An oxo-bridged dirhenium(III,III) complex of tris(2-pyridylmethyl)amine (tpa) and its one-electron oxidized (III,IV) species, [Re 2 (μ-O)Cl 2 (tpa) 2 ] 3 + , 4 + have been prepared. They are new members to a series of rhenium tpa complexes in various oxidation states. X-ray structural determination of the Re 2 (III,IV) complex revealed practically linear Re O Re bridge (178(1) o ) with short Re O distances of 1.85(2) A indicative of some multiple bonded character. The 1 H NMR spectrum disclosed the relatively slow rotation around the Re O Re axis in CH 3 CN solution in the timescale of 1 H NMR. The complex undergoes two consecutive reversible one electron oxidations Re 2 (III,III)/(III,IV) and Re 2 (III,IV)/(IV,IV) at E 1 / 2 =0.23 and 0.90 V vs Ag/AgCl, respectively. Strong visible absorption bands are observed for the Re 2 (III,III) species at 448 (ε=31 160) and 563 nm (19 550) which are tentatively assigned to MLCT transitions. A unique oxidation product, Re 2 (μ-O)(O) 2 Cl 2 (bpaO 2 ) 2 (bpaO 2 H=1,3-bis(2-pyridyl)-2-aza-propanedione) has also been isolated and its crystal structure was determined. The complex is dirhenium(V) species with linear O Re O Re O moiety. Ligand tpa has been oxidized to ketone with simultaneous dissociation of one of the 2-pyridylmethyl arms.