Enhanced photostability of a Ruthenium(II) Polypyridyl Complex under highly oxidizing aqueous conditions by its partial inclusion into a cyclodextrin

Abstract

The complex [Ru(bpy)2L]2+, where bpy=2,2′-bipyridine, L=4-(phenylethynyl)-2,2′-bipyridine, was prepared in its racemic and resolved forms (Δ and Λ). The phenylethynyl unit on the bipyridine for the complex acts as a binding site for α-cyclodextrin in water (1:1 complex, K=3390 L mol−1) or β-cyclodextrin (2:1 complex, K1=887 L mol−1, K2=8070 L mol−1). The presence of the cyclodextrin provides partial protection to the complex under light-activated water oxidation conditions.