Electrochemiluminescence studies of the cyclometalated iridium(III) complexes with substituted 2-phenylbenzothiazole ligands

Abstract

Electrogenerated chemiluminescence (ECL) studies have been performed for the iridium(III) cyclometalated L2Ir(acac) complexes with substituted 2-phenylbenzothiazole ligand L. Electron transfer (ET) generation of the excited 3*L2Ir(acac) has been studied using a triple-potential-step technique in acetonitrile–dioxane (1:1) solutions containing 0.1 M (n-C4H9)4NPF6 as the supporting electrolyte. ET reactions between electrochemically generated L2Ir(acac)+ and A− (radical anions of aromatic nitriles) species lead to very efficient generation of ECL emission. Extremely high ECL efficiencies (up to 0.40) close to the excited 3*L2Ir(acac) luminescence yields have been found.