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2003

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Bisabolane Type Sesquiterpenes From A Marine Didiscus Sponge, Deni̇z Taşdemi̇r, Timothy S. Bugni, Gina C. Mangalindan, Gisela P. Concepcion, Mary Kay Harper, Chris M. Ireland Jan 2003

Bisabolane Type Sesquiterpenes From A Marine Didiscus Sponge, Deni̇z Taşdemi̇r, Timothy S. Bugni, Gina C. Mangalindan, Gisela P. Concepcion, Mary Kay Harper, Chris M. Ireland

Turkish Journal of Chemistry

Two bisabolane type sesquiterpene phenols, (+)-curcuphenol (1) and (+)-curcudiol (2), were isolated from a Philippine marine sponge, Didiscus sp., in addition to \beta -sitosterol (3) and phenethylamine (4). The structures of the metabolites were established on the basis of spectral evidence (1D- and 2D NMR, [\alpha]_{D}, EIMS). (+)-Curcuphenol (1) showed cytotoxicity, which is indicative of a p53 independent mechanism.

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Cover And Contents Jan 2003

Cover And Contents

Turkish Journal of Chemistry

No abstract provided.

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Bromination Of 1-Cyclopent-1-En-1-Ylbenzene And 1-(5-Bromocyclopent-1-En-1-Yl)Benzene And Theoretical Investigation Of The Products, Mustafa Ceylan, Armağan Kinal, Yaşar Sütbeyaz, Meti̇n Balci Jan 2003

Bromination Of 1-Cyclopent-1-En-1-Ylbenzene And 1-(5-Bromocyclopent-1-En-1-Yl)Benzene And Theoretical Investigation Of The Products, Mustafa Ceylan, Armağan Kinal, Yaşar Sütbeyaz, Meti̇n Balci

Turkish Journal of Chemistry

The bromination of 1-cyclopent-1-en-1-ylbenzene (4) in different solvents and at different temperatures was accompanied by the evolution of hydrogen bromide and yielded 1-(5-bromocyclopent-1-en-1-yl)benzene (8). Further bromination of 8 gave exclusively 2R(S),5R(S)-1-(1,2,5-tribromocyclopentyl)benzene (11). The experimental results were compared with the theoretical ones based on semi-empirical (MM+ and AM1), Hartree-Fock (HF) and density functional theory (DFT). The formation of 11 was explained by the formation of a weakly bridged bromoniun ion of type 9.

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Iridoid And Phenylpropanoid Glycosides From Phlomis Samia, P. Monocephala And P. Carica, Funda Nuray Yalçin, Tayfun Ersöz, Pinar Akbay, İhsan Çaliş, Ali̇ Arslan Dönmez, Otto Sticher Jan 2003

Iridoid And Phenylpropanoid Glycosides From Phlomis Samia, P. Monocephala And P. Carica, Funda Nuray Yalçin, Tayfun Ersöz, Pinar Akbay, İhsan Çaliş, Ali̇ Arslan Dönmez, Otto Sticher

Turkish Journal of Chemistry

From the aerial parts of Phlomis samia an iridoid glucoside, shanzhiside methylester (1), and three phenylethanoid glycosides, martynoside (2), 4''-O-acetylmartynoside (3) and samioside (4), were isolated. From the overground parts of P. monocephala two iridoid glucosides, lamiide (5) and ipolamiide (6), as well as three phenylethanoid glycosides, verbascoside (= acteoside) (7), forsythoside B (8), alyssonoside (9), and one lignan glucoside, syringaresinol 4'-O-\beta -D-glucopyranoside (10), were isolated. From the aerial parts of P. carica one phenylethanoid glycoside, verbascoside (= acteoside) (7) and three phenylpropanoid monomeric glucosides, syringin (11), dihydrosyringin (12) and coniferin (13), were isolated. The structures of the isolated compounds …

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Determination Of Manganese, Copper, Cadmium And Lead By Faas After Solid-Phase Extraction Of Their Phenylpiperazine Dithiocarbamate Complexes On Activated Carbon, Hasan Cesur Jan 2003

Determination Of Manganese, Copper, Cadmium And Lead By Faas After Solid-Phase Extraction Of Their Phenylpiperazine Dithiocarbamate Complexes On Activated Carbon, Hasan Cesur

Turkish Journal of Chemistry

A solid-phase extraction method was developed for the pre-concentration of manganese, copper, cadmium and lead in water samples prior to their determination by flame atomic absorption spectrometry using phenylpiperazine dithiocarbamate as a new reagent. The optimum pre-concentration conditions have been investigated such as pH, volume of sample solution and the effects of some matrix elements. The obtained recovery was nearly 90 to 100, while the enrichment factor was 400 for metal spiked solutions.

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Spectrophotometric Determination Of Iron(Ii) With 5-Nitro-6-Amino-1,10-Phenanthroline, Nebahat Demi̇rhan, Fi̇kri̇ye Tuncel Elmali Jan 2003

Spectrophotometric Determination Of Iron(Ii) With 5-Nitro-6-Amino-1,10-Phenanthroline, Nebahat Demi̇rhan, Fi̇kri̇ye Tuncel Elmali

Turkish Journal of Chemistry

A new spectrophotometric method is developed for the determination of Fe(II) with 5-nitro-6-amino-1,10-phenanthroline (NAF). In this work, the effect of factors such as pH, amount of reagent (NAF), reaction time and temperature were investigated. The method is based on the formation of a colored product between Fe(II) and NAF. The reaction proceed quantitatively at 20 °C for 210 min in acidic medium. The absorption maximum was at 520 nm. A linear relationship existed between absorbance and Fe(II) concentration over the range 0.1 \mu g/mL and 0.4 \mu g/mL. The molar ratio of Fe(II) to the reagent was determined as 1:3. …

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Application Of A Three-Stage Sequential Extraction Procedure For The Determination Of Extractable Metal Contents In Highway Soils, Şeri̇fe Tokalioğlu, Şenol Kartal, Gökhan Bi̇rol Jan 2003

Application Of A Three-Stage Sequential Extraction Procedure For The Determination Of Extractable Metal Contents In Highway Soils, Şeri̇fe Tokalioğlu, Şenol Kartal, Gökhan Bi̇rol

Turkish Journal of Chemistry

A sequential extraction procedure, a three-step protocol proposed by the Standards, Measurements and Testing programme (SM & T--formerly BCR) of the European Union, was applied to soil samples for the determination of metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn). This procedure provides measurements of extractable metals from media such as acetic acid (0.11 mol L^{-1}), hydroxylammonium chloride (0.1 mol L^{-1}) and hydrogen peroxide (8.8 mol L^{-1}) plus ammonium acetate (1 mol L^{ - 1}), which are exchangeable, reducible and oxidisable metals, respectively. Analyses were carried out using flame atomic absorption spectrometry (FAAS). The results obtained from …

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Simultaneous Determination Of Copper, Zinc And Selenium In Chicken Liver By Differential Pulse Polarography, Güler Ekmekci̇, Güler Somer, Olcay Şendi̇l Jan 2003

Simultaneous Determination Of Copper, Zinc And Selenium In Chicken Liver By Differential Pulse Polarography, Güler Ekmekci̇, Güler Somer, Olcay Şendi̇l

Turkish Journal of Chemistry

A differential pulse polarographic method for the determination of copper, zinc and selenium in chicken liver is described. It was possible to determine these elements in a single sample solution after acid digestion. Dried liver samples weighing about 3 g were digested using HNO_{3} and HClO_{4} acids. Britton-Robinson or acetate buffer has been found suitable as the supporting electrolyte. For the determination of selenium, the hydrogen catalytic peak was used after the addition of molybdenum(VI) to the buffer solution at about pH 3. Then the pH of the same solution was increased to 4 and zinc was determined. For the …

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Effect Of Polyoxyethylene Chain Length And Electrolyte On The Viscosity Of Mixed Micelles, Hali̇de Akbaş, Tali̇ha Si̇di̇m, Mehmet İşcan Jan 2003

Effect Of Polyoxyethylene Chain Length And Electrolyte On The Viscosity Of Mixed Micelles, Hali̇de Akbaş, Tali̇ha Si̇di̇m, Mehmet İşcan

Turkish Journal of Chemistry

The viscosity measurements of micelles composed of mixtures of anionic/nonionic surfactants were carried out as a function of the mole fraction of surfactants. The systems studied were sodium dodecyl sulfate (SDS)-polyoxyethylene lauryl ether (C_{12}POE_{n} n = 4, 10 and 23) in water and 0.1 M sodium chloride solution. In the single systems, the relative viscosity of nonionic surfactant is greater than that of SDS, and increases with the increasing level of ethylene oxide. In the mixed surfactant systems, the relative viscosities vary at the mixed molar fraction of SDS, between 0.2 and 0.3, and then the relative viscosities of mixed …

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Production Of Bacterial Polyesters From Some Various New Substrates By Alcaligenes Eutrophus And Pseudomonas Oleovorans, Hali̇l Koçer, Mehli̇ka Borcakli, Songün Demi̇rel, Baki̇ Hazer Jan 2003

Production Of Bacterial Polyesters From Some Various New Substrates By Alcaligenes Eutrophus And Pseudomonas Oleovorans, Hali̇l Koçer, Mehli̇ka Borcakli, Songün Demi̇rel, Baki̇ Hazer

Turkish Journal of Chemistry

Poly(3-hydroxy alkanoate)s (PHA)s are bacterial polyesters that have, due to their biodegradability and biocompatibility, attracted considerable industrial interest. All the substrates used in feeding Alcaligenes eutrophus and Pseudomonas oleovorans have been reviewed as far as we know, and some more new substrates or mixtures have been used in PHA production by microorganisms. Alcaligenes eutrophus was fed with 4-pentenoic acid, 2-hydroxy ethyl methacrylate (HEMA), corn oil acids, linseed oil acids and limonene as well as mixtures of acetic acid and glucose or lactose. Either HEMA as a sole carbon source or the mixture of glucose did not produce polyester; limonene as …

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Aluminum Fractionation In The Water Of Karakaya Dam Lake (Malatya, Turkey), F. Zehra Küçükbay, Mustafa Demi̇r Jan 2003

Aluminum Fractionation In The Water Of Karakaya Dam Lake (Malatya, Turkey), F. Zehra Küçükbay, Mustafa Demi̇r

Turkish Journal of Chemistry

A method was developed for the determination of trace amounts of Al species in water samples using the amberlite type XAD-4 resin. For this purpose, total dissolved Al, organically bonded Al and particulate Al in water samples taken from Karakaya dam lake (Malatya, Turkey) were determined by flame atomic absorption spectroscopy (FAAS) or graphite furnace atomic absorption spectroscopy (GFAAS) after an enrichment procedure. The total dissolved Al in the water samples was determined using 8-hydroxyquinoline as complexing reagent at pH 8 and amberlite type XAD-4 resins for the enrichment. The organically bonded Al species in the water samples were destroyed …

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Atomic Absorption And Spectrophotometeric Determinations Of Salicylhydroxamic Acid In Its Pure And Pharmaceutical Dosage Forms, Alaaeldin Abdelaziz Salem, Mohamed Mohamed Omar Jan 2003

Atomic Absorption And Spectrophotometeric Determinations Of Salicylhydroxamic Acid In Its Pure And Pharmaceutical Dosage Forms, Alaaeldin Abdelaziz Salem, Mohamed Mohamed Omar

Turkish Journal of Chemistry

A new method for the indirect determination of salicylhydroxamic acid (SHAM) using atomic absorption spectrometry (AAS) was proposed. The method is based on precipitating the ion associate complex of SHAM with [Cu (NH_{3})_{4}]^{2+}. The excess, unreacted, Cu^{2+} ions were determined using AAS. Another spectrophotometric method based on measuring the absorbance of the formed [Cu (NH_{3})_{4}]-SHAM complex in dioxane was proposed. The green color of the complex formed was measured at 330 nm. The two methods were successfully used for determining SHAM in its pure and pharmaceutical dosage forms. Using AAS, the drug was determined over a concentration range of 3.06 …

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Purification And Characterization Of Glucose 6-Phosphate Dehydrogenase From Sheep Liver, Vedat Türkoğlu, Si̇nan Aldemi̇r, Mehmet Çi̇ftçi̇ Jan 2003

Purification And Characterization Of Glucose 6-Phosphate Dehydrogenase From Sheep Liver, Vedat Türkoğlu, Si̇nan Aldemi̇r, Mehmet Çi̇ftçi̇

Turkish Journal of Chemistry

Glucose 6-phosphate dehydrogenase (D-glucose 6-phosphate: NADP^{+} oxidoreductase, EC 1.1.1.49; G6PD) was purified from sheep liver by a simple and rapid method. The purification process consisted of two steps: preparation of the homogenate, and 2', 5'-adenosine diphosphate (ADP) Sepharose 4B affinity chromatography. Through the use of these two consecutive steps, the enzyme was purified with a yield of 35.6% and 1,920 fold, having the specific activity of 11.2 enzyme units (EU/mg protein). A K_{M} of 0.176 mM and a V_{\max} of 0.0179 EU/ml were obtained for G6-P, and 0.0194 mM and 0.0223 EU/ml for NADP^{+}. Enzymatic activity was measured spectrophotometrically according …

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Graft Copolymerization Of N-Vinylimidazole On Poly(Ethylene Terephthalate) Fibers In A Swelling Solvent Using Azobisisobutyronitrile As Initiator, Hali̇l İbrahi̇m Ünal, Can İnegöllü, Oya Şanli Jan 2003

Graft Copolymerization Of N-Vinylimidazole On Poly(Ethylene Terephthalate) Fibers In A Swelling Solvent Using Azobisisobutyronitrile As Initiator, Hali̇l İbrahi̇m Ünal, Can İnegöllü, Oya Şanli

Turkish Journal of Chemistry

In this study, poly(ethylene terephthalate) (PET) fibers were grafted in dimethylformamide (DMF) with n-vinylimidazole (n-VI) using azobisisobutyronitrile (AIBN) as an initiator. Variations of percentage grafting with time, temperature, monomer and initiator concentrations as well as monomer and initiator diffusions were investigated. It was observed that the percentage of grafting and grafting efficiency increased as time and temperature rose up to a certain value, and then they levelled off. The percentage of grafting was found to rise with increasing monomer and initiator concentrations, and then decrease. Monomer and initiator diffusions into PET fibers were shown to follow a similar trend and …

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Cover And Contents Jan 2003

Cover And Contents

Turkish Journal of Chemistry

No abstract provided.

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Preparation And Characterization Of Conducting Polybutadiene/ Polythiophene Composites, Senem Kiralp, Zuhal Küçükyavuz, Atef F. Qasrawi Jan 2003

Preparation And Characterization Of Conducting Polybutadiene/ Polythiophene Composites, Senem Kiralp, Zuhal Küçükyavuz, Atef F. Qasrawi

Turkish Journal of Chemistry

Conductive composite films of cis-1,4-polybutadiene (PBD) with polythiophene (PTh) were prepared electrochemically. Thiophene was polymerized on PBD-coated platinium electrodes. The composites with different PTh percentages showed conductivity in the order of 10^{-3} (\Omega cm)^{-1}. The characterization of the films was performed using FTIR, scanning electron microscope and differential scanning calorimetry techniques. In order to understand the dominant transport mechanism, the temperature dependence of conductivity was investigated.

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Vibrational Spectroscopic Studies On Trans-1,4-Polychloroprene, V. Arjunan, S. Subramanian, S. Mohan Jan 2003

Vibrational Spectroscopic Studies On Trans-1,4-Polychloroprene, V. Arjunan, S. Subramanian, S. Mohan

Turkish Journal of Chemistry

Fourier transform infrared and Raman spectra of trans-1,4-polychloroprene have been recorded in the range of 4000-400 and 3500-100 cm^{-1}, respectively. In the present investigation, detailed assignments of the observed fundamental bands of trans-1,4-polychloroprene were analysed in terms of peak positions and relative intensities. In the hope of providing more effective information on the fundamental vibrations, a normal coordinate analysis was performed on trans-1,4-polychloroprene, by assuming C_{S} symmetry. The simple general valance force field (SGVFF) was employed in normal coordinate analysis and to calculate the potential energy distribution (PED) for each fundamental vibration. The PED contribution corresponding to each of the …

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The Effect Of Tert-Butylhydroperoxide On The Thiol Redox Status In Human Erythrocytes And The Protective Role Of Glucose And Antioxidants, Yasemi̇n Aksoy, İ. Hamdi̇ Öğüş, Nazmi̇ Özer Jan 2003

The Effect Of Tert-Butylhydroperoxide On The Thiol Redox Status In Human Erythrocytes And The Protective Role Of Glucose And Antioxidants, Yasemi̇n Aksoy, İ. Hamdi̇ Öğüş, Nazmi̇ Özer

Turkish Journal of Chemistry

For survival, living cells maintain their thiol redox status within acceptable limits by three different mechanisms: i. glutathione disulfide export, ii. reduction of glutathione disulfide by pentose phosphate pathway and, iii. reduction of glutathione disulfide by Protein-SH. To assess the relative contribution of each one of the systems, intracellular [glutathione], [glutathione disulfide] and their export, in fresh and aged erythrocytes subjected to oxidative stress, in \pm glucose and \pm antioxidants, were measured. Glutathione was rapidly oxidized by tert-butylhydroperoxide in \pm glucose in both groups. The regeneration of glutathione, in both groups, in \pm glucose was about 100 and 50%, respectively. …

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Synthesis Of New Antimicrobial Agents; Amide Derivatives Of Pyranones And Pyridinones, Mutlu Di̇lsi̇z Aytemi̇r, Robert C. Hider, Di̇lek Demi̇r Erol, Meral Özalp, Meli̇ke Eki̇zoğlu Jan 2003

Synthesis Of New Antimicrobial Agents; Amide Derivatives Of Pyranones And Pyridinones, Mutlu Di̇lsi̇z Aytemi̇r, Robert C. Hider, Di̇lek Demi̇r Erol, Meral Özalp, Meli̇ke Eki̇zoğlu

Turkish Journal of Chemistry

In this study, 4(1H)-pyridinones with an amide function in Position 2 of the pyridinone ring showed antimicrobial activity. The synthesis and the biological properties of some novel amide derivatives of pyran-4(1H)-one and 4(1H)-pyridinone have been reported. Amide derivatives of pyran-4(1H)-one and 4(1H)-pyridinone were prepared using two different methods. Antimicrobial activities were determined as MIC values using the microdilution broth method against the bacteria Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa and the fungi Candida albicans, Candida krusei and Candida parapsilosis. Compounds 6 and 9 exhibited the best inhibitor activity against S. aureus.

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Some Polyamidoxime Derivatives And Their Metal Complexes, Fatma Kari̇pci̇n, İbrahi̇m Karataş, Hali̇l İsmet Uçan Jan 2003

Some Polyamidoxime Derivatives And Their Metal Complexes, Fatma Kari̇pci̇n, İbrahi̇m Karataş, Hali̇l İsmet Uçan

Turkish Journal of Chemistry

In this paper the synthesis of six polyamidoximes from their corresponding diamines with 4,4'-methylenebis (phenylglyoxylohydroximoyl chloride) and 4,4'-methylenebis(chlorophenylgly-oxime) is presented. The average molecular weights of these organic polymers were determined. In addition, the complexes of 4,4'-methylenebis (phenylglyoxylohydroximoyl chloride) with Ni(II), Co(II) and Cu(II) salts were prepared. The structures of these compounds were identified by IR or ^{1}H NMR spectral data, elemental analyses, magnetic measurements and thermal analysis.

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Synthesis And Antimicrobial Testing Of Some Flavonylsulfonamide Derivatives, Gülgün Ayhan Kilcigi̇l, Oya Bozdağ Dündar, Rahmi̇ye Ertan, Nurten Altanlar Jan 2003

Synthesis And Antimicrobial Testing Of Some Flavonylsulfonamide Derivatives, Gülgün Ayhan Kilcigi̇l, Oya Bozdağ Dündar, Rahmi̇ye Ertan, Nurten Altanlar

Turkish Journal of Chemistry

Six new 4-amino-N-heteroaryl,N-[(2-phenyl-4H-1-benzopyran-4- oxo-6-yl)metil]benzensulfonamide derivatives, (3a-3f) were prepared by reacting 6-bromomethylflavone with the corresponding sulfonamide derivatives and their antimicrobial activities against Escherichia coli were evaluated. All of the compounds exhibited better activity (except compound 3c) than the corresponding sulfonamide derivatives.

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Synthesis Of New 4-(5-Chloro-2-Oxo-3h-Benzoxazol-3-Yl)Butanamide Derivatives And Their Analgesic And Anti-Inflammatory Properties, H. Ozan Gülcan, Serdar Ünlü, Erden Banoğlu, M. Fethi̇ Şahi̇n, Esra Küpeli̇, Erdem Yeşi̇lada Jan 2003

Synthesis Of New 4-(5-Chloro-2-Oxo-3h-Benzoxazol-3-Yl)Butanamide Derivatives And Their Analgesic And Anti-Inflammatory Properties, H. Ozan Gülcan, Serdar Ünlü, Erden Banoğlu, M. Fethi̇ Şahi̇n, Esra Küpeli̇, Erdem Yeşi̇lada

Turkish Journal of Chemistry

In this preliminary screening study for developing potent analgesic and anti-inflammatory compounds, eight new 4-(5-chloro-2-oxo-3H-benzoxazol-3-yl)butanamide derivatives were synthesized and screened for their analgesic and anti-inflammatory activities as well as gastric ulceration potential in tested animals. Their structures were elucidated by their IR, ^{1}H-NMR and elemental analysis. All of the compounds exhibited high analgesic and anti-inflammatory activities. None of the compounds except compound 2g caused gastric lesions or bleeding in tested animals.

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Synthesis, Characterization And Applications Of Sol-Gel Derived Zirconium Oxide Adsorbent Powder: Removal From Aqueous Solution Of Phenol And P-Chlorophenol, Murat Akarsu, Hi̇kmet Sayilkan, Şadi̇ye Şener, Funda Sayilkan, Ertuğrul Arpaç Jan 2003

Synthesis, Characterization And Applications Of Sol-Gel Derived Zirconium Oxide Adsorbent Powder: Removal From Aqueous Solution Of Phenol And P-Chlorophenol, Murat Akarsu, Hi̇kmet Sayilkan, Şadi̇ye Şener, Funda Sayilkan, Ertuğrul Arpaç

Turkish Journal of Chemistry

Adsorbent powders were prepared from the uncatalysed hydrolysis-condensation reactions of different complexes that were synthesized by the reactions of Zr(OPr^{n})_{4} with different chelating ligands (such as allylacetic acid [AAH], vinylacetic acid [VAH] and citraconic acid [CAH]). The complex products were characterized by FT-IR, ^{1}H-NMR and ^{13}C-NMR spectra. The maximum combination ratios of AAH/Zr(OPr^{n})_{4}, VAH/Zr(OPr^{n})_{4} and CAH/Zr(OPr^{n})_{4} were 1.7, 0.9 and 1.3, respectively. The hydrolysis-condensation products of these complexes were calcinated at 900 °C and half of them were coated with 3-glycidyloxypropyltrimethoxysilane (GLYMO). The surface area and average pore diameter of the powders were estimated by the analysis of adsorption/desorption BET …

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Micelle Formation In Sodium Dodecyl Sulfate And Dodecyltrimethylammonium Bromide At Different Temperatures, Yüksel Bayrak Jan 2003

Micelle Formation In Sodium Dodecyl Sulfate And Dodecyltrimethylammonium Bromide At Different Temperatures, Yüksel Bayrak

Turkish Journal of Chemistry

pH changes as a function of concentration for sodium dodecyl sulfate (SDS) and dodecyltrimethylammonium bromide (DTAB) were observed by the addition of 1 N HCl and 1 N KOH. pH values increased up to the critical micellar concentration (CMC) for the SDS/HCl system and decreased for the DTAB/KOH system. In the SDS/HCl and DTAB/KOH systems, the micellar phase had a fixed composition and was homogeneous and monodisperse above the CMC. However, in the SDS/KOH and DTAB/HCl systems, pH values increased in a continuous and gradual manner below and above the CMC, and the properties of the micellar phase changed with …

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Isolation And Structure Elucidation Of Novel Natural Products From Turkish Lichens, Süheyla Kirmizigül, Ömer Koz, Hüseyi̇n Anil, Siddik İçli̇, Ulvi̇ Zeybek Jan 2003

Isolation And Structure Elucidation Of Novel Natural Products From Turkish Lichens, Süheyla Kirmizigül, Ömer Koz, Hüseyi̇n Anil, Siddik İçli̇, Ulvi̇ Zeybek

Turkish Journal of Chemistry

Three natural products were isolated from three different Turkish lichens. Microbiological investigations were also examined of these lichens. Compound 1 is known as 2-hydroxy-4-methoxy-3,6-dimethyl benzoic acid, and is isolated from Pseudevernia furfuracea for the first time. Compounds 2 and 3 are detected as new compounds and called, 3-acetyl-4-amino-2-chloro-1- (4-hydroxy-2-methoxy- 6-methylphenyl carbonyloxy) benzene and 2-(4-methoxyphenyl)-2-(5-oxo-4-phenyl-2,5- dihydro-2-furaniliden) acetic acid; they were isolated from Evernia prunastri and Letharia vulpina, respectively. All these compounds had different skeletons. Their structures were established by chemical methods and spectroscopic techniques using IR, UV, 1D and 2D NMR and EI and (+) FAB-Mass methods.

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A Novel, Semi-Pilot Scale Electrolysis System For The Production Of P-Aminophenol, Kamran Polat Jan 2003

A Novel, Semi-Pilot Scale Electrolysis System For The Production Of P-Aminophenol, Kamran Polat

Turkish Journal of Chemistry

Cyclic voltammetry (CV) and preparative electrolysis techniques were used to investigate the reduction of nitrobenzene into (NB) p-aminophenol (p-Ap). The electrodes used in CV experiments were glassy carbon (GC), TiO_{2}/Ti, Sn and Pb. The preparative electrolyses were carried out by the use of Pb, Sn, carbon cloth and TiO_{2}/Ti electrodes. The CV data were evaluated according to Nicholson-Shain criteria, and it was deduced that the reductions on TiO_{2}/Ti and GC electrodes were irreversible and monitored by an electrochemical-chemical-electrochemical mechanism. No reduction peak was observed with Sn and Pb electrodes. Preparative electrolyses were carried out under current-controlled conditions in the presence …

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Thermogravimetric Characterization Of Turkish Bituminous Coals For Combustion, Sai̇t Kizgut, Di̇lek Cuhadaroğlu, İhsan Toroğlu Jan 2003

Thermogravimetric Characterization Of Turkish Bituminous Coals For Combustion, Sai̇t Kizgut, Di̇lek Cuhadaroğlu, İhsan Toroğlu

Turkish Journal of Chemistry

This study focused on the thermal gravimetric characterization of Turkish bituminous coals for combustion. The combustion properties considered were based on the burning profile of coal samples and their chars produced in a PL 1500 TGA apparatus. The coal seam samples used in the study were obtained from TTK (Turkish Hardcoal Enterprise) mines as channel samples. The majority of the samples from 12 seams were medium-volatile bituminous and only three of them were high-volatile bituminous. Combustion profile parameters of coal samples and chars were correlated with petrographic, proximate and ultimate analysis data in order to establish the combustion differences of …

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Differential Pulse Polarographic Determination Of Cadmium After Solid Liquid Extraction And Preconcentration Using Pan, Mohammad Ali Taher Jan 2003

Differential Pulse Polarographic Determination Of Cadmium After Solid Liquid Extraction And Preconcentration Using Pan, Mohammad Ali Taher

Turkish Journal of Chemistry

A highly selective, sensitive, rapid and economical differential pulse polarographic method has been developed for the determination of trace amounts of cadmium in various samples after the adsorption of its 1-(2-pyridylazo)-2-naphthol (PAN) complex on microcrystalline naphthalene in the pH range of 8.2-11.0. After filtration, the solid mass is shaken with 9.0 mL of 1 M hydrochloric acid and cadmium is determined by differential pulse polarography. Cadmium can alternatively be quantitatively adsorbed on [1-(2-pyridylazo)-2-naphthol]-naphthalene adsorbent packed in a column and determined similarly. The detection limit is 0.07 \mu g/mL (signal-to noise ratio = 2) and the linearity is maintained in the …

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Cover And Contents Jan 2003

Cover And Contents

Turkish Journal of Chemistry

No abstract provided.

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Dna Cleavage Activity Of Diazonium Salts: Chemical Nucleases, Murat Kizil, Ebru İnce Yilmaz, Necmetti̇n Pi̇ri̇nççi̇oğlu, Çeti̇n Ayteki̇n Jan 2003

Dna Cleavage Activity Of Diazonium Salts: Chemical Nucleases, Murat Kizil, Ebru İnce Yilmaz, Necmetti̇n Pi̇ri̇nççi̇oğlu, Çeti̇n Ayteki̇n

Turkish Journal of Chemistry

4-Fenoldiazonium tetrafluoroborate and 4-benzoicaciddiazonium tetrafluoroborate was prepared and was shown to be an effective DNA cleavage agent in the presence of the 1-electron donor copper(II) chloride. Its mechanism involves the generation of the aryl radical cleaving DNA by hydrogen atom abstraction from deoxyribose sugar.

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