利用Cyanex 301萃取体系制备纳米硫化物的研究

溶剂萃取由于具有处理量大、操作简单、易于连续化等优点，被广泛应用于湿法冶金工业。而溶剂萃取过程通常都伴随着有机相微乳体系的形成、变化、甚至完全破乳的过程以及萃合物分子聚集状态的不断变化，因此可以认为，液－液萃取体系提供了一系列可调控的微乳体系。相对于液液萃取在金属分离方面的广泛应用，液液萃取过程中形成的微乳体系在材料制备方面的应用研究还处于起始阶段。本论文在广泛调研文献资料的基础上，开展了利用硫代有机膦萃取剂Cyanex 301萃取体系制备纳米硫化物的研究，取得了一些有意义的结果。该工作的开展将对促进溶剂萃取分离与纳米材料制备一体化研究起到一定的作用，并为寻找简便易行且适用于大规模生产的纳米材料制备新方法提供思路。主要内容如下： 1. 通过两相热法，利用Cyanex 301－AgNO3两相萃取体系制备了尺寸均匀、分散性好的Ag2S纳米粒子。并且发现了与通常纳米材料制备过程不一样的现象，即Ag2S产物的粒径随着反应温度的升高逐渐增大，这与通常观察到的产物颗粒随反应温度升高而变小的现象完全不同。通过红外谱图分析，确定了反应机理，并提出了影响产物粒径的可能机制，认为产物粒径的变化是Cyanex 301作为硫源与作为表面修饰剂相互竞争的结果。 2. 通过两步法合成了四面体、类六角锥和六角片型的Ag2S/CdS纳米复合材料。Ag2S纳米粒子在产物的形成中起到了晶种与模板导向作用，溶剂对产物的形貌也起到诱导作用。 3. 利用两相热法，一步合成了CuS微米花和微米球自组装结构，产物的形貌随水相金属离子浓度的改变而发生变化。

Synthesis, structure characterization and biological activity of a novel amino acid salt (HAla)(8)(H3O)(10)[PMo12O40](6) center dot 22H(2)O

A novel compound was synthesized and characterized by means of elemental analysis, IR and UV spectra, TG, CV and single crystal X-ray diffraction. The compound crystallized in an orthorhombic space group C222 with a=1. 622 4(3) nm, b=3. 498 4(7) nm, c=1. 301 5(3) nm, V=7. 387 (3) nm(3), Z=6, R-1= 0. 037 3, wR(2)=0. 114 0. The Ala (Ala = alanine) molecules were protonated at the amino nitrogen N (1) and the C (2) of Ala group with the terminal oxygen atom O(15), O(14), O(26) and O(27) of the polyoxometalates participating in the hydrogen bond network. The anti-tumor activity of the title compound was estimated against Hela and Pc-3m cancer cells.

Studies on the structure of tricyclohexyltin-2-(1,2-dithioethylene)methylene-3-oxo-5-aryl-4-pentenicate

Three title compounds were prepared and the structure of title compound 2 was characterized by IR, H-1 NMR, C-13 NMR, Sn-119 NMR spectroscopy and the crystal structure of compound 2a was determined by X-ray analysis with the final R indices[I >2 sigma (I)] R-1 = 0.0350 and R-2,R-omega = 0.0888. The crystal of compound 2a belongs to triclinic system, space group P1 with a = 1.0598(6) nm, b = 1.307 4(10) nm, c = 1.378 6(10) nm, alpha = 62.666(7)degrees, beta = 72.530(2)degrees, gamma = 80. 680(2)degrees, V = 1.618 0 nm(3), D-x = 1. 444 g (.) cm(-3), Z = 1, F (000) = 728. The bond length of Sn1-O1 is 0. 2076 nm and Sn1 . . . O2 distance is 0.301 3 nm. The coordination about the tin atom can be considered as a distorted tetrahedral. The detail values of H-1 NMR, C-13 NMR, Sn-119 NMR, (2)J(119Sn-1H) and J(119Sn-13C) were obtained. delta (119Sn) = 23.836, (2)J(119Sn-1H) = 88.0 Hz, (1)J(119Sn-13C) = 347.1 Hz, (2)J(119Sn-13C) = 45.6 Hz.

Theoretical investigation of LaC3n+ (n = 0, 1, 2) clusters by density functional theory

LaC3n+ (n = 0, 1, 2) clusters have been studied using B3LYP (Becke 3-parameter-Lee-Yang-Parr) density functional method. The basis set is Dunning/ Huzinaga valence double zeta for carbon and [2s2p2d] for lanthanum, denoted LANL1DZ. Four isomers are presented for each cluster; two of them are edge binding isomers with C-2 upsilon symmetry, the other two are Linear chains with C-infinity upsilon symmetry. Meanwhile, two spin states for each isomer, that is, singlet and triplet for LaC3+, doublet and quartet for LaC3 and LaC32+, respectively, are also considered. Geometries, vibrational frequencies, infrared intensities, and other quantities are reported and discussed. The results indicate that at some spin states; the C-2 upsilon symmetry isomers are the dominant structures, while for the other spin states, linear isomers are energetically favored. (C) 1998 John Wiley & Sons, Inc.