Nonlinear optical properties and crystal structure determination of a pentanuclear copper(I) cluster (NEt4)2[MoS4(CuBp)4] (Bp = H2B(pyrazolyl)2)

The pentanuclear cluster complex (NEt4)2[MoS4(CuBp)4] has been prepared in acetone as a new candidate for nonlinear optical activity. The NLO properties of the cluster were studied, giving n2 = −4.2 × 10−11 esu and β = 2.2 × 10−10 m W−1. The structure of the complex has been determined by single-crystal X-ray diffraction. The coordination environment around each copper atom is distorted tetrahedral with two N donors of the bidentate bis(pyrazolyl)borate ligands and two S donors of the MoS4 group, offering a structural model for some copper proteins. The Mo atom retains the tetrahedral geometry of the free [MoS4]2− anion and lies on a position with crystallographic S4 symmetry.

Graphical abstractThe bis(tetraethylammonium) salt of this molybdenum–copper cluster anion, with tetrahedral coordination of both Mo and Cu, shows non-linear optical activity as a potential optical limiter.Figure optionsDownload full-size imageDownload as PowerPoint slide