Self-assembly synthesis, crystal structure and nonlinear optical properties of cluster compound containing PPh2Py ligand

Self-assembly cluster compound [WS4Cu3(PPh2Py)3Br]2·CH3OH (1) was synthesized by the reaction of (NH4)2WS4, CuBr and diphenyl-2-pyridyl-phosphine (PPh2Py) in CH3OH solution under a purified nitrogen atmosphere using standard Schlenk techniques. Its structure was determined by X-ray crystallography. It crystallizes in the triclinic crystal system P-1 space group with a=1.178 6 (1) nm, b=1.302 6 (1) nm, c=1.991 7 (2) nm, α=74.671 (7)°, β=86.188 (8)°, γ=64.141 (6)°, V=2.649 5 (5) nm3, Z=1. The W center is slightly distorted from tetrahedral coordination geometry, and the structure is built up from three [Cu(PPh2Py)]+ units bridged by WS42- multifunctional ligand to form a tetranuclear symmetrical cube-like molecule. Measurement of the nonlinear optical (NLO) properties using the Z-scan technique with an 8 ns pulsed laser at 532 nm shows that the compound possesses NLO absorption and effective self-focusing effect at α2=6.7×10−11 m/W and n2=5.64×10−18 m2/W in a 1.5×10−4 mol/L DMF solution.