Luminescence Color and Intensity Changes of Nitridorhenium(V) Complexes Induced by Protonation/Deprotonation on the Bidentate Azolylpyridine Ligands.

Tricyanidonitridorhenium(V) complexes with azolylpyridines, namely, [ReN(CN)(H-N2py)] (, H-N2py = 2-(3-pyrazolyl)pyridine) and [ReN(CN)(L)] (, L = 2-[1,2,3]-triazol-4-yl-pyridine anion (N3py), and , that is, L = 2-(tetrazol-5-yl)-pyridine anion (N4py)), were newly synthesized and characterized. The structures of the new complexes were determined by single-crystal X-ray analysis. The complex includes two geometrical isomers in which an isomer is the conformation with the pyridyl (py) and pyrazolyl (pyrz) moieties of H-N2py occupying the site to the nitrido (the ax site) and the site to the cyanido (the eq site), respectively, in a bidentate fashion; the other isomer is the py and pyrz moieties coordinated to the eq and ax sites.