Synthesis, crystal structure and nonlinear optical properties of butterfly-shaped cluster [MoOS3Cu2PYPPh2)(3)]

Solid state reaction of [NH4](2)[MoS2O2], CuI and Et4NBr with 2 - (diphenylphosphino) pyridine (PyPPh2) results in trinuclear cluster [MoOS3Cu2 (PyPPh2)(3)]. Its crystal structure has been determined on a Simens Smart 1 - K CCD area - detector diffractometer. The crystal is triclinic, space group P (1) over bar with a = 1.16736 (4) nm, b = 1.42254 (5) nm, c = 1. 68034 (6) nm, alpha = 100.07 degrees, beta = 103.2450 (10)degrees, gamma = 105.0650(10)degrees, V = 2.53991(15) nm(3), Z = 2, D-c = 1.504 g . cm(-3), F (000) = 1166, mu = 13.57 cm(-1). The final R-1 = 0.0590, wR(2) = 0.1238. The cluster is highly bent with a butterfly - shaped core in which the MoOS32- unit acts as a tridentate ligand to coordinate with two Cu atoms of different configurations and the O atom serves as a terminal group. Investigation of third - order optical nonlinearity shows that it exhibits considerable nonlinear absorptive and self - defocusing effect with alpha (2) = 4.4 x 10(-11) m . W-1 and n(2) = - 8.225 x 10(-18) m(2) . W-1, respectively. The peripheral ligands also play an important role in the NLO properties of clusters.