新显色剂2-[2,3,5-三氮唑偶氮]-5-二甲氨基苯甲酸与铜的显色反应研究及应用

合成了 2 [2 ,3,5 三氮唑偶氮 ] 5 二甲氨基苯甲酸 (TZAMB) ,并研究了试剂与铜的显色反应。结果表明 ,在 0 .1mol·L- 1H3PO4 介质中 ,试剂与铜形成紫红色配合物 ,配合物至少稳定2 4h ,最大吸收波长位于 5 75nm处 ,表观摩尔吸收系数为 4 .2 3× 10 4 L·mol- 1·cm- 1,配合物的组成为 ηCu∶ηTZAMB=1∶2 ,铜浓度在 0～ 1.2mg·L- 1范围内服从比耳定律 ,所拟方法已用于镁合金和铝合金中微量铜的测定 ,试验结果与标准值相符 ,RSD为 0 .0 75 %～ 0 .5 1%。     

新试剂1-(2,6-二氯-4-硝基苯)-3-(4-硝基苯)-三氮烯与镉的显色反应及应用研究

研究了新试剂 1 -( 2 ,6 -二氯 -4 -硝基苯 ) -3 -( 4-硝基苯 ) -三氮烯与镉的显色反应。在 Triton X-1 0 0存在下 ,于 p H=9.8～ 1 1 .0的 Na2 B4 O7-Na OH缓冲溶液中 ,镉与试剂有高灵敏的显色反应 ,生成 1∶ 3型黄色配合物 ,最大吸收波长为 44 5nm。用双峰双波长法测定 ,其表观摩尔吸光系数为 2 .85× 1 0 5L·mol- 1·cm- 1。用拟定的方法测定了人发和废水中的镉含量 ,标准加入回收率分别为 1 0 4.5%和 1 0 5.8% ,相对标准偏差分别为 3 .2 %和 4.1 %。     

新显色剂1-（对-偶氮苯）-3-（5-硝基-2-吡啶）-三氮烯的合成及其与镉的显色反应

报道了新显色剂 1 - (对 -偶氮苯 ) - 3- ( 5-硝基 - 2 -吡啶 ) -三氮烯 ( APNPT)的合成及其与镉的显色反应。在非离子表面活性剂 OP的存在下 ,p H1 0 .8时 ,镉 ( )与 APNPT形成 1∶ 2的稳定红色配合物 ,其最大吸收波长为 52 5nm,表观摩尔吸光系数为 1 .7× 1 0 5L· mol-1· cm-1,线性范围为 0～ 2 .8μg/1 0 m L,是目前测定微量镉的高灵敏显色反应之一 ,所拟方法已用于水样中微量镉 ( )的测定。     

1-(2,6-二氯-4-硝基苯)-3-(4-硝基苯)-三氮烯与铜的显色反应研究及其应用

研究了新试剂1-(2,6-二氯-4-硝基苯)-3-(4-硝基苯)-三氮烯(DCNPNPT)与铜(Ⅱ)显色反应。在表面活性剂Tween-80存在下,pH 9.0～10.0范围内,铜(Ⅱ)与DCNPNPT形成1:4黄色配合物,其最大吸收波长为460nm,用双峰双波长法测定,表观摩尔吸光系数为1.I×10~5L·mol~(-1)·cm~(-1)。铜(Ⅱ)含量在0～240μg·L~(-1)范围内符合比耳定律。拟定方法用于铜矿和环境水标样中铜的测定,结果满意。     

新显色剂1-羟基-2-(5-NO2-2-吡啶偶氮)-8-氨基-3,6-萘二磺酸与铜显色反应的研究

探讨了新显色剂 1-羟基-2-(5-NO2-2-吡啶偶氮)-8-氨基-3,6-萘二磺酸(简称5-NO2-PAH)与铜离子显色的适宜条件及其共存离子的影响,建立了 5-NO2-PAH测定铜的新显色反应体系.在 pH 7.0～10.0 范围内,铜与试剂形成稳定的 1∶2 配合物,其最大吸收峰位于 653 nm, 表观摩尔吸光系数εCu=4.68×104 L·mol-1·cm-1,铜的浓度在 0 μg/10 mL～14 μg/10 mL 范围内遵守比尔定律.方法已用于合金中铜的测定.     

2-(2-喹啉偶氮)-4-二乙氨基苯甲酸光度法测定烟草样品中的铜

合成了新试剂 2 - (2 -喹啉偶氮 ) - 4-二乙氨基苯甲酸 (QADEAA) ,并研究了其与铜的显色反应 ,在 p H4.5HAc- Na Ac缓冲介质中 ,乳化剂 - OP存在下 ,QADEAA 与铜反应生成 2∶ 1稳定络合物 ,λmax=565nm,ε=1 .1 2× 1 0 5L·mol-1·cm-1。铜含量在 0～ 8μg/2 5m L内符合比尔定律 ,方法可用于烟草样品中铜含量的测定。     

新试剂HBPCF用于生物样品及铝合金中微量铜的测定

研究了新试剂 1 ,5-二 ( 2 -羟基 - 5-溴苯 ) - 3-氰基甲 ( HBPCF)与铜的显色反应 ,在p H=3.6的乙酸 -乙酸钠介质中 ,Cu( )与 HBPCF反应生成蓝色配合物 ,在 630 nm处有最大吸收 ,表观摩尔吸光系数为 2 .8× 1 0 4 L· mol- 1· cm- 1,Cu( )浓度在 0～ 2 5μg/2 5m L范围中皆服从比耳定律。该试剂在此条件下选择性很好 ,可应用于茶叶、绿豆及铝合金中微量铜的直接测定 ,结果令人满意。     

1-(4-硝基苯基)-3-(5-硝基-2-吡啶)-三氮烯的合成及其与汞(Ⅱ)的显色反应研究

合成了 1 -(4 -硝基苯基 ) -3 -(5-硝基 -2 -吡啶 ) -三氮烯 ,并研究了它与汞(Ⅱ )的显色反应。在TritonX -1 0 0的存在下 ,pH1 1 2的Na2 B4 O7-NaOH缓冲溶液中 ,试剂与汞生成 2∶1型桔黄色配合物 ,在 4 3 8nm和 52 5nm处分别有一正一负两个吸收波峰 ,用双峰双波长测定 ,其表观摩尔吸光系数为 2 1× 1 0 5L·mo1 1·cm 1,Hg2 +的浓度在 0～ 2 80 μg/L范围内符合比耳定律。成功地测定了人发和尿液中微量的汞。     

7—（苯偶氮）—8—羟基喹啉—5—磺酸钠—溴化十六烷基三甲基铵与铜的显色反应研究

研究了铜与 7- (苯偶氮 ) - 8-羟基喹啉 - 5-磺酸钠 ( PAHQS)的显色反应 ,发现 Cu( )与PAHQS形成棕黄色配合物 ,在表面活性剂溴化十六烷基三甲基铵 ( CTMAB)存在下 ,对配合物及PAHQS有明显的增溶增敏作用。在 p H3.3的邻苯二甲酸氢钾 -盐酸缓冲溶液中 ,配合物最大吸收峰位于 460 nm处 ,其表观摩尔吸光系数为 6.0 4× 1 0 4 L·mol-1· cm-1,铜浓度在 0～ 50 μg/2 5ml范围内符合比耳定律 ,方法应用于中药和环境水样中痕量铜的分析 ,结果满意     

新显色剂2-(5-羧基-1,3,4-三氮唑偶氮)-5-二乙氨基苯甲酸光度法测定钒的研究

研究了新显色剂 2 -( 5-羧基 -1 ,3 ,4-三氮唑偶氮 ) -5-二乙氨基苯甲酸 ( CTZD-BA)与钒的显色反应的条件。在 p H 3 .0的 HAc-Na Ac介质中 ,CTZDBA与 V( )形成稳定的摩尔比为 2∶ 1的紫红色络合物 ,最大吸收波长在 583 nm处 ,表观摩尔吸光系数为 4.0 6× 1 0 4 L·mol- 1·cm- 1,V( )在 0～ 0 .8mg/L范围内遵守比耳定律。方法可不经分离直接测定铝合金样品中的钒 ,结果满意     

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 and Characterization of New Schiff Bases 2-(2-(2-(Aryl)Methyleneamino)Phenylthio) Ethylthio)-N-((aryl)Methylene)Benzeneamine

A series of Schiff bases containing four to six coordination sites N₂S₂ X₂(X = O,N) 2-(2-(2-(aryl)methyleneamino)phenylthio)ethylthio)-N-((aryl)methylene)benzeneamine (2c–f) were prepared from the reaction of 1,2-di(2-aminophenylthio)ethane (1) with aromatic aldehydes. All compounds were characterized by means IR, mass, ¹H and ¹³C NMR spectroscopy, and elemental analysis, and in the case of 2b with a single crystal X-ray diffraction. The X-ray crystal structure of 2b showed that the resonance occurs between aromatic rings, through the C=N bonds of the molecule.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

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 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…     

Syntheses,crystal structures,and spectral properties of Mn(II) and Co(II) complexes with 3-(p-chlorophenyl)- 4-(p-methylphenyl)-5-(2-pyridyl)-1,2,4-triazole

Two new complexes, trans-[MnL₂(NCS)₂] (1) and trans-[CoL₂(H₂O)(EtOH)](ClO₄)₂?·?H₂O (2) with asymmetrical triaryltriazole ligands [L?=?3-(p-chlorophenyl)-4-(p-methylphenyl)-5-(2-pyridyl)-1,2,4-triazole], have been synthesized and characterized by elemental analysis, FT-IR, ESI-MS, and single-crystal X-ray diffraction. In the complexes each L adopts a chelating bidentate mode via the nitrogen of pyridyl and triazole. Both complexes have a similar distorted octahedral core with two NCS^? ions in the trans position in 1, while one H₂O and one EtOH are present in the axial sites in 2.     

Bis(diphenylphosphano)alkan- und 1-(Diphenylphosphano)-2-(2-pyridino)ethan-N-Arylsulfinylamin-Nickel(0)-Komplexe

Bis(diphenylphosphano)alkane- and 1-Diphenylphosphano-2-(2-pyridino)ethane-N-arylsulfinylamine Nickel(0) Complexes Synthesis and properties of the bis(diphenylphosphano)alkane-N-phenyl-sulfinylamine-nickel(0) complexes [Ni{Ph₂P(CH₂)_nPPh₂}(PhNSO)] (n = 2 dppe, n = 3 dppp, n = 4 dppb) as well as of the 1-(diphenylphosphano)-2-(2-pyridino)ethane nickel(0) complexes [Ni(dpppe)₂], [Ni(dpppe)(p-TolNSO)] and [Ni(dpppe)(PPh₃)₂] are described. These compounds have been characterized by i. r. and ³¹P n.m.r. spectroscopy. The N-arylsulfinylamine ligands are η²-(N, S)-side on coordinated.     

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.     

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.     

Novel (E)- and (Z)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles from (E)- and (Z)-3-styrylchromones: the unexpected case of (E)-3(5)-(2-hydroxyphenyl)-4-(4-nitrostyryl)pyrazoles

An efficient synthetic method for the preparation of (E)- and (Z)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles has been developed. The reaction of (E)- and (Z)-3-styrylchromones with hydrazine hydrate afforded the corresponding (E)- and (Z)-4-styrylpyrazoles, respectively, saved 4′-nitro-derivatives where both (E)- and (Z)-4′-nitro-3-styrylchromones afforded (E)-3(5)-(2-hydroxyphenyl)-4-(4-nitrostyryl)pyrazoles. The reaction mechanism for these transformations was discussed and the stereochemistry of all products was assigned by NMR experiments.     

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.