Synthesis and crystal structure of photoluminescent copper(I)–phosphine complexes with oxygen and nitrogen donor ligands

Two mononuclear copper(I) complexes, [Cu(PPh3)2(oxine)](BF4) (1) and [Cu(PPh3)2(Quin)](BF4) (2), have been prepared and their structures determined by X-ray crystallography. In complex 1, the copper(I) is coordinated by two PPh3 groups and one neutral bidentate oxine (8-hydroxyquinoline) in a distorted tetrahedral geometry. The copper(I) atom in complex 2 is surrounded by two PPh3 and one quinoline (quin) to complete a three-coordinate environment. At room temperature in the solid state both complexes exhibit photoluminescence originated from the intraligand (oxine or quinoline) triplet enhanced by copper coordination. This may provide a new entry to develop new kinds of photoemissive materials.