Quenching of photoluminescence from copolymer pendant Ru(bpy)32+complexes by colloidal Prussian Blue

Abstract

Static quenching of photoluminescence from nine copolymer pendant Ru(bpy)₃²⁺ complexes [pendant Ru(bpy)₃²⁺] by colloidal Prussian Blue (PB) has been studied. The quenching behavior was analyzed in terms of a stepwise complex formation mechanism between pendant Ru(bpy)₃²⁺ and negatively charged PB which obeys Poisson statistics. Seven of the pendant Ru(bpy)₃²⁺ complexes exhibited stronger tendency to bind onto colloidal PB particles in comparison with the free Ru(bpy)₃²⁺ complex. This was ascribed to the characteristics of the polymer–pendant Ru(bpy)₃²⁺ complexes, such as electrostatic and coordination effect, hydrophilicity/hydrophobicity and steric hindrance of the polymer. The importance of these factors to influence the interaction of the pendant Ru(bpy)₃²⁺ with colloidal PB particles has been discussed.