Heteroleptic Cu(I) Phenanthroline Complexes Bearing Benzoxazole and Benzothiazole Moieties for Visible Light Absorption

Three kinds of heteroleptic Cu(I) complexes having a phenanthroline-based ligand acting as a chromophore and bearing benzoxazole, benzothiazole, and thiazole moieties were synthesized. Introduction into the phenanthroline ligands of electron-withdrawing five-membered aryl groups caused large red-shifts in the metal-to-ligand charge transfer bands, showing visible light absorption up to 500 nm. The obtained Cu(I) complexes exhibited emissions with quantum yields of 0.01-0.04 and long lifetimes of 0.4-3 mu s.