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Full-Text Articles in Chemistry

Preparation, Characterization, And Potentiometric Titrations Of Some New Di-[3-(3-Alkyl/Aryl-4,5-Dihydro-1h-1,2,4-Triazol-5-One-4-Yl)-Azomethinphenyl] Isophthalate/Terephthalate Derivatives, Haydar Yüksek, Özlem Gürsoy Kol Jan 2008

Preparation, Characterization, And Potentiometric Titrations Of Some New Di-[3-(3-Alkyl/Aryl-4,5-Dihydro-1h-1,2,4-Triazol-5-One-4-Yl)-Azomethinphenyl] Isophthalate/Terephthalate Derivatives, Haydar Yüksek, Özlem Gürsoy Kol

Turkish Journal of Chemistry

3-Alkyl(Aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) reacted with di-(3-formylphenyl) isophthalate (3) and di-(3-formylphenyl) terephthalate (6) to afford the corresponding 6 novel di-[3-(3-alkyl/aryl-4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl)- azomethinphenyl] isophthalates (4) and 6 novel di-[3-(3-alkyl/aryl-4,5- dihydro-1H-1,2,4-triazol-5-one-4-yl)-azomethinphenyl] terephthalates (7), respectively. The acetylation reactions of compounds 4 and 7 were investigated, and 5 and 8 type compounds were obtained, respectively. The new compounds synthesized were characterized by using IR, ^1H-NMR, ^{13}C-NMR, and UV spectral data together with elemental analysis. In addition, to investigate the effects of solvents and molecular structure upon acidity, compounds 4 and 7 were titrated potentiometrically with tetrabutylammonium hydroxide in 5 non-aqueous solvents (isopropyl alcohol, tert-butyl alcohol, N,N-dimethylformamide, acetone, …


Microwave-Assisted Synthesis Of 1,4´-Diazaflavone And N-Alkyl Derivative Pigments With Anti-Microbial Activity, Nuran Yayli, Osman Üçüncü, Nuretti̇n Yayli, Emi̇ne Demi̇r, Zi̇hni̇ Demi̇rbağ Jan 2008

Microwave-Assisted Synthesis Of 1,4´-Diazaflavone And N-Alkyl Derivative Pigments With Anti-Microbial Activity, Nuran Yayli, Osman Üçüncü, Nuretti̇n Yayli, Emi̇ne Demi̇r, Zi̇hni̇ Demi̇rbağ

Turkish Journal of Chemistry

1,4'-Diazaflavone pigment (2) was synthesized by a simple environmentally friendly microwave-assisted one-pot method for the cyclization of 2'-amino (E)-4''-aza-chalcone (1) under solventless conditions using K-10 clay. In addition, 10 new N-alkyl (C_{5-12, 14-15}) substituted 1,4' -diazaflavonium bromide pigments (3-12) were prepared from compound 2 or directly from compound 1, with corresponding alkyl halides in acetonitrile under reflux. The anti-microbial activity of compounds 1-12 was tested. The N-alkyl substituted 1,4' -diazaflavonium bromides (3-12) showed good antimicrobial activity against the gram-positive bacteria tested with minimal bactericidal concentration (MBC) values for the reference antibiotic kanamycin. The optimum length of the alkyl chain for …


Synthesis Of Nitrogen-Containing Heterocycles From The Reaction Of Amidrazones With \Alpha-Haloesters, Hany M. Dalloul, Peter H. Boyle Jan 2007

Synthesis Of Nitrogen-Containing Heterocycles From The Reaction Of Amidrazones With \Alpha-Haloesters, Hany M. Dalloul, Peter H. Boyle

Turkish Journal of Chemistry

The reaction of amidrazones 1 with \alpha-haloesters 2 formed 1,3,5-substituted 4,5-dihydro-1,2,4-triazin-6-ones (4a-z) rather than 1,2,4-triazin-5-one derivatives (5a-z). The microanalysis and spectral data of the synthesized compounds are in full agreement with their molecular structure.


Synthesis And Cytotoxic Activity Of Platinum(Ii) And Platinum(Iv) Complexes With 2-Hydroxymethylbenzimidazole Or 5(6)-Chloro-2-Hydroxymethylbenzimidazole Ligands Against Mcf-7 And Hela Cell Lines, Semra Utku, Fatma Gümüş, Si̇bel Gür, Aykut Özkul Jan 2007

Synthesis And Cytotoxic Activity Of Platinum(Ii) And Platinum(Iv) Complexes With 2-Hydroxymethylbenzimidazole Or 5(6)-Chloro-2-Hydroxymethylbenzimidazole Ligands Against Mcf-7 And Hela Cell Lines, Semra Utku, Fatma Gümüş, Si̇bel Gür, Aykut Özkul

Turkish Journal of Chemistry

Four platinum(II) and 4 platinum(IV) complexes with the structures [PtL_2Cl_2], [PtL_2I_2], [PtL_2Cl_4], and [PtL_2Cl_2(OH)_2] (L = 5(6)-non/orchloro-substituted-2-hydroxymethylbenzimidazole ligands as ``non-leaving groups''), respectively, were synthesized and characterized by their elemental analyses, and IR and ^1H-NMR spectra. In vitro cytotoxic activities of the platinum(II) and platinum(IV) complexes were tested against the human MCF-7 (breast cancer) and HeLa (cervix cancer) cell lines using the cell culture method. In general, the platinum(II) complexes were more active than the corresponding platinum(IV) complexes. The complexes, which were found to be less active than cisplatin, exhibited cyctotoxicity comparable to carboplatin on the human MCF-7 and HeLa cell …


Preparation And Morphological Characterization Of A Catalytic Soot Oxidation Sic Foam Filter, Başar Çağlar, Deni̇z Üner Jan 2007

Preparation And Morphological Characterization Of A Catalytic Soot Oxidation Sic Foam Filter, Başar Çağlar, Deni̇z Üner

Turkish Journal of Chemistry

The coating characteristics of Pb-Co mixed metal oxide soot oxidation catalysts over a SiC foam filter were studied. The coating was done via incipient wetness impregnation of a slurry with Pb/Co weight ratio = 2. The coating was accomplished by 3 consecutive impregnation-drying-calcination cycles. After each cycle surface structure and composition were monitored by scanning electron microscope (SEM). SEM analysis revealed that the surface composition of Pb was high on the high porosity region and surface composition of Co was high on the low porosity region inside the filter. These overlayers were tested for their soot oxidation ability by depositing …


Preparation And Characterization Of Ordered Tio_2 Photocatalysts: Films And Mesoporous Structures, Orçun Ergün, Osman Karslioğlu, Ayşen Yilmaz, Deni̇z Üner Jan 2007

Preparation And Characterization Of Ordered Tio_2 Photocatalysts: Films And Mesoporous Structures, Orçun Ergün, Osman Karslioğlu, Ayşen Yilmaz, Deni̇z Üner

Turkish Journal of Chemistry

Two different ordered TiO_2 structures were prepared as sol-gel films coated on glass and as mesoporous structures in order to study the effect, in 2-D or in 3-D, of bulk size on photocatalytic activity. Multilayer TiO_2 films were coated on glass by the sol-gel dip coating method. The UV-VIS characteristics of the films, with respect to the number of coating layers, were monitored. UV-VIS measurements implied an ordered TiO_2 structure grown on ITO glass. The second approach involved loading TiO_2 in mesoporous SBA-15 powder. Ti-SBA-15 with Ti/Si (mole/mole) ratios between 0.05 and 0.30 were prepared and characterized by XRD and …


Dielectric Behavior Of The Catalyst Zeolite Nay, Ertuğrul İzci̇, Ali̇me İzci̇ Jan 2007

Dielectric Behavior Of The Catalyst Zeolite Nay, Ertuğrul İzci̇, Ali̇me İzci̇

Turkish Journal of Chemistry

Zeolites are crystalline hydrated aluminosilicates of alkaline and alkaline earth metals. The basic zeolite structure is an anionic frame of Si and Al T-atoms, which are tetrahedral and coordinated with oxygen atoms. The electrical properties of zeolites are of enormous technical importance due to their manifold applications as solid catalysts. Zeolite NaY was used in this investigation. Zeolite NaY is a synthetic zeolite and it has a faujasite structure. The electrical conductivity, dielectric permittivity, and loss factor of Na ion exchanged zeolite NaY was carried out in the 10^4-10^6 Hz frequency region at room temperature and different water contents using …


Examination Of Some Commercial Sorptive Organobentonites, Müşerref Önal Jan 2007

Examination Of Some Commercial Sorptive Organobentonites, Müşerref Önal

Turkish Journal of Chemistry

For controlling organophilic partition nanophase (OPN) formation in some commercial sorptive organobentonites (OBs), 4 sample were selected randomly and examined by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, differential thermal analysis (DTA), thermal gravimetric analysis (TGA), element analysis (EA), and nitrogen adsorption/desorption (N_2-AD) techniques. Since the d(001) values of the OB samples are between 1.94 and 3.36 nm, the pseudotrilayer or paraffin-type alkylammonium configuration located between the 2:1 layers of smectites is dominant. The bending and stretching type FTIR bands of the smectite surface and alkylammonium cations (AACs) are evidence of the formation of the OPN in the OBs. …


The Effect Of Ionic Electrolytes And Ph On The Zeta Potential Of Fine Coal Particles, Kemal Doymuş Jan 2007

The Effect Of Ionic Electrolytes And Ph On The Zeta Potential Of Fine Coal Particles, Kemal Doymuş

Turkish Journal of Chemistry

Many environmental problems are attributed to coal combustion and utilization, a subject receiving increasing attention worldwide. Some of these problems could be minimized or even avoided if coal cleaning, properly applied, was considered an economical and effective technique for removing hazardous elements or reducing their concentrations before combustion. The coal samples used in this study were separated into particle sizes of 4, 12, and 40 mesh. Then these samples were subjected to sink-float treatment in a ZnCl_2 solution of 1.3 density. The sample used for zeta potential determination was prepared by grinding both sink and float coal samples down to …


Preconcentration Of Trace Elements On Amberlite Xad-4 Resin Functionalised With 1,2-Bis (O-Aminophenylthio) Ethane And Their Determination By Faas In Environmental Samples, Ömer Dalman, Volkan Numan Bulut, İsmai̇l Deği̇rmenci̇oğlu, Mehmet Tüfekçi̇ Jan 2007

Preconcentration Of Trace Elements On Amberlite Xad-4 Resin Functionalised With 1,2-Bis (O-Aminophenylthio) Ethane And Their Determination By Faas In Environmental Samples, Ömer Dalman, Volkan Numan Bulut, İsmai̇l Deği̇rmenci̇oğlu, Mehmet Tüfekçi̇

Turkish Journal of Chemistry

The use of chemically modified XAD-4-1,2-bis (o-aminophenylthio) ethane chelating resin for preconcentrating Cr^{6+}, Mn^{2+}, Fe^{3+}, Co^{2+}, Cu^{2+}, Cd^{2+}, Zn^{2+}, Pb^{2+}, and Ni^{2+} was studied using flame atomic absorption spectrometry (FAAS) for metal monitoring in environmental samples. Cd^{2+}, Zn^{2+}, Pb^{2+}, and Ni^{2+} ions were quantitatively recovered at the rate of 96.0%, 101.0%, 101.0%, and 95.0%, respectively (RSD < 5%), from the studied solutions. The procedure is based on the retention of analytes on a short column of 1,2-bis (o-aminophenylthio) ethane-XAD-4 chelating resin from a buffered sample solution and subsequent elution with 1 M HNO_3. Various parameters, such as pH, eluent type, and concentration, flow rate of sample solution and matrix interference effect on the retention of the metal ions have been studied. The optimum pH for the sorption of the above-mentioned metal ions was about 6. The adsorption and batch capacity of adsorbent and loading half time (t_{1/2}) for Ni^{2+}, Zn^{2+}, Cd^{2+}, and Pb^{2+} were established. The limit of detection was 3.0 \mu g L^{-1} for Pb^{2+} and Ni^{2+}, 0.6 \mu g L^{-1} for Cd^{2+}, and 0.3 \mu g L^{-1} for Zn^{2+}. The validation of the procedure was carried out by analysis of certified reference materials and standard addition. The proposed enrichment method was applied to environmental samples from Trabzon.


Synthesis Of The Amide Derivatives Of 3-[1-(3-Pyridazinyl)-5-Phenyl-1h-Pyrazole-3-Yl]Propanoic Acids As Potential Analgesic Compounds, Erden Banoğlu, Murat Şüküroğlu, Burcu Çalişkan Ergün, Sultan Nacak Baytaş, Eda Aypar, Mustafa Ark Jan 2007

Synthesis Of The Amide Derivatives Of 3-[1-(3-Pyridazinyl)-5-Phenyl-1h-Pyrazole-3-Yl]Propanoic Acids As Potential Analgesic Compounds, Erden Banoğlu, Murat Şüküroğlu, Burcu Çalişkan Ergün, Sultan Nacak Baytaş, Eda Aypar, Mustafa Ark

Turkish Journal of Chemistry

A series of structurally diverse amide derivatives of 3-[1-(3-pyridazinyl)-5-phenyl-1H-pyrazole-3-yl]propanoic acids were prepared and tested for their in vivo analgesic activity using an acetic acid induced writhing test. All the test compounds displayed approximately equipotent analgesic activity to aspirin. The results showed that the analgesic activity of 5a, 5f, 5n, and 5o is significantly higher than that of 5d.


Electron Affinities, Solvation Energies And Redox Potentials Of Some Chalcones: Substituents` Effect And Correlation With Semi-Empirical Mo Energies, Abdur Rahman, Rumana Qureshi, Mehvish Kiran, Farzana Latif Ansari Jan 2007

Electron Affinities, Solvation Energies And Redox Potentials Of Some Chalcones: Substituents` Effect And Correlation With Semi-Empirical Mo Energies, Abdur Rahman, Rumana Qureshi, Mehvish Kiran, Farzana Latif Ansari

Turkish Journal of Chemistry

Experimental and theoretical investigations were carried out on 2 sets of chalcones. Set 1 has an OH group on ring A and Set 2 does not, and both have different substituents on ring B at different positions. The experimental investigations comprised cyclic voltammetric (CV) studies to determine the reactivity in terms of redox potentials in DMF at room temperature (23 \pm 1 °C). Electrochemical parameters from cyclic voltammograms were used to evaluate the reversibility of electron transfer, standard reduction potentials, solvation energies, electron affinities, diffusion coefficients, critical scan rates and heterogeneous electron transfer rate constants. Heterogeneous electron transfer rate constants …


A Convenient Method For The Preparation Of 2-Aminobenzophenone Derivatives Under Ultrasonic Irradiation, Javad Safaei-Ghomi, Manouchehr Fadaeian, Alireza Hatami Jan 2007

A Convenient Method For The Preparation Of 2-Aminobenzophenone Derivatives Under Ultrasonic Irradiation, Javad Safaei-Ghomi, Manouchehr Fadaeian, Alireza Hatami

Turkish Journal of Chemistry

A quick and convenient method for the preparation of 2-aminobenzophenone derivatives is described. This approach consists of the nucleophilic substitution reaction of nitrobenzenes by phenylacetonitrile under conventional and ultrasonic conditions followed by reduction of the produced 2,1-benzisoxazole to 2-aminobenzophenone. This 2-step reaction was studied by changing the reaction parameters (reaction temperature, ultrasound power, and reaction time). The results clearly demonstrated that using ultrasound irradiation results in a high yield within a short reaction time.


Synthesis Of 2-Acylamino, 2-Aroylamino And Ethoxycarbonyl Imino-1,3,4-Thiadiazoles As Antitumor Agents, Kemal Sancak, Yasemi̇n Ünver, Mustafa Er Jan 2007

Synthesis Of 2-Acylamino, 2-Aroylamino And Ethoxycarbonyl Imino-1,3,4-Thiadiazoles As Antitumor Agents, Kemal Sancak, Yasemi̇n Ünver, Mustafa Er

Turkish Journal of Chemistry

2-Amino-1,3,4-thiadiazoles compounds (2a-e) were obtained from the reaction of thiosemi carbazide with 2-cyanomethoxyphenoxyacetonitriles (1). Mono acylamino, mono aroylamino and diethoxycarbonyl imino-1,3,4-thiadiazole compounds (3a-e, 4a-e, 5a-c) were synthesized via the reaction of 2-amino-1,3,4-thiadiazole compounds (2a-e) with acetyl chloride or acetic anhydride, benzoyl chloride or benzoic anhydride and ethyl chloroformate, respectively. The in vitro antitumor activities of some selected compounds were screened and compounds 2a, 2b, 2c, 3a, 3b, 3c, 5a, 5b and 5c were found to be active.


Iridoid Glucosides From Lamium Garganicum Subsp. Laevigatum, Tayfun Ersöz, Duygu Kaya, Funda Nuray Yalçin, Cavi̇t Kazaz, Erhan Palaska, Charlott H. Gotfredsen, Soren R. Jensen, İhsan Çaliş Jan 2007

Iridoid Glucosides From Lamium Garganicum Subsp. Laevigatum, Tayfun Ersöz, Duygu Kaya, Funda Nuray Yalçin, Cavi̇t Kazaz, Erhan Palaska, Charlott H. Gotfredsen, Soren R. Jensen, İhsan Çaliş

Turkish Journal of Chemistry

Phytochemical investigations on the above-ground parts of Lamium garganicum subsp. laevigatum resulted in the isolation of 7 iridoid glucosides: shanzhiside methyl ester (1), barlerin (8-O-acetylshanzhiside methyl ester) (2), 6-O-syringyl-8-O-acetylshanzhiside methyl ester (3), 6\beta-hydroxyipolamiide (4), lamalbide (5), dehydropenstemoside (6), and sesamoside (7). The structure of the iridoids was elucidated by spectroscopic (UV, IR, 1D- and 2D-NMR, and ESI-MS) evidence.


Investigation Of Some 1,3-Diols For The Requirements Of Solvent Extraction Of Boron: 2,2,6-Trimethyl-1,3 Heptanediol As A Potential Boron Extractant, Bi̇lsen Tural, Servet Tural, Hali̇l Hoşgören Jan 2007

Investigation Of Some 1,3-Diols For The Requirements Of Solvent Extraction Of Boron: 2,2,6-Trimethyl-1,3 Heptanediol As A Potential Boron Extractant, Bi̇lsen Tural, Servet Tural, Hali̇l Hoşgören

Turkish Journal of Chemistry

Eighteen 1,3-diols were synthesized and their structure and distribution ratio for the solvent extraction of boron were studied. Diols with a high distribution ratio (D_{B(OH)_3 > 10) were investigated for the requirements of solvent extraction of boron. Their extraction capacity, and solubility in aqueous phase and in organic diluents were investigated by comparison to 2-ethyl-1,3-hexanediol (EHD), which is widely used as a boron extractant. Among a series of 1,3 diols, 1-benzyl-2,2-dimethyl-1,3-propanediol (4a) and 2,2,6-trimethyl-1,3-heptanediol (3a) were found to have very low solubility in the aqueous phase compared to the others. IPD (3a) was found to have a high solubility in aliphatic …


An Electrochemical Dna Biosensor For The Detection Of Dna Damage Caused By Radioactive Iodine And Technetium, Pinar Kara, Kağan Dağdevi̇ren, Mehmet Özsöz Jan 2007

An Electrochemical Dna Biosensor For The Detection Of Dna Damage Caused By Radioactive Iodine And Technetium, Pinar Kara, Kağan Dağdevi̇ren, Mehmet Özsöz

Turkish Journal of Chemistry

A DNA damage process by radioactive iodine (I-131) and technetium (Tc-99m) is described. The procedure relies on a label-free electrochemical DNA biosensor. Fish sperm double stranded DNA was immobilized onto a carbon paste electrode (CPE) by electro deposition and the changes to the guanine oxidation signal were observed upon exposure to radioactive I-131 and Tc-99m by differential pulse voltammetry (DPV). The changes to the signal of guanine after exposure to therapeutic doses of Tc-99m and I-131 showed conformational changes in DNA molecules.


Fft-Adsorptive Voltammetric Technique For Pico-Level Determination Of Tetracycline In Capsules At An Au Microelectrode In Flowing Solutions, Parviz Norouzi, Mohammad Reza Ganjali, Parandis Daneshgar Jan 2007

Fft-Adsorptive Voltammetric Technique For Pico-Level Determination Of Tetracycline In Capsules At An Au Microelectrode In Flowing Solutions, Parviz Norouzi, Mohammad Reza Ganjali, Parandis Daneshgar

Turkish Journal of Chemistry

This study illustrates a novel method for fast monitoring of tetracycline in flow-injection systems. The fast Fourier transformation, along with continuous cyclic voltammetry (FFTCV) at a gold microelectrode in a flowing solution system, was used for the determination of tetracycline in its pharmaceutical formulation. The benefit of the developed technique is that it is simple, precise, accurate, time-saving, and economical compared to all of the previously reported methods. The effects of various parameters on the sensitivity of the method were investigated. Three considerable advantages are demonstrated by this method, which other methods do not possess. Firstly, there is no requirement …


Synthesis Of Some Novel 3,5-Diaryl-1,2,4-Triazole Derivatives And Investigation Of Their Antimicrobial Activities, Mevlut Serdar, Nurhan Gümrükçüoğlu, Şengül Alpay Karaoğlu, Nesli̇han Demi̇rbaş Jan 2007

Synthesis Of Some Novel 3,5-Diaryl-1,2,4-Triazole Derivatives And Investigation Of Their Antimicrobial Activities, Mevlut Serdar, Nurhan Gümrükçüoğlu, Şengül Alpay Karaoğlu, Nesli̇han Demi̇rbaş

Turkish Journal of Chemistry

A series of acylhydrazones (2a-d) was synthesized from the reactions of iminoester hydrochlorides (1a-e) with acyl hydrazines. 2,5-Dialkyl 1,3,4-oxadiazoles (3a-d) were obtained in the same reaction media. The treatment of acylhydrazones with hydrazine hydrate afforded 4-amino-3,5-dialkyl-1,2,4-triazoles (4a-c). The acetylation of 4-amino-3-(4-hydroxyphenyl)-5-phenyl-4H-1,2,4-triazole (4a) produced 4-amino-5-(4-acetoxyphenyl)-3-phenyl-4H-1,2,4-triazole (9), while the acetylation of 4-amino-3-(4-tolyl)-5-phenyl-4H-1,2,4-triazole (4b) gave 4-acetylamino-3-phenyl-5-(4-tolyl)-4H-1,2,4-triazole (10). The treatment of compound 4b with various aromatic aldehydes or acetophenone and 4-nitroacetophenone resulted in the formation of 4-arylidenamino-3,5-dialkyl-4H-1,2,4-triazoles (5a-e and 7a,b). Sodium borohydride reduction of 4-arylidenamino derivatives of 1,2,4-triazoles afforded 4-alkylamino-3,5-dialkyl-4H-1,2,4-triazoles (6a-e and 8a,b). All newly synthesized compounds were screened for their antimicrobial and antifungal …


Synthesis, Characterization, And Biocidal Studies Of The Newly Synthesized Di- And Triorganotin(Iv) Complexes With N-Butylhydrogen Phthalate, Sadiq-Ur Rehman, Saqib Ali, Saira Shahzadi, Abdul Malik, Ejaz Ahmed Jan 2007

Synthesis, Characterization, And Biocidal Studies Of The Newly Synthesized Di- And Triorganotin(Iv) Complexes With N-Butylhydrogen Phthalate, Sadiq-Ur Rehman, Saqib Ali, Saira Shahzadi, Abdul Malik, Ejaz Ahmed

Turkish Journal of Chemistry

Di-(1, 3, 8) and triorganotin(IV) complexes (2, 5, 7) with the general formula R_nSnL_{4-n}, where R = Me, Et, n-Bu, n-Oct, Ph, and Bz, and L = the n-C_4H_9OCOC_6H_4COO^- monoanionic ligand have been synthesized by the reaction of the silver salt of the n-butylhydrogen phthalate with di- and triorganotin chloride in dry chloroform. However, di-n-butyl- and di-n-octyltin(IV) derivatives (4 and 6, respectively) were synthesized by the reaction of the corresponding organotin(IV) oxide with n-butylhydrogen phthalate in dry toluene. All the synthesized complexes were characterized by elemental analysis, FT-IR, multinuclear (^1H, ^{13}C, ^{119}Sn) NMR, and mass spectrometric techniques to assess the …


Selenium And Trace Element Distribution In Astragalus Plants: Developing A Differential Pulse Polarographic Method For Their Determination, Güler Somer, A. Cengi̇z Çalişkan Jan 2007

Selenium And Trace Element Distribution In Astragalus Plants: Developing A Differential Pulse Polarographic Method For Their Determination, Güler Somer, A. Cengi̇z Çalişkan

Turkish Journal of Chemistry

Astragalus plants have a wide range of applications in pharmaceuticals (gum tragacanth), as thickening agents in foods, and may have applications in controlling cancer cells. They are used as feed for animals and they are indicator plants for selenium. Because of their use in health-related areas it is very important to determine their selenium and trace element content with high accuracy. A new differential pulse polarographic method was established for trace element determination (10 elements) and their distribution in these plants. The Astragalus plants investigated in this work are Astragalus microcephalus and Astragalus lusitanicus, which grow almost everywhere. Their roots, …


Preparation, Spectroscopy, Antimicrobial Assay, And X-Ray Structure Of Dimethyl Bis-(4-Methylpiperidine Dithiocarbamato-S,S`)-Tin(Iv), Zia-Ur Rehman, Saira Shahzadi, Saqib Ali, Guo-Xin Jin Jan 2007

Preparation, Spectroscopy, Antimicrobial Assay, And X-Ray Structure Of Dimethyl Bis-(4-Methylpiperidine Dithiocarbamato-S,S`)-Tin(Iv), Zia-Ur Rehman, Saira Shahzadi, Saqib Ali, Guo-Xin Jin

Turkish Journal of Chemistry

Dimethyl bis(4-methylpiperidine dithiocarbamato-S,S')-tin(IV) was synthesized and characterized by elemental analysis, IR and mass spectrometry, multinuclear NMR (^1H- and ^{13}C-NMR), and X-ray single crystal analysis. IR data showed that the ligand acts as a bidentate in the solid state. X-ray data showed the unsymmetrical nature of the ligand towards coordination to tin. It crystallized in the monoclinic P2_1/n space group. Its geometry is distorted octahedral. Antimicrobial activity data shows that the complex exhibits significantly more activity than the free ligand.


Pvc-Membrane Electrodes Based On 18-Crown-6 And Dibenzo-18-Crown-6 Ethers For Determination Of Silver, Mohsen Mousa Zareh, Magda A. Akl, Ahmd Khlil Gohneim, Mohmed Hussin Abd El-Aziz Jan 2007

Pvc-Membrane Electrodes Based On 18-Crown-6 And Dibenzo-18-Crown-6 Ethers For Determination Of Silver, Mohsen Mousa Zareh, Magda A. Akl, Ahmd Khlil Gohneim, Mohmed Hussin Abd El-Aziz

Turkish Journal of Chemistry

PVC-membrane electrodes for Ag^+ based on either 18-crown-6 (I) or di-benzo-18-crown-6 ether (II) were applied for the first time. The effect of solvent mediator on the electrode performance was discussed. Nernstian slope values were 59 and 58.9 mV/decade for both I and II electrode types, respectively. The linear concentration range was 10^{-5}-10^{-1}M. The detection limit was 7.9 \times 10^{-6} M. The working pH ranges were 5-9 or 4-9, depending on the concentration of Ag^+ ion. The electrodes showed good selectivity towards most of the common alkali, alkaline earths, and transition metal cations. The electrodes were applied successfully for the determination …


Development Of A New Set Of Additive Parameters For The Estimation Of Geometrical Distortion Of Cycloalkanes From C-13 Nmr Chemical Shifts, Emad A. S. Al-Hyali Jan 2007

Development Of A New Set Of Additive Parameters For The Estimation Of Geometrical Distortion Of Cycloalkanes From C-13 Nmr Chemical Shifts, Emad A. S. Al-Hyali

Turkish Journal of Chemistry

A previous model for the calculation of C-13 chemical shifts is modified by replacement of 3 parameters representing the p-character of carbon atom in cyclic systems with a single parameter aiming for the development of a new set of parameters with a wide range of application for the calculation of C-13 NMR chemical shifts. The considered systems are cyclohexanes, trans decalins, and a number of hypothetical polycyclic 6-member ring hydrocarbons. The developed parameters include a combination of quantum mechanical and statistical methods. They are based on 2 factors: through bond (electronic) effect represented by the partial electronic charge on the …


The Synthesis Of 2-(Chloromethyl)-6-Hydroxy-2h-Pyran-3 (6h)-One Via Achmatowicz Rearrangement, Zuhal Gerçek Jan 2007

The Synthesis Of 2-(Chloromethyl)-6-Hydroxy-2h-Pyran-3 (6h)-One Via Achmatowicz Rearrangement, Zuhal Gerçek

Turkish Journal of Chemistry

Achmatowicz rearrangement was carried out with 2-chloro-1-(furan-2-yl) ethanol, which was synthesized starting from 1-(furan-2-yl) ethanone. It was shown that the oxidation of 2-chloro-1-(furan-2-yl) ethanol with m-CPBA produced 2-(chloromethyl)-6-hydroxy-2H-pyran-3 (6H)-one in good yield (70%).


Activation Of Light Alkanes On Pure And Fe And Al Doped Silica Clusters: A Density Functional And Oniom Study, Mehmet Ferdi̇ Fellah, Işik Önal Jan 2007

Activation Of Light Alkanes On Pure And Fe And Al Doped Silica Clusters: A Density Functional And Oniom Study, Mehmet Ferdi̇ Fellah, Işik Önal

Turkish Journal of Chemistry

C-H bond activation was studied by use of density functional theory (DFT) and ONIOM calculations as implemented in Gaussian 2003 at the B3LYP level utilising 6-31G* as the basis set for Si, Al, and Fe atoms and 3-21G** as the basis set for O and H atoms. Relative energy profiles were determined for pure silica modeled by a Si_7O_{21} cluster and Fe and Al doped silica clusters via coordinate driving calculations. The activation barriers for C-H bond activation of methane and ethane decrease with the substitution of Fe on the silica surface, which theoretically demonstrates a favorable effect of Fe …


Catalytic Combustion Of Ethyl Acetate, Tuğba Gürmen Özçeli̇k, Süheyda Atalay, Erden Alpay Jan 2007

Catalytic Combustion Of Ethyl Acetate, Tuğba Gürmen Özçeli̇k, Süheyda Atalay, Erden Alpay

Turkish Journal of Chemistry

The catalytic combustion of ethyl acetate over prepared metal oxide catalysts was investigated. CeO, Co_2O_3, Mn_2O_3, Cr_2O_3, and CeO-Co_2O_3 catalysts were prepared on monolith supports and they were tested. Before conducting the catalyst experiments, we searched for the homogeneous gas phase combustion reaction of ethyl acetate. According to the homogeneous phase experimental results, 45% of ethyl acetate was converted at the maximum reactor temperature tested (350 °C). All the prepared catalysts were tested in order to find the best catalyst for the complete combustion of ethyl acetate. According to the results, all these catalysts produced higher conversion rates than that …


Fused Heterocycles: Synthesis Of Some New Imidazopyridines As Anti-Mycobacterial Agents, Bi̇rgül Özden Kasimoğullari, Zafer Cesur Jan 2007

Fused Heterocycles: Synthesis Of Some New Imidazopyridines As Anti-Mycobacterial Agents, Bi̇rgül Özden Kasimoğullari, Zafer Cesur

Turkish Journal of Chemistry

The reaction of semicarbazones bearing an imidazo[1,2-a]pyridine ring system with mercaptoacetic acid was investigated. The anti-mycobacterial activity of the compounds thus obtained were evaluated against Mycobacterium tuberculosis H_{37}Rv, using rifampin as the standard. Only IVe showed activity at 6.25 \mu g mL^{-1}.


A New And Convenient Method Of Generating Alkyl Isocyanates From Alcohols, Thiols, And Trimethylsilyl Ethers Using A 2,4,6-Trichloro[1,3,5] Triazine/N-Bu_4nocn, Batool Akhlaghinia, Sima Samiei Jan 2007

A New And Convenient Method Of Generating Alkyl Isocyanates From Alcohols, Thiols, And Trimethylsilyl Ethers Using A 2,4,6-Trichloro[1,3,5] Triazine/N-Bu_4nocn, Batool Akhlaghinia, Sima Samiei

Turkish Journal of Chemistry

Alkyl isocyanates are prepared in good to excellent yields by treatment of alcohols, thiols, and trimethylsilyl ethers with 2,4,6-trichloro[1,3,5] triazine/n-Bu_4NOCN in acetonitrile. This method is highly selective for conversion of 1° alcohols to alkyl isocyanates in the presence of 2° and 3° alcohols, thiols, and trimethylsilyl ethers.


Studies On The Anion Recognition Properties Of Synthesized Receptors Iii: A Novel Thiourea-Based Receptor Constructed By Benzo-15-Crown-5 For Sensing Anions In A Strong Polar Solvent, You-Ming Zhang, Hai-Xian Ren, Yan-Qing Zhou, Rong Luo, Wei-Xia Xu, Tai-Bao Wei Jan 2007

Studies On The Anion Recognition Properties Of Synthesized Receptors Iii: A Novel Thiourea-Based Receptor Constructed By Benzo-15-Crown-5 For Sensing Anions In A Strong Polar Solvent, You-Ming Zhang, Hai-Xian Ren, Yan-Qing Zhou, Rong Luo, Wei-Xia Xu, Tai-Bao Wei

Turkish Journal of Chemistry

A new series of receptors were designed and synthesized, and their interactions with anions, such as F^-, Cl^-, Br^-, I^-, CH_3COO^-, HSO_4^-, and NO_3^-, in DMSO solvent were investigated using UV-Vis absorption spectroscopy. The results showed that hydrogen-bonding complexes were formed between the receptors and the tested anions, such as CH_3COO^- and F^-. It was also found that the selectivity of the receptors for anions could be efficiently tuned by changing the place of the substituent group at the N-phenyl moiety. The recognition mechanism and binding mode are discussed. These findings were expected to be of significance for designing and …