5''''-硝基水杨基荧光酮荧光熄灭法测定微量钨

本文基于Ｗ（Ⅵ）－５′－硝基水杨基荧光酮（５′－Ｎ－ＳＡＦ）－Ｔｗｅｅｎ－８０体系的荧光熄灭效应，提出一种测定微量钨的新荧光方法。在０．２～１．０ｍｏｌ／Ｌ的硫酸介质中，在Ｔｗｅｅｎ－８０存在下，５′－Ｎ－ＳＡＦ存在两个激发峰，其激发波分别为λｅｘ１＝４７５ｎｍ，λｅｘ２＝５０５ｎｍ，发射波长为λｅｍ＝５２５ｎｍ。Ｗ（Ⅵ）与５′－Ｎ－ＳＡＦ形成１∶３的配合物。钨浓度在每２５ｍＬ０．２５～２．５μｇ范围内呈线性关系，检测限为每２５ｍＬ０．２５μｇ。本法灵敏度高，选择性好，不经分离可直接测定合金钢中的钨，结果满意。     

荧光光度法直接测定环境水中苯酚和十二烷基苯磺酸钠的含量

本文研究了用荧光分光光度法直接测定环境水中苯酚和十二烷基苯磺酸钠（ＳＤＢＳ）二种水中污染物。在ｐＨ〉１１直接测定ＳＤＢＳ含量，波长为λｅｘ／λｅｍ＝２３０／２９５ｎｍ，检出限４．４ｎｇ／ｍＬ，线性范围０￣２．２μｇ／ｍｌ。在ｐＨ＝６，波长为λｅｘ／λｅｍ＝２３０／２９５ｎｍ，测得二者合量，从合量中减去ＳＤＢＳ含量即得苯酚含量，检出限４．０ｎｇ／ｍｌ，线性范围０￣０．８５μｇ／ｍＬ，回收率达９９％￣     

荧光法测定环境水中的痕量砷

建立了测定环境水中痕量砷的荧光新方法,在ＰＨ６．５－７．５的缓冲介质中,利用２′,７′－二氯荧光素（ＤＣＦ）作为荧光试剂,激发波长λｅｘ＝５１０ｎｍ,发射波长λｅｍ＝５２８ｎｍ下,测定痕量砷,亚砷酸根浓度在０．２５－３．５０μｇ／２５ｍＬ范围内,相对荧光强度差值与亚砷酸根浓度呈线性关系,检测限为０．１６μｇ／２５ｍＬ,用于检测自来水和池塘水中的痕量砷,回收率为９５％－１０５％。     

荧光光度法测定环境水中微量甲基对硫磷

研究了荧光分光光度法测定环境水中甲基对硫磷的一。在吲哚丙酮溶液０．２５％，过硼酸钠溶液０．２５％溶液中，温度５℃、λｅｘ／λｅｍ＝４１０ｎｍ／４９０ｎｍ，检出限５．０（５．２）μｇ／Ｌ，线性范围０－２．０（２．６）ｍｇ／Ｌ，回收率达９８－１０２％，结果满意。     

荧光光度法直接测定环境水中的苯酚和苯胺

了用荧光分光光度法通过控制酸度直接测定环境水中苯酚和苯胺两种水中污染物的新方法。在ｐＨ＝１时，直接测定苯酚的含量，波长为λｅｘ／λｅｍ＝２７０／２９７ｎｍ，检出限为４．０ｎｇ／ｍＬ，线性范围为０～３．２μｇ／ｍＬ。在ｐＨ＝１２时，直接测定苯胺的含量，波长为λｅｘ／λｅｍ＝２８０／３４０ｎｍ检出限为４．３ｎｇ／ｍＬ，线性范围为０～２．０ｕｇ／ｍＬ，回收率达９９～１０１％。     

痕量尼莫地平测定的紫外薄层色谱扫描法

以Ｖ氯仿∶Ｖ甲醇∶Ｖ二氯甲烷∶Ｖ正己烷＝２．６∶１．２∶１∶５为展开剂，建立了薄层色谱扫描法测定痕量药物尼莫地平的新方法。其Ｒｆ值为０．４８。扫描波长为３６５ｎｍ，该法的最低检出限为０．００５μｇ，相对标准偏差为２．９４％，工作曲线的线性范围为０．００５～１μｇ。用该法测定了加有尼莫地平的血清和尿样，尼莫地平的平均回收率为９６．７％～１０３％。     

5′—硝基水杨基荧光酮荧光熄灭法测定微量钨

本文基于Ｗ（Ⅵ）－５′－硝基水杨基荧光酮（５′－Ｎ－ＳＡＦ）－Ｔｗｅｅｎ－８０体系的荧光熄来效应，提出一种测定微量钨的荧光方法，在０．２～１．０ｍｏｌ／Ｌ的硫酸介质中，在Ｔｗｅｅｎ－８０存在下，５′－Ｎ－ＳＡＦ存在两个激发峰，其激发波分别为λｅｘ１＝４７５ｎｍ，λｅｘ２＝５０５ｎｍ发射波长为λｅｍ＝５２５ｎｍ。Ｗ（Ⅵ）与５′－Ｎ－ＳＡＦ形成１：３的配合物，钨浓度在每２５ｍＬ０．２５～２．５μｇ范围     

双波长分光光度法同时测定贵金属钯和锇

本文提出了在对羟基苯基荧光酮和溴化十六烷基三甲烷基甲胺存在下，双波长分光光度法同时测定微量和锇的新方法，在ｐＨ＝７．６～８．０的磷酸盐介质中，钯和锇的对羟基苯基荧光酮－ＣＴＭＡＢ配合物吸收光谱相互重叠，选择测定钯配合物的波长对为５８０．５ｎｍ与５３０．５ｎｍ，测定锇配合物的波长对为５５３．５ｎｍ与６０４．５ｎｍ，钯含量在０～７．０μｇ／１０ｍＬ范围内，锇含量在０～９．０μｇ／ｍＬ范围内，与ΔＡ值呈     

高效液相色谱法测定化妆品中的染料

采用反相高效液相色谱法测定化妆品中对苯二胺等５种染料中间体,以ＺｏｒｂａｘＣ８为固定相,Ｖ（三乙醇胺）∶Ｖ（水）∶Ｖ（乙腈）＝０．９５∶９４．０５∶５为流动相,加入磷酸调ｐＨ值为７．７,检测波长为２８０ｎｍ。样品用体积分数为９５％的乙醇超声提取,回收率为８７％～１０７％（ｎ＝６）,相对标准偏差为２．３％～６．４％。     

双显色剂双波长系数补偿法同时测定铝和铁的研究

本文提出了一种双显色双波长系数补偿法测定食品中微量铝、铁的新方法，在ｐＨ＝６．２缓冲液中，以络天青Ｓ为显色剂选择６２２／５０６ｎｍ波长对测定铝，以５－Ｂｒ－ＰＡＤＡＰ为显色剂选择５６０／６６０ｎｍ波长对测定铁，不经分离可直接测定样品中的铝、铁，铝量在０．２～５．０μｇ／２５ｍｌ、铁量在１．０～１５．０μｇ／２５ｍｌ符合朗伯比耳定律。本法应用于食品中铝、铁测定，得到较满意结果。     

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.