Hydrogen peroxide assisted photorelease of an anthraquinone-based ligand from [Ru(2,2′-bipyridine)2(9,10-dioxo-9,10-dihydroanthracen-1-olate)]Cl in aqueous solution

Abstract

A new class of light-activated ruthenium(II) complex was designed as a potential blocker of biological functioning, especially for targeting redox reactions within mitochondria under light activation. Based on our concepts the complex [Ru(bipy)₂(1-hydroxyanthra-9,10 quinone)]Cl (RU1) was prepared and studied to understand the preliminary reaction mechanisms and its excited state behaviour through a series of stability tests, electrochemistry, UV–Visible kinetics and femtosecond transient absorption spectroscopy experiments. Under white light in the presence of H₂O₂ two different reactions (fast and slow) appear to take place. The complex loses the quinone-based ligand and a resulting Ru(III) or Ru(V) species is produced. The complex RU1 shows potential to consume H₂O₂ from the one carbon metabolism in mitochondria, and hence may cut the energy cycle pathway of tumor cells.