The methanothermal reactions of M(CO)(6)(M=Mo, W) with Na2S2 gave a series of homonuclear clusters [{M(CO)(4)}(n)(MS(4))](2-) (M=Mo, W; n=1, 2), i.e. (Ph(4)P)(2)[(CO)(4)Mo(MoS4)] (I), (Ph(4)P)(2)[(CO)(4)W(WS4)] (II), (Ph(4)P)(2)[(CO)(4)Mo(MoS4)Mo(CO)(4)] (III) and (Ph(4)P)(2)[(CO)(4)W(WS4)W(CO)(4)] (IV). The two dimers, I and II, as well as the two trimers, III and IV, are isostructural to each other, respectively. All compounds crystallize in the triclinic space group P (1) over bar with Z=2. The cell dimensions are: a=12.393(8), b=19.303(9), c=11.909(6) Angstrom, alpha=102.39(5), beta=111.54(5), gamma=73.61(5)degrees V=2522(3) Angstrom(3) at T=23 degrees C for I; a=12.390(3), b=19.314(4), c=11.866(2) Angstrom, alpha=102.66(2), beta=111.49(1), gamma=73.40(2)degrees, V=2511(1) Angstrom(3) at T=23 degrees C for II; a=11.416(3), b =22.524(4), c=10.815(4) Angstrom, alpha=91.03(2), beta=100.57(3), gamma=88.96(2)degrees V=2733(1) Angstrom(3) at T= -100 degrees C for III, a =11.498(1), b=22.600(4), c=10.864(3) Angstrom, alpha=90.92(2), beta=100.85(1), gamma=88.58(1)degrees, V=2771(2) Angstrom(3) at T=23 degrees C for IV. The dimers are each formed by the coordination of the tetrathiometalate as a bidentate chelating ligand to an M(CO)(4) fragment while addition of another M(CO)(4) fragment to the dimers results in the trimers. All compounds contain both tetrahedral and octahedral metal centers with the formal 6+ and 0 oxidation states, respectively.