Three new Mo(V) dithiolene compounds have been synthesized by addition of alkynes ((Me3Si)(2)C-2 (TMSA), (Me-3- Si)(2)C-4, and (Ph)(2)C-4 to MoO2S22- in a MeOH/NH3 mixture: [MO2(O)(2)(mu-S)(2)(eta(2)-S-2)(eta(2)-S2C2H2)](2-) 1, [Mo-2(O)(X)(mu-S)(2) (eta(2)-S-2) (eta(2)-S2C2Ph(C2Ph))](2-) 2 (X = O or S), and [Mo-2(O)(2)(mu-S)(2)(eta(2)-S-2) (eta(2)-S2C2H(C2H))](2-) 3. The structure of 1 as determined by single-crystal X-ray diffraction study (space group Pbca, a = 13.3148(l) Angstrom, b = 15.7467(4) Angstrom, c = 28.4108(7) Angstrom, V = 5956.7(2) Angstrom(3)) is discussed. 2 and 3 have been identified by ESMS (electrospray mass spectrometry), H-1 NMR, C-13 NMR, and infrared spectroscopies. This investigation completes our previous study devoted to the addition of DPA (C2Ph2) to MoO2S22- which led to [Mo-2(O)(X)(mu-S)(2)(eta(2)-S-2) (eta(2)-S2C2Ph2)](2-) 4 (X = O or S). A reaction scheme is proposed to explain the formation of the different species present in solution. The reactivity of the remaining nucleophilic site of these complexes (eta(2)-S-2) toward dicarbomethoxyacetylene (DMA) is also discussed.