The cyclopentadienyl ligand with the (dimethylamino)ethyl substituent has been used in the synthesis of the dinuclear μ-sulfido molybdenum complex (Me2NCH2CH2CpMo(μ-S))2S2CH2, 4, and related derivatives. Complex 4 has been isolated and characterized by spectroscopic methods as well as by an X-ray diffraction study. The structure confirms a bis(μ-sulfido) derivative in which the dimethylamino substitutents of the Cp ligands are directed away from the Mo2S4 core. Protonation of 4 produces the dicationic complex with dimethylammonium substitutents, which is soluble in water and other polar solvents. Reaction of 4 with [CuOTf]2·C6H6 leads to the formation of a copper adduct [(Me2NCH2CH2CpMo(μ-S))2Cu(S2CH2)]OTF, 6a. NMR studies of 6a in CD2Cl2 suggest that the copper ion is stabilized by two sulfido ligands and by weakly coordinated dimethylamino groups.