重铬酸钾氧化偶氮胂Ⅲ褪色催化光度法测定痕量钴的研究

在醋酸－醋酸钠缓冲介质中痕量钴（Ⅱ）对重铬酸钾氧化偶氮胂Ⅲ褪色反应有显著的催化作用，催化反应的表现活化能为２５．６２ｋＪ．ｍｏｌ＾－１，据此建立了测定痕量钴的催化动力学分析法，线性范围为０～３５０ｎｇ．ｍＬ＾－１，检出限为２．０ｎｇ．ｍＬ＾－１（Ｃｏ），除Ｆｅ（Ⅱ）外，其余常见共存离子基本不影响钴的测定，本法重现性较好，用于测定人发，茶叶，土壤和废水中钴的含量，结果满意。     

催化褪色光度法测定痕量钴的研究

研究了在ＰＨ１０．５的Ｎａ２Ｂ４Ｏ７－ＮａＯＨ介质中，痕量钴（Ⅱ）对过氧化氢氧化桑色素初色反应的催化作用，建立了催化动力学光度法测定痕量钴的新方法。方法的线性范围为０－１．２μ／ｍＬ检出限为４．４＊１０＾－１８ｇ／Ｌ。用于水和维生素Ｂ１２中钴的测定，结果满意。     

荧光动力学法测定痕量硫氰根离子的研究

本文利用痕量硫氰根离子对溴酸钾氧化罗丹明６Ｇ反应的抑制作用，建立了痕量硫氰根离子的荧光动力学检测方法。方法检测限０．４ｎｇ／ｍＬ。线性范围０．４－３２．０ｎｇ／ｍＬ。应用于吸烟人和非吸烟人唾液、湖水、血清中痕量硫氰根离子的测定，结果令人满意。     

聚氯乙烯—尼龙6分离富集催化光度法测定痕量金

研究了在稀释酸介质中,痕量金（Ⅲ）催化溴酸钾氧化偶胂Ⅲ褪色的指示反应及其动力学条件,据此建立测定痕量金（Ⅲ）的新方法。方法的检出限为７．９６＊１０＾－１１ｇ／ｍＬ;测定范围为０－１．２＊１０＾－６ｇ／２５ｍＬ。采用聚氯乙烯－尼龙６树脂分离富集样品中的金,用于样品的测定获得满意结果。     

流动注射化学发光法测定痕量硫

基于硫离子对鲁米诺－过氧化氢化学发光反应的增敏作用,建立了测定痕量硫的流动注射化学发光反应的增敏作用,建立了测定痕量硫的流动注射化学发光的新方法。该方法的线性范围为２．０×１０－９～８．０×１０－７ｇ／ｍＬ,检出限为５．６×１０－１０ｇ／ｍＬ,相对标准偏差小于５％（１．０×１０－７ｇ／ｍＬＳ２－,ｎ＝１１）。方法简单,快速,灵敏,已用于环境水样中痕量硫的测定。     

铁（Ⅲ）—高碘酸钾—过氧化氢—变色酸2R催化动力学光度法测定痕量铁…

研究了测定铁的一种新指示反应，在稀硫酸介质中，痕量铁（Ⅲ）对高碘酸钾与过氧化氢协同氧化变色酸２Ｒ的褪色反应具有强烈催化作用，其反应动力学条件，表观活化能Ｅ′＝１８９．８１ｋＪ／ｍｏｌ表观反应速率常数Ｋ＝５．６７×１０＾－４／ｓ半衰期ｔ１／２＝２０．３７ｍｉｎ，反应温度为９０℃，试验表明１ｇＡ０／Ａ与Ｆｅ（Ⅲ）的浓度在３０～１００ｎｇ／２５ｍＬ，范围内符合Ｂｅｅｒ定律，建立了催化动力学光度法测定痕量     

催化褪色法测定痕量硒（Ⅳ）的研究

本研究发现，在盐酸介质中，Ｓｅ（Ⅳ）作活化剂，Ｐｄ~（２＋）催化次磷酸钠与甲基红的褪色反应。同时研究了反应动力学条件，建立了测定痕量Ｓｅ（Ⅳ）的新方法。方法检测限为４．８×１０~（－５）μｇ／ｍＬＳｅ（Ⅳ），测定范围为０～０．０１μｇ／ｍＬＳｅ（Ⅳ）。用于测定人发中的痕量Ｓｅ（Ⅳ），获得了满意结果。     

催化动力学法测定化探样品中的痕量铬

本对在弱酸性介质中铬（ＶＩ）强烈催化Ｈ２Ｏ２氧化铬蓝黑Ｒ褪色反应进行了一系列研究，拟定了用催化动力学法测定铬（ＶＩ）的最佳条件。该法检出限为３．２×１０＾－９ｇ／ｍＬ，测定线性范围０～１．５μｇ／２５ｍＬ铬（ＶＩ），用于化探样品中痕量铬的测定，结果良好。     

溴酸钾氧化靛红催化光度法测定痕量亚硝酸根

基于磷酸介质中ＮＯ２＾－催化溴酸钾氧化靛红的褪色反应，建立了测定痕量ＮＯ２＾－的新方法，并讨论了其动力学条件。方法检测限为１．３６×１０＾－６ｇ／Ｌ，线性范围０．３￣２μｇ／２５ｍＬ，方法简便，已用于环境水样中痕量ＮＯ２＾－的测定。     

催化动力学法测定痕量硒（Ⅳ）

１引言利用催化动力学光度法测定痕量硒已有报道，但都存在Ｆｅ３＋等一些共存离子干扰等问题。作者通过实验观察到，在盐酸介质中，Ｓｅ（Ⅳ）能强烈催化氯酸钾氧化甲苯胺兰褪色反应，据此建立了催化动力学光度法测定痕量硒的一种新方法。方法具有体系简单稳定，选择性好等特点，检出限为８４ｘ１０－７ｇ／Ｌ，线性范围为０～９×１０－７ｇ／２５ｍＬ。直接用于水；人发、面粉和牛奶等食品样中的痕量硒（Ⅳ）测定，结果较好。２实验方法在两支相同的２５ｍＬ比色管中，一支加入０．５μｇ的标准硒（Ⅳ）工作溶液，另一支不加。然后依次分…     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.