pH responsive luminescent switches of ruthenium(II) complexes containing two imidazole groups: Synthesis, spectroscopy, electrochemistry and theoretical calculations

A series of new ruthenium(II) complexes of ligands containing two imidazole groups have been synthesized and characterized. The complexes have been found to sensitively respond to the solutions pH changes though protonation and deprotonation of the imidazole-containing ligands, serving as luminescent pH switches with extraordinary sensitivity in aqueous solution.