Pressure effect on photo-induced electron-transfer reactions between tris-(2,2′-bipyridine)ruthenium(II) and various metal complex ions

Abstract

The electron-transfer quenching of photo-excited [Ru(bpy)₃²⁺](bpy = 2,2′-bipyridine) by [Mo(CN)₈]^4– and Eu_aq²⁺ gives large positive and negative activation volumes (ΔV^‡+ 24.7 and –11.0 cm³ mol^–1), respectively, whereas quenching by other quenchers having quenching rate constants of > 10⁹ mol^–1 dm³ s^–1 has a negligibly small pressure effect regardless of the charge of quencher.