Photochemistry of compounds adsorbed into cellulose. Part 4.—Diffusion-controlled mechanism of Ru(bpy) 2+3 luminescence quenching by copper(II)

Abstract

Ru(bpy)²⁺₃ luminescence quenching by Cu^II has been studied in 50% water + glycerol using nanosecond laser-photolysis techniques. Temperature studies over a wide range (77–295 K) show that Cu^II quenches Ru(bpy)²⁺₃ emission via both energy-transfer and electron-transfer mechanisms. The reaction probabilities corresponding to these reaction mechanisms depend on the separation of reactants in such a way that energy transfer is more efficient over large separations or distances while electron transfer is more efficient at short distances. Hence, the relative ratio of the contributions of the reactions is controlled by the viscosity of the medium. Other details about the reaction mechanism are also given.