Synthesis, structures and aggregation-induced emissive properties of copper(I) complexes with 1H-imidazo[4,5-f][1,10]phenanthroline derivative and diphosphine as ligands

Abstract

Reaction of 4-bromo-2-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)phenol (BIPP), chelating diphosphine ligands and [Cu(MeCN)4]ClO4 afforded five mononuclear [Cu(BIPP)(PP)]ClO4 (PP=dppe, 1; dppp, 2; bdpp, 3; POP, 4; xantphos, 5) complexes with good phosphorescent emission in the solid state. All the complexes are characterized by elemental analyses, electrospray Ionization mass spectra, 1H and 31P NMR spectra and X-ray single crystallography. The photoluminescence quantum yields of complexes 1–5 are from less than 0.010 to 0.262 in the solid state under air atmosphere, which increase with the increasing rigidity of diphosphine ligands and the increasing strength of intermolecular and intramolecular π⋯π interactions. The aggregation-induced emission of complexes 4 and 5 at room temperature was investigated.