Synthesis,Crystal Structure and Photoluminescence of a Cuprous Dimer with Tetrakis(pyrazol-i-yl)borate Linker

A cuprous dimer [Cu（POP）]2（pz4B）BF4·（CH3CN）3 （1, POP = bis（2-（diphenylphosphanyl）phenyl）ether, pz4B- = tetrakis（pyrazol-i-yl）borate anion） was synthesized from the reaction of Cu（CH3CN）4BF4, POP and Kpz4B in CH3CN at room temperature. The compound was characterized by elemental analysis and X-ray single-Crystal structure analysis. It crystallizes in monoclinic, space group P21/c with a = 12.3491（2）, b = 20.8845（3）, c = 33.0657（4） A, β = 94.251（1）°, V = 8504.3（2） A3, Z = 4, Mr = 1693.21, Dc = 1.322 g/cm3, F（000） = 3496,μ = 1.843 mm-1, GOOF = 1.031, the final R = 0.0442 and wR = 0.1235 for 14397 observed reflections with 1〉 2σ（I）. 1 is an ionic compound. It is composed of a BF4- anion and a {[Cu（POP）]2（pz4B）}＋ cation. The cation contains two [Cu（POP）]＋ cationic moieties and a pz4B- anionic linker. The Cu（I） ions show a distorted tetrahedral coordination geometry defined by two nitrogen atoms from a pz4B- bridging ligand and two phosphorous atoms from a POP terminal chelating ligand. The complex emits blue luminescence with the maximum peak at 457 nm with 3% quantum yield in solid state at room temperature. The Cu（I） centers are essentially electronically separated because both HOMO and LUMO contain very little contribution from the bridging ligand. The unexpected low emission is ascribed to the intramolecular interaction of the emissive centers.

Synthesis,Crystal Structure and Photoluminescence of a Dinuclear Cuprous Complex with Thiocyanate Bridges

A cuprous dinuclear copper complex [PPh_2PAr_2Cu（μ-SCN）_2CuPPh_2PAr_2]（1,PPh_2PAr_2 =（1-bis（2-methylphenyl）-phosphine-2-diphenylphosphino）benzene） was synthesized from the reaction of Cu SCN and PPh_2PAr_2 in CH_3CN at room temperature. The compound was characterized by Elemental Analysis,NMR,UV-Vis and X-ray single-crystal structure analysis. It crystallizes in triclinic,space group P1 with a = 10.225（2）,b = 11.360（2）,c = 13.420（3） ？,α = 95.81（3）,β = 93.45（3）,γ = 113.78（3）°,V = 1410.4（5） ？~3,Z = 1,Mr = 1192.21,Dc = 1.404 g/cm^3,F（000） = 616,μ = 3.029 mm^（–1）,GOOF = 1.052,the final R = 0.0359,and w R = 0.0964 for 4878 observed reflections with I 〉 2σ（I）. The Cu（I） atoms in the complex are four-coordinated and adopt a tetrahedral coordination geometry. The copper centers in the molecular structure are bridged by two thiocyanate anions and each Cu（I） is chelated further terminally by a PPh_2PAr_2 ligand. The [Cu（μ-SCN）_2Cu] cores have essential planar configurations. In the solid state,the complex exhibits blue photoluminescence with emission peaks λ_（max）= 478 nm（1）,lifetimes 4.7 μs and quantum yields（ф = 0.43） at room temperature. The studies of varied temperature emission spectra and decay behaviours of the complex indicate that it displays thermally activated delayed fluorescence at room temperature. The results of the experimental and DFT calculations suggest that the emission in the solid state originates from the ^（1,3）MLCT excited states.