Reactions of [M-2(O2CCH3)(2)(CH3CN)(6)] [BF4](2) (M = Mo, Rh) and Ru-2(O2CCH3)(4)Cl with pynp (2-(2-pyridyl)-1,8-naphthyridine) yield the homologous series of cations [M-2(O2CCH3)(2)(pynp)(2)](2+), which were fully characterized by X-ray crystallography, cyclic voltammetry, and UV-visible spectroscopy. Electrochemistry revealed interesting redox chemistry for both the dimolybdenum and diruthenium derivatives, which display class II and class III Robin-Day behavior, respectively, for the four one-electron reversible reductions of the two pynp ligands. [GRAPHICS]