The reaction of Mn-2(CO)(7)(mu-S-2) (1) with [CpMo(CO)(3)](2) (Cp = C5H5) and [Cp*Mo(CO)(3)](2) (Cp* = C-5(CH3)(5)) yielded the new mixed-metal disulfide complexes CpMoMn(CO)(5)(mu-S-2) (2) and Cp*MoMn(CO)(5)(mu-S-2) (3) by a metal-metal exchange reaction. Compounds 2 and 3 both contain a bridging disulfido ligand lying perpendicular to the Mo-Mn bond. The bond distances are Mo-Mn = 2.8421(10) and 2.8914(5) Angstrom and S-S = 2.042(2) and 1.9973(10) Angstrom for 2 and 3, respectively. A tetranuclear metal side product CpMoMn3(CO)(13)(mu(3)-S)(mu(4)-S) (4) was also isolated from the reaction of 1 with [CpMo(CO)(3)](2). Compounds 2 and 3 react with CO to yield the dithiocarbonato complexes CpMoMn-(CO)(5)[mu-SC(=O)S] (5) and Cp*MoMn(CO)(5)[mu-SC(=O)S] (6) by insertion of CO into the S-S bond. Similarly, tert-butylisocyanide was inserted into the S-S bond of 2 and 3 to yield the complexes CpMoMn(CO)(5)[mu-S(C=NBut)S] (7) and Cp*MoMn(CO)(5)[mu-S(C=NBut)S] (8), respectively. Ethylene and climethylacetylene dicarboxylate also inserted into the S-S bond of 2 and 3 at room temperature to yield the ethanedithiolato ligand bridged complexes CpMoMn-(CO)(5)(mu-SCH2CH2S) (9), Cp*MoMn(CO)(5)(mu-SCH2CH2S) (10), CpMoMn(CO)(5)[mu-SC(CO2Me)=C(CO2Me)S] (11), and Cp*MoMn(CO)(5)[mu-SC(CO2Me)=C(CO2Me)S] (12). Allene was found to insert into the S-S bond of 2 by using one of its two double bonds to yield the complex CpMoMn(CO)(5)[mu-SCH2C(=CH2)S] (13). The molecular structures of the new complexes 2-7 and 9-13 were established by single-crystal X-ray diffraction analyses.