Spektrophotometrische Untersuchung Der Wechselwirkung Zwischen Rh(III) und 4-(2-Pyridylazo)-Resorzin

Abstract

A detailed investigation has been made of Che pH versus light absorption curves of solutions of PAR and Rh(III) in various concentrations. It has been shown, that depending on tile acidity of the solution, two different substances will be formed; the optimal conditions of the formation of each substance has been found. The molar absorptivities have been determined and the equilibrium and stability constants of the formed substances have been computed from the absorbance versus pH curves.     

Untersuchung Der Kcmplexbildung Von Thallium(III) Mit 1-Phenyl-3-Methyl-4-Benzoylpyrazolon-5

Abstract

A study has been made of the method used for extracting the complex formed between thallium(III) and PhMBP. It has been demonstrated that thallium(III) can be readily extracted as a complex with PhMBP by organic solvents at low pH. The extraction of thallium(III) has been studied as a function of pH, concentration of reagent, nature of solvent, duration of contact of the phases and concentration of thallium(III). It has been established that thallium(III) forms a complex with PhMBP of the type MA_n, where n=3. The stability constants and distribution constant of the neutral complex has been calculated by the method of Leden-Rydberg.     

Simultaneous First Derivative Spectrophotometric Determination of Palladium and Nickel Using 2-(2-Thiazolylazo)-5-Dimethylaminobenzoic Acid as an Analytical Reagent

 A simple, rapid, selective, sensitive and economical method has been developed for the simultaneous determination of trace amounts of palladium and nickel in aqueous methanolic medium using 2-(2-thiazolylazo)-5-dimethylam inobenzoic acid as an analytical reagent by first derivative spectrophotometr y. Palladium is determined by measuring base to peak distance at λ=695.0 nm while nickel is estimated by zero crossing method in the mixture. The linearity is maintained between 0.12–1.75 μg mL⁻¹ for palladium and 0.07–1.60 μg mL⁻¹ for nickel in the pH range 2.8–7.2 and 3.4–8.8 respectively. Seven replicate determinations of 1.0 μ g mL⁻¹ of palladium and 0.8 μg mL⁻¹ of nickel in a mixture give a mean signal height of 0.391 for Pd and 0.541 for Ni with relative standard deviations of 0.9% and 1.2%, respectively. The sensitivity of the proposed method is 0.391 (dA/dλ)/(μg mL⁻¹) for palladium and 0.685 (dA/dλ)/(μg mL⁻¹) for nickel. Various parameters have been optimised for the simultaneous determination of palladium and nickel in various complex samples. Received March 30, 1999. Revision November 25, 1999.     

2-(2-噻唑偶氮)-5-[(N,N-二羧基甲基)氨基]苯甲酸浸渍树脂吸附金的特性及应用

用1300－Ⅱ型吸附树脂吸附噻唑偶氮类试剂制取浸渍树脂。研究了树脂对试剂和对金的吸附率及其与溶液pH值的关系，求得浸渍树脂吸附金的平衡速率和吸附容量，并在条件试验基础上拟订了柱操作分离富集微量金的方法，获得了满意的结果。     

Potentiometric Studies of Some Bivalent Metal Ion Complexes of a New Ligand,o-(2-Thiazolylazo)-4-Ethylphenol

Abstract

The complexations of a new ligand, o-(2-thiazolylazo)-4-ethylphenol(TAEP) with Ca(II), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hq(II) and Pb(II) have been studied by potentiometric titrations, at 25.0 ± 0.2°C and an ionic strength of 0.1 in 30% v/v dioxane-water mixture. The dissociation constant and spectral data of TAEP and formation constants of the complexes containing various molar ratios of metal ion to ligand, are reported. It is observed that Ca(II) forms only an ML complex in any molar ratios, whereas other metal ions react in two steps forming ML and ML₂ complexes in a 1:3 molar ratio. In the case of 1:1 and 1:2 molar ratios, Mn(II), Co(II), Cd(II) and Hg(II) seemed to form bi- or poly-nuclear complexes because of slightly different formation curves from those of 1:3 molar ratio. The sequence of the first successive formation constant is Cu > Hg > Ni > Pb > Co > Zn > Cd > Mn > Ca, showing Mellor-Maley's order. Further correlation is shown between the formation constants and the second ionization potentials of the metals.     

2-(2-Thiazolylazo)-pcresol (TAC) as a reagent for the spectrophotometric determination of titanium (IV)

The reaction between titanium(IV) and 2-(2-thiazolylazo)-p-cresol-(TAC) in aqueous methanol media at apparent pH 4.0–5.6 results in a intensely coloured complex that is stable for at least 2 h. The combining ratio is 1 1 cation TAC. Beer's law is obeyed up to 5.0 g/ml titanium(IV) at 580 nm. The apparent molar absorptivity at 580 nm is 9.82.10³ l.mole^–1.cm^–1 and the detection limit obtained was 5 ng/ml titanium (IV). A spectrophotometric method for the simultaneous determination of titanium and iron with TAC is proposed.     

A chelating resin containing 1-(2-thiazolylazo)-2-naphthol as the functional group; synthesis and sorption behavior for trace metal ions

A new polystyrene-divinylbenzene resin containing 1-(2-thiazolylazo)-2-naphthol (TAN) functional group was synthesized and its sorption behavior for 19 metal ions including Zr(IV), Hf(IV) and U(VI) was investigated by batch and column experiments. The chelating resin showed a high sorption affinity for Zr(IV) and Hf(IV) at pH 2. Some parameters affecting the sorption of the metal ions are detailed. The breakthrough and overall capacities were measured under optimized conditions. The overall capacities of Zr(IV) and Hf(IV) that were higher than those of the other metal ions were 0.92 and 0.87 mmol/g, respectively. The elution order of metal ions at pH 4 was evaluated as: Zr(IV)>Hf(IV)>Th(IV)>V(V)>Nb(V)>Cu(II)>U(VI)>Ta(V)>Mo(VI)>Cr(III)>Sn(IV)>W(VI). Quantitative recovery of most metal ions except Zr(IV) was achieved using 2 M HNO₃. Desorption and recovery of Zr(IV) was successfully performed with 2 M HClO₄ and 2 M HCl.     

Direct and Second Order Analogue Derivative Extraction-Spectrophotometric Determination of Iron with 2 (4, 5-Dimethyl-2-Thiazolylazo)-4, 6-Dimethylphenol

Abstract

An extraction-spectrophotometric method for the determination of trace amounts of iron based on its extraction into chloroform with 2-(4, 5-dimethyl-2-thiazolylazo)-4, 6-dimethylphenol has been developed, which allows the determination of 5–28 μg Fe (?₇₇₃ = 1.38×10⁴ 1. mol^?1. cm^?1). The use of second order analogue derivative spectrophotometry allows the determination of down to 0.2–5 μg, Fe. The methods are quite selective and have been applied to the determination of iron in mineral waters.     

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.     

[Z]-2-(芳基锡基)-1-(9-芴醇)乙烯的合成、结构与性质

用三苯基氢化锡,三对甲苯基氢化锡作为锡氢化试剂与9-乙炔基-9-芴醇进行反应,合成了2个有机锡化合物:[Z]-2-(三苯基锡基)-1-(9-芴醇)乙烯(1)和[Z]-2-(三对甲苯基锡基)-1-(9-芴醇)乙烯(2)。化合物1和2分别与ICl,Br~2,I~2反应,得到6个有机锡一卤化物,6个有机锡二卤化物和2个有机锡混合卤化物(3-16)。有机锡一碘化物7,13和有机锡二碘化物8,14与KOH乙醇溶液反应,分别得到相应的有机锡氢氧化物17,18和有机锡氧化物19,20。有机锡二碘化物8,14分别与含氮双齿配体1,10-邻菲罗啉(Phen),2,2'-联吡啶(Bipy),8-羟基喹啉(Oxin)反应,得到6个相应的配合物21-26。26个新化合物通过元素分析,锡含量测定,IR,^1HNMR测定对其结构进行了表征。同时测定了化合物2的晶体结构,晶体属单斜晶系,空间群P2~1/c。化合物2是以Sn原子为中心扭曲的四面体构型。     

Determination of transition and rare earth elements in low-alloy steels as chelates with 4-(2-Thiazolylazo)resorcinol by reversed-phase high performance liquid chromatography

4-(2-Thiazolylazo)resorcinol (TAR) is used as a chelating reagent in the reversed-phase HPLC separation and determination of transition and rare earth elements in low-alloy steels. A precolumn derivatization method is used, followed by separation on an octadecyl-bonded silica stationary phase with a sodium octane-1-sulphonate-tartaric acid mobile phase. The eluted metal chelates are detected by uv-visible spectrophotometry. The requirements for sample preparation, characterization of precolumn derivatization and the optimum conditions for the sensitive detection of metal ions after liquid chromatography (LC) separation are discussed. The influence of the pH of the chelating medium and the eluent, the concentration of TAR and the eluent were investigated. The results are compared with those of other methods such as atomic absorption spectrometry (AAS) and inductively coupled plasma atomic emission spectrometry (ICP-AES).     

Iron(III) complexes bearing 2-(benzimidazole)-6-(1-aryliminoethyl)pyridines: Synthesis, characterization and their catalytic behaviors towards ethylene oligomerization and polymerization

A series of iron(III) complexes ligated by 2-(benzimidazole)-6-(1-aryliminoethyl)pyridines was synthesized and examined by ¹H NMR, ESI-MS, IR spectroscopic, elemental analysis and X-ray photoelectron spectroscopy (XPS). Activated with methylaluminoxane (MAO), all ferric complexes exhibited good activities (up to 5.38 × 10⁶ g mol⁻¹(Fe) h⁻¹) of ethylene oligomerization and polymerization, and resultant oligomers and polyethylene waxes showed high α-olefin feature, meanwhile the distribution of oligomers mostly resembled Schulz-Flory rules. The various reaction parameters were investigated in detail, and the less bulky and electron-withdrawing substituents of ligands could enhance the catalytic activities of their ferric complexes. The observations explain the cause for unstable activities performed by stored iron(II) complexes.     

The Colour Reaction of Mercury with 1-(6-Ethoxyl-2-benzothiazolyl)-3-(4-Nitrophenyl)-Triazene and its Application

Thetfiazenereagentswereusedforthedeterminationofcadmium,mercuryandzinc.Wehavesynthesizedthetriazenereagentscontainingheterocyclicring'-'.Recently,annewreagentEtOBTNPTwassynthesized.Becausethereagentcontainsanelectronpropellinggroup(-OCH,CH,)inoneendandanelectronwithdrawinggroup(-NO,)intheotherend,sotheconjugatesystemisenlargedinthemolecularstructure,thisresultinginadvantageofmigrationofelectroniccloud.ThesensitivityofthecolourreactionofEtOBTNPTwithmercuryissuperiortoothertfiazenereage…     

Erbium(III) PVC Membrane Ion-Selective Sensor based on 4-(2-Thiazolylazo)resorcinal

Abstract

4-(2-Thiazolylazo)resorcinol (TR) was used as a new compound to play the role of an excellent ion carrier in the fabrication of an Er(III) membrane electrode. The electrode shows a very good selectivity toward Er(III) ions over a wide variety of cations, including alkali, alkaline earth, transition, and heavy-metal ions. The proposed sensor exhibits a Nernstian behavior (with slope of 19.6 ± 0.6 mV per decade) over a wide concentration range (1.0 × 10^?6 to 1.0 × 10^?2 M). The detection limit of the sensor is 6.6 × 10^?7 M. It has a very short response time, in the whole concentration range (～10 s), and can be used for at least 12 weeks in the pH range of 2.8–9.3. The proposed sensor was successfully applied as an indicator electrode for the potentiometric titration of a Er(III) solution, with EDTA. It was also successfully applied to the F^? ion determination in some mouthwashing solutions.     

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.     

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…     

Complex formation studies on Ho(III) and Lu(III) with 1-(2-pyridylazo)-2-naphthol (PAN) in alcohol-water solutions

The formation ofPAN complexes in the systemsLn(III)—PAN—alcohol-water (where:Ln(III)=Ho, Lu and alcohol=ethanol,n-propanol,iso-propanol) was investigated by a spectrophotometric method. Equilibrium constants for the reactionLn ³⁺ + HLLnL ²⁺ + H⁺ (HL=PAN) and stability constants of complexesLnL ²⁺ were calculated.

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Untersuchungen zur Komplexbildung von Ho(III) und Lu(III) mit 1-(2-Pyridylazo)-2-naphthol (PAN) in alkoholisch-;wä\rigen Lösungen

Zusammenfassung Die Bildung der Komplexe vonPAN in den SystemenLn(III)—PAN—Alkohol-Wasser (Ln(III)=Ho, Lu; Alkohol=Ethanol,n-Propanol,iso-Propanol) wurde mit einer spektrophotometrischen Methode untersucht. Die Gleichgewichtskonstanten der ReaktionenLn ³⁺ + HLLnL ²⁺ + H⁺ (HL==PAN) und die Stabilitätskonstanten der KomplexeLnL ²⁺ wurden berechnet.

     

Spectrophotometric Study on the Extraction of 4-(2- Thiazolylazo)Resorcinol Chelates of Cobalt(II), Nickel(II), Copper(II), and Zinc(II) with Zephiramin

Abstract

The solvent extraction of the transition metals(II)4-(2-thia-zolylazo)resorcinol(TAR) chelate anions with cation of zephiramin (Z⁺ Cl^?) was spectrophotometrically investigated. The composition of the extracted species was estimated to be 2Z⁺ MR₂ ^2-, which had the absorption maxima in the same ranges of wavelength at about 550 nm, and the constant extractions were obtained at pH 6.7–10.2 for cobalt, 7.2–9.1 for nickel, 8.2–10.1 for zinc, and 8.5–10.7 for copper system. In the presence of sodium chloride, cobalt chelate could be effectively separated from the other transition metals. The extraction equilibrium was also investigated and the extraction constants were calculated.     

4—（2—噻唑偶氮）—2,4—二氨基甲苯与铑显色反应的研究

本研究了４－（２－噻唑偶氮）－２，４－二氨基甲苯（简称ＴＡＤＡＴ）与铑的显色反应。在ｐＨ＝３．７～４．９的酸度范围内试剂与铑形成红色络合物，加入无机酸后色泽加深，络合物的最大吸收位于５９０ｎｍ，表观摩尔吸光系数为１．１×１０＾５Ｌ·ｍｏｌ＾－１·ｃｍ＾－１，其组成为Ｒｈ：ＴＡＤＡＴ＝１：３。铑浓度在０～１２μｇ／２５ｍｌ范围内服从比尔定律。该方法用于模拟样中铑的测定，结果满意。     

(2S)-(+)-2-溴-1-(6'-甲氧基-2'-萘基)丙-1-酮的不对称合成

以(2R,3R)-酒石酸二甲酯为手性辅助剂,6-甲氧基-2-丙酰基萘经缩酮化、溴化铜不对称溴化、水解等反应合成了(2S)-2-溴-1-(6'-甲氧基-2'-萘基)丙-1-酮。总收率94%。