The ester substituted cyclopentadienyl ligand C5H4CO2CH3- was used in the synthesis of dinuclear molybdenum complexes with bridging sulfur ligands. New derivatives include [MeO2C-CPMoSC2H4S]2, 3, [MeO2C-CpMoSCHCPhS]2, 4, and [MeO2C-CpMO)2(S2CH2)(SC2H4S)], 7. Analogous dinuclear complexes with one ester substituted and one unsubstituted Cp ligand have also been isolated and characterized. The base hydrolysis reaction of 7 leads to the formation of the water soluble derivative (NaO2C-CpMo(mu-S))2S2CH2,9. A second water soluble derivative containing three carboxylate substituents, (NaO2C-CpMo(mu-S))2S2C(H)CO2Na, 11, was also synthesized and characterized. The formyl substituted cyclopentadienyl ligand was used in the preparation of new dinuclear molybdenum derivatives, including (OHC-CpMoSC2H4S]2, 13, and [OHC-CpMoSC2H2S]2,14. Spectroscopic data for the new complexes are presented. The reactivity of the new series of complexes has been surveyed and found to be qualitatively similar to that of the unsubstituted cyclopentadienyl derivatives. The new products will permit a more detailed study of solvent and substituent effects on sulfur ligand reactivity.