| The thesis focuses on studies of synthetic reactions and structural characterizations of V(Mo, W)-S-Cu(Ag) clusters and optical properties of V-S-Cu species.Several new cluster compounds with different skeletons were synthesized. V2S6O2Cu6(3-MePy)6 1; VS4(μ3-I)(CuPPh3)4 2; MoOS3(μ3-Br)Ag3(PPh3)3 3;[Et4N]n[WS4Ag]n 4; [MoOS3Cu3I(C7H9N)2]2 5; (Bu4N)3[WOS3Cu3(NeS)3]I 6; (Bu4N)3[MoOS3Cu3(NCS)3]I 7 and cluster 8 (Py, SCN-ligand). Three structures were determined by Single-crystal X-ray diffraction. The collected data is given: a = 9.756(2) A, b = 10.422(2) A, c = 11.937(2) A, α = 108.32(3) °,β = 98.11(3)°, γ = 99.38(3)°, Z = 2, R1 = 0.0327, wR2 = 0.0728 (1) ; a = 11.916(2) A, b = 13.247(3) A, c = 22.511(5) A, α = 91.75(3) °, β = 99.09(3) °, γ = 116.04(3) °, Z = 2 , R1 = 0.1064, wR2 = 0.2838(2); a=15.736(3)A, b=11.193 (2) A, c=30.357(6) A, α=90 °, β=98.11(3)°, γ=90°, Z=4, R1 = 0.0955, wR2 =0.1591(3). The structures or molecule formulas of other compounds were deduced from the reported homologues by their IR spectra and elemental analyses.The third-nonlinear optical (NLO) properties of cluster 1 and 2 were investigated with an 8ns pulsed laser at 532nm. These two clusters exhibit moderately strong third-order NLO absorption effects [α2= 3.5×10-10m/W 1, 1.7×10-10 m/W 2] and self-focusing or self-defocusing performance in 1.58×10-4mol/dm3 1 and 1.24×10-4 mol/dm3 2 DMF solution. The third-order NLO refractive coefficients (n2) of cluster 1 and 2 are 1.27 × 10-18 m2/W and -6.86 × 10-19 m2/W, respectively. The corresponding effective NLO susceptibilities x(3) are calculated to be 1.2×10-11esu 1 and 5.9×10-12 esu 2, white the hyperpolarizabilities y to be 4.2×10-32esu 1 and 1.6×10-32esu 2. Based on the NLO experimental results, it can be drawn that the symmetry of skeleton, the number of heavy atoms and the rigidity of structures are the main reasons for the differences in NLO properties. |
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