砷钼杂多酸/罗丹明B三元离子缔合物的二级散射光谱研究

在0.12 mol/L H2SO4介质中,As(Ⅴ)、Mo(Ⅵ)与罗丹明B形成砷钼杂多酸/罗丹明B三元缔合物,它在λex/λem为325 nm/650 nm波长处产生一个灵敏的二级散射峰.据此建立了一个测定1～20 ng/mL As的二级散射光谱分析新方法.本法具有灵敏度高、选择性好、操作简便等特点.     

砷锑钼三元杂多酸光化学光度法测定痕量砷

砷锑钼三元杂多酸光化学分光光度法是测定０ ．０４ ～１ ．０ ｍ ｇ／ Ｌ 砷的新方法。在０ ．１２ ｍｏｌ／ Ｌ Ｈ２ Ｓ Ｏ４２ ．０ ×１０ － ４ ｍ ｏｌ／ Ｌ Ｓｂ（ Ⅲ）２ ．０ ×－ ３ ｍ ｏｌ／ Ｌ Ｍｏ（ Ⅵ）４ ％ （ Ｖ／ Ｖ） 甲醇介质中, Ａｓ（ Ⅲ） 、 Ｓｂ（ Ⅲ） 、 Ｍｏ（ Ⅵ） 形成的三元杂多酸被紫外光还原生成三元杂多蓝（λｍ ａ ｘ ＝ ７８０ ｎｍ ） 。实验结果表明,方法具有灵敏度高,选择性好,操作简便等特点。     

DBSAQ的合成及荧光光度法测定粮食中痕量铝(Ⅲ)的研究

报道了新席夫碱试剂３,５－二溴水杨醛缩－８－氨基喹啉（ＤＢＳＡＱ）的合成,用元素分析,红外光谱法测定了其结构,测定了ＤＢＳＡＱ的配度常数,在ｐＨ４．００～５．５０范围内ＤＢＳＡＱ与Ａｌ⒓）形成稳定的荧光配合物,且在λｅｘ／λｅｍ＝４３０ｎｍ／５３５ｎｍ处产生强烈的荧光,其荧光强度与Ａｌ（Ⅲ）的浓度在１．２～２４０ｕｇ／Ｌ范围内呈线性关系,检出下限为１．２ｕｇ／Ｌ,并考察了共存离子的影响,选择性高,     

The retention behavior of arsenic compounds on PRP-X100 column under alkaline condition.

系统地研究了碱性条件下（ｐＨ８～１０．８）Ａｓ３＋,Ａｓ５＋,ＭＡ,ＤＭＡ和ＡＢ等砷化合物在ＰＲＰ－Ｘ１００阴离子交换柱上的保留行为。用火焰原子吸收光谱（ＦＡＡＳ）测定从ＨＰＬＣ分离的砷化合物,即通过一根１ｍ×０．２３ｍｍｉ．ｄ．不锈钢毛细管,将ＨＰＬＣ柱出口与ＦＡＡＳ的雾化器连接起来,采用乙炔／空气火焰,在１９３．７ｎｍ处测定。具体研究了两个流动相（２０ｍｍｏｌ／ＬＮＨ４ＨＣＯ３和２．５ｍｍｏｌ／Ｌ对－羟基苯甲酸－１．０ｍｍｏｌ／Ｌ苯甲酸水溶液）。     

Fe（Ⅱ）与溴连苯三酚红和罗丹明B协同显色反应的研究及其应用

研究了Ｆｅ（Ⅱ）与溴连苯三酚红和罗丹明Ｂ（ＲｈＢ）的协同显色反应。在非离子型表面活性剂ＰＶＡ－１２４存在下，ＰＨ３．０－５．５范围内，Ｆｅ（Ⅱ）与ＢＲＰ和ＲｈＢ形成红紫色三元配合物，其最大吸收峰λｍａｘ位于５９０ｎｍ，表观摩尔吸光系数ε５９０为６．４×１０＾－４。     

离子缔合物二级散射光谱的分析应用：Ⅲ.汞（Ⅱ）—硫氰酸盐—罗丹明染…

本文研究［Ｈｇ（ＳＣＮ）４］＾２－络阴离子与罗丹明Ｂ和罗丹明６Ｇ离子缔合络物的二级散射和“反二级散射光谱；考察了光谱特生、影响因素及适宜的反应条件；确定了ＤＳ和ＡＤＳ强度与溶液中汞（Ⅱ）浓度的关系；提出了用ＡＤＳ法测定痕量汞的新的高灵敏度分析方法，并有对关机理作了初的探讨。     

用钼酸盐和罗丹明B光度法测定铂

本文研究了在聚乙烯醇（ＰＶＡ）存在下用钼酸盐和罗丹明Ｂ（ＲＢ）光度法测定铂，铂（Ⅳ）与相酸铵和罗丹明Ｂ形成离子缔合物，它的最大吸收波长位于５７０ｎｍ处；摩尔吸光系数６值为６．８３×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），铂量在０～３．５μｇ／２５ｍＬ范围内服从比耳定律，缔合物至少稳定１月。报告了４１种共存离子的影响，除生成杂多酸元素和Ａｕ（Ⅲ）、Ｏｓ（Ⅷ）、Ｒｕ（Ⅲ）外，大多数元素不干扰。测定铂（Ⅳ）的适宜条件为［ＨＣｌＯ＿４］＝０．９３ｍｏｌ／Ｌ，［ＲＢ］＝４．２×１０￣（－５）ｍｏｌ／Ｌ，ＰＶＡ０．８ｇ／Ｌ，本法已用于催化剂和某些铂矿中铂的测定，结果满意。缔合物的摩尔比为Ｐｔ（Ⅳ）：ＲＢ＝１：２，初步探讨了反应机理。     

茜素红S与人血清白蛋白相互作用的分光光度研究

在ｐＨ４．３左右的Ｂｒｉｔｏｎ－Ｒｏｂｉｎｓｏｎ（Ｂ－Ｒ）缓冲溶液中,茜素红Ｓ（ＡＲＳ）与人血清白蛋白（ＨＳＡ）结合,生成红色的复合物,吸光度值与ＨＳＡ含量呈线性关系。复合物的吸收峰值λｍａｘ为５３０ｎｍ,比ＡＲＳ试剂本身红移１１０ｎｍ。其表观摩尔吸光系数ε＝１．０×１０４Ｌ·ｍｏｌ－１·ｃｍ－１。ＨＳＡ标准曲线在其质量浓度１０～９００ｍｇ／Ｌ间呈线性关系,最低检出限为３ｍｇ／Ｌ。研究了该配合物用于蛋白质分光光度法测定的基本条件。应用该法测定了人血清样品,回收率在９６．９％～１０２．１％范围内。实验表明该反应选择性、重现性和对照性均好,操作简便,适用测定浓度范围宽     

THE RETENTION BEHAVIOR OF ARSENIC COMPOUNDS ON PRP-X100 COLUMN UNDER ALKALINE CONDITION

系统地研究了碱性条件下（ｐＨ８～１０．８）Ａｓ３＋，Ａｓ５＋，ＭＡ，ＤＭＡ和ＡＢ等砷化合物在ＰＲＰ－Ｘ１００阴离子交换柱上的保留行为。用火焰原子吸收光谱（ＦＡＡＳ）测定从ＨＰＬＣ分离的砷化合物，即通过一根１ｍ×０．２３ｍｍｉ．ｄ．不锈钢毛细管，将ＨＰＬＣ柱出口与ＦＡＡＳ的雾化器连接起来，采用乙炔／空气火焰，在１９３．７ｎｍ处测定。具体研究了两个流动相（２０ｍｍｏｌ／ＬＮＨ４ＨＣＯ３和２．５ｍｍｏｌ／Ｌ对－羟基苯甲酸－１．０ｍｍｏｌ／Ｌ苯甲酸水溶液），并系统研究了ｐＨ值和缓冲液浓度对上述５个砷化合物的保留时间的影响，发现对于２０ｍｍｏｌ／ＬＮＨ４ＨＣＯ３体系，在ｐＨ８．７时，ＡＢ，Ａｓ３＋，ＤＭＡ可以得到完全分离，通过梯度洗提（ｐＨ８．７到９．８，流速１．６５ｍＬ／ｍｉｎ），在１５ｍｉｎ内上述５个砷化合物可以得到良好分离；对于２．５ｍｍｏｌ／Ｌ对－羟基苯甲酸－１．０ｍｍｏｌ／Ｌ苯甲酸体系，在ｐＨ９．０及流速１．５ｍＬ／ｍｉｎ时，可以在１２ｍｉｎ内将上述５个砷化合物分离。     

钍（Ⅳ）与偶氮溴膦—mB和溴化十四烷基吡啶在乙醇—水溶液中的显色反应及其分

在ｐＨ１￣２的酸性介质中,钍（Ⅳ）与偶氮溴膦－ｍＢ（ＢＰＡｍＢ）形成最大吸收波长（λｍａｘ位于６８６ｎｍ的蓝色络合物,摩尔吸光系数（ε）为８．２７×１０＾４Ｌ·ｍｏｌ＾－１·ｃｍ＾－１。在有少量乙醇存在的０．５￣１．０ｍｏｌ／Ｌ盐酸溶液中,钍（Ⅳ）能与ＢＰＡｍＢ和溴化十四烷基吡啶形成更灵敏的三元络合物,最大吸收位于６９５ｎｍ,具有更大的对比度（Δλ＝１３５ｎｍ）和更高的灵敏度。ε值达１．４１×１０     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

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.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

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.