A hydrogen rearrangement of formamidine and the solvent effects thereupon

The nature of the 1,3 hydrogen rearrangement of formamidine (H₂N-CH=NH) and the solvent effects on that reaction are studied with ab initio molecular orbital calculations on the basis of the supermolecule model. The reaction path and the motion of the migrating hydrogen atom are traced by using the concept of the intrinsic reaction coordinate (IRC). Four types of orientation of one water molecule to formamidine at the transition state of reaction are examined and the results are discussed from the standpoint of the orbital interactions.     

Synthesis and crystal structure of a new one-dimensional system with end-to-end single dicyanamide bridges between nickel(II) centres

The complex [Ni(tn)₂{N(CN)₂}]ClO₄ (tn=trimethylenediamine) has been synthesized and the structure has been determined. The complex forms a one-dimensional chain structure via the bidentate bridging ligand dicyanamide. A two-dimensional networks is formed via interchain hydrogen bond interactions.     

含喹噁啉环的化合物改性聚己内酰胺

合成了14种由三种含喹(哑心)啉环的芳香化合物改性的聚己内酰胺(MC尼龙),并对其形态、抗冲击强度、吸水性及熔融行为等进行了表征。聚苯基单醚喹(哑心)啉(PPQ)单模型化合物对MC尼龙结晶部分几乎没有影响。少量(0.005—5.0％)吩嗪的引入使MC尼龙的颜色、形态及性能等发生巨大变化,改性体系被认为是氢键相互作用,PPQ双模型化合物的改性作用介于二者之间。     

简便快速的硫化氢测定法

本文提出了有一种简易快速测定剂来测定水样中的硫化氢的方法。该法的检出限为０．１ｍｇ／Ｌ，对１．０１ｍｇ／Ｌ的Ｈ２Ｓ样品７次测定的相对标准偏差＜４．１％，１ｈ能测定１２个样品。用本测定了几种水样中的Ｈ２Ｓ含量，回收率为８４％－１０５％。应用它可上标准法的４ｈ左右缩短到５ｍｉｎ；使分析成本降低９／１０；不需配制一系列分析试剂和仪器，只需一支小型塑料管和几片药片，便于渔业水质和环境水质的野外现场监测。     

三缺位杂多化合物K_8［P_2W_（18）Mo_2Co_2（H_2O）_2O_（68）］·MoO_6·15H_2O的合成、结构及催化H_2O_2分解研究

合成了杂多化合物Ｋ８［Ｐ２Ｗ（１８）Ｍｏ２Ｃｏ２（Ｈ_２Ｏ）２Ｏ（６８）］·ＭｏＯ６·１５Ｈ２Ｏ，依据ＸＲＤ、ＩＲ、ＵＶ－Ｖｉｓ及ＸＰＳ确定了其晶体结构和配位原子价态，考察了该化合物催化Ｈ２Ｏ２分解的动力学行为。     

A spectroscopic study on the 12-heteropolyacids of molybdenum and tungsten (H3PMo12−nWnO40) combined with cetylpyridinium bromide in the epoxidation of cyclopentene

The epoxidation of cyclopentene with hydrogen peroxide catalyzed by 12-heteropolyacids of molybdenum and tungsten (H₃PMo_12−nW_nO₄₀, n = 1–11), 12-tungstophosphoric acid and 12-molybdophosphoric acid combined with cetylpyridinium bromide as a phase transfer reagent was carried out in acetonitrile. Among 13 heteropolyacids investigated, catalyst of H₃PMo₆W₆O₄₀ showed the highest activity, giving a conversion of 60% and a selectivity of 95% in the epoxidation of cyclopentene. The fresh catalysts and the catalysts under reaction condition were characterized by UV–vis, FT-IR and ³¹P NMR spectroscopy, which has revealed that all of the molybdotungstophosphoric acids were degraded in the presence of hydrogen peroxide to form a considerable amount of phosphorus-containing species. The active species resulted from H₃PMo₆W₆O₄₀ are new kinds of phosphorus-containing species, which is different from {PO₄[WO(O₂)₂]₄}³⁻.     

Syntheses and Crystal Structures of Two Coordination Polymers with Aromatic Dioxide as Bridge Ligands

Two coordination polymers, namely, two-dimensional complex 1 {[Cu(μ- L)1.5(ClO4)2(H2O)].(H2O)0.5}n (L = pyrazine-1,4-dioxide) and one-dimensional complex 2 [Co(μ-L)Br2(H2O)2]n, have been synthesized with pyrazine-1,4-dioxide as bridging ligands, and their crystal structures were determined by X-ray crystallography. Crystal data for complex 1: monoclinic system, space group C2/c, with a = 23.310(3), b = 12.2338(17), c = 10.6075(15) , β = 110.487(2)°, V = 2833.6(7) 3, Z = 8, C6H9Cl2CuN3O12.5, Mr = 457.60, Dc = 2.145 g/cm3, F(000) = 1832 and μ = 1.998 mm-1; and those for 2: monoclinic system, space group C2/c, with a = 11.012(3), b = 7.483(2), c = 11.451(3) , β = 101.654(4)°, V = 924.2(4) 3, Z = 4, C4H8Br2CoN2O4, Mr = 366.87, Dc = 2.637 g/cm3, F(000) = 700 and μ = 10.487 mm-1. 1 shows a two-dimensional sheet structure on the ac plane through the coordination of μ-L bridging ligands with Cu(II) ions, while 2 displays a zigzag one-dimensional chain along the c axis via the coordination of μ-L bridging ligand with Co(II) ions. Hydrogen bonds in 1 and 2 make the sheets (or chains) connect each other to form a three-dimensional structure.     

傅立叶变换红外光谱对灰指甲组织结构的研究

对健康指甲和灰指甲的红外光谱特征吸收峰进行了指认,并对其相应官能团的吸收峰进行了对比分析.结果表明,灰指甲增厚、变脆的原因系α-角蛋白螺旋结构遭到破坏,肽链伸展并发生断裂,形成了不同化学环境的氨基酸,同时蛋白质分子的有序排列也发生了改变.     

贮氢合金材料电化学与表面性能的研究进展

贮氢合金材料电化学与表面性能的研究进展①杨勇李骏林祖赓（厦门大学化学系，固体表面物理化学国家重点实验室，厦门３６１００５）八十年代后期以来，人们对地球的环境保护提出了更高的要求，而便携式电器（如移动电话，摄像机与笔记本电脑等）对电池的需求也大量增加...     

Hydrogen cycling induced diffraction peak broadening in C14 and C15 Laves phases

The diffraction peak broadening induced by hydrogen absorption-desorption cycling has been analyzed in four different Laves phase compounds with the C14 and C15 structures. The broadening is due to strain most probably originating from dislocations generated at the interface between the α and β hydride phases in connection with the cell volume difference between the two phases. It has been shown that it is strongly compound dependent. In the case of the C14 structure, the broadening is large and isotropic, and the latter can be related to the isotropy of the elastic constants of the metallic phase. The broadening is less for the compounds with the C15 structure, which can be related to a possibly softer lattice. Better ageing properties after long-term cycling are predicted for this crystal structure.