7－（4，5－二甲基－2－噻唑偶氮）－8－羟基喹啉与锌显色反应的研究和应用

探讨题示试剂（ＤＭＴＡＱ）与锌离子的显色反应条件，当ｐＨ为５．５，在ＴｒｉｔｏｎＸ－１００存在下，ＤＭＴＡＱ与锌离子形成红色配合物，最大吸收峰位于５４５ｎｍ，表观摩尔吸光系数９．４×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），锌量在０～２５μｇ／５０ｍＬ范围内符合比尔定律。该法可用于测定人发中的微量锌。     

新试剂5－（2，6－二溴－4－硝基苯偶氮）－8－羟基喹啉的合成及与锌的显色反应研究和应用

本文合成了５－（２，６－二溴－４－硝基苯偶氮）－８－羟基喹啉。研究了在Ｔｗｅｅｎ－８０增溶下新试剂与Ｚｎ￣（２＋）的显色反应。试验表明，配合物的最大吸收峰位于５４５ｎｍ，表观摩尔吸光系数为６．７ｘ１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），Ｚｎ（Ⅱ）浓度在０～１５μｇ／２５ｍＬ范围内符合比耳定律。该法用于人发中微量锌的直接测定，结果满意。     

镍（Ⅱ）与2－（5－溴－2－吡啶偶氮）－5－二甲氨基苯胺显色反应的研究及铝合金中镍的测定

本文研究了新显色剂２－（５－溴－２－吡啶偶氮）－５－二甲氨基苯胺与镍（Ⅱ）的反应条件。试验结果发现，在阴离子表面活性剂十二烷基硫酸钠存在下，在ｐＨ５．２～６．５范围内，试剂与镍（Ⅱ）形成稳定的２∶１配合物。其最大吸收波长在５７０ｎｍ处，表观摩尔吸光系数为１．２４×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）。镍（Ⅱ）浓度在０～０．４μｇ·ｍＬ￣（－１）之间符合比尔定律。以硫脲和氟化按作掩蔽剂，可消除Ｃｕ￣（２＋）、Ｐｄ￣（２＋）、Ｆｅ￣（３＋）等离子的干扰。所拟方法用于铝合金中微量镍的测定，结果满意。     

新显色剂N－辛基－N＇－（氨基对苯磺酸钠）硫脲（OPT）与铜（Ⅱ）显色反应的研究和应用

Ｎ－辛基－Ｎ＇－（氨基对苯磺酸钠）硫脲是新合成的一种显色剂，该试剂极易溶于水而形成无色溶液。在ｐＨ３．６～５．２的ＨＡｃ－ＮａＡｃ缓冲体系中，试剂与铜（Ⅱ）形成一种稳定的蓝色水溶性配合物，其组成比为：Ｃｕ（Ⅱ）：ＯＰＴ＝１：３。配合物的最大吸收波长位于３０１．４ｎｍ，表观摩尔吸光系数ε＿（３０１．４）＝１．８２×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）。Ｃｕ（Ⅱ）在０～１０μｇ／２５ｍＬ服从比尔定律，相关系数ｒ＝０．９９９６，方法的检出限为３．８５×１０￣（－９）ｇ／ｍＬ。本法灵敏度高，选择性好、操作简单，可直接在水相中测定。将本法用于合金钢和生物制品中微量铜的测定，均获得满意结果。     

锌与7－（2－羧基－4－溴－苯偶氮）－8－羟基喹啉－5－磺酸的显色反应研究及茶叶中锌的测定

本文研究了新显色剂７－（２－羧基－４－溴－苯偶氮）－８－羟基喹啉－５－磺酸与锌的反应条件，试验结果发现在乳化剂ＯＰ存在下，酒石酸介质中新试剂与锌形成稳定配合物，其最大吸收波长为５００ｎｍ，表观摩尔吸光系数为１．１５×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），Ｚｎ￣（２＋）浓度在０～８μｇ／ｍＬ之间符合比尔定律，方法用于茶叶中微量锌的测定结果满意。     

meso－四（3－氟－4－磺基苯）卟啉与钯（Ⅱ）显色反应的分光光度研究

本文对新多卤代水溶性ｍｅｓｏ－四（３－氟－４－磺基苯）卟啉与Ｐｄ（Ⅱ）的显色反应进行了研究，在ｐＨ４．８，有抗坏血酸存在，沸水浴中加热，形成稳定的１：１配合物，最大吸收波长在４０９ｎｍ处。工作曲线回归方程Ａ＝０．００１＋０．０６４ｘ，相关系数ｒ＝０．９９６４。摩尔吸光系数达１．７×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），Ｐｄ（Ⅱ）浓度在０～７．５μｇ／２５ｍＬ范围内符合比耳定律。灵敏度和选择性高于其它多卤代水溶性卟啉。对催化剂中钯含量的测定，获得满意的结果。     

5，10，15，20－四（3－溴－4－磺酸苯基）卟啉光度法测定痕量铜的研究

本文研究了新水溶性卟啉试剂５，１０，１５，２０－四（３－溴－４－磺酸苯基）卟啉［Ｔ（３－ＢｒＰ）ＰＳ＿４与铜的显色反应。在ｐＨ３，铜与５，１０，１５，２０－四（３－溴－４－磺酸苯基）卟啉形成１：１的稳定配合物。此配合物的最大吸收波长位于４１２．８ｎｍ，摩尔吸光系数为２．６１×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）。铜量在０～３．０μｇ／２５ｍＬ范围内符合比尔定律，工作曲线回归方程为ｙ＝０．００９４３、＋０．１６７ｘ，相关系数为ｒ＝０．９９９７。方法有较高的灵敏度和较好的选择性，直接用于大米和茶叶中痕量铜的测定，结果与ＡＡＳ法一致。     

5，10，15，20－四（3－溴－4－磺酸苯基）卟啉光度法测定痕量锌的研究

本文研究了新水溶性卟啉试剂５，１０，１５，２０－四（３－溴－４－磺酸苯基）卟啉［Ｔ（３－ＢｒＰ）ＰＳ４］与锌的显色反应。在ｐＨ４，锌与５，１０，１５，２０－四（３－溴－４－磺酸苯基）卟啉形成稳定的１：１配合物，其最大吸收波长位于４２２．０ｎｍ，摩尔吸光系数为３．９×１０５Ｌ·ｍｏｌ（－１）·ｃｍ（－１）。锌量在０～２．５μｇ／２５ｍＬ范围符合比尔定律。方法具有较高的灵敏度和较好的选择性，用于人发和大米中痕量锌的测定，结果与原子吸收法一致。     

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）－５－二甲氨基苯胺与铂（Ⅳ）的显色反应，在ｐＨ３．５～６．０醋酸－醋酸钠介质中，沸水浴加热２５ｍｉｎ，试剂与铂（Ⅳ）形成１：４的紫色配合物，再提高酸度至２．９～４．０ｍｏｌ／Ｌ盐酸溶液，其最大吸收峰红移至６３０ｎｍ，灵敏度显著提高，表现摩尔吸光系数ε＿（６００）＝７．０×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），铂含量在０～３２μｇ／２５ｍＬ范围内符合比耳定律。大多数常见金属离子不干扰测定，所拟方法操作简便，用于催化剂中微量铂的测定，结果满意     

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。     

Synthesis and Molecular Structure of (E)-1-(Morpholino)-2-(thiomethyl)-2-phenylvinylphosphonate

1 INTRODUCTION Phosphorus-containing vinyl compounds havebeen widely studied due to their versatile physiolo-gical activities and applications in transition metalchemistry, asymmetric catalysis and photorearrange-ment[1～4]. In our previous papers, we have reportedthe syntheses of 2,2,4,5-tetrasubstituted-1,3-dithio-les[5] and 2,5-bis(morpholino)-3,4-bis-(p-chloro-phe-nyl)thiophenes[6] by the reactions of α-thioaroyl-thiofor-mamide with trimethyl phosphite at room tempera-ture and in refl…     

Synthesis of 1-(alkylamino)- and 1-(dialkylamino)benzimidazoline-2-thiones

Unlike 1-aminobenzimidazoles, 1-alkylaminobenzimidazoles are thiolated on fusing with sulfur without elimination of theN-amino group, yielding the previously unknown 1-(alkylamino)benzimidazoline-2-thiones. These compounds can be more conveniently obtained on a preparative scale by thiolation of 1-alkylacetamidobenzimidazoles with subsequent hydrolytic elimination of the acetyl group. When 1-(dialkylamino)benzimidazoles are fused with sulfur, they are converted into 1-(dialkylamino)benzimidazoline-2-thiones. By alkylation of 1-(methylamino)- and 1-(diethylamino)benzimidazoline-2-thiones with methyl iodide in alkaline media the corresponding 2-(methylthio)benzimidazoles were prepared.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2231–2235, November, 1995.The authors are grateful to the Contest Center of Basic Natural Science at St. Petersburg University for financial support of this study.     

1-(2-Quinoxalyl)-, 1-[3,5-Di(trifluoromethyl)phenyl]-, 1-(2-Carboxyphenyl)-, and 1-Ethoxycarbonyl-4-oxo-4,5,6,7-tetrahydroindazoles

The corresponding 1-(2-quinoxalyl)-, 1-[3,5-di(trifluoromethyl)phenyl]-, and 1-ethoxycarbonyl-3-methyl-4-oxo-4,5,6,7-tetrahydroindazoles have been obtained from reactions of 2-acetyl-1,3-cyclohexanedione, its 5,5-dimethyl and 5-(2-furyl) derivatives, with 2-hydrazinoquinoxaline, 3,5-di(trifluoromethyl)phenylhydrazine, and ethoxycarbonylhydrazine. On interaction with ethoxycarbonylhydrazine the intermediate 2-[1-(-ethoxycarbonyl)hydrazino]ethylidene-1,3-cyclohexanediones were also isolated. From the potassium salt of 2-formyldimedone and 2-carboxyphenylhydrazine hydrochloride, 2-(2-carboxyphenyl)hydrazinomethylene-5,5-dimethyl-1,3-cyclohexanedione was obtained, the cyclization of which in ethanol in the presence of HCl led to 1-(2-carboxyphenyl)- and 1-(2-ethoxycarbonylphenyl)-6,6-dimethyl-4-oxo-4,5,6,7-tetrahydroindazole.     

Synthesis, Crystal Structure and Fluorescent Properties of 1-（4-（Dimethylamino）benzylidene）- 4-（naphthalen- 1-yl） Thiosemicarbazide

1 INTRODUCTION Recently, for the fluorescent properties, Schiff base has been more and more important and widely studied in density optical memories, nonlinear op- tics (NLO), organic light-emitting diodes (OLED), polymer LED and electrogenerated chemilumines- cence (ECL)[1~5]. Thiosemicarbazones are a kind of Schiff bases with thiourea and good ligands easily chelating with transition metal ions. Although they have been studied extensively for a long time due to their chemical and b…     

A New Chiral Synthesis of Naturally Occurring (-)-(S)-4-Hydroxy-2-pyrrolidinone

4-Hydroxy-2-pyrrolidinoneIisanattractivesimplemolecule.First,ithasservedasakeyintermediateinthesynthesis'ofoxiracetam,adrugusefulforimprovinglearningandmemory.Second,IcanbeeasilytransformedintoantiepilepticandhypotensivedrugGABOB',andhypolipidemicagentcarnitine'.Third,(-)-4-hydroxy-2-pyrro-lidinoneIhasbeenisolated'fromthetoadstollAmanitamuscaria.Itsabsoluteconfigurationhasbeenerroneouslyassigned'as(R).ThefirstchiralsynthesisofthiscompoundhasbeenreportedbyPifferi#.However,notuntil1984didi…     

Selective Spectrophotometric Determination of Palladium (II) With 2-(5-Bromo-2-Pyridylazo)-5-(Diethylamino)-Phenol

Abstract

A spectrophotometric study of the Pd(II) complex of a reagent 2-(5-Bromo-2-Pyridylazo)-5-(diethylamino)-Phenol (5-Br-PADAP) is presented. A violet complex is formed at pH 3.53, and shows maximal absorbance at 585 nm with molar absorptivity of 3.86 × 10⁴ 1. mol^?1 cm^?1. Beer's law is obeyed up to 50 μ of Pd(II). The method offers the advantages of simplicity, high precision, requires no extraction and is very selective, where 5.0 mg Pt(VI) and 0.3 mg Au(III) ions do not interfere.     

Spectral-luminescent and solvatochromic properties of 2-(3-coumarinyl)-5-(2′-(R-amino)-phenyl)-1,3,4-oxadiazoles

Spectral-luminescent properties of the newly synthesized 2-(3^′-coumarinyl)-5-(2′-(R-amino)-phenyl)-1,3,4-oxadiazoles has been investigated in solvents of various polarity and hydrogen-bonding ability. It has been found that for all the studied compounds no excited state intramolecular proton transfer occurs despite the presence of coumarinyl fragment - electron acceptor effect of the coumarinyl fragment is not sufficient to increase the excited state acidity of the amino group. It has been found that the absorption spectra of the studied compounds shift to higher energy with increase in solvent polarity, whereas corresponding fluorescence spectra shift to lower energy with solvent polarity increase. It has been suggested that long-wavelength shifts of the fluorescence spectra of the studied compounds with increase in solvent polarity is caused by the solvent relaxation. The observed solvent relaxation effect allow us to propose some of the studied compounds as potential probes to monitor changes in solvent relaxation in low-polar media and as potential probes for rigidochromic effect.     

1—间甲氧苯基—2—二甲胺甲基环己醇的合成与结构研究

通过间溴苯甲醚与２－二甲胺甲基环己酮反应制得１－间甲氧苯基－２－二胺甲基环己醇，对其分离得到相应的顺反异构体，对反应的立体化学进行了分析，并对＾１３Ｃ ＮＭＲ谱确定了顺反异构体的构型。     

3-(2-Quinolyl)- and 3-(5-carbethoxyfuryl-2)coumarins

3-(2-Quinolyl)- and 3-(5-carbethoxyfuryl-2)coumarins were prepared by reaction of substituted salicylaldehydes and hetarylacetonitriles. Alkylation and acylation of 3-hetaryl-7-hydroxycoumarins were studied. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 432–434, September–October, 2005.     

A practical stereoselective synthesis of (S)-( - )-ofloxacin

A very efficient and practical procedure for preparation of ( S)-( - )-ofloxacin has been developed (10 steps, overall yield ≥ 45 % ) . The key step of this approach is the regioselective nucleophilic substitution of 2-position fluorine atom of 2,3,4-tirfluoronitrobenzene by (S)-glycerol acetonide.