Two new oxamidato-bridged CuII-CuII complexes: Synthesis, structure, spectra, and cyclic voltammetry studies

New oxamido-bridged binuclear Cu^II-Cu^II complexes, [Cu(Oxen)Cu(Bipy)₂](ClO₄)₂ (I) and [Cu(Oxen)Cu(4,4??-Bipy)₂(H₂O)₂](ClO₄)₂ (II) (Oxen is N,N??-bis(2-aminoethyl)oxamide dianion, Bipy = 2,2??-bipyridine, 4,4??-Bipy = 4,4??-bipyridine), have been constructed and structurally characterized by X-ray crystallography. In these two complexes, each Cu²⁺ ion is located in a slightly distorted square-pyramidal environment. Complex I is extended to two-dimensional by face-to-face ??-??-stacking with a distance of 3.648 II is raised to one-dimensional by face-to-face ??-??-stacking and intermolecular H-bonding interaction with distances of 3.651 and 2.767 I is also investigated.