X-ray structure of dodecasodium tricopper(II)bis[nonatungstabismuthate(III) hydrate, a polyoxometalate salt containing α-B-BiW9O33 units

The reaction of [Bi₂W₂₂O₇₄(OH)₂]^12– with Cu²⁺ in hot aqueous solution in the presence of Na⁺ affords the polyoxometalate salt Na₁₂[Cu₃Bi₂W₁₈O₆₆]32H₂O. Single-crystal X-ray analysis [monoclinic, space-group C2/m, a = 33.082(6) Å, b = 19.615(5) Å, c = 14.885(2) Å, = 90.632(12)°, Z = 4; R(F) = 0.065 for 6029 data with I> (I), wR(F ²) = 0.135 for all 8793 independent reflections] shows that the anion [{Cu(H₂O)}₃{BiW₉O₃₃}₂]^12–, on a crystal mirror-plane, has noncrystallographic symmetry close to D_3h. Two B--[Bi^IIIW₉O₃₃]^9– units are linked by an equatorial belt of three Cu(H₂O)²⁺ units. Three Na(H₂O)₂ ⁺ units are also attached in the equatorial plane. The bond geometry is square-pyramidal about each Cu atom and trigonal–prismatic about each Na.     

The Role of Liquid Water in Crystalline Hydrate Dehydration: Copper sulphate pentahydrate

Simultaneous Differential Thermal Analysis/Thermogravimetric experiments carried out on one large single crystal, several small single crystals and powdered crystals of pentahydrate copper sulphate have been used to demonstrate the role that retained liquid water plays in maintaining crystal morphology during dehydration. Measured activation energies for stepwise dehydration in the system show the presence of solution-based transformations provide lower energy paths for the dehydration steps and stress relieving mechanisms. Skeletal anhydrous crystals from large-sized pentahydrate copper sulphate have the same morphology as the starting crystal on complete dehydration at controlled heating rates as long as a solution phase is maintained within the crystal during decomposition. The athermal activation energies, in this work, are in agreement with those obtained by isothermal methods as long as coincident reaction paths for the two techniques are maintained. The literature has been reviewed in the light of this work and a three-stage process is presented to rationalise the conflicting information obtained by workers using a variety of different experimental techniques.This revised version was published online in November 2005 with corrections to the Cover Date.     

Synthesis, spectroscopy, and X-ray structure of the polymer catena-[bis(azido-N)-copper(II)-μ-bis(2-benzimidazolyl)butane]

The title compound, catena-[bis(azido-N)-copper(II)-(bis(2-benzimidazolyl)butane), [Cu(C₁₈H₁₈N₄)(N₃)₂]_n, was obtained from the reaction of the ligand bis(2-benzimidazolyl)butane and Cu(N₃)₂. The x-ray crystal structure is reported. The compound crystallizes in the monoclinic space group P2₁/c with a = 8.2524(10), b = 12.765(5), c = 9.1125(15) Å, = 106.423(12)°, Z = 2. The Cu(II) ions are square-planar coordinated with trans-oriented end-on binding azido ligands. The structure is a polynuclear chain with the benzimidazole bridging at each end. In addition a N_(ligand)-H···N_(azido) H-bridge [N_(ligand)···N_(azido) = 2.994(7) Å] is present, resulting in a pseudo 2-dimensional lattice. The characteristic azido infrared vibrations are found at 2060 and 2077 cm^–1 (_as(N₃)) and 1284 and 1297 cm^–1 ((N₃)).     

Mo(15)S(20): first evidence of a new molybdenum cluster type in a metastable solid-state compound

The Mo(15)S(20) compound was obtained by thermal decomposition of the metastable binary Mo(15)S(19) in sealed silica tube at temperatures above 500 degrees C. Its crystal structure was solved and refined from a two-component composite crystal by X-ray diffraction in the hexagonal space group P6(3)/m and consists of an equal mixture of the original Mo(9)S(27) cluster unit and the classical one Mo(6)S(8)S(6) interconnected through Mo--S bonds. The Mo core of the Mo(9)S(27) unit is totally new and formed a tricapped trigonal prism. Quantum chemical calculations carried out in order to understand these trends as well as magnetic susceptibility measurements are also reported. The title compound becomes superconducting below 5 K.     

信息化对区域经济影响的数理分析

本文以信息化与经济指标资料为基础,运用加权回归、因子分析和聚类分析等方法,讨论了全国31个省(市、区)信息化水平及其与经济发展关系,给出地区综合发展水平的排行榜。并提出若干促进信息化建设的建议。     

铜的喹哪啶配合物[Cu(Me-quin)2H2O]的合成、表征及晶体结构

本文合成了铜的喹哪啶配合物[Cu(Me-quin)     

颗粒内传质参数作为工具用于催化剂颗粒的设计(英文)

A chromatographic method and a dynamic Wicke-Kallenbach method (DMWK) were used to determine the diffusion characteristics of two industrial copper containing catalysts. The first catalyst was used in nitrobenzene hydrogenation to aniline and the second was used in a low temperature water-gas shift reaction. Experimental results show that application of these two methods leads to similar results. Experimental data obtained allow for monitoring changes in the texture of the catalyst grains and intraparticle diffusivity of gaseous reagents at different states of the catalyst activity and use, which can be used as criteria for designing optimal industrial catalyst pellets.