A terpyridine-based copper complex for electrochemical reduction of nitrite to nitric oxide.

In biological systems, nitrite reductase enzymes (NIRs) are responsible for reduction of nitrite (NO) to nitric oxide (NO). These NIRs have mostly Cu- or Fe-containing active sites, surrounded by amine-containing ligands. Therefore, mononuclear Cu complexes with N-donor ligands are highly relevant in the development of NIR model systems and in the mechanistic investigation of the nitrite reduction reaction.

Acid-catalyzed Transformation of Nitrite to Nitric Oxide on Copper(II)-Cobalt(II) Centers in a Bimetallic Complex.

Nitrite (NO ) serves as a pool of nitric oxide (NO) in biological systems under hypoxic conditions, and it is transformed to NO by nitrite reductase (NiR) enzyme in the presence of acid (H ions). However, NO synthases (NOSs) generate NO via L-arginine oxidation in normoxic conditions. Previously, acid-induced NO reduction chemistry was modeled on mono-metallic 3d-metals, generating metal-nitrosyls or NO with HO or HO products.