三(邻氯苄基)氯化锡的合成、结构和量子化学研究

邻氯苄基氯与锡反应合成三(邻氯苄基)氯化锡，经x射线方法测定了新化合物 的晶体结构，化合物属三方晶系，空间群为R-3，晶体学参数：α=b=1．3583(4) mn，c=2．1147(8)am，v=3．3790(19)nm~3，Z=6，μ(Mo kα)=16．11cm~-1， r (000)：1572，R_1=O．0755；Sn-C键长分别为0．2148(13)和0．220(2)nm，Sn-C1 键为0．2528(15)和0．2477(13)Bill．中心锡原子与亚甲基碳和氯原子构成畸型四 面体．并对其结构进行量子化学从头计算，探讨化合物的稳定性、分子轨道能量、 原子净电荷布居规律以及一些前沿分子轨道的组成特征．     

工业氨基三甲叉膦酸中副产物的核磁共振分析

采用多种核磁共振(NMR)技术测定了工业氨基三甲叉膦酸(ATMP)产品中副产物的分子结构，发现该物质为甲氨基二甲叉膦酸(MADMP)，它是甲醛歧化反应导致的副产物；给出了可能的反应方程式；测出了MADMP的相对含量，MADMP与ATMP摩尔比约为2。     

Electrochemical determination of iodide on a vanadium oxide-polypropylene carbonate coated glassy carbon electrode

A vanadium oxide-modified glassy carbon electrode was simply and conveniently fabricated by casting vanadium tri(isoproxide) oxide (VO(OC₃H₇)₃) and poly(propylene carbonate) (PPC) onto the glassy carbon electrode surface. The electrochemical properties of iodide at the VO(OC₃H₇)₃-PPC film-modified glassy carbon electrode were investigated by cyclic voltammetry, and an anodic peak was observed at approximately +0.71 V (vs. SCE). Based on this, a sensitive and convenient electrochemical method was proposed for the determination of iodide. Flow injection amperometry (FIA) exhibited a good linear relationship with the concentration of iodide in the range of 5 × 10⁻⁷ mol L⁻¹ and 1 × 10⁻³ mol L⁻¹, and the detection limit was 1 × 10⁻⁷ mol L⁻¹. Quantitative recovery of iodide in synthetic samples has been obtained and the interferences from different cations and anions have been studied. The method has been successfully applied to the determination of iodide in dry edible seaweed. The concentrations of iodide measured by this method are in good agreement with those obtained by spectrophotometric method.     

Synthesis and some properties of 6-di(tri)fluoromethyl-and 5-di(tri)fluoroacetyl-3-methyl-1-phenylpyrano[2,3-<Emphasis Type="Italic">c</Emphasis>]pyrazol-4(1<Emphasis Type="Italic">H</Emphasis>)-ones

Condensation of 4-acetyl-5-hydroxy-3-methyl-1-phenylpyrazole with R^FCO₂Et (R^F = CF₂H, CF₃) in the presence of LiH affords 4-di(tri)fluoroacetoacetyl-5-hydroxy-3-methyl-1-phenylpyrazoles from which 6-di(tri)fluoromethyl-and 5-di(tri)fluoroacetyl-3-methyl-1-phenylpyrano[2,3-c]pyrazol-4(1H)-ones were synthesized. The reactions of pyrano-pyrazoles with hydrazine hydrate, ethyl mercaptoacetate, or aromatic amines proceed at the C(6) atom with pyrone ring opening and formation of aminoenones, pyrazoles, or thiophenes with the 5-hydroxy-3-methyl-1-phenyl-4-pyrazolyl fragment. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2750–2754, December, 2005.     

十二烷基磺酸铁催化合成丙酸正丁酯

以十二烷基磺酸铁催化合成了丙酸正丁酯。实验结果表明最佳反应条件为：丙酸100mmol,n(丙酸)：n(正丁醇)=1．0：1．2,十二烷基磺酸铁0．8g(约1．0mmol),带水剂环己烷6mL,回流分水60min,酯化率94．6％。催化剂重复使用5次仍保持较高活性。     

Blue electroluminescence from 3,6‐silafluorene‐based copolymers

Poly(3,6‐silafluorene) is a typical wide band‐gap conjugated polymer with ultraviolet light emission. The blue electroluminescence from the 3,6‐silafluorene‐based copolymers via intrachain energy transfer was reported in this study. The monomer containing vinylene, anthracene, and tri‐arylamine moieties incorporated into the poly(3,6‐silafluorene) backbone can form efficient deep‐blue emitting copolymers with EL efficiency of 1.1–1.9%. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3286–3295, 2009     

Facile, aprotic degradation of η-CpZrCl3·dme by ternary sodium/group 14 tert-butoxides: From η-CpZrCl3·dme back to NaCp in two easy steps

CpZrCl₃·dme was treated with Na[El(O^tBu)₃], El = Ge, Sn, Pb, respectively. The addition of Na[Sn(O^tBu)₃] to CpZrCl₃·dme caused rapid cyclopentadienide loss and the equally rapid appearance of CpSnCl, half of which crystallized as the trinuclear complex {[ZrCl(O^tBu)₃]₂·CpSnCl}. Pristine CpSnCl reacted almost instantly with NaO^tBu to give NaCp and Na[Sn(O^tBu)₃], which co-crystallized as a coordination polymer. Na[Ge(O^tBu)₃] also displaced Cp from zirconium, but with a different product distribution, giving Cp₂Ge, fac-[Ge(μ-^tBuO)₃ZrCl(O^tBu)₂], and ZrCl(O^tBu)₃. By contrast, Na[Pb(O^tBu)₃] only exchanged its tert-butoxide groups with zirconium to furnish CpZr(O^tBu)₃ and PbCl₂. The solid-state structures of {[ZrCl(O^tBu)₃]₂·CpSnCl}, fac-[Ge(μ-^tBuO)₃ZrCl(O^tBu)₂], and {NaCp·Na[Sn(O^tBu)₃]}_n were determined.     

Numerical simulation of fluid flows using an unstructured finite volume method with adaptive tri‐tree grids

A tri‐tree grid generation procedure is developed together with a finite volume method on the unstructured grid for solving the Navier–Stokes equations. A hierarchic numbering system for the data structure is used. The grid is adapted by adding and removing cell elements dependent on the vorticity magnitude. A special treatment is developed to ensure good quality triangular elements around the cylinder boundary. The adopted finite volume method is based on the cell‐centred scheme. The pressure–velocity coupling is treated using the SIMPLE algorithm. A modified QUICK scheme for unstructured grids is derived. The developed method is used to simulate the flow past a single and multiple cylinders at low Reynolds number. The obtained results are in good agreement with the published data. Copyright © 2002 John Wiley & Sons, Ltd.     

Reaction of bis[bis(tri-tert-butoxysilanethiolato) cadmium(II)] with 3,5-dimethylpyridine - 113Cd NMR solution study

NMR studies on the reaction of bis[bis(tri-tert-butoxysilanethiolato)cadmium(II)] with 3,5-dimethylpyridine in benzene-d(6) and toluene-d(8) solutions provide clear evidence for the equilibrium character of formation of mixed S,N-ligand cadmium complex.     

A New potentiometric determination of L-ascorbic acid(Vitamin C) in Pharmaceuticals with hexamine cobalt (III) tri carbonato cobaltate

Abstract

A new potentiometric method is developed for determination of 10–100 μg ml of L-ascorbic acid in pure solution and Pharmaceuticals with 0.1 to 0.8% RSD.

Interference study is carried out for different acids, Most importantly, the new method is applied for variety of vitamine C in Pharmaceuticals and successful results are achieved.