河口水体中痕量稀土元素的共沉淀预富集-电感耦合等离子体质谱法测定研究

建立了氢氧化铟共沉淀预富集 -电感耦合等离子体质谱法测定河口水体中痕量稀土元素的方法。实验结果表明 ,在80mg·L -1的In3 +和pH9.5的实验条件下 ,在1.0L水样中添加5.0～200.0ng的混合稀土标准溶液 ,均能定量回收 ,回收率在82.2 %～106.9 %之间。方法的分析流程空白为0.04(Tb)～10.17(La)ng·L -1,检出限在0.17(Yb)～1.46(La)ng·L-1之间 ,精密度 (RSD ,n=3)小于11.7 % ,可满足河口淡水和海水样品中的痕量稀土元素定量分析的要求     

镧对含锡、锑残余元素的34CrNi3Mo钢热塑性的改善作用

采用Gleeble-1500热模拟机测定了不同含量的残余元素锡、锑及稀土镧对低氧、低硫的34CrNi3Mo钢热塑性的影响;采用SEM及EDS手段研究了稀土镧对不同锡、锑含量的钢断裂方式的影响及在其中形成夹杂物的情况。结果表明,用稀土金属可以改善低氧、低硫钢中残余元素对钢性能的危害;镧可以和钢中较低含量的锑作用生成镧锑金属间化合物,并且发现了少量的镧锡金属间化合物。     

含吩噻嗪金属配合物的合成及非线性光学性质研究

本文报道了一种新的配体:10-乙基-3-甲酰吩噻嗪缩肼基二硫代甲酸甲酯(HL)及其金属配合物的合成。采用了元素分析、质谱、核磁共振、红外光谱对配体及其金属配合物进行了表征。此外,并应用紫外、荧光和Z-扫描技术,测定了配体及其金属配合物的荧光最佳发射波长(λ_max^em)、荧光量子产率(Φ_f)、寿命(τ)和非线性光学性质。结果表明它们在DMF溶液中都能发射出较强的橄榄色荧光,配体及其金属配合物都有双光子吸收,并且金属配合物的非线性光学效应比配体明显增强。用半经验量子化学方法(RHF/PM3)计算结果与实验值较为吻合。     

新颖的二维超分子化合物[CoⅢ(aea)(2,2''''-bipy)]Cl·H2O的水热合成及结构表征

0IntroductionInrecentyearsgreatattentionhasbeenpaidtosupramolecularchemistryandawidevarietyofnet鄄workshavealreadybeenconstructedbasedupontheprincipleofcrystalengineering[1~3].Usually,variousmultifunctionalorganicligands,bothrigidandflexiblemulticarboxyli…     

An unusual new reaction of α-olefins with magnesiumn-alkyl derivatives catalyzed by Cp2ZrCl2

The reaction of organomagnesium compounds (OMC) containing alkyl radicals of normal structure with -olefins, resulting in the formation of alkenylorganomagnesium compounds and accompanied by hydride transfer was discovered and systematically investigated. A scheme providing for the formation of zirconacyclopentane complexes was proposed for the mechanism of the reaction.Institute of Organic Chemistry, Ural Branch, Russian Academy of Sciences, 450054 Ufa. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 5, pp. 1187–1196, May, 1992.     

An investigation of the aromaticity of transition metal heterocyclic complexes by conventional criteria and indices of aromaticity

Conventional criteria and indices of aromaticity, including electronic, geometric, energetic and magnetic aspects have been applied to examine the aromaticity of five typical transition metal heterocyclic complexes, i.e. six-membered osmabezene 1 and iridabenzene 2, five-membered cobaltacyclopentadiene 3 and iridacyclopentadiene 4, and four-membered tungstacyclobutadiene 5. The results show that the cyclic, planar, conjugated and Hückel 4n+2 rule’s criteria in the transition-metal-containing heterocycles of the five complexes studied are all met. Five quantitative aromaticity indices, including Bird aromatic index (I_n), homodesmotic reaction aromatic stabilization energy (HASE), absolute hardness (η), diamagnetic susceptibility exaltation (Λ) and NMR chemical shift (δH), qualitatively lead to a consistent and affirmative conclusion that all of them are aromatic. However, they fail to draw a common conclusion for their relative magnitudes of aromaticity, which proves once again the multidimensional character of aromaticity.     

Reaction of indium ate complexes with allylic compounds. Controlling SN2/SN2′ selectivity by solvents

Vinyl and methylindium ate complexes (indates) were prepared and both the tendency of immigration and regioselectivity toward cinnamyl bromide were investigated. The vinyl group was more preferably transferred than the Me group, giving a regioisomeric mixture of S_N2 and S_N2′ products. The ratio of S_N2/S_N2′ selectivity can be controlled by solvents; in the presence of polar solvents, such as N-butylpyrrolidone (NBP) and THF, the S_N2′ product was mainly obtained, whereas the S_N2 product was selectively prepared in solutions containing hexane. The vinylindium compound, generated by the reaction of allylic-type diindium reagents with imine, was also converted to the corresponding vinyl indate, which was allowed to react with allyl chloride to give a three-component coupling product.     

微乳凝胶法制备MoO3/SiO2纳米复合氧化物及DSC-TG分析

由微乳凝胶法制备了一系列不同MoO3含量的MoO3/SiO2纳米复合氧化物,运用DSC-TG,TEM,XRD和FT-IR等技术对其进行了相应表征.结果表明:所制备复合氧化物适宜的焙烧温度为300℃;样品粒径分布在20~24 nm;样品中MoO3在SiO2表面分散良好,其单层分散阈值在12~12.5%之间;表面Mo与Si原子以Mo—O—Si键联接.     

高碲酸合铜（Ⅱ,Ⅲ）配合物的合成和性质

在Ｈ６ＴｅＯ６／ＫＯＨ水溶液中以臭氧为氧化剂，将二价铜化合物氧化成三价铜化合物，并获得一个新的三价铜化合物Ｂａ４Ｋ［Ｃｕ（Ｈ２ＴｅＯ６）２］（ＯＨ）４．６Ｈ２Ｏ；描述了碱性溶液中“Ｃｕ（Ⅲ）／Ｃｕ（Ⅲ）”循环伏安图。对铜（Ⅲ）化合物，Ｎａ４Ｈ［Ｈ２ＴｅＯ６）２］．１７Ｈ２Ｏ以及相应的铜（Ⅱ）配合物的电子光谱和Ｃｕ２ｐＸＰＳ进行了研究，给出了其配位场场强参数和Ｃｕ２ＰＸＰＸ的电子结合能。由于价态升高     

Nd（P_（507））_3－Al（i－Bu）_3催化马来酸酐与环氧丙烷开环交替共聚

本文研究了马来酸酐和环氧丙烷交替共聚，发现Ｎｄ（Ｐ_（５０７））_３－Ａｌ（ｉ－Ｂｕ）_３是马来酸酐（ＭＡｎ）和环氧丙烷（ＰＯ）交替共聚的良好催化剂，并用红外光谱，核磁共振谱研究了共聚物的结构。