苯并-15-冠-5取代的有机硅化合物的合成及其性能

我们提出了一条合成含有苯并-15-冠-5取代基的某些有机硅冠醚化合物的简易路线。通过Wittig反应合成的4'-乙烯基苯并-15-冠-5,经过双键上的硅氢加成反应,得到几种新型含有冠醚基团的有机硅烷或氯硅烷。后者可以进一步烷氧基化或者水解成冠醚取代的聚有机硅氧烷。此外,还测定了它们对碱金属离子的络合容量和作为相转移催化剂的能力。     

Cyclische,gekreuzt-konjugierte Bindungssysteme. XIII. NMR.-untersuchungen am Phenafulven-system

The HNMR. spectra of phenalene, phenalenone, of some protonated and alkylated derivatives and the spectra of some substituted phenafulvenes are discussed and very qualitatively correlated with the π-electron distribution in some of these systems.     

Tribo-electricity

Tribo-electrification is a process in which two bodies are contacted and separated with the result that each body becomes electrically charged. The connection between chemistry and charging is illustrated by describing, in some detail, contacting experiments between mercury and insulating organic materials after various chemical treatments of the organic surface. Introductions to selected topics are presented; principles for methods of measurment, some experimental results, an electroni model involving surface states for charging between a metal and an insulator, some factors limiting chargin, and some qualitative correltaions with the macroscopic compositions of the materials.     

微量元素与老年性痴呆

阐明了几种微量元素在人体内某些部位的含量变化及其对神经系统产生的影响 ,以及与阿尔茨海默病 (老年性痴呆病 ,AD)临床症状的关系。研究表明 ,一些AD发病机制诸如突触及神经元的丢失、细胞内神经原的缠结和细胞外的老年斑等 ,与病人体内某些微量元素含量的异常密切相关 ,而且影响机制复杂 ,途径多样。探明微量元素的作用机制 ,对AD病的防治和诊断意义重大     

微流体技术制备聚合物微粒的研究进展 Ⅰ.合成聚合物颗粒的方法及颗粒种类

综述了微流体技术合成聚合物颗粒的研究进展,包括基于液滴的合成、用流动刻蚀的技术合成及在设备中交替组装成复杂颗粒等合成组装技术,介绍了由此合成的一些不同形状和结构的颗粒及其性能,其中包括具备低密度和特殊表面性能的多孔性颗粒、可以通过加入功能物质制备出的性能优异的复合颗粒、拥有层状结构及多重性能的多功能颗粒、基础的球形颗粒以及通过微流体设备制备的非球形颗粒。     

An ESR study of the radical interactions of NOx with lignin-containing pulps and papers and several model lignin compounds

The reactions of alkyl peroxyl radicals with cellulosic and lignin-containing papers have significance in both the problems of brightness reversion and paper aging phenomena. Since transient peroxyl radicals are elusive to ESR and other spectroscopic detection, we have explored the controlled study of the interactions of nitrogen oxides with paper and some model lignin compounds in solution as a comparable model of free radical oxidation. Formations of intermediate iminoxyl and nitroxide radicals are identified by ESR with products in some model systems analysed by GC/MS to elucidate the primary mechanisms of the interactions of these gaseous free radicals with papers and with some simple organic model lignin compounds.     

Behaviour of Mo,Al, As,Cs, Sn,Sb, Pd,Rh, Ru,Ge, Se and Te on the macroporous resin AG MP-1 in alkaline medium

The behaviour of Mo and some other elements on Ag MP-1 in alkaline medium was investigated. Equilibrium distribution coefficients, K_d, are presented for Mo on the anion exchangers AG 1-X2, AG 1-X4, AG 1-X8 and AG MP-1, and for some elements on AG MP-1 in alkaline medium. An anion exchange chromatographic separation of Mo from some of these elements is described and some results obtained with this method are reported.     

Prediction and correlations of some delayed neutron precursor yields for certain actinide nuclides

In this paper some predictions about some delayed neutron precursor yields are presented. The predictions are applied for certain actinides with some special interest in the nuclear energy field. The predictions are based on correlations which might be related to the cluster structure of the nucleus.     

基于受体结构的AHAS抑制剂的设计、合成及生物活性

在AHAS与磺酰脲类除草剂复合物的晶体结构基础上, 利用分子对接程序DOCK 4.0, 通过MDL/ACD三维数据库虚拟筛选, 得到了296个与AHAS结合能较低的小分子化合物结构信息, 从中选取了部分小分子进行化学合成, 并且测试了其生物活性. 部分化合物的体内和体外活性表现出一定的一致性.     

Some Homo- and Copolymerization Studies of Dimethyldiallylammonium Chloride

This paper summarizes some of the experimental procedures used for making homopolymers and copolymers of dimethyldiallylammonium chloride, along with a discussion of some of the experimental variables such as effects of catalyst ratio, monomer concentration, and impurities. Also discussed are some of the procedures used for evaluation of the polymers and copolymers in flocculation and sludge dewatering.     

Riboflavin Interactions with Oxygen—A Survey from the Photochemical Perspective

In this short review we provide some insights to the main processes that riboflavin is involved in upon absorption of a photon. We describe riboflavin properties in its interactions with oxygen, comparing them to the properties of some other singlet oxygen sensitizers. Data are provided on riboflavin photosensitizing properties in vivo and in vitro, and its properties as an endogenous singlet oxygen sensitizer are discussed. We additionally report flavin catalytic role in organic synthesis and photochemical reactivity in solutions of riboflavin and some of its derivatives.     

2D-QSAR Studies on Pyrazole Compounds Containing Pyrimidine Amino

The quantitative structure-activity relationship (QSAR) of 16 pyrazole compounds was studied by ab initio method at the HF/3-21G level using Guassian03 soft. The optimized structures together with some characteristic and electric parameters of the title compounds were obtained; some stereo-parameters were calculated by HyperChem software. Stepwise multiple regression method was adopted to establish bi-and tri-parametric models between biological activity and some parameters. The lager ΔE and logP,the higher biological activity; and the biological activity would be promoted with the smaller μ,QN and QPYRA. It provided a theory direction to synthesize some compounds with high activity.     

Testing the performance of density functionals for the calculation of energetic properties of complex-forming radical-molecule reactions

The performance of some popular and some more recent density functional methods for the calculation of energies of stationary points on the potential surfaces of radical-molecule reactions was examined. The functionals studied are B3-LYP, BH&H, BH&H-LYP, MPW1K, MPWB1K, TPSS, TPSSh, BB1K, M05 and M05-2X, in conjunction with nine different AO basis sets. The reaction energies, barrier heights and the relative energies of the pre-and post-reaction complexes were compared with those obtained at the CCSD(T)/CBS limit for the reactions of OH radicals with HOOH and CH₃OOH. Very poor barrier heights are provided by the B3-LYP, TPSS and TPSSh functionals. The best overall performance was obtained with the BB1K, MPW1K and MPWB1K functionals. In these reactions all of the studied functionals provide converged results only if they are used with large basis sets like aug-cc-pVTZ and def2-TZVP. The data show that before relying on a functional for a specific reaction, it is desirable to make some test calculations on the performance. The same functional can predict some relative energies very well and some others very poorly even in systems including chemically similar reactants.     

A study of the chemiluminescence of some acidic triphenylmethane dyes

Chemiluminescence was observed when some acidic triphenylmethane dyes were oxidized with hydrogen peroxide in alkaline solution. Trace amounts of Co(II) catalysed this chemiluminescent reaction strongly, especially in the presence of the cationic surfactant cetyltrimethylammonium bromide. The chemiluminescence spectra of some compounds and the absorption spectra of some products of the chemiluminescent reactions were investigated, and some acidic triphenylmethane dyes were studied by the Hückel molecular orbital method. On the basis of these investigations, a possible mechanism for this chemiluminescent reaction, and an initial explanation for the relationship between the structure of the reagents and their chemiluminescent behaviour were proposed. The optimum conditions for use of some of the chemiluminescent reaction systems were selected by means of the modified simplex method, and a chemiluminescent analytical method for determination of ultratrace amounts of cobalt was established, with a detection limit of 5 pg/ml. It was used for analysis of natural water samples, and good results were obtained.     

Ir-catalyzed chemoselective reduction of β-amido esters: A versatile approach to β-enamino esters

The conversion of β-amido esters to β-enamino esters is an indispensable step for some synthetic approaches to alkaloids and related medicines. Known methods for such transformation are not only stepwise, but also proceed with low atom-efficiency. Herein, we report a direct and versatile approach that features the Ir-catalyzed chemoselective reduction of β-amido esters with 1,1,3,3-tetramethyldisiloxane (TMDS). In addition, a lack of some signals was observed in the ¹³C NMR spectra of some alicyclic β-enamino esters. This revealed a longstanding existing but being ignored phenomenon in the literature.     

Synthesis and biological evaluation of structural variants of carbazoquinocin C

Some new structural variants of the alkaloid carbazoquinocin C were synthesized in a few steps with good to excellent yields. The key step comprises a cyclisation reaction of appropriate 2‐vinylindoles with oxalyl chloride. The carbazole‐3,4‐quinones are able to trap oxygen‐centred radicals. In some biological/biochemical assays some of these compounds exhibit extraordinary results including inhibition of cyclooxygenase‐1 and 5‐lipoxygenase in the μM‐range. Moreover some of the carbazoquinocin C‐variants inhibit significant oxidative damage of cellular DNA in nM‐range.     

胆红素,胆绿素与金属离子的作用机制初探

用电化学方法和光谱方法对胆红素、胆绿素与金属离子在碱性水溶液中的作用机制进行了研究。发现它们与金属离子的作用情况依金属离子种类和反应条件不同而异。在有氧情况下，碱土、稀土等金属离子不与它们发生作用，Ｈｇ＾２＋、Ａｇ＾＋、Ｔｌ＾＋、Ｈｇ＾２＋２等则可与它们发生直接氧化还原或催化氧化反应；而在除氧的条件下，胆红素、胆绿素则可与Ｆｅ＾３＋、Ｃｕ＾２＋、Ｚｎ＾２＋、Ｃｄ＾２＋等形成配合物，而无催化氧化反…     

过渡金属催化的炔烃芳构化反应

综述了过渡金属催化的炔烃环三聚芳构化反应的历史沿革及最新研究进展，并 重点对含有不同电性取代基的炔烃环三聚反应、几种典型的催化体系和作用机理、 该领域的一些前沿热点作了评述．     

Highly diastereoselective 1,4-addition of an organocuprate to methyl alpha-D-gluco-, alpha-D-manno-, or alpha-D-galactopyranosides tethering an alpha,beta-unsaturated ester. Novel asymmetric access to beta-C-substituted butanoic acids

The 1,4-addition of magnesium divinylcuprate prepared from vinylmagnesium bromide and cuprous bromide to some 4-O-crotonyl derivatives of methyl alpha-D-glucopyranoside proceeds with a high level of diastereochemical induction, providing the adduct in good-to-excellent yields. Other organocuprates also serve as effective carbon nucleophiles for the 1,4-addition. Removal of the carbohydrate moiety from each adduct afforded a variety of beta-C-substituted butanoic esters in remarkable enantiomeric excess. The 1,4-addition of the same cuprate to some methyl alpha-D-manno- or alpha-D-galactopyranosidic substrates in which a crotonyl group was incorporated, each at 3-OH, was also investigated. The reverse pi-facial attack of the cuprate was observed when some D-manno-type substrates were subjected to 1,4-addition conditions similar to those used for the D-gluco-type substrates. Furthermore, some D-galacto-type substrates provided 1,4-adducts with higher diastereoselectivities.     

Microwave-Assisted Synthesis of Some Novel Thiazolidinone and Thiohydantoin Derivatives of Isatins

A simple, rapid, and efficient method for the synthesis of some new thiazolidinone and thiohydantoin derivatives of isatins along with some Mannich bases has been achieved in excellent yield from indole-2,3-dione-3-thiosemicarbazone employing microwave irradiation.