测定钴的化学发光新体系

研究了新吖啶衍生物９，１０－二甲基吖啶氟磺酸盐的化学发光特性。建立了测定Ｃｏ６２＋的化学发光新体系。方法线性范围为１．０×１０＾－１０－１．０×１０＾－７ｇ／ｍＬ；检测限为５．０×１０＾－１１ｇ／ｍＬＣｏ＾２＋。测定５．０×１０＾－９ｇ／ｍＬＣｏ６２＋的相对标准偏差为６．０％。方法选择性好，用于自来水，江水，池塘水中痕量钴的测定，结果令人满意。     

反相离子对液相色谱分离—柱后衍生化学发光检测痕量金…

报道了反相离子对液相色谱－柱后衍生化学发光检测方法分离测定痕量的钴（Ⅱ）、铁（Ⅱ）、铜（Ⅱ）、铁（Ⅲ）及铬（Ⅲ）。利用弱络合性的乳酸作为淋洗剂，加入适量的十二烷基磺酸钠作对离子试剂，研究了分离条件、发光条件及二者的匹配方式等因素对分离检测的影响。测定线性范围分别为（ｇ／ｍＬ）：Ｃｒ（Ⅲ）５．０×１０＾－９～１．０×１０＾－５；Ｆｅ（Ⅱ）２．０×１０＾－９～１．０×１０＾－５；Ｆｅ（Ⅲ）８．０×１０     

无机偶合流动注射化学发光法测定锑（Ⅲ）

将锑（Ⅲ）对铬（Ⅵ）氧化Ｉ＾－产生Ｉ２的诱导作用和Ｉ２氧化鲁米诺化学发光反应相偶合，建立了一种流动注射化学发光测定痕量锑的新方法。本方法线性范围１×１０＾－９￣１×１０＾５ｇ／ｍＬ；ＲＳＤ〈４％（ｎ＝１１，Ｃ＝７×１０＾－９ｇ／ｍＬ）；检出限为１×１０＾－１０ｇ／ｍＬ。本法用于矿样中锑的测定，结果令人满意。     

以偶合反应流动注射化学发光法测定铅

基于Ｐｂ（Ⅱ）能置换出Ｆｅ（Ⅱ）－ＥＤＴＡ络合物中的Ｆｅ（Ⅱ）和Ｆｅ（Ⅱ）－鲁米诺－溶解氧产生化学发光的反应，建立了置换偶合反应流动注射化学发光测定痕量铅的新方法。本方法线性范围１×１０＾－７￣１×１０＾－５ｇ／ｍＬ，相对标准偏差为２．５％（ｎ＝１１，Ｃ＝１０＾－６ｇ／ｍＬ），检出限为２×１０＾－８ｇ／ｍＬ。用于污水中铅的测定，结果令人满意。     

偶合反应化学发光法测定痕量银的研究——K4Fe（CN）6—Luminol体系

将Ａｇ（Ｉ）催化Ｋ４Ｆｅ（ＣＮ）６的水合反应与Ｌｕｍｉｎｏｌ同Ｃｕ（ＣＮ）＾２－４的化学发光反应相偶合，建立起一种新的灵敏测定痕量银的化学发光分析法，在所研究的优化条件下，该法测定银的选择性较好，检测限达到４．０×１０＾－１３ｇ／ｍＬＡｇ线性浓度范围为１．０×１０＾－１２～１．０×１０＾－６ｇ／ｍＬＡｇ对４×１０＾－１１ｇ／ｍＬＡｇ（Ｉ）溶液连续１１次测定的ＲＳＤ≤３．５％，用于环境水和岩矿中银的     

荧光法测定补骨脂素和异补骨脂素

以溴代十六烷基三甲胺（ＣＴＭＡＢ）为胶束试剂，β－环糊精（β－ＣＤ）为包含试剂，在优化实验条件下，用荧光光度法测定了补骨脂中补骨脂素和异补骨脂素．线性范围分别为２×１０－９～８×１０－６ｇ／ｍＬ，２×１０－９～８×１０－７ｇ／ｍＬ；检出限分别为２．６７×１０－１１ｇ／ｍＬ和１．１５×１０－１１ｇ／ｍＬ．     

流动注射-胶束增敏-光泽精与铁(Ⅱ)化学发光反应的研究

采用Ｊｏｎｅｓ柱在线还原铁（Ⅲ）为铁（Ⅱ），研究了铁（Ⅱ）与光泽精的化学发光反应，加 入ＣＴＭＡＢ和乳化剂ＯＰ能明显提高发光的信噪比，基于此建立了痕量铁的流动注射化学发光 分析法。此法线性范围为 １×１０－１１～ １×１０－５ｇ／ｍＬ，检出限为 ２×１０－１２ｇ／ｍＬ，相对标准偏差为 ２．０％（１×１０－８ｇ／ｍＬ，ｎ＝１１），已用于人发中铁的测定。深入探讨了反应机理。     

高灵敏反相流动注射化学发光法测定抗坏血酸

基于抗坏血酸对Ｆｅ２＋－Ｌｕｍｉｎｏｌ－Ｏ２体系化学发光的抑制效应，利用反相流动注射技术，建立了一个测定抗坏血酸的高灵敏化学发光新方法。该法检出限达２×１０－１０ｇ／ｍＬ；抗坏血酸浓度在 １×１０－９～１× １０－６ｇ／ｍＬ范围内与体系化学发光强度减小量呈良好线性相关；相对标准偏差为１．９％（Ｃ＝５×１０－８ｇ／ｍＬ，ｎ＝１１）。     

催化光度法测定水中痕量铜

采用抗坏血酸还原性铬蓝Ｋ的反应,在２,２’－联吡啶活化下被Ｃｕ＾２＋催化加速,建立了催化光度法测定水中痕量铜的新方法。考察了影响反应速度的最佳条件。探讨了反应机理。方法的测定范围是０．００－１．２ｎｇ／ｍＬ,检出限达１．８＊１０＾－１１ｇ／ｍＬ。方法已经用于蒸馏水,自来水中痕量Ｃｕ＾２＋的测定。     

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。     

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.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

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.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.