Reaction of chlorotrisulfidomolybdate [PPh 4 ][MoClS 3 ] (1) with one equivalent of tridentate ligand PyCH 2 NHC 2 H 4 SNa (PyNSNa) in THF generated both a mononuclear and a dinuclear complexes, [PPh 4 ][(PyNS)MoO(η 2 -S 2 ) 2 ] (2) and [PPh 4 ][(PyNS)Mo(O)(μ-S) 2 Mo(S)(η 2 -S 2 )]·0.5MeCN (3·0.5MeCN). These two complexes were separated mechanically and fully characterized using IR, UV/Vis spectra, 1 H NMR spectra and X-ray single crystal diffraction analysis. In both complexes, one terminal sulfido ligand was substituted by one oxo group. In complex 3, two types of intermolecular hydrogen bonding in its solid state led to a 1-D structure in which each unit was a dimmer formed via hydrogen bonding.