Direct evidence for electrochemically induced, reversible, proton transfer involving a quinone/hydroquinone redox couple

The complex [Ru(bpy)2L](PF6)[HL = 3-(2,5-dihydroxyphenyl)-5-(pyridin-2-yl)-1,2,4-triazole], exhibits electrochemically induced proton transfer between the hydroquinone moiety and the triazole; evidence for this phenomenon is derived from electrochemical and spectroelectrochemical experiments, and suggests that the transfer occurs intramolecularly via a hydrogen-bridge formation between the hydroquinone and trizole.