Molecular Structure of Copper Nitrito Complex as the Reaction Intermediate of Dissimilatory Reduction of NO2−

Electrochemical reduction of NO2− by [Cu(tpa)(H2O)](ClO4)2 (tpa = tris[(2-pyridyl)methyl]amine) under the controlled potential electrolysis at −0.40 V (vs. Ag/AgCl) in H2O (pH 7.0) catalytically produced N2O with concomitant NO evolution. As the precursor of NO evolution, [Cu(tpa)(ONO)]PF6 was characterized by X-ray crystallography.