Synthesis, characterization and luminescence properties of a Copper(I) complex

Binuclear complex [Cu ₂(μ-I) ₂ (phen) ₂]·CH ₃CN(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: a=10.505 Å, b=23.628 Å, c=10.676 Å, α=90°, β=91.40° and γ=90°. 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 460 ^sh 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 π*→π 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 π-π 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 τ ₁=1.36 μs and τ ₂=5.98 μs, corresponding factors are 50.21% and 49.79% in DMSO solutions, and τ ₁=1.42 μs, τ ₂=8.85 μs, corresponding factors are 51.15% and 48.85% in the solid state.