苯并噻唑重氮氨基偶氮苯与汞（Ⅱ）的显色反应及其应用

报道了新试剂苯并噻唑重氮氨基偶氮苯的合成及其与汞（Ⅱ）的显色反应，在ＴｒｉｔｏｎＸ－１００存在下弱碱性介质中，试剂与汞形成２：１的橙红色络合物，最大吸收波长位于５２０ｎｍ处，表观摩尔吸光系数为１．５１×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１。汞量在０～１．２ｍｇ／Ｌ范围内遵守比尔定律，直接应用于废水中微量汞的测定，结果满意。     

镓(Ⅲ)-芦丁体系的吸附伏安行为及其应用于镓(Ⅲ)的测定

对镓（Ⅲ）－芦丁体系在悬汞电极上的吸附伏安法作了研究,确字电极过程。在ＰＨ５．０的ＨＡｃ－ＮａＡｃ缓冲底液中用该体系的１．５阶微分吸附伏安法测定镓,其线性范围是１＊１０＾－１０－１＊１０＾－７ｍｏｌ／Ｌ;检测限为７．５＊１０＾－１１ｍｏｌ／Ｌ。用此法测定了粮食中的镓。     

1—（2—苯并噻唑）—3—（4—偶氮苯基）—三氮烯与汞的显色反应研究及…

研究了新试剂１－（２－苯并噻唑）－３－（４－偶氮苯基）－三氮烯（ＢＴＰＡＰＴ）与汞的显色反应，在Ｔｗｅｅｎ－８０存在下，ｐＨ为１１．２０时，Ｈｇ（Ⅱ）与试剂生成红色的１：１配合物，最大吸收峰位于５１０ｎｍ，表现摩尔吸光系数为１．１０×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１线性范围０－１４μｇ／２５ｍＬ，建立了可用于饮用水，生活用水和工业废水汞含量测定的方法。     

米托蒽醌的吸附行为及其吸附伏安测定法研究

本文研究了米托蒽醌在悬汞电极上的吸附行为，在此基础上建立了米托蒽醌的吸附伏安测定方法。在ｐＨ为２．２的Ｂ．Ｒ缓冲体系中，米托蒽醌浓度在１．１×１０＾－６ｍｏｌ／Ｌ～１．１×１０＾－９ｍｏｌ／Ｌ范围内，浓度与电流呈线性，检出限可达５．５×１０＾－１０ｍｏｌ／Ｌ。若在盐酸－柠檬酸钠（ｐＨ为１．２５）缓冲体系中，检出限可低至１．１×１０＾－１１２ｍｏｌ／Ｌ。方法可用于尿样或血样中米托蒽醌的测定。     

5—氟腺嘧啶选择性碳糊电极的研制与应用

研制了以５－氟脲嘧啶离子与汞离子的摩尔比为１：１的配位化合物作为电活性物质的５－氟脲嘧啶碳糊电极,得到了良好的电极响应曲线,线性范围为３个数量级,检出限为１０＾－３ｍｍｏｌ．Ｌ＾－１,电极稳定性较好,具有较好的抗干扰能力。采用直接电位法测定商业药品,结果令人满意。     

钼（Ⅵ）—7—（1—苯偶氮）—8—羟基喹啉—5—磺酸钠络合吸附研究及应用

在ｐＨ４．８的０．０１３ｍｏｌ／Ｌ的ＨＡｃ－ＮａＡｃ介质中,钼－７－（１－苯偶氮）－８－羟基喹啉－５－磺酸钠体系在滴汞电地－０．４６Ｖ电位处得到良好的吸附还原波,其二阶导数峰电流Ｉ＾ｎ,ｐ与Ｍｏ在２．５×１０＾－８－４．５×１０＾－７ｍｏｌ／Ｌ浓芳范围内呈良好的线性关系,检测限为１．２５×１０＾－８ｍｏｌ／ＬＭｏ（Ⅵ）,方法用于钢样中策量钼的测定,结果较好。     

安力农的极谱测定及其电化学行为

在ｐＨ５．６，０．１５ｍｏｌ／Ｌ磷酸盐缓冲溶液（ＰＢＳ）中，得到了安力农的灵敏极谱吸附波，波的二阶导波高在２×１０＾－８～８×１０＾－６ｍｏｌ／Ｌ范围内与安力农的浓度成直线关系，检测下限为１×１０＾－８ｍｏｌ／Ｌ，测定出电极过程的电子传递系数ａ＝０．４３，表面电极反尖速率常数ｋｓ＝３．３ｓ＾－１，安力农在汞电极上的吸附遵从Ｌａｎｇｍｕｉｒ等温式，测得其吸附系数β＝８．１×１０＾５。     

Nafion修饰金膜玻碳电极溶出伏安法测定痕量Se（Ⅳ）的研究

提出了Ｎａｆｉｏｎ修饰膜玻碳电极测定痕量硒的新方法。在０．１ｍｏｌ．Ｌ＾－１硫酸和０．０１．Ｌ＾－１硝酸钠的介质中，Ｓｅ（Ⅳ）浓度在５．０＊１０＾－１０－２．５＊１０＾－８ｍｏｌ．Ｌ＾－１范围与二次导数峰电流呈良好线性关系，测定下限为５．０＊１０＾－１０ｍｏｌ．Ｌ＾－１。     

安替比林基重氮氨基—2,4—二硝基苯与汞（Ⅱ）的显色反应及其应用

本研究了试剂安替比林基重氮氨基－２４－二硝基苯（ＡＰＤＮＢＴ）与汞的显色反应，在Ｔｗｅｅｎ－８０存在下和ｐＨ＝１０．２～１２．３的缓冲溶液中，ＡＰＤＮＢＴ与汞生成黄色络合物，其络合比为Ｈｇ∶ＡＰＤＮＢＴ＝１∶２，建立了以４４５ｎｍ为参比波长，５３８ｎｍ为测量波长的双波长分光光度法，其表观摩尔吸光系数为２．１×１０＾５Ｌ·ｍｏｌ＾－１·ｃｍ＾－１，线性范围是０     

3,5—Br2—PADAP—IO^—30SCN—三元离子缔合物测定微量IO^— …

研究了３，５－Ｂｒ２－ＰＡＤＡＰ在酸性介质中质子化，与ＩＯ＾－３和ＳＣＮ＾－形成三元离子缔合物的最佳条件，其表现摩尔吸光系数为１．４＊１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，缔合物组成比为３，５－Ｂｒ２－ＰＡＤＡＰ：ＩＯ＾３：ＳＣＮ＾－＝１：１：１。     

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.