Photochemical reduction of nitrite catalyzed by a Cu-containing nitrite reductase model complex and a photosensitizer under irradiation with visible light

The photochemical reduction of nitrite (image) to nitrogen monooxide (NO) was catalyzed by a copper complex containing a tridentate aromatic amine compound (bis(6-methyl-2-pyridylmethyl)amine), which is a model for the active site of copper-containing nitrite reductase, with a visible light irradiation system containing a [Ru(bpy)3]Cl2 photosensitizer in H2O under acidic conditions at 30 °C. The rate-limiting step of the reaction was found to be the generation step of the excited Ru complex or the intermolecular electron transfer between Cu and Ru complexes.