Unravelling the aggregation induced emission enhancement in Tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II) complex

Abstract For the first time, we unearthed the aggregation induced emission enhancement of well-known ruthenium(II) complex attached with bathophenanthroline ligand, Ru(dpphen) 3 2+ (dpphen = 4,7-diphenyl-1,10-phenanthroline). Complex Ru(dpphen) 3 2+ displayed a weak emission at 613 nm in CH 3 CN while exciting at its MLCT band (464 nm). However, upon response with incremental addition of poor and viscous solvents into the CH 3 CN solution of Ru(dpphen) 3 2+ , the emission intensity drastically increased due to the formation of nanoaggregates. Restricted intramolecular rotation (RIR) of peripheral phenyl rings attached to the bathophenanthroline ligands in Ru(dpphen) 3 2+ complex is responsible for this unique phenomenon, thereby stimulates the emission intensity. The formation of these nanoaggregates was confirmed by TEM studies.