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D.A. Lemenovskii V.P. Fedin A.V. Aleksandrov Yu.L. Slovohotov Yu.T. Struchkov 《Journal of organometallic chemistry》1980,201(1):257-268
Electron-acceptor properties of bis-niobocenes (η5-C5H4Y)(H)b(H)(η5-C5H4Y) with X Y H and XY SiMe2OSiMe2have been investigated. Bis-niobocenes are shown to readily add two electrons forming stable salts of the corresponding dianions [(η5-C5H4Y)(H)Nb(η5 : η1- C5H3X)2Nb(H)(η5-C5H4Y)]2-. The surplus electrons can be removed to give quantitative regeneration of initial neutral bis-niobocenes. The crystal and molecular structure of the title compound has been determined; R 0.044, interatomic distance are Nb…Nb 3.93, NbH 1.62, average NbC(π) 2.36, NbC(σ) 2.31 Å, other distances correspond to the usually observed values. Unlike the neutral bis-niobocenes, there is no direct metalmetal bond in the dianionic structures. This conclusion is supported by electronic spectra of neutral and dianionic species. 相似文献
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Z.H. Sun G.H. ZhangX.Q. Wang G. YuL.Y. Zhu H.L. FanD. Xu 《Journal of Crystal Growth》2009,311(13):3455-3460
The organic nonlinear optical crystal of amino-carboxyl acid family, l-lysinium trifluoroacetate (abbreviated as LLTF) was successfully grown from its aqueous solution by the temperature-lowering technique. Its growth morphology was investigated based on the X-ray single-crystal diffraction data and the growth habits were studied using the micro-crystallization method. The metastable zonewidth and induction period were determined for the aqueous solution growth of LLTF. The surface free energy values were calculated from the experimental data. Nucleation kinetics and fundamental growth parameters such as critical radius, critical free energy and volume free energy change were also evaluated. Crystals of LLTF were obtained by the optimized nucleation parameters. 相似文献
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Z.H. Sun G.H. ZhangX.Q. Wang G. YuL.Y. Zhu H.L. FanD. Xu 《Journal of Crystal Growth》2009,311(16):4152
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