Ligand reactivity was demonstrated for sulfide alkylation, thiolate dealkylation, and dithiophosphate de-esterification within molybdenum(V) dimers. The cationic complex [Mo-2(NC6H4Me)(2)(S2P(OEt)(2))(2)(mu-O2CMe)(mu-SR)(2)](+) was inductively activated toward thiolate C-S and dithiophosphate C-O heterolyses. The dealkylations were studied using anionic nucleophiles, and various reactivity patterns were characterized. The de-esterification of the diethyl dithiophosphate ligands produced complexes containing the rare monoester EtO(O)PS22- ligand. This ligand's phosphoryl group was poorly nucleophilic but weakly basic. Crystallographic comparisons between the activated cation and the neutral complex [Mo-2(NC6H4Me)(2)(S2P(OEt)(2))(2)(mu-O2CMe)(mu-S)(mu-SMe)] were conducted to delineate structural differences related to the activation. A crystallographic study was also done of the complex [Mo-2(NC6H4CH3)(2)(S2P(OEt)(2))(S2P(O)OEt)(mu-O2CMe)(mu-SEt)(2)], which provided internal comparison of monoester EtO(O)PS22- and diester (EtO)(2)PS2- ligand types.