以溴化钾-溴酸钾-2′,7′-二氯荧光素为试剂对痕量水杨酸的间接荧光测定法

在pH为3．8－7．90范围内,利用Br2(0.5mol/L H2SO4介质中,Br^-与BrO3^-反应生成）与2′,7′－二氯荧光素反应,使2′,7′－二氯荧光素荧光猝灭,当加入水杨酸时,水杨酸的溴代反应使体系荧光增强,建立了荧光法间接测定痕量水杨酸的新方法。该体系激发波长,发射波长分别为λex505nm,λem520nm,水杨酸浓度在2．0－48．0ug/L范围内呈线性关系,检出限为2．0ug/L。本法选择性好,用于脚癣药水中水杨酸的测定,结果满意。     

色氨酸荧光猝灭法测定人发稀土总量

研究了稀土元素对色氨酸的荧光猝灭效应，结果发现，在pH=11的HAc-H3BO3-H3PO4-NaOH缓冲溶液中，。各种稀土元素对色氨酸的荧光有猝灭效应，在此基础上建立了色氨酸荧光猝灭法测定稀土总量的分析新方法。稀土总量在0－50ug/25mL范围内，色氨酸荧光强度的差值与稀土总量呈现良好的线性关系，方法检出限为0．23ug/L；相对标准偏差为1．1％－2．9％；样品加标回收率为98．9％－101．2％，方法简便，灵敏度高，已用于人发样品中稀土总量测定。     

氧氟沙星在胶束体系中的荧光特性及应用

研究发现十二烷基硫酸钠胶束对氧氟沙星荧光有明显的增敏作用，据此建立了直接测定人体尿液中氧氟沙星的等波长差同步荧光光谱法（△λ=90nm）。经样品测定，其线性范围为0．12－3．6mg/L，检出限为0．12mg/L，回收率为92．2％－97．8％，相对标准偏差为1．2％－2．7％。     

环境水样中痕量肼的荧光分析

基于在硫酸介质中，肼与罗丹明6G反应，使其荧光增强，建立了一种荧光测定痕量肼的新方法。该方法线性范围2．0－14．0μg/L，检出限为0．62μg/L。可用于环境水样中肼含量的测定，并进行了回收实验，回收率为97％－107％。     

荧光红-曙红Y能量转移及荧光猝灭法测定痕量铜(Ⅱ)的研究

在λex／λem=404．7／550nm,乳化剂OP存在下,荧光红-曙红Y能够发生有效能量转移,使曙红Y荧光强度大大提高;在pH6．5～7．6的KH2PO4-NaOH缓冲溶液中,Cu(Ⅱ)与曙红Y和邻菲罗啉形成配合物,使曙红Y的荧光猝灭,从而建立了测定痕量铜的荧光分析新方法。铜含量在0～250μg／L范围内与曙红Y的荧光猝灭程度呈良好的线性关系。方法的检出限为0．82μg／L;测定100μg／L铜溶液,其RSD为4．6％(n=11);样品加标回收率为102．1％～105％。本法用于人发、茶叶和大米中痕量铜的测定,结果满意。     

荧光红-曙红Y能量转移荧光猝灭法测定痕量铜(Ⅱ)的研究

探讨了荧光红与曙红Y之间的荧光能量转移,研究了Cu(Ⅱ)-荧光红-曙红Y-邻菲罗啉能量转移荧光猝灭体系的最佳条件,建立了荧光分析测定痕量铜的新方法.实验结果表明,在λex/λem=404.7 nm/545 nm,乳化剂0P存在下,荧光红的荧光光谱(λem=524 nm)和曙红Y的吸收光谱(λmax=520 nm)能有效重叠.当荧光红和曙红Y单独存在时,其最大发射波长分别为524 nm和545 nm;当荧光红和曙红Y同时存在时,曙红Y的最大发射波长不变,但其荧光强度明显增大,可见,荧光红和曙红Y分别作为能量给予体和能量接受体发生能量转移,使曙红Y荧光光谱灵敏度增大.在pH 6.5～7.6的KH2PO4-NaOH缓冲溶液中,Cu(Ⅱ)与曙红Y和邻菲罗啉形成配合物使曙红Y的荧光猝灭,加入荧光红后,体系的荧光猝灭值大大增加.利用荧光红-曙红Y能量转移荧光猝灭法测定痕量铜,提高了测定铜的灵敏度和选择性.铜含量在0～250μg/L范围内与曙红Y的荧光猝灭程度成良好的线性关系.方法的检出限为0.082μg/L;测定100μg/L铜溶液,其相对标准偏差为4.6%;样品加标回收率为101%～107.7%.方法已应用于人发、茶叶中痕量铜的测定.     

双波长双指示物催化光度法测定水中痕量铜

研究了在pH5.5的Na2HPO4-NaH2PO4缓冲溶液介质中，痕量Cu（Ⅱ）催化过氧化氢氧化吖啶黄和酸性品红褪色的指示反应。通过测量450nm和540nm处，催化反应体系和非催化反应体系吸光度的变化，利用铜离子浓度与两波长处吸光度差值的和呈线性关系，建立了双波长双指示物催化光度法测定痕量铜的新方法。在最佳实验条件下，测定铜的线性范围为0．60～32μg/L，检出限为0．24μg/L。该方法操作简单，灵敏度高，选择性好，用于水样中痕量铜的测定，获得满意结果。     

氧化还原荧光法测定痕量亚硝酸根

建立了碘化钾与亚硝酸根氧化还还原反应生成游离碘使异硫氰酸荧光素荧光猝灭测定痕量亚硝酸根的新方法,其线性范围为25－100ug/L,回归方程为ΔF＝7．98C－10．5,r=0.990,方法的检测限为12ug/L。本法快速,灵敏,操作简便,用于水样中痕量亚硝酸根的测定,结果良好。     

分光光度法连续测定发样中铜和铁

建立了一种在表面活性剂OP存在下,用2－（5－溴－2－吡啶偶氮）－5二乙氨基酚（5－Br-PADAP)作显色剂分光光度法同时测定铜和铁含量的新方法,用该法测定铜和铁,显色络合物最大吸收波长均为558nm,PH3．5时,测得Cu-5-Br-PADAP的为9．1＊1010^4ug/10mL,铁线性范围为0－5．0ug/10mL,此法应用于人发样品分析,方法简便,快速结果,准确,满意。     

2，3，4-兰羟基苯乙酮缩-2-羧基苯胺与铜的高灵敏度荧光反应及其应用

合成了新荧光试剂2,3，4-三羟基苯乙酮缩-2-羧基苯胺(TAFA)。详细研究了试剂与铜的荧光反应新体系的最佳适宜条件。在pH9．0的乙醇／水(3．5：6．5，V/V)溶液中，该试剂与铜离子形成稳定的络合物，组成比为1：1(金属：试剂)，λex/em=422．4／561．6nm。所建立的铜的荧光分析方法的线性范围为0.5～120.0μg／L；检出限为0．26μg／L。方法成功地应用于矿泉水和水中痕量铜的测定。     

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.