同步荧光法同时测定强力霉素和土霉素

本文提出了表面活性剂增敏碱性降解同步荧光测定强力霉素（ＤＣ）和土霉素（ＯＴＣ）新法。土霉素和强力霉素在０．１ｍｏｌ／ＬＮａＯＨ溶液中反应，生成强荧光降解物，加入十六烷基三甲基溴化铵（ＣＴＭＡＢ）后，荧光强度分别增加４．２倍和１０．７倍。其同步荧光峰在△λ＝７０ｎｍ时基本分离，ＯＴＣ和ＤＣ浓度比在１＋４０～１０＋１范围内可同时测定ＯＴＣ和ＤＣ。本法测定尿液中ＯＴＣ和ＤＣ的回收率为９０％～１０４％。     

桑色素荧光光度法测定二氯化双(丁氧羰乙基)锡

在ｐＨ３．０的ＨＡｃ－ＮａＡｃ缓冲溶液中和有Ｔｒｉｔｏｎ Ｘ－１００存在下,二氯化双（丁氧羰乙基）锡（简写为Ｒ２ＳｎＣｌ２）与桑色素形成１：１的荧光络合物。络合物的激发波长和发射波长分别为４４３．２ｎｍ和５１４。４ｎｍ。Ｒ２ＳｎＣｌ２中的Ｓｎ浓度在０￣３．０ｍｇ／Ｌ范围内,与络合物荧光强度呈线性关系。方法检出限为７．８１μｇ／Ｌ Ｓｎ,用于ＰＶＣ中间产品和污水中Ｒ２ＳｎＣｌ２的测定,结果满意,相对     

二溴羟基苯基荧光酮—乳化剂OP荧光熄灭法测定微量铬（Ⅵ）

本文基于Ｃｒ（Ⅵ）－二溴羟基苯基荧光酮（ＤＢＨ－ＰＦ）－ＯＰ体系的荧光熄灭效应，提出一种测定痕量铬（Ⅵ）的新荧光方法。在ｐＨ２．４－４．１的ＨＣｌ－ＮａＡｃ缓冲介质和ＯＰ存在下，Ｃｒ（Ⅵ）与ＤＢＨ－ＰＦ形成１：２的橙红色络合物，络合物的最大激发发工和发射波长分别是３６５ｍｍ和５２８ｎｍ。铬（Ⅵ）量在０．０５－１．５μｇ／２５ｍｌ范围内与△Ｆ呈线性关系，检测限是２．０ｎｇ／ｍｌ。方法用于电镀废液，废     

显色剂N—烯丙基—N‘—（氨基对苯磺酸钠）硫脲与钯（Ⅱ）显色反应的研究和…

本报道了极易溶于水的显色剂Ｎ－烯丙基－Ｎ＇－（氨基对苯磺酸钠）硫脲光度法测定钯的条件，：在ＰＨ４．０－５．５缓冲介质中，ＡＳＡＴｕ与钯生成易溶于水的、稳定的黄色络合物，组成比为：Ｐｄ（Ⅲ）：ＡＳＡＴｕ＝１：４；络合物的最大吸收波长为２９６．０ｎｍ表观摩尔吸光系数ε２９６＝１．３３×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１；钯（Ⅱ）在０－２０嗳μｇ／２５ｍＬ呈线性，相关系数γ＝０．９９９５。该法灵敏度     

钪—水杨醛苯甲酰腙高灵敏度荧光反应及其应用

研究了水杨醛苯甲酰腙（ＳＡＢＨ）与钪荧光反应新体系的最佳条件。在ｐＨ＝６．４乙醇／水（６．２：３．８）溶液介质中，形成络合物的组成比１：３（钪、试剂），λｅｘ／λｅｍ＝３８５ｎｍ／４５５ｎｍ，建立钪荧光分析法的线性范围为０￣１００μｇ／Ｌ；相对标准偏差１．５％；检出下限为０．０２５μｇ／Ｌ。考察了３０种共存离子的干扰情况，方法成功用于地质中样中痕量钪的测定。     

显色剂交换萃取光光度法测定微量铜

用三氯甲烷萃取Ｃｕ－ＤＤＴＣ络合物，然后在ｐＨ＝９．２三羟甲基氨基甲烷（Ｔｒｉｓ）缓冲液中用５－Ｂｒ－ＰＡＤＡＰ交换络合物中ＤＤＴＣ，形成了Ｃｕ－ＰＡＤＡＰ络合物。该络合物最大吸收波长λｍａｘ＝５２０ｎｍ，表观摩尔吸光系数ε５２０＝１．２２×１０＾５，铜量在０．２￣１０．０μｇ／１２ｍｌ范围内服从比耳定律。本法应用于食品、生物材料中微量铜测定，得到较为满意的结果。     

钐,铕—四环素类抗生素络合物荧光性能的研究及其在荧光分析中的应用

本文探讨了钐、铕－四环素、强力霉素、土霉素、金霉素络合物的荧光性能及利用该体体系以荧光分析光度法测定痕量钐和铕的可能性与最佳测定条件。结果表明：在高碱度条件下，以四环素体系的稳定性、灵敏性最好，钐和铕的检测限分别为３８．２和０．０９ｎｇ／ｍＬ。     

铬（VI）与5—溴水杨基荧光酮的显色反应及应用

本文研究了Ｃｒ（Ⅵ）与５－溴水杨基荧光酮（５－Ｂｒ－ＳＡＦ）的显色反应。在ｐＨ６．０ＫＨ２ＰＯ４－ＮａＯＨ缓冲溶液中，Ｃｒ（Ⅵ）与５－Ｂｒ－ＳＡＦ、ＣＴＭＡＢ形式稳定的三元络合物，其最大吸收波长为５７２ｎｍ，表观摩尔吸光系数为１．４２×１０＾５Ｌ·ｍｏｌ＾－１·ｃｍ＾－１。Ｃｒ（Ⅵ）浓度在０￣２．５μｇ／１０ｍＬ间服从比耳定律。用此法测定了环境水样中微量Ｃｒ（Ⅵ），获得满意结果。     

铬（Ⅵ）与5－溴水杨基荧光酮的显色反应及应用

本文研究了Ｃｒ（Ⅳ）与５－溴水杨基荧光酮（５－Ｂｒ－ＳＡＦ）的显色反应。在ｐＨ６．０ＫＨ＿２ＰＯ＿４－ＮａＯＨｉＬ冲溶液中，Ｃｒ（Ⅳ）与５－Ｂｒ－ＳＡＦ、ＣＴＭＡＢ形式稳定的三元络合物，其最大吸收波长为５７２ｎｍ，表现摩尔吸光系数为１．４２×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）。Ｃｒ（Ⅳ）浓度在０～２．５μｇ／１０ｍＬ间服从比耳定律。用此法测定了环境水样中微量Ｃｒ（Ⅳ），获得满意结果。     

铁（Ⅲ）—过氧化氢—水杨基荧光酮—溴化十六烷基三甲铵荧光猝灭反应？…

在ｐＨ３．１～５．２的ＨＣｌ－ＮａＡｃ缓冲介质中,溶液中的铁（Ⅲ）与过氧化氢（Ｈ２Ｏ２）,水杨基荧光酮（ＳＡＦ）和溴化十六烷基三发（ＣＴＭＡＢ）反应产生一多元混合络合物,使水杨基荧光酮溶液的荧光明显猝灭,据此建立了测定痕量铁的荧光猝灭分析法,该体系的激发波长λｅｘ＝４３５．８ｎｍ,发射波长λｅｍ＝５４０ｎｍ。铁的浓度在２～１００ｕｇ／Ｌ范围内有良好的线性关系;方法的检出限为０．４１ｕｇ／Ｌ。该方法     

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.