An investigation on catalytic nitrite reduction reaction by bioinspired Cu complexes.

Catalytic nitrite reductions by Cu complexes containing anionic Tp, neutral Tpm, or neutral TIC ligands in the presence of L-ascorbic acid, which served as an electron donor and proton source, were investigated. The results showed that auxiliary ligands are important for copper-mediated catalytic nitrite reduction. Furthermore, the electronic effects of the ligand govern the nitrite reduction efficiency, which should be considered at two control points: one is the susceptibility of the LCu-nitrite species to protonation and the other is the susceptibility of LCu to reduction giving LCu. In addition, an external strong acid leads to the production of nitrous acid, which may suggest that the reactivity of nitrous acid toward the LCu species is a third control point.