锡—向红菲Luo啉络合物的1.5次微分吸附伏安法研究

本研究了锡－向式菲Ｌｕｏ啉体系在悬汞电极上的伏安行为，为ＰＨ＝２．８０的０．０７ｍｏｌ／Ｌ氯乙酸－氯乙酸钠介质中，Ｓｎ（Ⅳ）－向菲Ｌｕｏ啉络合物于１．５次微分伏安图上在－０．５６Ｖ电位处产生一良好的吸附还原波，波高与Ｓｎ（Ⅳ）的浓度在５．０×１０＾－９－６．０×１０＾－７ｍｏｌ／Ｌ范围内呈线性关系，检出下限为２．５×１０＾－９ｍｏｌ／ＬＳｎ（Ⅳ），用本法对冶金标样中锡进行测定，取得了满意的结果。     

示波极谱测定天然水,食品和生物样品中痕量锡

在Ｈ２ＳＯ４－ＨＣｌＯ４－ＮａＢｒ－（ＮＨ４）２ＶＯ３的体系中，Ｓｎ（Ⅳ）在－０．６０Ｖ左右产生一个非常灵敏的极谱催化谱，Ｓｎ（Ⅳ）浓度在０．８－１６０ｎｇ．ｍＬ＾－１之间与峰电流成线性关系，检测限为０．２６ｎｇ．ｍＬ＾－１。该法应用于天然水、食品和生物样品中痕量锡的测定，结果令人满意。     

5-Br-PADAP-NO2--SCN-三元离子缔合物分光光度法测定微量NO2-的研究

研究了在硫酸介质中５－Ｂｒ－ＰＡＤＡＰ与ＮＯ＾－２和ＳＣＮ＾－形成三元离子缔合物的最佳条件,其表观摩尔吸光系数ε５５０＝２．４＊１０＾４Ｌ／（ｍｏｌ．ｃｍ）,缔合物组成比为ｎ（５－Ｂｒ－ＰＡＤＡＰ）：ｎ（ＮＯ＾２）：ｎ（ＳＣＮ＾＿＝１：１：１。     

铍（Ⅱ）—均三溴偶氮胂配合物吸附波的研究

在ｐＨ９．２０的ＮＨ３．Ｈ２Ｏ－ＮＨ４Ｃｌ介质中，铍与均三溴偶氮胂（ＴＢＡ）的形成配合物，于－０．５５Ｖ（ｖｓ．ＳＣＥ）处产生一灵敏的配合物吸附波，峰电流与Ｂｅ浓度在８．０×１０＾－８～２．０×１０＾－６ｍｏｌ／Ｌ范围内呈线性关系。测得铍与均三溴偶氮胂的配合比为Ｂｅ（Ⅱ）：ＴＢＡ＝１：１，稳定常数β＝３．０×１０＾，电子转移数ｎ＝２，峰电流由配合物中配位体ＴＢＡ还原产生。可不经分离直接测定矿样中铍     

钌（Ⅲ）—钼酸盐—耐尔蓝—PVA124体系缔合显色反应的研究

在聚乙烯醇存在下，钌与钼酸盐和耐尔蓝（ＮＢ）形成离子缔合物，缔合物的λｍａｘ为５８５ｎｍ，ε为１．３２×１０＾６Ｌ．ｍｏｌ．ｃｍ＾－１，符合比耳定律范围０～１．２μｇ／２５ｍＬＲｕ，检测限为２．６ｎｇ／ｍＬ（ｎ＝１１），用平衡移动法测定缔合物的摩尔比为Ｒｕ：ＮＢ＝１：２。考察了４３种共存离子的影响，仅Ｏｓ（Ⅲ），ＳｉＯ＾２－３，Ａｓ（Ⅲ），Ｓｂ（Ⅲ），Ｇｅ（Ⅳ）有干扰，需用蒸馏分离。本法已用于某些     

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     

在Fe（Ⅲ）存在下DAoBM与锰的高选择性显色反应

研究了在碱性介质中,空气氧化Ｍｎ（Ⅱ）为Ｍｎ（Ⅳ）后,在酸性介质中Ｍｎ（Ⅳ）氧化二安替比林邻溴苯基甲烷（ＤＡｏＢＭ）生成橙色产物,λｍａｘ＝４８０ｎｍ, ５．６２·ｍｏｌ＾－０１·ｃｍ＾－１。锰的含量在０￣２０μｇ／２５ｍｌ内符合比耳定律,用于钢铁样品中的测定,结果满意。     

用钼酸盐和罗丹明B连续光度法测定铈和钪

聚乙烯醇存在下，铈或钪钼杂多酸与罗丹明Ｂ（ＲＢ）形成离子缔合物，最大吸收均位于５７０ｎｍ，摩尔吸光系数分别为１．１６×１０＾６和５．６２×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，ｃｍ＾－１，０－１．２μｇ／２５ｍＬＣｅ和０－２．０μｇ／ｍＬＳｃ服从比耳定律，检测限１．５ｎｇ／ｍＬＣｅ（ｎ＝１０）和１．１ｎｇ／ｍＬＳｃ（ｎ＝９）。缔合物的摩尔比为Ｃｅ：ｍＯ：ＲＢ＝１：６：３和 Ｓｃ：Ｍｏ：ＲＢ＝１：１     

锡（Ⅱ）—1—苯基—3—甲基—4—苯甲酰基—吡唑啉酮—5—络合物吸附波的研究

在ｐＨ４．０的ＨＡｃ－ＮａＡｃ缓冲介质中，Ｓｎ（Ⅱ）与１－苯基－３－甲基－４－苯甲酰基－吡唑啉酮－５（ＰＭＢＰ）生成络合物，于－０．７４Ｖ（ｖｓ．ＳＣＥ）出现一灵敏的极谱峰。锡含量在４．２×１０－８ｍｏｌ／Ｌ～３．４×１０－６ｍｏｌ／Ｌ范围内与峰高呈线性关系，检出限为１．７×１０－８ｍｏｌ／Ｌ。用多种电化学方法研究了极谱波的性质及电极反应机理，证明该极谱波为络合吸附波，峰电流由中心离子Ｓｎ（Ⅱ）还原产生，络合物组成为Ｓｎ（Ⅱ）∶ＰＭＢＰ＝１∶１。试验了多种离子对峰电流的影响。方法已用于矿样中痕量锡的测定。     

铟（Ⅲ）—2—硫基苯骈噻唑—7—碘—8—羟基喹啉—5—磺酸三元络合物吸附波研究

在ＨＣｌ－ＮａＡｃ介质（ｐＨ２．５）中，用单扫示波极谱法可获得高灵敏的Ｉｎ（Ⅲ）－２－巯基苯骈噻唑（ＭＢＴ）－７－碘－８－羟基喹啉－５－磺酸（Ｆｅｒｒｏｎ）三元络合物吸附波，峰电位在一－０．６４Ｖ（ｖｓ．ＳＣＥ），峰电流与铟浓度在７．０×１０＾－１０ｍｏｌ／Ｌ～８．８×１０＾－７ｍｏｌ／Ｌ之间呈线性关系，检出限可达３．０×１０＾－１０ｍｏｌ／Ｌ，测得电活性络合物的组成为Ｉｎ（Ⅲ）：ＭＢＴ：１∶１∶     

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.