诱导效应指数与脂肪族胺、醇和醚的气相碱性

用烷基诱导效应指数I和RX分子中质子亲合原子X所带电荷qx及元素电负性XN与 脂肪胺，醇、醚的气相质子亲合PA进行关联，结果表明，脂肪胺，醇、醚的气相碱 性可以用下式定量描述：PA(kJ.mol^-1)-2732.0333-2457.1510∑I-1492.2351qx- 732.6277XN利用上式对64种化合物的气相碱性进行预测，平均相对误差为0．34％ ，预测值和实验值的偏差均在实验误差范围内。     

Catalytic asymmetric cyanosilylation of ketones with chiral Lewis base

The development of broadly applicable and practical catalytic approaches for the enantioselective creation of quaternary stereocenters remains a highly desirable yet challenging goal. In this Communication, we describe a highly enantioselective cyanosilylation of acetal ketones (alpha,alpha-dialkoxy ketones) catalyzed by modified cinchona alkaloids. This reaction is the first highly enantioselective cyanosilylation of ketones catalyzed by an organic chiral Lewis base and is found to be highly efficient with acetal ketones bearing a broad range of alkyl, aryl, alkenyl, and alkynyl substituents. This new catalytic asymmetric reaction, coupled with the versatility of the acetal functionality, provides a broadly useful synthetic method for chiral building blocks bearing quaternary stereocenters. Acetal ketones, readily accessible but previously unexplored in asymmetric synthesis, demonstrate unusual reactivity and selectivity toward the nucleophilic cyanosilylation, thereby suggesting that they may be interesting substrates for other catalytic enantioselective reactions.     

1,3‐dipolar cycloaddition reactions of nitrile oxides to prop‐1‐ene‐1,3‐sultone

The reaction of prop‐1‐ene‐1,3‐sultone 1 with a variety of nitrile oxides 3 afforded novel [3+2] cycloaddition products 4 in good yield. The cycloaddition reaction achieved excellent regioselectivity.     

CoCl_2·6H_2O or LaCl_3·7H_2O Catalyzed Biginelli Reaction. One-Pot Synthesis of 3,4-Dihydropyrimidin-2(1 H)-ones

Ｉｎｔｒｏｄｕｃｔｉｏｎ1,4 Ｄｉｈｙｄｒｏｐｙｒｉｄｉｎｅｓｏｆｔｈｅｎｉｆｅｄｉｐｉｎｅｔｙｐｅ (ｅ .ｇ .Ｉ—ＩＩＩ)ａｒｅｔｈｅｍｏｓｔｓｔｕｄｉｅｄｃｌａｓｓｏｆｏｒｇａｎｉｃｃａｌｃｉｕｍｃｈａｎｎｅｌｍｅｄｉｃｉｎｅ ,ｗｈｉｃｈｈａｖｅｂｅｃｏｍｅａｌｍｏｓｔｉｎｄｉｓｐｅｎｓ ａｂｌｅｆｏｒｔｈｅｔｒｅａｔｍｅｎｔｏｆｃａｒｄｉｏｖａｓｃｕｌａｒｄｉｓｅａｓｅｓｓｕｃｈａｓｈｙｐｅｒｔｅｎｓｉｏｎ ,ｃａｒｄｉａｃａｒｒｈｙｔｈｍｉａｓ ,ｏｒａｎｇｉｎａ .1Ｉｎｔｈｅｐａｓｔｄｅｃａｄｅ…     

Electrochemical behavior and determination of epinephrine at a mercaptoacetic acid self-assembled gold electrode

The electrochemical behavior of epinephrine (EP) at a mercaptoacetic acid (MAA) self-assembled monolayer modified gold electrode was studied. The MAA/Au electrode is demonstrated to promote the electrochemical response of epinephrine by cyclic voltammetry. The possible reaction mechanism is also discussed. The diffusion coefficient D of EP is 6.85 × 10⁻⁶ cm² s⁻¹. In 0.1 mol L⁻¹ phosphate buffer (pH 7.20), a sensitive oxidation peak was observed at 0.177 V, and the peak current is proportional to the concentration of EP in the range of 1.0 × 10⁻⁵–2.0 × 10⁻⁴ mol L⁻¹ and 1.0 × 10⁻⁷–1.0 × 10⁻⁶ mol L⁻¹. The detection limit is 5 × 10⁻⁸ mol L⁻¹. The modified electrode is highly stable and can be applied to the determination of EP in practical injection samples. The method is simple, quick, sensitive and accurate.     

A Novel Dinuclear Nickel(II) Complex with Three Bridges of Cl–, OAc– and (‐OCH2CH2O‐) Group of N,N, N′, N′‐Tetrakis(2‐benzimidazolyl methyl‐1, 4‐di‐ethylene amino) Glycol Ether

The novel dinuclear Ni²⁺ complex [Ni₂(μ‐Cl)(μ‐OAc) (EGTB)]·Cl·ClO₄·2CH₃OH, where EGTB is N, N, N′, N′‐tetrakis (2‐benzimidazolyl methyl‐1, 4‐di‐ethylene amino)glycol ether, crystallizes in the orthorhombic space group Pnma with a = 15.272(2), b = 14.768(2), c = 22.486(3) Å, V = 5071.4(12) ų, Z = 4, D_calc = 1.414 g cm^?3, and is bridged by triply bridging agents of a chloride ion, an acetate and an intra‐ligand (‐OCH₂CH₂O‐) group. The nickel coordination geometry is that of a slightly distorted octahedron with a NiN₃O₂Cl arrangement of the ligand donor atoms. The Ni–Cl distance is 2.361(2) Å, and two Ni–O distances are 1.996(5) and 2.279(6) Å. The three Ni–N distances are 2.033(7), 2.060(6), and 2.166(6) Å with the Ni–N bond trans to an ether oxygen the shortest, the Ni–N bond trans to an acetate oxygen the middle and the Ni–N bond trans to Cl the longest.     

Synthesis of nanosized TiO2/SiO2 particles using microwave processes and their photocatalytic activity on the decomposition of orange II

The nanosized titania and TiO₂/SiO₂ particles were prepared by the microwave-hydrothermal method. The effect of physical properties TTIP/TEOS ratio and calcination temperature has been investigated. The major phase of the pure TiO₂ particle is of the anatase structure, and a rutile peak was observed above 800°C. In TiO₂/SiO₂ particles, however, no significant rutile phase was observed, although the calcination temperature was 900°C. No peaks for the silica crystal phase were observed at either silica/titania ratio. The crystallite size of TiO₂/SiO₂ particles decreases as compared to pure TiO₂ at high calcination temperatures. The TiO₂/SiO₂ particles show higher activity on the photocatalytic decomposition of orange II as compared to pure TiO₂ particles.     

铁掺杂TiO2纳米管阵列对不锈钢的光生阴极保护

在含FeSO4的HF、H2SO4/HF、NaF/Na2SO4溶液中,通过电化学阳极氧化直接在纯钛表面制备Fe 掺杂的TiO2(Fe-TiO2)纳米管阵列. 应用X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见吸收光谱(UV-Vis)、X 射线光电子能谱(XPS)等手段对纳米管阵列的结构、形貌及化学组成进行表征. 利用光电化学测量研究Fe-TiO2纳米管阵列在不同波长范围内的光电响应特性和光生阴极保护行为. 考察了温度、时间、掺杂含量等参数对TiO2纳米管阵列的几何尺寸、形貌和光电性能的影响. 结果表明, Fe掺杂可有效减缓TiO2纳米管阵列载流子的复合, 窄化TiO2带隙宽度, Fe-TiO2在410-650 nm范围显示强吸收, 并使光谱响应扩展到波长大于400 nm 的可见光区. 实验结果还表明, Fe-TiO2纳米管阵列对316不锈钢(316L)具有良好的光生阴极保护作用, 暗态下阴极保护作用可继续维持.     

The preparation and fluorescence properties of europium nanoparticles

A new structured metallic nanomaterial of europium nanoparticle was prepared using tannic acid as the reductive agent,and nanoeuropium protein conjugates were synthesized by the method of lipoic acid modification on the surface of nanoparticle,which opens a new field of application of lanthanides in nanotechniques.Their properties were also characterized by UV-vis absorption spectroscopy,transmission electron microscopy (TEM),and fluorescence spectroscopy.The europium nanoparticle and its protein conjugates solution were stable and water-soluble.The fluorescence intensity of the composite europium nanoparticles was significantly increased in the presence of trace protein,and was linear proportional to the concentration of proteins under optimum conditions.According to this,a fluorimetric method for the determination of protein was developed in this paper.     

Simultaneous Reduction of Nitro Group and S-S Bond in Nitrodisulfides by Samarium Diiodide: A New Approach to Benzothiazolines

Asapowerfulandversatileone-electrontransferreductant,Sml,hasbeenappliedwidelyinorganicsynthesis'.OurpreviousworksonthereductionofnitrocompoundsandreductivecleavageofS-S,Se-Se,Te-TebondswithSml,'ledustoinvestigatethesimultaneousreductionofnitrogroupandS-SbondbySml,.Benzothiazolinesderivativesareimportantreagentsandusefulintermediatesinorganicsynthesisandpharmaceuticalchemistry.Forinstance,theycanbeusedasadditionagentsforphotographicemulsions",effectiveacaricides",antituberculousagents",lubr…