无机还原剂与光泽精化学发光反应的研究：Ⅱ.钼（Ⅲ）—光泽精化学发光反应

本利用流动注射技术研究了Ｊｏｎｅｓ柱产生的钼（Ⅲ）与光泽精的化学发光反应。建立了痕量相的流动注射化学发光分析法。方法的检出限是１×１０＾－＾１＾１ｇ／ｍｌ；校准曲线的线性范围是１×１０＾－＾１＾０－１×１０＾－＾６ｇ／ｍｌ；相对标准偏差为２．０％（１×１０＾－＾７ｇ／ｍｌ钼，ｎ＝１１）。此法已用于水样的分析，结果令人满意。本还进行了反应机理的探讨。     

停流流动注射—动力学方法多组份同时测定的研究：铁（Ⅱ）,钛（Ⅲ）和…

依据诱导反应原理，提出了同时测定多组份的动力学方法，并以停流流动注射分析研究了Ｆｅ（Ⅱ），Ｔｉ（Ⅲ）及Ｖ（Ⅳ）诱导的Ｃｒ（Ⅵ）－Ｉ＾－反应体系，建立了铁，钛和钒同时测定的条件。对铁，钛和钒测定的线性范围分别为０－２．２μｇ／ｍｌ，０－３．１μｇ／ｍｌ及０－１．８μｇ／ｍｌ，检测限分别为０．０１２，０．０２０和０．０１８μｇ／ｍｌ。     

2,6—二氯—4—溴偶氮胂光度法测定微量铀（Ⅵ）

本报道用了２，６－二氯－４－溴偶氮胂作显色剂测定微量铀（Ⅵ）的光度法。在Ｈ２ＳＯ４介质中，铀（Ⅵ与）２，６－二氯－４－溴偶氮胂形成１：２络合物，其λｍａｘ＝６４０ｎｍ；表观摩尔吸光系数为１．１×１０＾５Ｌ．ｍｏｌ＾－＾１．ｃｍ＾－＾１；铀的浓度在０．０－２２．０μｇ／ｍｌ内符合比耳定律。方法具有灵敏度高，选择性好，操作方便等特点并已用于废水及矿样中微量铀（Ⅵ）的测定。     

铬（Ⅵ）—SAF—H2O2褪色光度法测定污水中微量铬（Ⅵ）

在硼砂－氢氧化钾介质中，铬（Ⅵ）对过氧化氢氧化水杨基荧光酮褪色有催化作用，加入三乙醇胺可阻止催化反应。以此建立了微量铬（Ⅵ）的褪色光度法测定，该法不需加热，允许干扰量较大，灵敏度为１．０×１０＾－９ｇ／ｍＬ，ε＝１×１０＾５Ｌ．ｍｏｌ＾－１，０．０５－５．０μｇ／２５ｍｌ铬符合比尔定律，用于测定某些污水中之铬（Ⅵ）不需分离富集，其结果与二苯碳酰二肼法相符，加样回收９６－１０３％。     

Tl（I）—Cr（VI）—碘化钾—鲁米诺体系化学发光法测定铊

利用Ｔｌ（Ｉ）对Ｃｒ（Ⅵ）氧化碘化钾反应的催化作用，以碘－鲁米诺化学发学反应指示反应的进程。建立了测定铊的化学发光新方法。线性范围为Ｔｌ（Ｉ）０．００１￣１μｇ·ｍｌ＾－１，检出限为Ｔｌ（Ｉ）０．０００６μｇ·ｍｌ＾－１。     

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。     

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。     

新试剂3,5—二溴—4—偶氮—8—羟基喹啉苯基荧光酮光度法测 …

研究了在表面活性剂溴化十六烷基三甲铵（ＣＴＭＡＢ）存在下，Ｍｏ（Ⅵ）与新试剂３，５－二溴－４－偶氮－８－羟基喹啉苯基荧光酮的显色反应，在０．６ｍｏｌ·Ｌ＾－１盐酸介质中，配合物最大吸收峰位于５４０ｎｍ处，表观摩尔吸光系数为１．６４×１０＾５，钼浓度在０￣１０μｇ／２５ｍｌ范围内符合比耳定律，体系反应酸度高，选择性好，忆用于钢铁样品中微量钼的测定，结果满意。     

丁基罗丹明B—钼酸盐光度法连续测定铈和钪

在聚乙烯醇（ＰＶＡ）存在下，丁基罗丹明Ｂ（ＢＲＢ）分别与铈钼、钪钼杂多酸络阴离子形成离子缔合物，其最大吸收均位于５７０ｎｍ，表面摩尔吸光度分别为εＣｅ＝３．９６×１０＾６Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，εＳｃ＝４．７１×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，服从比耳定律范围分别为０－２４μｇ／Ｌ Ｃｅ和０－６０μｇ／ＬＳｃ，测定极限为Ｃｅ１．０μｇ／Ｌ（ｎ＝１２）和Ｓｃ１．９μｇ／Ｌ（ｎ＝１０），对     

钼（Ⅵ）—向红菲罗啉络合物的吸附伏安行为

在ＰＨ＝４．０的０．３ｍｏｌ／Ｌ的ＨＡｃ－ＮａＡｃ介质中，钼（Ⅵ）－向红菲罗啉体系在悬汞电极上，于－０．５８Ｖ电位处得到钼（Ⅵ）－向红菲罗啉络合物的吸附还原波，其１．５次微分伏安图的峰峰值ｅｐｐ与Ｍｏ（Ⅵ）在３．０×１０＾－１０－－１．２×１０＾－７ｍｏｌ／Ｌ浓度范围内呈良好的线性关系；检测限可达８×１０＾－１１ｍｏｌ／ＬＭｏ（Ⅵ）。方法用于豆类样品微量钼的测定，结果较邹。     

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.