催化动力学光度法测定痕量铬（Ⅵ）的研究

作发现铬（Ⅵ）在ｐＨ４．７的ＨＡｃ－ＮａＡｃ缓冲溶液中，能催化过氧化氢氧化邻苯二酚紫的褪色反应，研究了影响催化褪色反应速度的最佳条件，建立了测定痕量铬（Ⅵ） 的新方法，方法的检测限为１．２８×１０＾－６ｇ／Ｌ，测定范围为０～３２μｇ／ＬＣｒ（Ⅵ）。本法已用于测定环境水样，钢样以及电镀废水中痕量的铬（Ⅵ）结果令人满意。     

固氮蓝藻分离富集石墨炉原子吸收光谱法测定痕量Cr（Ⅵ）／Cr（Ⅲ）

本文选取固氮蓝藻分离富集Ｃｒ（Ⅵ）／Ｃｒ（Ⅲ），用墨炉原子吸收光谱法测定。结果表明该方法对１０ｍＬ试样，测定Ｃｒ（Ⅵ）的检测限为０．１μｇ．Ｌ＾－１＇变异系数为３．２％，在０－４５μｇ．Ｌ＾－１范围内线性关系好；测定Ｃｒ（Ⅲ）的检测限为０．３μｇ．Ｌ＾－１、变异系数３．７％，在０－４０μｇ．Ｌ＾－１范围内线性关系好。方法选择性高、富集率高。测定矿泉水、海水及自来水中的铬，获得满意结果。     

活性氧化铝富集火焰原子吸收法测定铬（Ⅲ）和铬（Ⅵ）

研究了内装活性氧化铝的微型柱流动注射富集分离火焰原子吸收光谱法（Ｆｌ－ＦＡＡＳ）测定水体中μｇ／Ｌ级的Ｃｒ（Ⅲ）、Ｃｒ（Ⅵ）。用０．２ｍｏｌ／Ｌ氨水将活性氧化铝转为碱式以吸附Ｃｒ（Ⅲ），１ｍｏｌ／Ｌ硝酸洗脱；用０．０１ｍｏｌ／Ｌ的硝酸将活性氧化铝转为酸式以吸附Ｃｒ（Ⅵ），０．２ｍｏｌ／Ｌ的氨水洗脱，洗脱液直接送到喷雾器中。进样３０ｓ，浓度富集２５倍。两种价态离子的校正曲线浓度范围在１～５０μｇ／Ｌ之间，检测限分别为０．６和０．７μｇ／Ｌ，样品分析速率为６０样／ｈ。研究了共存离子的干扰情况，实际水样中的加标回收率在８５％～１０５％之间。     

催化荧光法测定痕量铬(Ⅵ)

在ＨＡc－ＮaＡc缓冲介质中,痕量铬（Ⅵ）对过氧化氢与罗丹明Ｂ的氧化还原反应具有催 化作用,使罗丹明Ｂ的荧光减弱,据此建立了催化荧光法测定痕量铬（Ⅵ）的新方法。方法的检测限为３．３２ｒｇ／Ｌ,测定范围为０．０１～０．１６ｍｇ／ＬＣｒ（Ⅵ）。本法已用于测定电镀液、电镀废液中痕量Ｃr（Ⅵ）,结果令人满意。     

催化褪色光度法测定痕量钡

Ｂａ＾２＋能在ｐＨ５弱酸性介质中催化十二烷基苯磺酸钠（ＤＢＳ）对铬黑Ｔ（ＥＢＴ０的褪色反应。详细研究了动力学条件,确立测定钡的最适宜催化动力学条件。表观摩尔吸光系数ε６２０＝３．０×１０＾－６Ｌ．ｍｏｌ＾－１ｃｍ＾－１,校正曲线方程为ｌｏｇＡ０／Ａ＝０．００６２６０＋０．０８７０４ＣＢａ＾２＋（μｇ／Ｌ）;线性范围０－１６μｇ／Ｌ（ｒ＝０．９９９１）;     

非催化动力学光度法测定铬的研究

研究了在ＨＣｌ介质中，Ｃｒ（Ⅵ）氧化碘离子显色反应的动力学条件，建立了测定Ｃｒ（Ⅵ）的非催化动力学分析法。方法的灵敏度７．２７×１０－７ｇ·Ｌ－１，检测限５．３３×１０－６ｇ·Ｌ－１，测定范围２×１０－５～３×１０－４ｇ·Ｌ－１。用于测定标钢中的铬，测定值与标准值基本一致     

铬（VI）与5—溴水杨基荧光酮的显色反应及应用

本文研究了Ｃｒ（Ⅵ）与５－溴水杨基荧光酮（５－Ｂｒ－ＳＡＦ）的显色反应。在ｐＨ６．０ＫＨ２ＰＯ４－ＮａＯＨ缓冲溶液中，Ｃｒ（Ⅵ）与５－Ｂｒ－ＳＡＦ、ＣＴＭＡＢ形式稳定的三元络合物，其最大吸收波长为５７２ｎｍ，表观摩尔吸光系数为１．４２×１０＾５Ｌ·ｍｏｌ＾－１·ｃｍ＾－１。Ｃｒ（Ⅵ）浓度在０￣２．５μｇ／１０ｍＬ间服从比耳定律。用此法测定了环境水样中微量Ｃｒ（Ⅵ），获得满意结果。     

催化光度法测定煤矸石中微量铜的研究

在乙酸－乙酸钠介质中痕量铜对抗坏血酸还原二溴对甲基偶氮羟（２－Ｂｒ－ｐＭＡＣ）褪色反应有催化作用,催化程度与Ｃｕ（Ⅱ）量线性相关。借此建立了测定痕量Ｃｕ（Ⅱ）的分光光度法。实验表明,有色溶液所最大吸收波长为５８６ｎｍ,方法检出限为０．０４８μｇ／Ｌ,Ｃｕ（Ⅱ）量在０￣０．８μｇ／５０ｍＬ范围内符合比耳定律,可用于测定煤矸石中的微量铜。     

测定电镀废水中痕量Cr(Ⅵ)的高灵敏光度法

利用偶氮胂Ⅲ与Ｃｒ２Ｏ７２ － 的褪色反应, 对含Ｃｒ６ ＋ 电镀废水中痕量铬（ Ⅵ） 进行测定。结果表明, 在硝酸介质中褪色反应具有高的灵敏度, 反应产物的摩尔吸光系数为３ ．９ ×１０６ Ｌ·ｍｏｌ － １ ·ｃｍ － １ 。铬（ Ⅵ） 含量在０ ．０ ～４０ ．０ μｇ／Ｌ 范围内服从比耳定律。 该法用于测定电镀废水中的铬（ Ⅵ） , 得到了满意的结果。     

二安替比林基—（对二甲氨基）苯基甲烷与铬（Ⅵ）的显色反应

合成了二安替比林基－（对二甲氨基）苯基甲烷（ＤＡＤＭ）。在Ｍｎ（Ⅱ）和吐温－６０存在下，Ｃｒ（Ⅵ）与ＤＡＤＭ反应生成生色化合物，λｍａｘ为５５０ｎｍ，ε为１．０３×＾５Ｌ．ｍｏｌ＾－＾１．ｃｍ＾－＾１。Ｃｒ（Ⅵ）量在０－１０μｇ／２５ｍｌ间符合比尔定律。用于天然水和电镀废液中微量铬（Ⅵ）的测定，结果满意。     

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.