Electrogenerated chemiluminescence of tris(2-phenylpyridine)iridium(III) in water, acetonitrile and trifluorethanol

摘要

The spectroscopic, electrochemical and coreactant electrogenerated chemiluminescence (ECL) properties of Ir(ppy)3 (where ppy=2-phenylpyridine) have been obtained in aqueous buffered (KH2PO4), 50 : 50 (v/v) acetonitrile-aqueous buffered (MeCN-KH2PO4) and 30% trifluoroethanol (TFE) solutions. Tri-n-propylamine was used as the oxidative-reductive ECL coreactant. The photoluminescence (PL) efficiency (phi em) of Ir(ppy)3 in TFE (phi em approximate to 0.029) was slightly higher than in 50 : 50 MeCN-KH2PO4 (phi em approximate to 0.0021) and water (phi em approximate to 0.00016) compared to a Ru(bpy)32+ standard solution in water (phi em approximate to 0.042). PL and ECL emission spectra were nearly identical in all three solvents, with dual emission maxima at 510 and 530nm. The similarity between the ECL and PL spectra indicate that the same excited state is probably formed in both experiments. ECL efficiencies (phi ecl) in 30% TFE solution (phi ecl=0.0098) were higher than aqueous solution (phi ecl=0.00092) system yet lower than a 50% MeCN-KH2PO4 solution (phi ecl=0.0091). Copyright (c) 2014 John Wiley & Sons, Ltd.