Dinuclear Eu(III) complexes with macrocyclic tetraphosphine tetraoxide ligand and their photoluminescence properties

Abstract

Dinuclear Eu(III) complexes with macrocyclic tetraphosphine tetraoxide (TPTO) ligand (1,5,9,13-tetraphosphacyclohexadecane-1,5,9,13-tetraphenyl-1,5,9,13-tetraoxide) that keep the Eu(III) ions apart were synthesized and their photoluminescence properties were investigated. It was found that quantum yield of Eu(III) complex 2 in ethyl acetate was excellent (Φ = 0.54) even at a large concentration (1 × 10−3 mol/l) and strong photoluminescence was obtained. Macrocyclic TPTO ligand has a function of a “separator” of Eu(III) ions that prevents concentration quenching in the Eu(III) complexes.