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Electrooxidation Of Methanol And Formic Acid On Platinum Dispersed Polypyrrole Electrodes, İpek Beceri̇k, Fi̇gen Kadirgan
Electrooxidation Of Methanol And Formic Acid On Platinum Dispersed Polypyrrole Electrodes, İpek Beceri̇k, Fi̇gen Kadirgan
Turkish Journal of Chemistry
The present study was performed in order to investigate the electrocatalytic properties of platinum incorporated polypyrrole films for methanol and formic acid oxidations. The behaviour of this modified electrode was characterised in acidic media (0.1M HClO_4). The electrodes exhibited excellent long-term stability in this media. After the modification and optimisation, the electrocatalytic properties of polypyrrole-metal particles and kinetics of the oxidation reactions were interpreted with regard to fuel cell applications.
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 …
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.
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.
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.
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 …
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.
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 …
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 …
Voltammetry Of The Anticancer Drug Mitoxantrone And Dna, Arzum Erdem, Mehmet Özsöz
Voltammetry Of The Anticancer Drug Mitoxantrone And Dna, Arzum Erdem, Mehmet Özsöz
Turkish Journal of Chemistry
The interaction of mitoxantrone (MTX) with calf thymus double-stranded DNA (dsDNA) and calf thymus single-stranded DNA (ssDNA) was studied electrochemically by using differential pulse voltammetry (DPV) and cyclic voltammetry (CV) at a carbon paste electrode (CPE). The changes in the experimental parameters (the concentration of MTX, the concentration of DNA and the accumulation time of MTX) were studied by DPV; in addition, the detection limit and the reproducibility were determined. It was observed for the interaction of MTX with dsDNA and ssDNA that the signal of the bare electrode was higher than the signal of the dsDNA modified CPE. The …
Separation Process Of Citric Acid With Tertiary Amines/Diluents In Supercritical Co_{2}, Arzu Koparan, Afi̇fe Güvenç, Nurcan Kapucu, Ülkü Mehmetoğlu, Ayla Çalimli
Separation Process Of Citric Acid With Tertiary Amines/Diluents In Supercritical Co_{2}, Arzu Koparan, Afi̇fe Güvenç, Nurcan Kapucu, Ülkü Mehmetoğlu, Ayla Çalimli
Turkish Journal of Chemistry
Reactive extraction of citric acid was investigated at atmospheric and supercritical conditions. The most suitable diluent and amine from among the tertiary amines and eight different diluents were determined at atmospheric conditions. The distribution coefficient values obtained with Hostarex A 327 were higher than those of Alamine 336. The selected amine (Hostarex A327) and the diluent (Oleyl alcohol) were used for reactive extraction of citric acid at supercritical conditions. Separation yields of citric acid were obtained in the temperature ranges of 308 to 328 K and in the pressure ranges of 80 to 180 bars in a supercritical extraction system …
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, …
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.
Heavy Metal Contents Of Lake Sapanca, Nevi̇n Yalçin, Vahdetti̇n Sevi̇nç
Heavy Metal Contents Of Lake Sapanca, Nevi̇n Yalçin, Vahdetti̇n Sevi̇nç
Turkish Journal of Chemistry
The heavy metal pollution of Lake Sapanca located in the Marmara region (Turkey), was investigated over time. The lake is the drinking water source of the city of Adapazarı and its environs. The D-80 (TEM) motorway passes about 5 km along the lake's zero point in the Sapanca district. The motorway's wastewater drainages have been connected to the lake without having been subjected to any wastewater treatment. The motorway was opened to service in October 1990. Analyses were performed in 1991 and were repeated in 1999 in order to observe changes in Pb, Fe and Zn contents. Samples were collected …
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, …
Photocuring Of Acrylate Oligomers In The Presence Of Vinyl Phosphonic Acids As A Flame Retarding Monomer And The Properties Of The Cured Films, Tüli̇n İmamoğlu, Yusuf Yağci
Photocuring Of Acrylate Oligomers In The Presence Of Vinyl Phosphonic Acids As A Flame Retarding Monomer And The Properties Of The Cured Films, Tüli̇n İmamoğlu, Yusuf Yağci
Turkish Journal of Chemistry
Photocuring of formulations containing polyurethane based acrylates and a flame retarding monomer (FR), namely vinyl phosphonic acid with an \alpha -cleavage type photoinitiator; 2-hydroxy-2-methylphenyl propane-1-one were studied. The flame retardancy, and the physical and mechanical properties of the cured films were determined.
Determination Of Hydrochlorothiazide And Enalapril Maleate In Tablet Formulations By Reversed-Phase Hplc, Idrees F. Al-Momani̇
Determination Of Hydrochlorothiazide And Enalapril Maleate In Tablet Formulations By Reversed-Phase Hplc, Idrees F. Al-Momani̇
Turkish Journal of Chemistry
A high-performance liquid chromatographic procedure is presented for the determination of hydrochlorothiazide (HCT) and enalapril maleate (EM) in pharmaceutical tablets. An aliquot of the sample is dissolved in 15% acetonitrile (ACN) containing thiophylline as an internal standard and chromatographed on a Supelcosil LC-8 (5 \mu m), (150 mm x 4.6 mm i.d.) column. The mobile phase was 3.0 mM tetrabutylammoniumhydrogen sulfate (TBAHS) in ACN/water/triethylamine (TEA), (14, 85.6, 6.4 V/V) adjusted to pH 4.1 by glacial acetic acid. The detection was at 220 nm. The method was tested for linearity, accuracy, recovery, and specificity.
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.
Fluorimetric Detection Of Insulin In The Presence Of Eu(Iii) - {Pyridine - 2,6 - Dicarboxylate} Tris Complex, Elmas Gök, Serdar Ateş
Fluorimetric Detection Of Insulin In The Presence Of Eu(Iii) - {Pyridine - 2,6 - Dicarboxylate} Tris Complex, Elmas Gök, Serdar Ateş
Turkish Journal of Chemistry
Bovine insulin solutions (pH=9.3) have maximum absorption at 278 \pm 2 nm and an intrinsic emission at 305 nm when excited at 282 nm. The relative fluorescence intensities show linear dependence on its concentration: 10 \mug/mL< [Ins] < 200 \mug/mL. When Eu(PDA)_{3}^{3-} tris complex is added to these solutions, it has a hyperchromic effect at 278 nm absorption band of insulin, sensitizing the emission intensities of central Eu^{3+} metal ion of the complex at 590 and 615 nm, and simultaneously quenching the emission intensity of hormone at 305 nm. Stern-Volmer plots show that a mechanism of bimolecular quenching at 305 nm and sensitization at 615 nm are valid up to a mole ratio, R = [Eu(PDA)_{3}^{3-}]/[Ins] < 2.0. An intramolecular rather than an intermolecular energy transfer is proposed. An apparent binding constant, log K_{app}=4.70 \pm 0.13, is calculated for Ins-[Eu(PDA)_{3}^{3-}]_{2} type product, the presence of which may offer a new luminescence technique as a diagnostic tool and an alternative to radio-iodinated (^{131}I -) insulin. A simple, rapid and accurate quantitation of insulin is proposed by using a fixed concentration of Eu(PDA)_{3}^{3-}, and measuring its initial F_{0} at \lambda_{exc}/ \lambda_{em}=282/615 nm and the difference, \DeltaF after sensitization when \sim 100 microliters of insulin sample is added. The coefficient of variation (CV), the relative error and minimum detectable amount of bovine insulin hormone are found to be 3.0%, 1.2% and 7.3 \pm 0.2 \mug /mL respectively.
Evidence For A Hybrid Ping Pong-Semirandom Mechanism For Human Jejunal Glutathione Disulfide Reductase, Nazmi̇ Özer, İzzet Hamdi̇ Öğüş
Evidence For A Hybrid Ping Pong-Semirandom Mechanism For Human Jejunal Glutathione Disulfide Reductase, Nazmi̇ Özer, İzzet Hamdi̇ Öğüş
Turkish Journal of Chemistry
Initial rate versus substrate concentration, [S], profiles (at pH 7.4, 37^oC) for human jejunal glutathione disulfide reductase indicated partial substrate inhibition by GSSG at fixed [NADPH] \le 40 \mu M. Saturation by NADPH assumed an increasingly sigmoidal character at fixed [GSSG] \ge 20 \mu M. The results were interpreted in terms of a hybrid ping pong-semirandom mechanism proceeding through both E.NADPH (ping pong pathway) and E.GSSG (ordered pathway) complexes. When V(apparent) versus [GSSG] and [NADPH] were plotted, hyperbolic curves were obtained. Plotting 1/Vm(apparent) versus 1/[NADPH] and 1/[GSSG] yielded two lines with different slopes but intersecting at the same point on …
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.
Simultaneous Determination Of Inorganic Anions And Organic Acids By Capillary Electrophoresis, Nevi̇n Özteki̇n, F. Bedi̇a Eri̇m Berker
Simultaneous Determination Of Inorganic Anions And Organic Acids By Capillary Electrophoresis, Nevi̇n Özteki̇n, F. Bedi̇a Eri̇m Berker
Turkish Journal of Chemistry
A rapid, easy, and reproducible method for the simultaneous determination of inorganic anions and organic acids is reported. The method is based on the separation of anions in a capillary coated with a cationic polymer, polyethyleneimine (PEI). Four inorganic anions (chloride, sulfate, iodate and phosphate) and eight organic acids (oxalate, tartarate, malate, succinate, citrate, acetate, lactate, and propionate) were separated and quantified within 7 min by using 2,6-pyridinedicarboxylic acid (PDC) as the background electrolyte. The minimum detection limits are 0.67-2.87 \mu g/mL for inorganic ions and 0.38-2.84 \mu g/mL for organic acids. Reproducibilities in migration times (RSD%) for both inorganic …
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 …
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 …
Towards The Asymmetric Synthesis Of Ascochlorin, Özdemi̇r Doğan, Wolfgang Oppolzer
Towards The Asymmetric Synthesis Of Ascochlorin, Özdemi̇r Doğan, Wolfgang Oppolzer
Turkish Journal of Chemistry
A synthetic approach is described to the asymmetric synthesis of ascochlorin (1), an antiviral antibiotic, based on the construction of a sesquiterpene unit via asymmetric Diels-Alder reaction of tigloyl sultam 4 & butadiene, and the introduction of the aromatic side chain (C9-C12 unit) by employing cuprate chemistry.
Purification And Partial Characterisation Of Superoxide Dismutase From Chicken Erythrocytes, Tüli̇n Aydemi̇r, Leman Tarhan
Purification And Partial Characterisation Of Superoxide Dismutase From Chicken Erythrocytes, Tüli̇n Aydemi̇r, Leman Tarhan
Turkish Journal of Chemistry
Superoxide dismutase (SOD), which plays a very important role in protecting organisms from oxygen toxicity, was purified from chicken erythrocyte and partially characterised. Erythrocyte membranes were disintegrated via freeze-thaw methods in the presence of Triton X-100. Following ethanol precipitation, SOD-containing solution was applied to DEAE-cellulose and then Sephadex G-100 gel columns. Chicken erythrocyte SOD was purified 508-fold with a specific activity of 8,480 units per mg. The molecular weight was estimated to be 30.6 kDa \pm 0.4 by gel filtration. The enzyme was composed of two subunits of equal size and contained one atom of copper and one atom of …