoN bond, while it is square-pyramidal about the other Mo atom. The terminal oxygen atoms are in the syn conformation. The dithiophosphate groups are bidentate in all complexes.