Synthesis and structural characterization of five copper(I) complexes of [2,3-f]-pyrazino-[1,10]phenanthroline-2,3-dicarbonitrile and triphenylphosphine

Five new copper(I) complexes containing PPh3 and C16H6N6, [Cu(PPh3)(C16H6N6)Cl]·H2O (1), [Cu(PPh3)(C16H6N6)Br]·CH3CN (2), [Cu(PPh3)(C16H6N6)I]·CH3CN (3), [Cu(PPh3)(C16H6N6)(CN)]·0.5 CH2Cl2 (4) and Cu(PPh3)(C16H6N6)(SCN) (5) {PPh3 = triphenylphosphine, C16H6N6 = [2,3-f]-pyrazino-[1,10] phenanthroline-2,3-dicarbonitrile} have been synthesized for the first time. These complexes are obtained by the reactions of CuX (X = Cl, Br, I, CN, SCN) with the bidentate ligand C16H6N6 and the monodentate ligand PPh3 in the molar ratio of 1:1:1 in the mixed solvent of CH2Cl2 and CH3CN(5 ml/5 ml). They are characterized by X-ray crystallography, luminescence, IR, 1H NMR and 31P NMR. In solid state the complexes 1–5 are mononuclear with similar structures, but in solution they have different structures according to their different 1H NMR signals. All the complexes exhibit intense luminescence in solid state at room temperature.