萃取—缝管原子捕集原子吸收法测定水中碲（Ⅳ）和磅（Ⅵ）

研究了碲（Ⅳ）和碲（Ⅵ）在ＤＤＴＣ－ＣＣｌ４体系中的萃取和反萃取行为，并用缝管原子捕集技术结合火焰原子吸收法测定了水样中的碲（Ⅳ）和碲（Ⅵ），特征浓度为１．２ｇ／Ｌ／１％吸收，检出限０．２μｇ／Ｌ，相对标准偏差１．７％，富集倍中达１００％。     

催化动力学光度法测定痕量锆

研究了在弱酸性介质中，锆（Ⅳ）催化过氧化氢氧化铬蓝黑Ｒ这一新的指示反应及其动力学条件，建立了一种高灵敏、高选择性测定痕量锆的新方法，方法检出限为３．７４×１０－１１ｇ／ｍＬ，线性范围０～１．１μｇ／２５ｍＬＺｒ（Ⅳ）．用于合金钢中痕量锆的测定，结果满意．     

用钨酸盐和耐尔蓝光度法测定痕量碲

报告一个简单、灵敏、快速光度测定碲的方法。聚乙烯醇（ＰＶＡ）存在下，碲与钨酸盐和耐尔蓝（ＮＢ）反应形成离子缔合物。离子缔合物的最大吸收峰位于５８０ｎｍ；表观摩尔吸光系数ε值为３．３３×１０＾７Ｌ·ｍｏｌ＾－１·ｃｍ＾－１。本方法允许的碲浓度范围为０￣６．０μｇ／Ｌ；对４．８μｇ／Ｌ碲（Ⅳ）测定的相对标准偏差为１．３％（ｎ＝１１）；检测限（３σ）为０．０１１μｇ／Ｌ（ｎ＝１２）。考察了许多离子的影响     

催化动力学法测定痕量碲的研究

本发现以钯（Ⅱ）作催化剂，碲（Ⅳ）作活化剂，能催化加速次磷酸钠与靛红的褪色反应，建立了一种测定碲的新方法，方法检测限为３．９×１０＾－１１ｇＴｅ（Ⅳ）／ｍｌ，测定范围为０－０．５μｇＴｅ（Ⅵ）／２５ｍＬ，用以测定人发中的痕量碲，获得了满意的结果。     

动力学光度法测定痕量钛的研究

利用Ｔｉ（Ⅳ）对溴酸钾氧化酸性品红的抑制作用，建立了动力学光度法测定痕量Ｔｉ（Ⅳ）的新方法，检出限为２．９×１０＾－８ｇ／Ｌ，测定范围为０～０．０２２ｇ／Ｌ。用于测定人发中Ｔｉ（Ⅳ）结果满意。     

人发和血清中痕量碲的示波极谱测定

碲（ＩＶ）在０．０３ｍｏｌ／Ｌ草酸－０．０００６％次甲基蓝介质中，在电位－０．６５Ｖ（ｖｓ．ＳＣＥ）处，有一尖锐灵敏的导数极谐波，峰电流与浓度在１．０×１０－４～１．５×１０－２μｇ／ｍＬ之间里线性关系，检测限为４．０×１０－５μｇ／ｍＬ．该法应用于人发及血清中痕量碲的测定，结果准确可靠．     

催化褪色光度法测定痕量钛的研究

本发现钛（Ⅳ）在稀硫酸介质中催化孔誉绿与碘化钾、碘酸钾之间的褪色反应，建立了褪色反应速率方程式和测定痕量钛（Ⅳ）的新方法。方法检测限为３．４ ×１０＾－１０ｇＴｉ（Ⅳ）／ｍＬ，测定范围为０～１．０μｇ／２５ｍＬＴｉ（Ⅳ）。用于测定人发中的微量元素钛的含量，获得了满意结果。     

催化褪色法测定痕量硒（Ⅳ）的研究

本研究发现，在盐酸介质中，Ｓｅ（Ⅳ）作活化剂，Ｐｄ~（２＋）催化次磷酸钠与甲基红的褪色反应。同时研究了反应动力学条件，建立了测定痕量Ｓｅ（Ⅳ）的新方法。方法检测限为４．８×１０~（－５）μｇ／ｍＬＳｅ（Ⅳ），测定范围为０～０．０１μｇ／ｍＬＳｅ（Ⅳ）。用于测定人发中的痕量Ｓｅ（Ⅳ），获得了满意结果。     

水杨基荧光酮—过氧化氢催化动力学光度法测定痕量锇（Ⅳ）

在碱性介质中，痕量锇（Ⅳ）对水杨基荧光酮（ＳＡＦ）与过氧化氢的氧化还原反应有显著的催化作用。本文以此为基础，提出用分光光度催化动力学测定痕量锇（Ⅳ）的新方法。本法未加掩蔽剂时的线性范围是０．０８－０．８０μｇ／Ｌ，加入掩蔽剂后的线性范围是０．０８－０．８０μｇ／Ｌ，检出限为０．０８μｇ／Ｌ。本法用于实际样品中Ｏｓ（Ⅳ）的测定，结果良好，本实验还测定了此催伦反应的活化能和反应级数。     

催化动力学光度法测定海产品中痕量硒

在硝酸介质中,硒（Ⅳ）能催化溴酸钾氧化亚甲蓝使之褪色。研究了这一催化反应的动力学条件,建立了一种动力学光度法测定痕量Ｓｅ（Ⅳ）的新方法。其灵敏度为３．８×１０＾－７ｇ／Ｌ Ｓｅ（Ⅳ）,Ｓｅ（Ⅳ）的含量在０￣８μｇ／Ｌ范围内与褪色反应速率１ｇ（Ａ０／Ａ）成正比。通过萃取纯化,使方法具有良好的选择性和准确度。用于多种海产品中痕量硒的测定,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.