电致化学发光法测定天然水中痕量银（Ⅰ）

对四正丁基碘化胺（ＴＢＡＩ）－银（Ⅰ）－硫脲体系的电致化学发光进行了研究。当在Ｐｔ－Ｐｔ－Ａｇ／ＡｇＣｌ三电极上施加＋１．５Ｖ的正矩形脉冲时，前述体系可观察到电致化学发光现象。银（Ⅰ）对此发光过程有明显的催化作用。银（Ⅰ）的浓度在１．０×１０－８～３．０×１０－６ｍｏｌ／Ｌ范围内与发光强度呈良好的线性关系，检出限为８．０×１０－９ｍｏｌ／Ｌ。相对标准偏差为４％。该法用于测定天然水中的痕量银。结果满意。     

催化库仑法测定天然水中硫化物

催化库仑法测定天然水中的硫化物表明，在０．０２ｇ／ｍＬＮａＮ＿３、０．１ｍｏｌ／ＬＫＩ、０．２ｍｏｌ／Ｌ（ＣＨ＿３ＣＯＯ）＿２Ｚｎ、０．０７５ｍｏｌ／ＬＣＨ＿３ＣＯＯＮａ及适量ＨＡｃ的库仑滴定体系中，利用碘－叠氮化钠诱导反应，可测定水中的痕量、超痕量硫化物。当滴定溶液ｐＨ＝６．０，温度控制在２０±０．２℃，在铂电极上以微小恒电流电解产生碘为库仑滴定剂，双铂电极安培法指示终点测定硫化物的灵敏度可达１０￣（－９）或更低的数量级。此法用于测定天然水中痕量硫化物，结果满意。     

催化动力学光度法测定痕量银

研究了在稀盐酸介质中,银催化氯化物还原铈（Ⅳ）而使其褪色的反应,建立了测定痕量银（Ⅰ）的新方法。测定银（Ⅰ）的线性范围为０～４０μｇ／Ｌ,检出限为５．７×１０－ ７ｇ／Ｌ。方法用于环境水样中痕量银的测定,结果满意。     

用亚硝基R盐螯合树脂分离富集催化极谱法测定矿石中的铱

本文研究了利用亚硝基Ｒ盐螯合形成的树脂，分离富集试液中痕量贵金属元素铱的实验条件。并利用ＪＰ－１型示波极谱仪，在１．５０ｍｏｌ／Ｌ盐酸＋５．０×１０＾－５ｍｏｌ／Ｌ硫脲＋０．２ｍｏｌ／Ｌ盐酸＋５．０×１０＾－５ｍｏｌ／Ｌ硫脲＋０．２ｍｏｌ／Ｌ碘化钾＋碲（ρ（Ｂ）＝０．４ｍｇ／Ｌ）的混合底液中，对铱进行极谱催化波测定。在示波极谱仪上峰电位约－０．５５Ｖ（银汞齐为参比电极），可测定试液中５．０×１．０     

过碘酸钾氧化鸡冠花红动力学光度法测定食品中痕量碘

基于硫酸介质中，草酸钠作活化剂，碘催化过碘酸钾氧化鸡冠花红而使其褪色的反应，建立了测定痕量碘的新方法。方法灵敏、简便、选择性好。测定碘的线性范围为０－２０μｇ／Ｌ；检出限为０．６６μｇ／Ｌ。用于食品中痕量碘的测定，结果满意。     

阻抑动力学光度法测定痕量对苯二酚

基于在硫酸和聚乙烯醇溶液中,对苯二酚能抑制Ｆｅ（Ⅲ）催化中性红与Ｈ２Ｏ２之间的褪色反应,建立了一种测定痕量对苯二酚的新方法,同时研究了该方法的动力学条件。该方法的测定范围为０．２０～６．０ｍｇ／Ｌ;检出限为２．３×１０－４ｇ／Ｌ;ε５３５＝１．２×１０４Ｌ·ｍｏＬ－１·ｃｍ－１。用于废水中对苯二酚的测定,结果满意。     

测定超氧化物歧化酶活性的一种新的极谱分析方法

报道一种测定超氧化物歧化酶活生的新极谱分析方法，在０．１２５ｍｏｌ／ＬＮＨ３．Ｈ２Ｏ－０．７５ＭＯＬ／ｌ ｎｈ４ｃＬ－２．５％，Ｎａ２ＳＯ３－０．５％，吐温－８０－的介质中，ＳＯＤ在－０．５２Ｖ处产生一氧极谱催化波。ＳＯＤ在１．０×１０＾３Ｕ／Ｌ－４．０×１０＾３Ｕ／Ｌ的活性含量范围内与催化电流呈线性关系，检出限为８．０×１０＾２Ｕ／Ｌ。     

银（I）—硫脲—四正丁基溴化铵体系电致化学发光法测定水中痕量银

本研究了银（Ｉ）－硫脲－四正丁基溴化铵体系的电致化学发光（ＥＣＬ）。发现在正矩形脉冲下，银对含有硫脲的ＴＢＡＢｒ的溶液ＥＣＬ有明显催化作用，银（Ｉ）的浓度在１．４×１０＾－８－３．５×１０＾－６ｍｏｌ／Ｌ范围内与有ＥＣＬ强度呈良好线性关系。检出限为９．０×１０＾－９ｍｏｌ／Ｌ，相对标准偏差为５％。用于天然水中银的测定，获得较满意的结果。     

茚三酮缩7—氨基—8—羟基喹啉—5—磺酸催化荧光测定痕量钒（Ⅴ）及其…

合成了新型席夫碱类试剂茚三酮缩７－氨基－８－羟基喹啉－５－磺酸，建立了该剂催化荧光测定痕量钒的 新体系，反应在盐酸体系中进行，其λｅｘ／λｅｍ为３２５／４４８（ｎｍ），钒（Ⅴ）的量在０－４０．０μｇ／Ｌ、４０．０－１６０．０μｇ／Ｌ呈良好线性关系，检测下限为１．７μｇ／Ｌ，方法用于水样痕量钒的测定，结果令人 满意。     

催化反应吸光光度法测定痕量银

研究了Ａｇ对亚铁氰化钾与邻菲罗啉显色反应的催化研究，建立了痕量银的催化吸光光度法。灵敏度为１．０×１０＾－３μｇ．ｍｌ＾－１，线性范围为０－０．４μｇ／２５ｍＬ。用于水样中痕量银的测定，结果满意。     

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.     

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.     

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.     

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.     

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.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.