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Articles 2401 - 2430 of 2720
Full-Text Articles in Chemistry
Accumulation Of Heavy Metals In Freshwater Organisms: Assessment Of Toxic Interactions, Neylan Di̇ri̇lgen
Accumulation Of Heavy Metals In Freshwater Organisms: Assessment Of Toxic Interactions, Neylan Di̇ri̇lgen
Turkish Journal of Chemistry
Heavy metals are continuously released into the terrestrial environment by natural sources and human activities. The uptake and accumulation of heavy metals by plants promotes a mechanistic understanding of the biological significance of particular metal concentrations and distributions in biota. The toxicity of chromium, zinc, copper and cobalt ions and their binary mixtures are studied at varying test levels using duckweed as the test organism. The accumulation of metal ions are determined by atomic absorption spectroscopy. The type of toxic interactions in binary mixtures is assessed as `synergistic', `antagonistic' and `additive' by a statistical approach.
The Composition Of Essential Oils From Two Varieties Of Sideritis Erythrantha Var. Erythrantha And Var. Cedretorum, Nurhayat Tabanca, Neş'E Kirimer, K. Hüsnü Can Başer
The Composition Of Essential Oils From Two Varieties Of Sideritis Erythrantha Var. Erythrantha And Var. Cedretorum, Nurhayat Tabanca, Neş'E Kirimer, K. Hüsnü Can Başer
Turkish Journal of Chemistry
Water distilled essential oils from two varieties of Sideritis erythrantha: var. erythrantha} and var. cedretorum, both endemic in Turkey, were analysed by GC/MS. The main components were characterized as \alpha -pinene (16.3-19.5%) and sabinene (6.1- 10.4%) for var. erythrantha; myrcene (21.9-24.3%) and \alpha -pinene (11.4- 12.4%) for var. cedretorum.
Structural Studies Of Water-Soluble \Beta-Brominated Manganese Porphyrins: Stabilities Of Mntdcsppbr _{8} And Mntsppbr _{8} As Homogeneous And Supported Reagents Toward Hydrogen Peroxide And Sodium Hypochlorite, Hayretti̇n Türk, Hüseyi̇n Berber
Structural Studies Of Water-Soluble \Beta-Brominated Manganese Porphyrins: Stabilities Of Mntdcsppbr _{8} And Mntsppbr _{8} As Homogeneous And Supported Reagents Toward Hydrogen Peroxide And Sodium Hypochlorite, Hayretti̇n Türk, Hüseyi̇n Berber
Turkish Journal of Chemistry
This article describes the structural stabilities of [2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetrakis(2,6-dichloro-3-sulfonatophenyl)porphinato]manganese(III) X (where X = H_{2}O and/or OH^{-} , depending on pH) (MnTDCSPPBr_{8} ) and [2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetra(4-sulfonatophenyl)porphinato] manganese(III) X (where X = H_{2}O and/or OH^{-} , depending on pH) (MnTSPPBr_{8} ) toward H_{2}O_{2} and NaOCl at various pH's, I = 0.2 M and 30^oC. In addition, the structural stabilities of these manganese porphyrins were investigated when they were bound to quaternary ammonium containing supports, namely, hexadecyltrimethylammonium bromide (CTAB), 2,6-ionene, 2,10-ionene and a poly[(vinylbenzyl)trimethylammonium chloride] latex. In alkaline media, both manganese porphyrins degraded and precipitated even in the absence of both of the oxidants. In …
Optimization Of Process Parameters For Reactive Lactic Acid Extraction, Emi̇ne Kahya, Emi̇ne Bayraktar, Ülkü Mehmetoğlu
Optimization Of Process Parameters For Reactive Lactic Acid Extraction, Emi̇ne Kahya, Emi̇ne Bayraktar, Ülkü Mehmetoğlu
Turkish Journal of Chemistry
The reactive extraction method was used to separate lactic acid from its aqueous solutions. In this method, the amine in the solvent phase reacts with the lactic acid in the aqueous phase, resulting in the extraction of acid into the organic phase. In this study, Alamine 336 diluted with oleyl alcohol was used as the solvent. The effects of initial lactic acid concentration, pH, temperature, extraction time, stirring rate, the amount of Alamine 336 in oleyl alcohol and the ratio of organic phase volume to aqueous phase volume, V_{org}/V_{aq}, on the distribution coefficient of the lactic acid, K_D, were investigated. …
Incorporation Of Edta For The Elimination Of Metal Inhibitory Effects In An Amperometric Biosensor Based On Mushroom Tissue Polyphenol Oxidase, Arzum Erdem, Di̇lşat Özkan, Burcu Meri̇ç, Kağan Kerman, Mehmet Özsöz
Incorporation Of Edta For The Elimination Of Metal Inhibitory Effects In An Amperometric Biosensor Based On Mushroom Tissue Polyphenol Oxidase, Arzum Erdem, Di̇lşat Özkan, Burcu Meri̇ç, Kağan Kerman, Mehmet Özsöz
Turkish Journal of Chemistry
Enzyme based biosensors are highly selective devices which rely on the specific binding of the target analyte (the substrate) to the active-site regions of the enzyme. The enzymatic reaction between mushroom tissue polyphenol oxidase and its substrate phenol is coupled with the use of potassium ferrocyanide (K_{4}Fe(CN)_{6}) as the mediator in ammonia buffer solution (pH 8.80). The response of devices is often affected by the presence of inhibitors, which combine with the free enzyme in a manner that prevents substrate binding. The objective of this study is to describe an efficient and yet simple strategy to eliminate the interference of …
Determination Of Some Of The Physicochemical Properties Of Fine Alumina Powders Prepared By Emulsion Evaporation, Yüksel Sarikaya, İsmet Sevi̇nç, Müşerref Önal, Tülay Alemdaroğlu
Determination Of Some Of The Physicochemical Properties Of Fine Alumina Powders Prepared By Emulsion Evaporation, Yüksel Sarikaya, İsmet Sevi̇nç, Müşerref Önal, Tülay Alemdaroğlu
Turkish Journal of Chemistry
In order to prepare fine alumina powders, an emulsion was prepared under optimum conditions. The emulsion was examined by optical microscopy and the prepared fine alumina powders were characterised by electron microscopy. The particles were formed of porous spheres and their sizes were between 1 and 10 \\mum. The powder samples were sintered by varying the temperature between 700 and 1600°C. The adsorption and desorption of nitrogen on these samples were investigated. By using the adsorption data, the specific surface areas were calculated according to different procedures and the correlation between them was discussed. The specific micropore and mesopore volumes …
Flow Injection Analysis For Boron Determination By Using Methyl Borate Generation And Flame Atomic Emission Spectrometry, Deni̇z Yurtsever Sarica, Nusret Ertaş
Flow Injection Analysis For Boron Determination By Using Methyl Borate Generation And Flame Atomic Emission Spectrometry, Deni̇z Yurtsever Sarica, Nusret Ertaş
Turkish Journal of Chemistry
Boron is one of the least sensitive elements in atomic emission spectrometry. As various refractory substances interfere in the analysis and because of the low sensitivity, sample enrichment and the separation of the interfering matrix is needed. Methyl borate has many advantages because of its simple generation conditions and its stability in the absence of moisture. New procedures for the generation of methyl borate without using external heating have also been investigated to produce a more rapid determination of boron. The on-line combination of flow injection analysis using methyl borate generation with flame atomic emission spectrometry as the detector is …
Thermogravimetric Investigation Of The Dehydration Kinetics Of Ksf, K10 And Turkish Bentonite, Yalçin Tonbul, Kadi̇r Yurdakoç
Thermogravimetric Investigation Of The Dehydration Kinetics Of Ksf, K10 And Turkish Bentonite, Yalçin Tonbul, Kadi̇r Yurdakoç
Turkish Journal of Chemistry
The kinetic parameters for the dehydration of bentonite from Turkey, KSF and K10 were determined by using dynamic TG techniques. The Ozawa method is better for the dehydration of the clay samples than the first order equation of Coats and Redfern. The former function calculates consistently higher activation energies than the latter. The mean values of the activation energies in the \\alpha range 0.1-0.7, are 56-66 kJ mol^{-1} in the Ozawa method.
Selenium Speciation In Karakaya Dam Lake's Water (Malatya-Turkey), F. Zehra Küçükbay, Mustafa Demi̇r
Selenium Speciation In Karakaya Dam Lake's Water (Malatya-Turkey), F. Zehra Küçükbay, Mustafa Demi̇r
Turkish Journal of Chemistry
Concentrations of total inorganic selenium, Se(IV), Se(VI) and organically bonded selenium from samples of Karakaya dam lake\\\'s water were determined using ammonium pyrollidine dithio carbamate (APDC) as a chelating agent and subsequent adsorption on amberlite type XAD-8 resins. Eluted analytes are taken up in a matrix free acidic solution suitable for graphite furnace atomic absorption spectroscopy (GFAAS). According to our results, levels of the total inorganic selenium, Se(IV), Se(VI) and organically bonded selenium were found to be between 0.11 \\pm 0.01 and 0.17 \\pm 0.01 \\mug/L, 0.07 \\pm 0.01 and 0.12 \\pm 0.01 \\mug/L, 0.02 \\pm 0.01 and 0.05 \\pm …
Lewis Acid Catalyzed 1,3-Dipolar Cycloadditon Reactions Of Stabilized Azomethine Ylides, Özdemi̇r Doğan, Hasan Koyuncu, Ümi̇t Kanişkan
Lewis Acid Catalyzed 1,3-Dipolar Cycloadditon Reactions Of Stabilized Azomethine Ylides, Özdemi̇r Doğan, Hasan Koyuncu, Ümi̇t Kanişkan
Turkish Journal of Chemistry
Diethylzinc was tested for the first time as the Lewis acid in 1,3-dipolar cycloaddition reactions of azomethine ylides to synthesize pyrrolidine derivatives. A new, easily applicable and highly selective method was developed for the synthesis of highly substituted pyrrolidines. By the application of this method, the synthesis of three new pyrrolidine derivatives was achieved.
Characterization Of Lipids And Fatty Acid Methyl Ester Contents In Leaves And Roots Of Crocus Vallicola, Nuretti̇n Yayli, Zerri̇n Kiran, Hasan Seymen, Hasan Genç, Mustafa Küçüki̇slamoğlu
Characterization Of Lipids And Fatty Acid Methyl Ester Contents In Leaves And Roots Of Crocus Vallicola, Nuretti̇n Yayli, Zerri̇n Kiran, Hasan Seymen, Hasan Genç, Mustafa Küçüki̇slamoğlu
Turkish Journal of Chemistry
The chemical composition of the fatty acids methyl esters (FAMEs) and other lipids in leaves and roots of Crocusvallicola were analyzed by gas chromatography-mass spectrometry(GC-MS). In this work, twenty-eight compounds, including 22 FAMEs, 1 aldehyde, 3 hydrocarbons (substitute alkane and alkene), 2 alcohols in the leaves and twenty-one compounds (17 FAMEs, 1 anhydride, 1 substitute alcohol, 1 ketone, 1 substitute amide) in the roots were identified by GC-MS from C. vallicola. The FAMEs in leaves and roots were highly similar; only the amounts of the esters were different. Key Words: Crocus vallicola, leaves, roots, FAMEs
Effect Of Acid Treatment On Volumetric Swelling Ratios Of Coals, Nejat Mesci̇, Aki̇f Şenelt, Taner Toğrul, Aral Olcay
Effect Of Acid Treatment On Volumetric Swelling Ratios Of Coals, Nejat Mesci̇, Aki̇f Şenelt, Taner Toğrul, Aral Olcay
Turkish Journal of Chemistry
To remove Ca^{2+} ions, six low rank coals and one coking coal were treated with 0.1 and l.0 N HC1 for 24 h. IR spectra and proximate analysis of the lignites indicated that only slight structural changes had occurred during acid treatment. The swelling ratios of parent and acid-treated coal samples showed that removal of Ca^{2+} resulted in an increase in the swelling ratios. Higher swelling ratios were obtained with acid-washed coal samples. While the highest swelling ratios of the parent lignites were obtained in ethylenediamine, those of acid-treated samples were obtained in pyridine and dimethylformamide.
Calculation Of Multi-Center Integrals For The Region Of Moderate And Weak Overlap, Abdulhali̇k Karabulut, Gökhan Budak, Lütfü Demi̇r, Nagi̇f Sefteroğlu Nabi̇yev, Yusuf Şahi̇n
Calculation Of Multi-Center Integrals For The Region Of Moderate And Weak Overlap, Abdulhali̇k Karabulut, Gökhan Budak, Lütfü Demi̇r, Nagi̇f Sefteroğlu Nabi̇yev, Yusuf Şahi̇n
Turkish Journal of Chemistry
In this study a general formula was established for multi-center integrals over Gaussian basis sets using the two-center expansion of nuclear attraction and electron repulsion potentials. The terms of the formula are the analytical functions of interatomic distances. Three kinds of integrals contained in these formulae can be evaluated analytically. In the presented method, unlike many other popular methods, the numerical integrations procedure is unnecessary since it does not contain the incomplete gamma function. A computer program was written and tested for various orbitals. The calculations show that the series converge very rapidly.
Propylene Dimerization Over Nickel-Ion Exchanged Zeolites In The Liquid Phase, Mina K. Munshieva
Propylene Dimerization Over Nickel-Ion Exchanged Zeolites In The Liquid Phase, Mina K. Munshieva
Turkish Journal of Chemistry
The possibility of the dimerization of propylene in the liquid phase over nickel-ion exchanged zeolites (Ni-zeolites) modified by treatment with AlEt_{2}Cl to provide enhanced activity is studied. In order to determine the influence of the crystalline structure of zeolites on their catalytic activity and the selection of the most active catalyst the zeolites of faujasite (NaX, NaY), eryonite and mordenite types with various structures and different cell sizes have been chosen. The samples of Ni-zeolites were prepared by ion exchange with nickel nitrate in a corresponding zeolite. The treatment of these zeolites with AlEt_{2}Cl leads to the formation of active …
Hydrothermal And Microwave Synthesis Of Boron Phosphate, Bpo_{4}, A. Baykal, Meral Kizilyalli, M. Toprak, R. Kniep
Hydrothermal And Microwave Synthesis Of Boron Phosphate, Bpo_{4}, A. Baykal, Meral Kizilyalli, M. Toprak, R. Kniep
Turkish Journal of Chemistry
BPO_4 was previously synthesized by the solid state reactions of (NH_4)_2HPO_4 and B_2O_3 at 1000 ^oC and was characterized by X-ray powder diffraction and IR methods. We have now succeeded in preparing BPO_4 from H_3BO_3 and P_2O_5 using hydrothermal synthesis by heating at 160 ^oC for 2 days and obtained a single phase product. We observed that a microwave-assisted synthesis takes only 3 to 5 minutes to transform a solid mixture of (NH_4)_2B_4O_7.4H_2O, and solid H_3PO_4 or B_2O_3 + P_2O_5 into the crystalline title compound. Its X-ray powder diffraction data and IR spectra were in good agreement with the literature …
The Influence Of Transition Metal Ions On The Kinetics Of Ascorbic Acid Oxidation By Methylene Blue In Strongly Acidic Media, M. Nasiruddin Khan, Anila Sarwar
The Influence Of Transition Metal Ions On The Kinetics Of Ascorbic Acid Oxidation By Methylene Blue In Strongly Acidic Media, M. Nasiruddin Khan, Anila Sarwar
Turkish Journal of Chemistry
The kinetics of the oxidation of L-ascorbic acid (H_{2} A) by methylene blue was investigated in strongly acidic media over the temperature range 22-40 ^oC. The kinetic studies were carried out as a function of different variables like concentration, pH, ionic strength and temperature. The rate was found to be a linear relation with [H_{2} A], [M.B.] and [H^{+}]. Ionic strength dependence formation indicated complex formation by monocationic and anionic species in solution. The reaction rate was greatly catalyzed by the presence of trace amounts of copper (II) ion. Possible mechanisms for the catalyzed and uncatalyzed reactions are proposed. Kinetic …
Synthesis Of Azobenzo[B]Thiophene Derivatives And Their Dyeing Performance On Polyester Fibre, Hari Raghav Maradiya
Synthesis Of Azobenzo[B]Thiophene Derivatives And Their Dyeing Performance On Polyester Fibre, Hari Raghav Maradiya
Turkish Journal of Chemistry
Ethyl 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate was synthesised by the reaction of cyclohexanone and sulphur with ethylcyanoacetate. The 2-aminothiophene derivative was diazotised and coupled with various N-arylmaleimides to give monoazo disperse dyes. The dyeing performance of these dyes was assessed on polyester fabric. These dyes were found to give light pink to reddish pink shades with very good depth and levelness on polyester fabric. The dyed fabric showed fair light fastness and excellent washing, rubbing, perspiration and sublimation fastness. The dyebath exhaustion on polyester fabric was found to be good and acceptable.
Spectrophotometric Determination Of Propranolol As Cu(Ii), Ni(Ii) And Co(Ii) Dithiocarbamate Complexes, Ayşegül Gölcü, Mustafa Dolaz, Selahatti̇n Seri̇n
Spectrophotometric Determination Of Propranolol As Cu(Ii), Ni(Ii) And Co(Ii) Dithiocarbamate Complexes, Ayşegül Gölcü, Mustafa Dolaz, Selahatti̇n Seri̇n
Turkish Journal of Chemistry
A spectrophotometric method was developed for the determination of the beta adrenergic blocking drug propranolol. The method was based on the formation of Cu(II), Ni(II) and Co(II)-dithiocarbamate complexes from the secondary amine group of propranolol with carbondisulfide (CS_{2}) and the acetate salts of the metals in ammonia medium. The method was applied to the analysis of propranolol tablets and the results were statistically compared with those obtained by the official method using t- and F-tests. There was no significant difference between the mean values and the precisions of the two methods at the 95% confidence level.
Conductimetric And Potentiometric Titration Of Some Hydroxylated Cinnamic Acids With Tetrabutylammonium Hydroxide In Non-Aqueous Media, A.Hakan Aktaş, Gülsüm Yaşar, Güleren Özkan Alsancak, Şahi̇nde Demi̇rci̇
Conductimetric And Potentiometric Titration Of Some Hydroxylated Cinnamic Acids With Tetrabutylammonium Hydroxide In Non-Aqueous Media, A.Hakan Aktaş, Gülsüm Yaşar, Güleren Özkan Alsancak, Şahi̇nde Demi̇rci̇
Turkish Journal of Chemistry
In this study, four hydroxycinnamic acids, namely 3,4-dihydroxycinnamic acid, 4-hydroxycinnamic acid, 4-hydroxy --3- methoxycinnamic acid and 4-hydroxy-3,5-dimethoxycinnamic acid, were titrated conductimetrically and potentiometrically using triethylamine and tetrabutylammonium hydroxide in acetonitrile, 2-propanol, and pyridine solvents under a nitrogen atmosphere at 25 ^oC. In conductimetric titration with tetrabutylammonium hydroxide all of the compounds exhibited conventional stoichiometric titration curves in 2-propanol . As is evident from the titration curves, all these compounds gave two well-defined end points. The first end point corresponds to exactly one equivalent and the second one to the two equivalents of the base. In conductimetric titration with tetrabutylammonium hydroxide, …
New Photochemical And Electrochemical Methods For The Degradation Of Pesticides In Aqueous Media. Environmental Applications, J. J. Aaron, Mehmet A. Oturan
New Photochemical And Electrochemical Methods For The Degradation Of Pesticides In Aqueous Media. Environmental Applications, J. J. Aaron, Mehmet A. Oturan
Turkish Journal of Chemistry
The development of new electrochemical and photochemical methods for the decontamination of natural water containing significant concentrations of aromatic pesticides is described. The electrochemical method is based on the electro-Fenton process, i.e. the simultaneous reduction of O_{2} and Fe^{3+} ions. Hydroxyl (OH^{.}) radicals are electrosynthesized in aqueous solutions, followed by complete mineralization of the initial pollutants. The photochemical methods involve either a direct photodegradation reaction of pesticides by UV light, or indirect photodegradation processes including H_{2}O_{2} photolysis or photo-Fenton reagents (H_{2}O_{2}/ Fe^{3+} ). Examples of the application of these methods to chlorophenoxy acid herbicides and four aromatic pesticides (bendiocarb, pirimiphos-methyl, …
Adsorption Of Some Textile Dyes By Hexadecyltrimethylammonium Bentonite, Özlem Ceyhan, Demet Baybaş
Adsorption Of Some Textile Dyes By Hexadecyltrimethylammonium Bentonite, Özlem Ceyhan, Demet Baybaş
Turkish Journal of Chemistry
In this study, hexadecyltrimethylammonium (HDTMA) bentonite was synthesized by placing alkylammonium cation onto bentonite. Adsorption of some textile dyes such as Everdirect Supra Yellow PG, Everdirect Supra Orange 26 CG, Everdirect Supra Rubine BL, Everdirect Supra Blue 4BL and Everdirect Supra Red BWS on Na-bentonite and HDTMA-bentonite was investigated. While the Na-bentonite had no affinity for the dyes, the HDTMA-bentonite showed significant adsorption from aqueous solution. The Langmuir and Dubinin-Rasdushkevich (D-R) isotherm equations were applied to the data and values of parameters of these isotherm equations were evaluated. The mean energy of adsorption, E, was also calculated from the adsorption …
Synergistic Solvent Extraction Of Zinc(Ii) And Cadmium(Ii) From Sulfate Medium By A Mixture Of 1 - Phenyl - 3 - Methyl - 4 - Benzoylpyrazol - 5 - One And Methyl - Isobutyl Ketone, Djamel Barkat, Zoubir Derriche, Abdelkader Tayeb
Synergistic Solvent Extraction Of Zinc(Ii) And Cadmium(Ii) From Sulfate Medium By A Mixture Of 1 - Phenyl - 3 - Methyl - 4 - Benzoylpyrazol - 5 - One And Methyl - Isobutyl Ketone, Djamel Barkat, Zoubir Derriche, Abdelkader Tayeb
Turkish Journal of Chemistry
The solvent extraction of zinc(II) and cadmium(II) from sulfate medium by 1 - phenyl - 3 - methyl - 4 - benzoylpyrazol - 5 - one (HPMBP) was studied in the following parameter functions: pH, concentration of the extractant, nature of diluent, concentration of the mineral anion and synergism. In the absence of the synergic agent methyl - isobutyl ketone (MIBK), the complexes extracted are ZnL_2(H_2O)_{x(org)} and CdL_2(H_2O)_{y(org)} . In the presence of MIBK, the curves of extraction show the presence of several species of complexes that depend on the concentration of MIBK. For very weak concentrations, the extracted complexes …
Synthesis And Spectrophotometric Investigation Of A New Vic-Dioxime Ligand And Its Transition Metal Complexes, Mustafa Dolaz, Mehmet Tümer, Ayşegül Gölcü, Selahatti̇n Seri̇n
Synthesis And Spectrophotometric Investigation Of A New Vic-Dioxime Ligand And Its Transition Metal Complexes, Mustafa Dolaz, Mehmet Tümer, Ayşegül Gölcü, Selahatti̇n Seri̇n
Turkish Journal of Chemistry
A new vic-dioxime ligand and its Cu(II), Co(II), Ni(II), Pd(II), VO(IV) and Zn(II) complexes have been prepared and characterized by elemental analyses, infrared, electronic spectra, magnetic moment and molar conductance data. The Ni(II), Pd(II) and Zn(II) complexes have a diamagnetic character. The ^{1}H- and ^{13}C-nmr and GC/MS spectra of the vic-dioxime ligand and its Ni(II), Pd(II) and Zn(II) complexes were recorded. In addition, all compounds are non-electrolyte.
A Novel Technique For Silver Extraction From Silver Sulphide Ore, Sevda Ayata, Hüseyi̇n Yildiran
A Novel Technique For Silver Extraction From Silver Sulphide Ore, Sevda Ayata, Hüseyi̇n Yildiran
Turkish Journal of Chemistry
A novel technique for silver extraction from Ag_2S is described. The method utilizes thiosulphate as complexing reagent and the redox reaction between SO_2 added as Na_2SO_3 powder and H_2S gas evolved. The parameters of the reaction such as pH, the reaction temperature, the complex equilibrium of Ag^+ ion with thiosulphate and the solubility of Ag_2S were investigated. Silver ions, obtained by this means are collected in high purity (99%) by applying appropriate electrolysis conditions. The interference from other metallic impurities, namely copper, gold, iron and zinc, is eliminated by choosing an appropriate electrolysis potential.
Study Of The Effect Of Number Of Layers On The Electrosynthesis Of Cobalt(Iii) Acetate In A Bipolar Packed-Bed Flow Reactor, Altan Güvenç, Belgi̇n Karabacakoğlu
Study Of The Effect Of Number Of Layers On The Electrosynthesis Of Cobalt(Iii) Acetate In A Bipolar Packed-Bed Flow Reactor, Altan Güvenç, Belgi̇n Karabacakoğlu
Turkish Journal of Chemistry
Cobalt(III) acetate, which is an important oxidizing agent and catalyst in organic reactions, was electrosynthesized from cobalt(II) acetate solution in a bipolar packed-bed flow reactor. In order to determine the effect of the number of layers on the yield of cobalt(III) acetate, experiments were performed in three different lengths of bipolar electrode cells, namely 16, 29 and 55 layers of graphite Raschig rings. The experiments were carried out at controlled potentials of 50-450 V, measuring the total current and using the solution (5% H_{2}O, 95% CH_{3}COOH, 0.06MCo(CH_{3}COO)_{2}.4H_{2}O, 0.2M CH_{3}COONa.3H_{2}O) at 298 K and 0.133 L.h^{-1} flow rate. According to the …
Voltammetric And Polarographic Studies Of Eriochrome Black T - Nickel(Ii) Complex, Osman Çakir, Emi̇ne Ertürk Coşkun, Ender Bi̇çer, Semi̇ha Çakir
Voltammetric And Polarographic Studies Of Eriochrome Black T - Nickel(Ii) Complex, Osman Çakir, Emi̇ne Ertürk Coşkun, Ender Bi̇çer, Semi̇ha Çakir
Turkish Journal of Chemistry
The electrochemical behaviour of complexes of Eriochrome Black T (EBT) with Ni(II) was studied. It was observed that EBT forms 1:1 and 1:2 complexes with Ni(II) in 0.1 M phosphate buffer at pH 6.0 by using Square-wave voltammetry (SWV), Cyclic voltammetry (CV), Direct Current Polarography (Sampled DCP) and Controlled Potential Coulometry (CPC). It was found that the reduction processes of Ni(II)-EBT complexes are irreversible. The stability constants of the Ni(II)-EBT complexes were evaluated with the DeFord-Hume procedure at different ligand concentrations using SWV. The logarithm values of stability constants of 1:1 and 1:2 Ni(II)-EBT complexes are 8.17 and 11.17, respectively.
Determination Of The Thermodynamic Properties Of Poly [2-(3-Phenyl-3-Methylcyclobutyl)-2-Hydroxyethyl Methacrylate-Co-Methacrylic Acid] At Infinite Dilution By Inverse Gas Chromatography, İsmet Kaya, Kadi̇r Demi̇relli̇
Determination Of The Thermodynamic Properties Of Poly [2-(3-Phenyl-3-Methylcyclobutyl)-2-Hydroxyethyl Methacrylate-Co-Methacrylic Acid] At Infinite Dilution By Inverse Gas Chromatography, İsmet Kaya, Kadi̇r Demi̇relli̇
Turkish Journal of Chemistry
Some thermodynamic quantities were obtained for the interactions of poly [2-(3-phenyl -3- methylcyclobutyl)-2-hydroxyethyl methacrylate-co-methacrylic acid] Poly (PCHEMA-co-MA) with alcohols, ketones, acetates, aromatics and n-alkanes by inverse gas chromatography in the temperature range of 150-180^oC. The specific retention volumes, Vg^o, weight fraction activity coefficients of solute probes at infinite dilution, \Omega_{1}^{\infty} and Flory-Huggins thermodynamic interaction parameters, \chi_{12}^{\infty} between polymers and solvents were determined. The partial molar free energy, \DeltaG_{1}^{\infty} , the partial molar heat of mixing, \DeltaH_{1}^{\infty} , at infinite dilution and the solubility parameters of the polymer, \delta_{2} , were calculated. The copolymer was characterized by ^1 H-NMR, FT-IR and …
Spectrophotometric Determination Of Cobalt, Nickel Palladium, Copper, Ruthenium And Molybdenum Using Sodium Isoamylxanthate In Presence Of Surfactants, Ashok Kumar Malik, K. N. Kaul, B. S. Lark, W. Faubel, A. L. J. Rao
Spectrophotometric Determination Of Cobalt, Nickel Palladium, Copper, Ruthenium And Molybdenum Using Sodium Isoamylxanthate In Presence Of Surfactants, Ashok Kumar Malik, K. N. Kaul, B. S. Lark, W. Faubel, A. L. J. Rao
Turkish Journal of Chemistry
A direct method has been developed for the spectrophotometric determination of microamounts of Co(II), Ni(II), Cu(II), Pd(II), Ru(III) and Mo(VI) using sodium isoamylxanthate as a reagent in the presence of surfactant as solubilising agent. The method has been applied to the determination of these metal ions in various alloys and in environmental samples (fly ash).
Unusual Chemical Constituents Of Lotus Garcinii (Fabaceae), Muhammad Shaiq Ali, Farman Ahmad, Viqar Uddin Ahmad, Iqbal Azhar, Khan Usmanghani
Unusual Chemical Constituents Of Lotus Garcinii (Fabaceae), Muhammad Shaiq Ali, Farman Ahmad, Viqar Uddin Ahmad, Iqbal Azhar, Khan Usmanghani
Turkish Journal of Chemistry
The methanol soluble part of Lotus garcinii, belonging to the family Fabaceae, yielded three new interesting metabolites: garceine (1), garoside (2) and garthiol (3), which have never been detected from any natural source. In addition, isophytol, hexadecanoic acid, cholesterol, oleanolic acid, butulinic acid and lupeol were also obtained for the first time from L. garcinii}. All the isolated metabolites were characterized by spectroscopic means.
Synthesis And Structure Of Systems Containing Pyramidalized And Strained Double Bond: An Investigation On The Cycloaddition Reactions Of Cis- And Trans-3,8-Dicarbomethoxy-3,8-Dihydroheptalene, Nurullah Saraçoğlu, Abdullah Menzek, Meti̇n Balci
Synthesis And Structure Of Systems Containing Pyramidalized And Strained Double Bond: An Investigation On The Cycloaddition Reactions Of Cis- And Trans-3,8-Dicarbomethoxy-3,8-Dihydroheptalene, Nurullah Saraçoğlu, Abdullah Menzek, Meti̇n Balci
Turkish Journal of Chemistry
The cycloaddition reactions of cis-3,8-dicarbomethoxy-3,8-dihydroheptalene cis-2 and trans-3,8-dicarbomethoxy-3,8-dihydroheptalene trans-2 with various dienophiles such as dimethyl acetylenedicarboxylate (DMAD), p-benzoquinone, maleic anhydride, tetracyanoethylene, naphtoquinone gave monoaddition products 15-23. Further addition of benzyne and dimethyl acetylenedicarboxylate to 18 resulted in the formation of the compounds syn-25 and syn-26 having pyramidalized double bonds. The addition of benzyne to 21 and the addition of dimethyl acetylenedicarboxylate to 21, 22 and 23 gave the anti configuration products anti-26, 27 and 28, respectively. X-ray structures of syn-25, syn-26 and anti-26 show the pyramidalized angles to be 16.5^o, 19.9^o and 8.0^o, respectively.