SOLID-STATE SYNTHESIS, CRYSTAL-STRUCTURE, AND EFFECTIVE 3RD-ORDER NONLINEAR-OPTICAL PROPERTIES OF NET(4))(3)[MOOS3CU3BR3(MU(2)-BR)]CENTER-DOT-2H(2)O

The title compound [NEt(4)](3)[MoOS3Cu3Br3(mu(2)-Br)]. 2H(2)O was synt hesized by a solid-state reaction of(NH4)(2)MoO2S2, CuBr, and Et(4)NBr at 70 degrees C. Single-crystal X-ray diffraction data show that the anionic cluster [MoOS3(CuBr)(3)(mu-Br)](3-) has a half-open-cage struc ture which is an intermediate between cubic cage and nest structures. The crystal has an orthorhombic symmetry with a space group of Pnma. C ell parameters are a = 18.648(3) Angstrom, b = 15.156(2) Angstrom, c = 16.226(3) Angstrom, V = 4586 Angstrom(3) and Z = 4. The crystal struc ture was refined to R = 0.061, R(w) = 0.053. The cluster exhibits both optical self-defocusing and optical nonlinear absorption (effectively n(2) = -2.3 x 10(-16) m(2) W-1, alpha(2) = 1.6 x 10(-10) m W-1 in a 1 .9 x 10(-3) mol dm(-3) acetonitrile solution) as measured with a 7-ns pulsed laser at 532 nm. The corresponding effective third-order nonlin ear optical susceptibilities (chi((3))) is 5.4 x 10(-10) esu. These no nlinear optical properties of the cluster were compared with those of cubic-cage-shaped and nest-shaped clusters to reveal a qualitative str ucture/NLO property correlation.