Dicopper(I) oxalate complexes as molecular precursors for the deposition of copper compounds

The synthesis, characterization, and thermal decomposition behavior of dicopper(I) oxalato complexes L₄Cu₂(C₂O₄) (L = CNtBu (2a), CNCMe₂CH₂tBu (2b), CNC₆H₃Me₂-2,6 (2c)) is reported. 2c can be prepared in a straightforward manner by the reaction of stoichiometric amounts of Cu₂O and oxalic acid with four equivalents of CNC₆H₃Me₂-2,6, while those complexes with aliphatic isocyanides are better prepared from a copper(I) oxalato complex with alkine capping ligands (Me₃SiCCSiMe₃)₂Cu₂(C₂O₄) (1) via ligand exchange. Crystallographic and spectroscopic evidence for 2a-c confirms the anticipated dinuclear structure with the oxalate in a μ-1,2,3,4 bridging mode and an essentially σ-character of the terminal isocyanides. In solid form the complexes are stable at room temperature and can be handled in air for some time. Their decomposition was studied by thermal gravimetric analysis coupled with mass spectrometry, and the degradation pathway was shown to depend on the type of isocyanide capping ligand. Decomposition of 2a,b takes place between 150 and 200 °C to give CuCN in a clean process that involves isobutene elimination from the terminal ligands, with elimination of (CN)₂ and conversion to elemental copper at higher temperatures. Heating of 2c leads to CuO (and then to Cu₂O) via release of the intact isocyanide, CO₂, and CO in a well-behaved thermal process around 200-280 °C.     

The first example of the C-3 alkylation of indoles with cyclopropyl ketones promoted by CeCl3·7H2O/LiI

Indoles undergo smooth alkylation with cyclopropyl ketones in the presence of the CeCl₃·7H₂O/LiI reagent system in refluxing acetonitrile under neutral conditions to produce the corresponding C-3 substituted indole derivatives in good to high yields and with high selectivity. The use of CeCl₃·7H₂O/LiI makes this method simple, convenient, and cost-effective.     

高含量钒的钼钒磷杂多化合物的合成和性质研究

本工作改进了文献[4]报导的几种原料同时混合、加热煮沸合成的方法采用分步加入原料,控制反应温度、多次重结晶的方法合成了6、7、8个钒原子取代的钼钒磷杂多酸铵;并以铵盐为原料,用离子交换、冷冻分离和真空抽吸相结合的提纯方法制备了未见文献报导的相应的固体杂多酸;H₅[PMo₅V₇O_37.5]·xH₂O,H₆[PMo₄V₈O_37.5]·xH₂O。通过元素组成分析确定了它们的组成。这些杂多酸在水溶液、非水溶液中的电位滴定表明,杂多阴离子在分解前没有发生自电离、水解等情况,它们在水溶液中是稳定的。酸的碱度分别为5、5、6。通过纸上色谱实验,讨论了杂多酸的分解过程。由热重分析和溶解性实验得到它们的分解温度,本文还讨论了这些化合物的红外、紫外光谱,x光粉末衍射及极谱性质。光谱结果表明,它们可能具有Keggin结构,由导数脉冲极谱得到它们的峰电位。     

Decomposition of EuPdIn and EuPtIn at high temperature and high pressure—formation of the hexagonal Laves phases EuPd0.72In1.28 and EuPt0.56In1.44

EuPd_0.72In_1.28 and EuPt_0.56In_1.44 were prepared under multianvil high-pressure (10.5 GPa) high-temperature (1500 and 1400 K) conditions from the precursor compounds EuPdIn and EuPtIn. They were investigated by X-ray diffraction on both powders and single crystals: MgZn₂-type, space group P6₃/mmc, a=578.7(1) pm, c=944.9(3) pm, wR2=0.0734, 263 F² values for EuPd_0.72In_1.28 and a=591.1(2) pm, c=933.8(2) pm, wR2=0.0853, 151 F² values for EuPt_0.56In_1.44 with 13 variable parameters per refinement. Both structures are built up from face- and corner-sharing tetrahedra of palladium (platinum) and indium atoms. The europium cations are located in cavities within the three-dimensional [Pd_0.72In_1.28] and [Pt_0.56In_1.44] networks. The 2a and 6 h positions of the tetrahedral networks show mixed Pd/In and Pt/In occupancy in EuPd_0.72In_1.28 and EuPt_0.56In_1.44, respectively. The crystal chemistry of these indides is briefly discussed.     

WS2 超细粉体的固相法合成

WS2 超细粉体的固相法合成;WS2;固相反应;过硫系数;高能球磨;粒度     

高分辨双晶XRF研究酞菁化合物中硫杂质的化学态

酞菁化合物是一种大π键共轭体系的平面分子结构，它以颜色鲜艳、化学稳定性和价格便宜等特点，已在颜料工业上得到了广泛地应用．随着高科技的发展，酞菁化合物的应用进入静电复印的领域．研究中发现：酞普化合物的晶体结构直接影响它的色泽、耐热性、稳定性以及光电导性．在诸多的酸苦晶型中，β-型酞菁是比较稳定的一种，其它晶型届亚稳态型．近年来，光敏性较好的X-型用于激光印刷机感光鼓的载流子产生层［1］．用作静电复印中的酞育粗颜料，一般多为a一型，且含有大量的有机和无机杂质[2]，经高温真空升华提纯后，转变为卢一型．有趣…     

Elimination of matrix effects for headspace solid-phase microextraction of important volatile compounds in red wine using a novel coating

In this paper, hydroxy-terminated silicone oil-butyl methacrylate-divinylbenzene (OH-TSO-BMA-DVB) copolymer was first synthesized and used as stationary phase with the aid of γ-methacryloxypropyltrimethoxylsilane (KH-570) as bridge in solid-phase microextraction (SPME) using sol–gel method and cross-linking technique. It has high extraction efficiency for both polar alcohols and fatty acids and nonpolar esters in comparison with commercial PDMS, PDMS-DVB and PA fibers. A simple and sensitive headspace SPME-gas chromatography (HS-SPME-GC) method using the novel fiber was presented for the simultaneous analysis of both polar alcohols and fatty acids and nonpolar esters in wine. To check the matrix effects, various model wine matrices, including distilled water; 11.5% ethanol/water (v/v) solution; a concentrated synthetic wine; a ‘volatile-free’ wine and a real wine were investigated in detail. Matrix effects were compensated for by using internal standard method and selecting the ‘volatile-free’ wine as working standard. The method presented in this study showed satisfactory linearity, precision, detection limits and accuracy. The recoveries obtained ranged from 85.87 to 104.2%, and the relative standard deviation values were below 9%. The results obtained indicated that the present method is a validated and accurate procedure for the simultaneous determination of both polar and nonpolar aroma compounds in wine.     

化学计量学在有机物电分析化学中的应用

化学计量学在有机物电分析化学中的应用日益广泛，并发挥重要的作用。本文就化学计量学方法在色素、抗氧化剂、维生素、氨基酸、环境污染物、农药及药物等电分析化学方面的应用作一综述。引用参考文献58篇。