Hydrogen-bonded assemblies of ruthenium(II)-biimidazole complex cations and cyanometallate anions: structures and photophysics

The complex cations [RuL2(H2biim)]2+ (L = bipy, 4,4′-tBu2-bipy) interact with cyanometallate anions via a chelating hydrogen-bonding interaction between the two N–H donors of the complex cation and the N lone pair of one cyanide ligand in the complex anion; the anion hexacyanoferrate(III) quenches the Ru(II)-based luminescence in CH2Cl2 solution by photoinduced electron-transfer within the H-bonded assembly, whereas hexacyanocobaltate(III) enhances the Ru(II)-based luminescence.