[Synthesis, characterization and luminescence properties of a copper (I) complex]

Binuclear complex [Cu2 (mu-I)2 (phen)2] x CH3CN(1)(phen = 1,10-phenanthroline) was synthesized under solvothermal conditions and characterized by elemental analysis, IR spectrum, and single-crystal X-ray diffraction. X-ray diffraction analysis reveals that complex 1 is monoclinic, space group P2(1/n), and the cell parameters are: alpha = 10.505 A, b = 23.628 A, c = 10. 676 A, alpha = 90, beta = 91.40 degrees and gamma = 90 degrees. The authors have studied the luminescence property of 1, Complex 1 has blue-purple luminescence in solutions of DMSO with emission bands at 369, 380 and 460sh nm; and has red luminescence in the solid state at room temperature with a broad emission band at 650-678 nm. These all can be attributed to the pi* --> pi transition based on the ligand. In the solid state, the emission frequencies for complex 1 are red-shifted about 280 nm compared with their emission maximum peaks in solutions of DMSO. This red-shift of emission energy from solution to solid is likely to be caused by the intermolecular pi--pi packing interaction in the solid state which effectively decreases the energy gap. The fluorescence decay curve of complex 1 indicated that the processes of decay consists of two components, whose corresponding lifetimes are tau1 = 1.36 micros and tau2 = 5.98 micros, corresponding factors are 50.21% and 49.79% in DMSO solutions, and tau1 = 1.42 micros, tau2 = 8.85 micros, corresponding factors are 51.15% and 48.85% in the solid state.