硫酸盐水合物催化下的有机合成及反应

报道了在硫酸盐水合物催化下的酯化反应、酯交换反应、δ-酮酸环合反应、羟醛缩合反应、酮的烯醇化反应、缩醛酮反应、呐咵重排反应及醇脱水反应。研究了硫酸盐水合物的催化活性及催化反应动力学,对这一类型反应的反应机理进行了探讨,证明反应是配位催化过程。     

连续流微反应

近几个世纪,传统釜式反应为我们解决了大量化工产品需求的问题。但其本身存在着很多的缺点,如安全隐患、环境污染、能源消耗巨大、占地面积大以及工艺放大困难等。连续流微反应以其高效的传质传热、精确控温控时、安全稳定、无放大效应以及反应的实时监控等优点,能很好地解决传统釜式反应存在的问题。本文对连续流微反应在最近五年的研究进展进行了概述,特别对连续流中的硝化反应、叠氮基丙烯酸酯的热解反应、格氏反应与类格氏反应、偶联反应、胺化反应、氧化还原反应、缩合反应、环化反应、多步骤反应及常用连续流微反应器进行了介绍。同时,对连续流微反应的优缺点进行了简要评述。     

4-甲氧基-7H-呋喃[3,2-g][1]苯并吡喃-7-酮制备的新方法

以间苯三酚为起始原料,通过醚化反应、碘化反应、Pechmann反应、偶联反应、水解反应和脱羧反应合成了目标产物4-甲氧基-7H-呋喃[3,2-g][1]苯并吡喃-7-酮。经红外光谱、质谱、核磁共振测试技术对各化合物的结构进行了表征。优化了醚化反应和碘化反应的工艺条件,并探索了通过选择性碘化反应、Pechmann反应和偶联反应来合成目标化合物的可行性。反应均在常压下进行,反应条件温和,后处理相对简单,为呋喃香豆素类化合物的制备提供了新方法。     

微波促进离子液体相反应在有机合成中的应用

微波促进离子液体相有机合成技术作为一种新型的绿色化学合成法,引起了人们极大的兴趣。在离子液体中,微波辅助下反应快速、收率高、选择性好、后处理简单,离子液体经简单再生后可多次套用。本文综述了以离子液体为反应介质或催化剂的微波辅助技术在多种类型有机反应中的研究成果,主要包括了环合反应、亲核取代反应、金属复分解反应、酰化反应、重排反应、聚合反应、偶联反应、氧化还原反应和选择性脱溴反应等。     

Mo（W）—Cu（Ag）—S原子簇化合物的反应

总结了Ｍｏ（Ｗ）－Ｃｕ（Ａｇ）－Ｓ原子簇化合物的反应，并把这些反应分成５类：取代反应，加成反应，降价反应，多聚反应和氧化还原反应。从低热固相反应的角度探讨了簇合物反应对合成新原子族化合物的重要性。     

聚酯反应动力学的研究

在最近三年中,我们在聚酯反应动力学方面进行了下列工作:(一)确定了聚酯反应动力学的反应级数,澄清了长久以来关于聚酯反应级数的争论;(二)建议了一种新的酯化反应,聚酯反应和三向聚酯反应的氫离子催化机构;(三)从反应动力学的观点讨论了三向缩聚反应中的凝胶化问题;(四)研究了反应速度常数与二元酸和二元醇的分子结构的关系。下面我们分别作简要说明。     

乙酰乙酸乙酯－BR化学振荡反应的研究

本文首次报道了乙酰乙酸乙酯－ＩＯ－３－Ｈ２Ｏ２－Ｍｎ２＋－Ｈ２ＳＯ４体系的化学振荡反应。研究了各种因素对振荡反应的影响，测定了最佳反应条件及振荡反应的浓度范围。研究了温度变化对振荡反应的影响，并计算了振荡反应的表观活化能，对振荡反应产物进行了分析，并测定了体系主要反应的计量关系，采用ＵＶ法对金属离子的作用和催化机理作了研究，探索了ＢＲ反应中Ｉ２的产生机理及消耗机理，对体系中有关反应物的作用作了说明。在ＦＫＮ机理的基础上，对ＢＲ反应的自催化反应步骤和控制机理进行了初步的探索，并对有关实验现象作了说明。     

肉桂酸的催化氧化反应研究

研究了季铵盐催化下高锰酸钾氧化肉桂酸的反应。考察了催化剂、反应时间、温度、高锰酸钾的用量及反应体系的酸碱性对反应的影响。在优化反应条件下,反应产率可达72.30%。     

二氧化碳直接加氢合成反应的热力学分析(英文)

二氧化碳直接加氢合成反应是二氧化碳活化和有效利用的重要途径之一。列举了１８个二氧化碳氢化反应,并对相应的反应热和平衡常数进行了计算。假定各反应物以反应的摩尔计量比参加反应、反应物的总量均为１ｍｏｌ,求出了各反应中ＣＯ２的平衡转化率。     

由邻苯二甲酸二乙酯制备水合茚三酮的反应机理探讨

以邻苯二甲酸二乙酯为原料,经Claisen酯缩合反应、酸性酯水解反应、热脱羧反应、亚硝化反应、脱肟反应、羰基还原反应、Aldol反应、邻二醇氧化裂解反应制备了水合茚三酮,对各步的反应机理进行了详细的讨论。     

Improvement of properties of silica‐filled styrene‐butadiene rubber composites through plasma surface modification of silica

The performance of plasma surface modified silica filler in styrene‐butadiene rubber (SBR) matrix has been analyzed. The conditions of plasma modification have been optimized by taking secant modulus as a standard parameter and the occurrence of the modification has been confirmed by surface area determination and Fourier transform infrared spectroscopy. The plasma‐modified surface of silica has been found to be composed of carbon–carbon double bonds and carbon–hydrogen bonds. Silane treatment also has been carried out on silica filler surface for a comparative assessment of its influence in the curing behavior and filler–rubber interaction. The cure reactions of all the rubber compounds have been found to be proceeded according to first‐order kinetics. A reduction in the cure reaction rate constant has been observed with the loading of unmodified and surface modified silica, emphasizing the cure deactivation of the matrix rubber by the silica filler. The filler dispersion, as revealed by scanning electron microscopy, has been found to be greatly improved by the plasma as well as silane treatment. The filler–rubber interaction has been found to be greatly improved by both surface treatments, but the best balance of mechanical properties has been observed with plasma surface modification only. Copyright © 2004 John Wiley & Sons, Ltd.     

Synthesis and studies of structure and biological properties of D-homoanalogs of steroid estrogens

In order to estimate the potential of steroid estrogens modification, three D-homoanalogs of estrogens have been prepared; their structures and biological properties have been studied. The expansion of D-ring in such compounds has lead to strong decrease if the uterotropic action, however, the unfavorable hypertriglyceridemic effect has been retained. The latter has been eliminated by combined action of the studied steroids and ursolic acid; therewith the hypocholesterolemic activity has been retained.     

Radioimmunoassay of human placental lactogen

A sensitive and specific radioimmunossay procedure (RIA) has been developed for the measurement of Human Placental Lactogen (HPL). Pure HPL has been labelled with¹²⁵I and a specific activity of 100 μCi/μgm of HPL has been attained. Dextran-coated charcoal has been employed to separate the bound from the free hormone in radioimmuno-assay. The sensitivity of this technique has been found to be 0.2 ng of HPL. Intraassay and inter assay variations have been found to be less than 10%. This procedure has been adopted to establish the normal range of HPL in pregnant women at different periods of gestation, and to evaluate risk pregnancies.     

Extraction of cations as salts of fatty acids : Analytical and chromatographic separation of beryllium from iron and aluminium

Quantitative extractions of aluminium and ferric ions are carried out in presence of butyric acid. A method has been given for quantitative extraction of beryllium from aluminium and ferric ion in presence of ethylenediaminetetra-acetic acid. Interference has been studied and interference due to phosphate has been avoided by addition of zirconium salt. The method has been applied to thc analysis of beryl.     

Radioimmunoassay of human chorionic gonodotropin

A rapid and sensitive radioimmunoassay has been developed for the measurement of Human Chorionic Gonadotropin (HCG) in serum. Human chorionic gonadotropin has been labelled with¹²⁵I to attain a specific activity between 80–120 μCi/μg. Aqueous dioxane (74 vol. %) has been employed to separate the bound and freehormone in the radioimmunoassay. The sensitivity of this technique has been found to be ∼1.5 mIU/ml of HCG. The intra assay variation has been found to be less than 5% and inter assay variation has been found to be less than 12%.     

The influence of the concentration and size of silver nanoparticles on the conductivity of ring-shaped deposits resulting from evaporation of colloidal solution droplets

The conductivity of ring-shaped deposits formed at the periphery of evaporating droplets of silver nanoparticle colloidal solutions has been studied. The dependence of the resistance of the ring-shaped deposits on nanoparticle size has been shown to exhibit a percolation transition. The specific conductivity of the deposits has been estimated in relation to their geometric shapes. The conductivity has been established to nonmonotonically depend on nanoparticle sizes. It has been noted that, in rather strong fields, the conductivity of the composite layers dramatically increases after some induction period. The X-ray spectra of silver have been revealed to alter for samples the conductivity of which has increased under the action of an external electric field.     

Selective Potentiometric Measurement of Physiologically Significant Thiols

The reaction of benzoquinone with reduced thiol species has been investigated using potentiometric techniques. The specificity of this reaction for thiol functionality has been briefly assessed and the nature of the electrode response has been elucidated. The system has been characterized in terms of selectivity, sensitivity and the efficacy of using the system for the quantification of thiol containing pharmaceuticals has been demonstrated. The simplicity of the detection methodology is shown to markedly contrast alternative thiol detection strategies. The transfer of the technology to a mass production format through the adoption of screen print electrode formats has been achieved and the efficacy of the approach demonstrated. Recovery experiments using captopril and penicillamine in tissue culture as a model analyte system were performed.     

Ionization probability of the hydrogen atom suddenly released from confinement

The problem of the stability of a confined atom when it is extracted from the confining cavity has been investigated, modeled by a spherical hard wall potential. The ionization probability when the atom is released from confinement has been obtained. The dependence of the ionization probability on the confinement radius and on the quantum numbers of the initial confined state has been studied. The probability density function of the ionization energy of the ejected electron has been obtained for the different cases considered. The oscillatory structure of this distribution function, with a principal maximum located in the neighborhood of the energy of the initial state and minima very close to zero has been elucidated. The sudden approximation has been applied and the analytic continuation method has been used to calculate the different stationary states.     

Kinetics and mechanism of oxidation of cyclopentanone by N-bromosuccinimide

N-bromosuccinimide oxidation of cyclopentanone in acidic media in presence of mercuric acetate has been made. A zero order dependance to N-bromosuccinimide and a first order dependence to cyclopentanone and hydrogen ion concentration has been observed. Ionic strength, mercuric acetate and succinimide has negligible effect while methanol addition has a positive effect. Various rate parameters have been computed and 1,2-cyclopentanedione identified as the end product. A suitable mechanism in confirmity with the above observations has been proposed.With 2 Figures     

贵金属Au冷却过程中结构及能量变化的分子动力学计算机模拟

通过分子动力学方法,研究了不同冷速下贵金属Au在温度2000～300K的冷却过程中微观结构的变化特点。结果发现,冷却速度对Au的微观结构产生重要影响。采用偶关联函数和键对分析技术对原子局域团簇结构进行分析,并考察了冷却过程中原子势能随温度的变化,比较了Au的微观结构转变与能量变化的对应关系,从能量转化的角度对冷却过程中Au的结构变化进行了说明。