2-(3,5-二氯-2-吡啶偶氮)-5-二甲氨基苯胺与铂(Ⅳ)显色反应的研究

研究了２－（３，５－二氯－２－吡啶偶氮）－５－二甲氨基苯胺（３，５－ｄｉＣｌ－ＰＡＤＭＡ）与铂（Ⅳ）的显色反应及铂配合物的质子化行为。结果表明，在０．０４～０．４８ｍｏｌ／Ｌ的Ｈ２ＳＯ４溶液中，于加热的条件下，试剂可与铂（Ⅳ）形成稳定的１∶２绿蓝色ＰｔＬ２Ｈ２＋２配合物，其最大吸收波长位于６３４ｎｍ，表观摩尔吸光系数为９．７３×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，桑德尔灵敏度为０．００２μｇ·ｃｍ－２。铂配合物的三级质子化常数分别为：ｌｇＫａ１＝３．９１，ｌｇＫａ２＝－２．２１，ｌｇＫａ３＝－３．３７。较大量的常见金属离子及除钯、钌外的其它贵金属离子不干扰测定。利用Ｐｔ，Ｐｄ与试剂反应所需的温度差异，可以用差减法消除微量Ｐｄ的干扰．铂（Ⅳ）浓度在每１０ｍＬ０～７．５μｇ范围内符合比尔定律。所拟方法用于二次合金管理样－８８及催化剂中微量铂的测定，结果满意。     

2-羟基-3-羧基-5-磺酸基苯基重氮氨基偶氮苯与铊反应的分光光度法研究

于ｐＨ１０．０～１１．０的ＮＨ３－ＮＨ４Ｃｌ缓冲介质中，在ＴｒｉｔｏｎＸ－１００存在下，铊（Ⅲ）与２－羟基－３－羧基－５－磺酸基苯基重氮氨基偶氮苯（ＨＣＳ－ＤＡＡ）形成组成比为１∶３的红色配合物，其最大吸收波长和对比度分别为５１０ｎｍ和８０ｎｍ，表观摩尔吸光系数为１．５２×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，线性范围为０～０．７０ｍｇ／Ｌ，室温下显色反应立即完成，配合物至少稳定２ｈ。方法用于水样、烟叶和煤灰中痕量铊的分析，回收率为９０．０％～１０１．４％，５次测定的相对标准偏差不大于４．６％。     

1-(2-苯并噻唑)-3-(4-偶氮苯基)-三氮烯与汞的显色反应研究及应用

研究了新试剂１－（２－苯并噻唑）－３－（４－偶氮苯基）－三氮烯（ＢＴＰＡＰＴ）与汞的显色反应．在Ｔｗｅｎ－８０存在下，ｐＨ为１１．２０时，Ｈｇ（Ⅱ）与试剂生成红色的１∶１型配合物，最大吸收峰位于５１０ｎｍ，表观摩尔吸光系数为１．１０×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，线性范围０－１４μｇ／２５ｍＬ．建立了可用于饮用水、生活用水和工业废水汞含量测定的方法．     

新显色剂1-(2.4-二硝基苯)-3-(2-噻唑)-三氮烯的合成及与汞的显色反应研究

报道了新显色剂１－（２．４－二硝基苯）－３－（２－噻唑）－三氮烯的合成及其与Ｈｇ（Ⅱ）的显色反应。实验表明，在非离子表面活性剂ＴｒｉｔｏｎＸ－１００存在下，于ｐＨ１１．７５的三酸缓冲介质中，试剂与Ｈｇ（Ⅱ）能生成蓝绿色配合物，最大吸收波长位于６９０ｎｍ处，试剂的最大吸收波长位于４１０ｎｍ处，对比度高达２８０ｎｍ，其配合比为１∶２，表观摩尔吸光系数为１．１×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，Ｈｇ（Ⅱ）含量在０～１８μｇ／２５ｍＬ范围内符合比耳定律。测定了废水中汞的含量，结果令人满意。     

安替比林基重氮氨基—2,4—二硝基苯与银（I）的显色反应及其应用

本文报道了安替比林基重氮氨基－２，４－二硝基苯（ＡＰＤＮＢＴ）与银（Ｉ）的显色反应，在吐温－８０存在下，ＰＨ＝９．０－１０．０的范围内，试剂与银（Ｉ）形成２：１的配合物；配合物对试剂的最大吸收在４８５ｎｍ处，ε为７．２×１０＾４Ｌ＾－１．ｍｏｌ．ｃｍ＾－１提出了消除阳离子干燥的银镜分离法；方法用于洞察工样及照相显影液中银的含是一定回收率为９６－１０３％，相对标准偏差小于２．０％。     

新试剂1-(6-硝基-2-苯并噻唑)-3-(4-硝基苯)-三氮烯与锌的显色反应研究及应用

研究了新显色剂１－（６－硝基－２－苯并噻唑）－３－（４－硝基苯）－三氮烯（ＮＢＴＮＰＴ）与锌的显色反应，在非离子表面活性剂ＴｒｉｔｏｎＸ－１００存在下，ｐＨ１０．１～１０．８的Ｎａ２Ｂ４Ｏ７－ＮａＯＨ缓冲溶液中，Ｚｎ２＋与试剂能形成１∶２的橙黄色配合物，最大吸收波长为４４６ｎｍ，同时在５２８ｎｍ处配合物表现有最大负吸收，其表观摩尔吸光系数分别为ε＝７．０３×１０４Ｌ·ｍｏｌ－１·ｃｍ－１和ε＝１．０６×１０５Ｌ·ｍｏｌ－１·ｃｍ－１．用拟定的方法测定了人发和婴儿奶粉中的微量锌，结果令人满意．     

新试剂二溴对硝基苯基重氮氨基-4-苯基-2-噻唑的合成及其与钯显色反应的研究

报道了新试剂二溴对硝基苯基重氮氨基－４－苯基－２－噻唑的合成方法，并研究了在表面活性剂ＣＰＣ存在下，该试剂与钯（Ⅱ）的显色反应。结果表明，在ｐＨ６．４～７．８范围内，钯（Ⅱ）与该试剂可形成１∶２灰紫色的配合物，其最大吸收波长位于６５０ｎｍ，表观摩尔吸光系数为７．０２×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，钯量在０～２２μｇ／２５ｍＬ范围内符合比尔定律，该方法已用于Ｐｄ－Ｃ催化剂中微量钯的测定，结果满意。     

新显色剂1－（对－偶氮苯）－3－（2－噻唑）－三氮烯与锌显色反应的研究及应用

本文研究了新显色剂１－（对－偶氮苯）－３－（２－噻唑）－三氮烯在非离子表面活性剂ＴｒｉｔｏｎＸ－１００存在下，与锌（Ⅱ）显色反应的适宜条件。结果表明，在ｐＨ１３．０～１４．０范围内，锌（Ⅱ）与题示试剂形成１：３的稳定粉红色配合物，其最大吸收波长为５４５ｎｍ，试剂的最大吸收波长为４６３ｎｍ。配合物表现摩尔吸光系数在５４５ｎｍ处为９．６×１０￣４Ｌ·ｍｏｌ￣（－１）＊ｃｍ￣（－１）；０～２４μｇ／２５ｍＬＺｎ符合比耳定律。该试剂对锌的选择性良好。方法用于铝合金中锌的直接测定，结果令人满意。     

钼(Ⅵ)-4-(5-溴-2-噻唑偶氮)邻苯二酚-二苯胍三元离子缔合物的萃取分光光度研究

在ｐＨ４．０的介质中，Ｍｏ（Ⅵ）与新试剂４－（５－溴－２－噻唑偶氮）邻苯二酚（５－Ｂｒ－ＴＡＰＣ）和二苯胍（ＤＰＧ）反应形成稳定的三元离子缔合物，其组成比Ｍｏ（Ⅵ）：５－Ｂｒ－ＴＡＰＣ∶ＤＰＧ为１∶３∶２。该三元缔合物氯仿萃取液的λｍａｘ为５３６ｎｍ，对比度为１１９ｎｍ，表观ε为６．３３×１０４Ｌ·ｍｏｌ－１·ｃｍ－１。钼（Ⅵ）含量在０～０．８０ｍｇ／Ｌ范围内遵从比耳定律，并探讨了离子缔合物的结构。将在最佳显色条件下拟定的分析方法用于合金钢中小量或痕量钼的测定，取得了满意的结果。     

新显色剂2－（5－硝基－2－吡啶偶氮）－5－二甲氨基苯胺与钯显色反应的研究及其应用

用新合成的偶氮试剂２－（５－硝基－２－吡啶偶氮）－５－二甲氨基苯胺（５－ＮＯ＿２－ＰＡＤＭＡ）研究了光度法测定他的反应条件。结果表明，在０．４５～１．２ｍｏｌ／Ｌ盐酸介质中，钯与试剂形成稳定的蓝色配合物，其最大吸收波长位于６２１ｎｍ处，表观摩尔吸收系数为９．４×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），配合成的组成为Ｐｄ：５－ＮＯ＿２－ＰＡＤＭＡ＝１：２，钯浓度在０～１０μｇ／１０ｍＬ范围内符合比尔定律。本方法是目前测定钯的高灵敏度和高选择性体系之一。用于含钯分子筛及二次合金管理样－８８中微量钯的测定，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%.     

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.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

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.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.