Electrochemical reduction of the piperidine N-oxido complexes MoS2(C5H10NO)(2), MoOS(C5H10NO)(2) and MoO2(C5H10NO)(2) has been studied in detail by cyclic voltammetry, hydrodynamic voltammetry, and bulk electrolysis in aprotic organic solvents. Depending on the time domain, temperature or compound, a reversible one-electron reduction process or an overall irreversible process involving the apparent transfer of between 1 and 2 electrons may be observed. The initial reversible electron transfer process is metal-based and produces a transient molybdenum(V) complex [Mo(v)XY(C5H10NO)(2)](-) (X and Y = O or S) which may be detected voltammetrically in the case of [MoS2(C5H10NO)(2)](-) and [MoOS(C5H10NO)(2)](-). By contrast, on longer time domains, the overall irreversible process generates the reduced form of the ligand, C5H10NH, as well as free ligand itself, C5H10NOH, and involves redox-induced interconversion of the metal complexes. For example, MoS2(C5H10NO)(2) is converted to MoOS(C5H10NO)(2) and MoO2(C5H10NO)(2) with the oxo complexes being identified on the voltammetric time scale as well as by Mo-95 NMR measurements on the much longer synthetic time scale. The mechanism for the redox interconversion is complex, but is probably associated with an internal redox reaction where piperidine N-oxido ligand appears to act as an oxygen atom transfer reagent.