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2015

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Articles 991 - 1020 of 1428

Full-Text Articles in Chemistry

A New And Simple Procedure For The Trace Determination Of Mercury Using Differential Pulse Polarography And Application To A Salt Lake Sample, Güler Somer, A. Cengi̇z Çalişkan, Olcay Şendi̇l Jan 2015

A New And Simple Procedure For The Trace Determination Of Mercury Using Differential Pulse Polarography And Application To A Salt Lake Sample, Güler Somer, A. Cengi̇z Çalişkan, Olcay Şendi̇l

Turkish Journal of Chemistry

A new and simple differential pulse polarographic procedure was established for the trace determination of mercury(II). An indirect method had to be used since no polarographic peak can be observed for its direct determination. According to their standard potentials, the reaction between SO$_{3}^{2-}$ and Hg(II) was suitable. The peak height of sulfite at about -0.70 V (pH 6, 7) was sharp, high, and very reproducible, enabling the accurate determination of low concentrations of Hg(II). It was found that sulfite concentration had to be 3 times larger than mercury at pH 6, in order to have a quantitative reaction. The procedure …

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Dinitrogen Reduction On A Polypyrrole Coated Pt Electrode Under High-Pressure Conditions: Electrochemical Impedance Spectroscopy Studies, Di̇dem Balun Kayan, Fati̇h Köleli̇ Jan 2015

Dinitrogen Reduction On A Polypyrrole Coated Pt Electrode Under High-Pressure Conditions: Electrochemical Impedance Spectroscopy Studies, Di̇dem Balun Kayan, Fati̇h Köleli̇

Turkish Journal of Chemistry

The electrochemical impedance spectroscopy (EIS) responses of a polypyrrole (PPy)-coated platinum electrode were investigated during N$_{2}$-reduction to ammonia in aqueous medium. Kinetic parameters such as film resistance, pore resistance, and double layer capacitance were analyzed as a function of applied potential and polymer film thickness. The relation between kinetic parameters was discussed by combining electrolysis results. It was found that the optimum film thickness of polypyrrole was 0.73 $\mu $m and optimum potential for ammonia synthesis was -0.150 V under 60 bar N$_{2}$-pressure. The impedance responses under these conditions presented the lowest pore resistance value of ca. 2 $\Omega $ …

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Characterization Of A Cu$^{2+}$-Selective Fluorescent Probe Derived From Rhodamine B With 1,2,4-Triazole As Subunit And Its Application In Cell Imaging, Na Li, Chunwei Yu, Yuxiang Ji, Jun Zhang Jan 2015

Characterization Of A Cu$^{2+}$-Selective Fluorescent Probe Derived From Rhodamine B With 1,2,4-Triazole As Subunit And Its Application In Cell Imaging, Na Li, Chunwei Yu, Yuxiang Ji, Jun Zhang

Turkish Journal of Chemistry

A rhodamine B derivative containing 1,2,4-triazole as subunit was characterized as an "off-on" type Cu$^{2+}$-selective fluorescent probe. It exhibited high selectivity and sensitivity for Cu$^{2+}$ in ethanol-water solution (9:1, v:v, pH 7.0, 20 mM HEPES) and underwent ring opening. A prominent fluorescence enhancement at 570 nm was observed in the presence of Cu$^{2+}$ with the change in the absorption spectrum, and a 1:1 metal-ligand complex was formed. With the optimized experimental conditions, the probe exhibited a dynamic response range for Cu$^{2+}$ from 8.0 $\times $ 10$^{-7}$ to 7.5 $\times $ 10$^{-6}$ M with a detection limit of 2.3 $\times $ …

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Green Synthesis Of 2-Amino-7-Hydroxy-4-Aryl-4$H$-Chromene-3-Carbonitriles Using Zno Nanoparticles Prepared With Mulberry Leaf Extract And Zncl$_{2}$, Akbar Mobinikhaledi, Atisa Yazdanipour, Majid Ghashang Jan 2015

Green Synthesis Of 2-Amino-7-Hydroxy-4-Aryl-4$H$-Chromene-3-Carbonitriles Using Zno Nanoparticles Prepared With Mulberry Leaf Extract And Zncl$_{2}$, Akbar Mobinikhaledi, Atisa Yazdanipour, Majid Ghashang

Turkish Journal of Chemistry

A highly efficient and environmentally benign protocol for the synthesis of 2-amino-7-hydroxy-4-aryl-4$H$-chromene-3-carbonitrile derivatives in good to high yields (77%-97%) by one-pot three-component coupling reaction of aromatic aldehydes, malononitrile, and resorcinol under reflux condition was developed in aqueous media using ZnO nanoparticles that were prepared in the presence of mulberry leaf extract under mild conditions.

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Acid-Free Synthesis Of S-Nitrosothiols At Neutral Ph By Shock-Freezing In Liquid Nitrogen, Dimitrios Tsikas, Anke Böhmer, Arne Trettin, Arslan Arinç Kayaçelebi̇ Jan 2015

Acid-Free Synthesis Of S-Nitrosothiols At Neutral Ph By Shock-Freezing In Liquid Nitrogen, Dimitrios Tsikas, Anke Böhmer, Arne Trettin, Arslan Arinç Kayaçelebi̇

Turkish Journal of Chemistry

A laboratory method for the acid-free synthesis of S-nitrosothiols (RSNO) from NaNO$_{2}$ and thiols in aqueous buffer of neutral pH is reported. Equimolar amounts of NaNO$_{2}$ and thiol are added to a 100-$\mu $M Na$_{4}$EDTA-containing Na$_{2}$HPO$_{4}$ buffer (100 mM, pH 7.4). Samples are set into liquid nitrogen for 1 min and then thawed to room temperature or in an ice bath. Dependent upon the RSNO, repetition of the procedure may be required. This method may be of particular importance when the classical acid-based method fails or releases harmful gases such as H$_{2}$S.

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Optimization Of The Adsorption Of A Textile Dye Onto Nanoclay Using A Central Composite Design, Aydin Hassani, Murat Kiranşan, Reza Darvishi Cheshmeh Soltani, Alireza Khataee, Semra Karaca Jan 2015

Optimization Of The Adsorption Of A Textile Dye Onto Nanoclay Using A Central Composite Design, Aydin Hassani, Murat Kiranşan, Reza Darvishi Cheshmeh Soltani, Alireza Khataee, Semra Karaca

Turkish Journal of Chemistry

The main aim of this study was to evaluate the efficacy of montmorillonite clay for the adsorption of C.I. Basic Yellow 2 (BY2) dye from aqueous media. The experimental results were processed by response surface methodology based on a central composite design (CCD). The effect of four main variables, including initial BY2 concentration, adsorbent dosage, reaction time, and temperature on the removal of BY2 was evaluated by the model. The accuracy of the model and regression coefficients was appraised by employing analysis of variance. The results demonstrated a good agreement between the predicted values obtained by the model and the …

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Synthesis Of Metal-Free And Metallophthalocyanines Containing 18- And 21-Membered Macrocycles With Mixed Donor Atoms And Their Metal-Ion Binding Properties, Hali̇l Zeki̇ Gök Jan 2015

Synthesis Of Metal-Free And Metallophthalocyanines Containing 18- And 21-Membered Macrocycles With Mixed Donor Atoms And Their Metal-Ion Binding Properties, Hali̇l Zeki̇ Gök

Turkish Journal of Chemistry

This paper describes the synthesis of a series of metal-free phthalocyanines and metallophthalocyanines peripherally substituted by macrocycles of different ring sizes with the same donor atom sets. The effects of varying ring size of the macrocycle on the spectroscopic and metal ion binding properties of phthalocyanines were examined. For these purposes, electronic absorption properties for metal-free phthalocyanines and metallophthalocyanines were studied in dimethylformamide and tetrahydrofuran. The liquid-liquid extraction of metal picrates such as Ag(I), Hg(II), Cd(II), Zn(II), Cu(II), Ni(II), Pb(II), and Co(II) from the aqueous phase to the organic phase was carried out using metallophthalocyanines. All new compounds were characterized …

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Purification, Refolding, And Characterization Of Recombinant Human Paraoxonase-1, Yeli̇z Demi̇r, Şükrü Beydemi̇r Jan 2015

Purification, Refolding, And Characterization Of Recombinant Human Paraoxonase-1, Yeli̇z Demi̇r, Şükrü Beydemi̇r

Turkish Journal of Chemistry

A high density lipoprotein (HDL)-linked enzyme with antioxidant and antiatherogenic properties, paraoxonase-1(PON1), prevents the formation of atherosclerotic lesions in humans. In the present study, a recombinant hPON1 gene was produced using a small ubiquitin-related modifier (SUMO) fusion protein expression system. To that end, the hPON1 gene was amplified from human liver-ready cDNA, cloned into the expression vector pET SUMO, and expressed in Escherichia coli BL21 (DE3). The predominance of the expressed fusion SUMO-hPON1 protein was inclusion bodies and purified using 6xHis affinity chromatography under natural and denaturing conditions. Subsequently, the enzyme was purified and refolded directly on the affinity matrix …

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Synthesis And Characterization Of Novel Urea And Thiourea Substitute Cyclotriphosphazene Compounds As Naked-Eye Sensors For F$^{-}$ And Cn$^{-}$ Anions, Hava Özay, Mehmet Yildirim, Özgür Özay Jan 2015

Synthesis And Characterization Of Novel Urea And Thiourea Substitute Cyclotriphosphazene Compounds As Naked-Eye Sensors For F$^{-}$ And Cn$^{-}$ Anions, Hava Özay, Mehmet Yildirim, Özgür Özay

Turkish Journal of Chemistry

Novel hexakisurea and thiourea cyclotriphosphazene compounds (3-7) were synthesized. The structure of all compounds was identified using FT-IR $^{1}$H, $^{13}$C, and $^{31}$P NMR spectroscopy; MALDI-TOF MS; and elemental analysis. The optical sensor properties for anions of 3-7 were investigated using UV-Vis spectroscopy. It was determined that compounds 6 and 7 are spectrophotometric and naked eye sensors for F$^{-}$ and CN$^{-}$ anions, respectively. Sensor properties of these compounds for anions were investigated using UV-Vis spectroscopy. The stoichiometry of host-guest complexes was found to be 1:6.

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Microwave-Assisted Regioselective [1,3]-Dipolar Cycloaddition Of 3-Methyl-2-(Substitutedbenzylidene)-5-Oxopyrazolidin-2-Ium-1-Ides To Benzothiophene 1,1-Dioxide, Yaşar Dürüst, Eda Sağirli, Akin Sağirli Jan 2015

Microwave-Assisted Regioselective [1,3]-Dipolar Cycloaddition Of 3-Methyl-2-(Substitutedbenzylidene)-5-Oxopyrazolidin-2-Ium-1-Ides To Benzothiophene 1,1-Dioxide, Yaşar Dürüst, Eda Sağirli, Akin Sağirli

Turkish Journal of Chemistry

A series of pyrazolidinium ylides was reacted with benzothiophene 1,1-dioxide to afford (3R,5S,5aS,10bS)-3-methyl-5-substitutedphenyl-2,3,5,5a-tetrahydrobenzo[4,5]thieno[3,2-c]pyrazolo[1,2-a]pyrazol-1(10bH)-one 6,6-dioxides under microwave irradiation and their structures were identified by means of spectral/physical characteristics including X-ray diffraction data and HRMS measurements.

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A Case Study On In Vitro Investigations Of The Potent Biological Activities Of Wheat Germ And Black Cumin Seed Oil, Di̇dem Ağ Şeleci̇, Zi̇nar Pinar Gümüş, Murat Yavuz, Muharrem Şeleci̇, Rebecca Bongartz, Frank Stahl, Hakan Coşkunol, Suna Ti̇mur, Thomas Scheper Jan 2015

A Case Study On In Vitro Investigations Of The Potent Biological Activities Of Wheat Germ And Black Cumin Seed Oil, Di̇dem Ağ Şeleci̇, Zi̇nar Pinar Gümüş, Murat Yavuz, Muharrem Şeleci̇, Rebecca Bongartz, Frank Stahl, Hakan Coşkunol, Suna Ti̇mur, Thomas Scheper

Turkish Journal of Chemistry

The objectives of this study were to investigate the potential biological activities of black cumin seed oil (BCSO) and wheat germ oil (WGO) on different cell lines. Initially, commercially available BCSO and WGO obtained by supercritical carbon dioxide extraction were analyzed in terms of tocopherol, aliphatic alcohols, and thymoquinone content via HPLC and GC analysis. Cell free antioxidant activities and total phenolic content of both oils were detected by DPPH assay and Folin-Ciocalteu method, respectively. As well as the DPPH assay, the protective effect against reactive oxygen species (ROS) was determined by microscopic observation of ROS generation in NIH-3T3 cells …

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Enhanced Electrocatalytic Efficiency Of C/Mwnts For Methanol Oxidation Using Ni Deposited On Mwnts, Murat Farsak, Gülfeza Kardaş Jan 2015

Enhanced Electrocatalytic Efficiency Of C/Mwnts For Methanol Oxidation Using Ni Deposited On Mwnts, Murat Farsak, Gülfeza Kardaş

Turkish Journal of Chemistry

The power density of direct methanol fuel cells (DMFCs) can be changed by using different anode materials. Especially porous materials are preferred for the anode. In the present study, multiwall carbon nanotubes were first injected into graphite. Then, by depositing nickel, a catalyst was prepared for use as the anode material of the DMFC. This catalyst was named Ni@MWNTs. The oxidation of methanol and some kinetic parameters were investigated in KOH solution. Cyclic voltammetry was used for the electrochemical measurements. Kinetic parameters of the methanol oxidation were determined at different temperatures, scan rates, and concentrations of methanol. The surface morphologies …

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Conversion Of Racemic Allylic Hydroperoxides Into Corresponding Chiral 1/2,3-Triols By Using Catalytic Oso$_{4}$ And Chiral Cinchona Ligands In The Absence Of Co-Oxidant, Haydar Göksu, Mehmet Serdar Gülteki̇n Jan 2015

Conversion Of Racemic Allylic Hydroperoxides Into Corresponding Chiral 1/2,3-Triols By Using Catalytic Oso$_{4}$ And Chiral Cinchona Ligands In The Absence Of Co-Oxidant, Haydar Göksu, Mehmet Serdar Gülteki̇n

Turkish Journal of Chemistry

For the first time, removal of oxygen atoms from allylic hydroperoxide functionality and reintroduction to the double bond was achieved using catalytic OsO$_{4}$ and chiral cinchona alkaloid derivatives in an acetone-water mixture to give corresponding chiral 1/2,3-triol with an enantioselectivity up to 99% ee. The hydroperoxide group was used as both a co-oxidant and a source of hydroxyl groups. This protocol is thought to have potential to provide opportunities for chiral synthesis of 1/2,3-triols from corresponding allylic hydroperoxides in the absence of co-oxidant in one stage for the first time in the literature.

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Synthesis And Biological Evaluation Of A New Series Of 4-Alkoxy-2-Arylquinoline Derivatives As Potential Antituberculosis Agents, Gonca Tosun, Tayfun Arslan, Zeynep İskefi̇yeli̇, Murat Küçük, Şengül Alpay Karaoğlu, Nuretti̇n Yayli Jan 2015

Synthesis And Biological Evaluation Of A New Series Of 4-Alkoxy-2-Arylquinoline Derivatives As Potential Antituberculosis Agents, Gonca Tosun, Tayfun Arslan, Zeynep İskefi̇yeli̇, Murat Küçük, Şengül Alpay Karaoğlu, Nuretti̇n Yayli

Turkish Journal of Chemistry

Three new series of 33 quinolone compounds, 2-(2-, 3-, and 4-fluorophenyl)-4-O-alkyl(C$_{5-15})$quinolines (7a-k, 8a-k, and 9a-k), were synthesized from 2-(2-, 3-, and 4-fluorophenyl)-2,3-dihydroquinolin-4(1H)-one (4, 5, and 6) by the reaction of alkyl halides under basic conditions in DMF. The new compounds 7a-k, 8a-k, and 9a-k were synthesized from flavonones 4-6, which can be considered new precursors for quinoline synthesis through a one-step reaction. All the target compounds (7a-k, 8a-k, and 9a-k) were evaluated for their in vitro antimicrobial activity against nine test microorganisms. They showed the most activity against Mycobacterium smegmatis with minimum inhibitory concentrations (MIC) of 62.5-500 $\mu $g/mL, indicating …

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Microwave-Assisted Synthesis Of Novel 8-Chloro-[1,2,4]Triazolo[4,3-$A$]Pyridine Derivatives, Linjiong Zhang, Mingyan Yang, Beizhen Hu, Zhaohui Sun, Xinghai Liu, Jianquan Weng, Chengxia Tan Jan 2015

Microwave-Assisted Synthesis Of Novel 8-Chloro-[1,2,4]Triazolo[4,3-$A$]Pyridine Derivatives, Linjiong Zhang, Mingyan Yang, Beizhen Hu, Zhaohui Sun, Xinghai Liu, Jianquan Weng, Chengxia Tan

Turkish Journal of Chemistry

A series of novel 1,2,4-triazolo[4,3-$a$]pyridine derivatives were synthesized from 2,3-dichloropyridine and hydrazine hydrate as starting materials by multistep reactions under microwave assistance, and their structures were characterized by $^{1}$H NMR, MS, and elemental analysis. This method provides several advantages such as high yields, facile work-up, and environmental friendliness.

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Microwave-Assisted Synthesis Of Condensed 1,4-Dihydropyridines As Potential Calcium Channel Modulators, Erdem Kami̇l Özer, Mi̇yase Gözde Gündüz, Ahmed El-Khouly, Mehmet Yildirim Sara, Rahi̇me Şi̇mşek, Alper Bektaş İski̇t, Osman Ci̇hat Şafak Jan 2015

Microwave-Assisted Synthesis Of Condensed 1,4-Dihydropyridines As Potential Calcium Channel Modulators, Erdem Kami̇l Özer, Mi̇yase Gözde Gündüz, Ahmed El-Khouly, Mehmet Yildirim Sara, Rahi̇me Şi̇mşek, Alper Bektaş İski̇t, Osman Ci̇hat Şafak

Turkish Journal of Chemistry

This study reports the design, synthesis, and calcium channel modulatory activity evaluation of a series of 14 novel fused 1,4-dihydropyridine derivatives. The molecular design of the compounds was based on modifications of nifedipine, which is a calcium channel blocker. The compounds were achieved by one-pot microwave-assisted reaction of 4,4-dimethyl-1,3-cyclohexanedione, 5-chlorosalicylaldehyde/3,5-dichlorosalicylaldehyde, an appropriate alkyl acetoacetate, and ammonium acetate in ethanol according to a modified Hantzsch reaction. The structures of the compounds were confirmed by spectral methods and elemental analysis. To evaluate their relaxant activities, the maximum relaxant response (E$_{\max})$ and pD$_{2}$ values of the compounds and nifedipine were determined on isolated …

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A Comparative Study On Fabrication Of Cu$_{2}$Znsns$_{4}$ (Czts) Nanofibers Using Acetate And Chloride Metal Precursors, Burak Zafer Büyükbekar, Faruk Özel, Hüseyi̇n Şakalak, Hali̇t Çavuşoğlu, Mustafa Ersöz, Mahmut Kuş, Mustafa Selman Yavuz Jan 2015

A Comparative Study On Fabrication Of Cu$_{2}$Znsns$_{4}$ (Czts) Nanofibers Using Acetate And Chloride Metal Precursors, Burak Zafer Büyükbekar, Faruk Özel, Hüseyi̇n Şakalak, Hali̇t Çavuşoğlu, Mustafa Ersöz, Mahmut Kuş, Mustafa Selman Yavuz

Turkish Journal of Chemistry

This study reports, for the first time, the fabrication of electrospun Cu$_{2}$ZnSnS$_{4}$ (CZTS) nanofibers using metal acetate precursors. Viscous poly(vinyl pyrrolidone) (PVP) solution containing acetate or chloride salts of copper, zinc, and tin was electrospun onto a conductive substrate. The PVP nanofibers that have a mixture of metal salts were annealed at elevated temperatures. After calcination, these nanofibers were treated with the sulfur source and then annealed again in order to generate CZTS nanofibers. The CZTS nanofibers generated from acetate and chloride salts were characterized and compared. Belt-like and wire-like nanofibers were obtained when using metal acetate and chloride precursors, …

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Tetraphenylsilane Group Containing Carbazoles As High Triplet Energy Host Materials For Solution-Processable Pholeds, Sali̇ha Öner, İlker Öner, Haydar Akdağ, Canan Varlikli Jan 2015

Tetraphenylsilane Group Containing Carbazoles As High Triplet Energy Host Materials For Solution-Processable Pholeds, Sali̇ha Öner, İlker Öner, Haydar Akdağ, Canan Varlikli

Turkish Journal of Chemistry

A series of solution processable, wide band-gap host materials composed of carbazole and tetraphenylsilane groups were designed and synthesized. Their thermal, electrochemical, and photophysical properties were fully investigated. The introduction of bulky tetraphenylsilane and \textit{tert}-butyl groups around the carbazole led to high glass transition temperatures (T$_{g})$ between 120 and 204 $^{\circ}$C. The triplet energies (E$_{T})$ of the synthesized materials were examined by low temperature (77 K) photoluminescence studies and determined as E$_{T}>$ 2.6 for all compounds. Phosphorescent organic light-emitting devices with the ITO/PEDOT:PSS/EML/TPBi/Cs$_{2}$CO$_{3}$/Al device structure were fabricated by using synthesized materials as the host and two kinds of phosphorescent …

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Solid-Phase Total Synthesis Of Cyclic Peptide Brachystemin A And Its Immunomodulating Activity, Zafar Ali Shah, Almas Jabeen, Samreen Soomro, M.Ahmed Mesaik, M.Iqbal Choudhary, Farzana Shaheen Jan 2015

Solid-Phase Total Synthesis Of Cyclic Peptide Brachystemin A And Its Immunomodulating Activity, Zafar Ali Shah, Almas Jabeen, Samreen Soomro, M.Ahmed Mesaik, M.Iqbal Choudhary, Farzana Shaheen

Turkish Journal of Chemistry

Brachystemin A (\textbf{1}) is a biologically active peptide from a Chinese traditional plant \textit{Brachystemma calycinum} D. Don. (Caryophyllaceae). The current study describes the complete solid-phase total synthesis of peptide \textbf{1} by using Kenner's sulfonamide safety-catch linker strategy. It was identified by QTOF/MS data and NMR studies. Synthetic peptide \textbf{1} was tested for its immunomodulatory effect on different inflammatory parameters, including production of inflammatory cytokines, interleukin 2 (IL-2), tumor necrosis factor-$\alpha $ (TNF-$\alpha )$, and interleukin-1$\beta $ (IL-1$\beta )$, and generation of nitric oxide (NO$^{.})$. The synthetic peptide \textbf{1} showed a moderate to low level of inhibition on the production of …

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Influence Of Acid And Heavy Metal Cation Exchange Treatments On Methane Adsorption Properties Of Mordenite, Meryem Sakizci, Leyla Özgül Kilinç Jan 2015

Influence Of Acid And Heavy Metal Cation Exchange Treatments On Methane Adsorption Properties Of Mordenite, Meryem Sakizci, Leyla Özgül Kilinç

Turkish Journal of Chemistry

In this study, the adsorption of methane (CH$_{4})$ capacities onto natural mordenite obtained from \.{I}zmir, Turkey, and its cationic forms (CuM, AgM, FeM, and HM samples) were investigated at the temperatures of 0 and 25 $^{\circ}$C up to 100 kPa. Natural and modified samples were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier transform infrared (FT-IR), thermogravimetry (TG-DTG), differential thermal analysis (DTA), scanning electron microscopy (SEM) coupled with energy dispersion spectroscopy (EDS), and N$_{2}$ adsorption methods. Quantitative XRD analysis showed that the major component of the natural zeolite was mordenite, together with minor amounts of quartz, feldspar, and clay …

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Effective Recognition Of Multiple Anions By An Azobenzene--Al$^{\Mathbf{3+}}$ System, Ye Zhang, Ping Jia, Zhangfa Tong, Hai-Bo Liu, Jing Wang Jan 2015

Effective Recognition Of Multiple Anions By An Azobenzene--Al$^{\Mathbf{3+}}$ System, Ye Zhang, Ping Jia, Zhangfa Tong, Hai-Bo Liu, Jing Wang

Turkish Journal of Chemistry

A ready-to-use multifunctional coordinative system, 2,2'-dihydroxyazobenzene --aluminum (III) (DHAB--Al$^{3+})$, was created to recognize several anions effectively through three channels, namely colorimetric detection, UV-Vis spectroscopy, and fluorescence spectroscopy. Under naked eye visualization, the H$_{2}$PO$_{4}^{-}$ can be readily distinguished from the other anions by the DHAB--Al$^{3+}$ system through a change in color from reddish-orange to light yellow. H$_{2}$PO$_{4}^{-}$ was qualitatively detected by using UV-Vis and fluorescence spectra. Differentiating SO$_{3}^{2-}$, HPO$_{4}^{2-}$, and HCO$_{3}^{-}$ anions colorimetrically is difficult; thus, CO$_{3}^{2-}$, SO$_{3}^{2-}$, HPO$_{4}^{2-}$, and HCO$_{3}^{-}$ were discriminated by adopting distinct changes in the UV-Vis spectra. CO$_{3}^{2-}$, HPO$_{4}^{2-}$, and HCO$_{3}^{-}$ were accurately quantified using fluorescence spectra. …

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New Tetrazolic Azo Dyes Linked To (Thio)Barbiturate And Electron-Rich Aromatics As Potential Antimicrobial Agents, Nader Noroozi Pesyan, Davoud Soleimani, Nima Hosseini Jazani Jan 2015

New Tetrazolic Azo Dyes Linked To (Thio)Barbiturate And Electron-Rich Aromatics As Potential Antimicrobial Agents, Nader Noroozi Pesyan, Davoud Soleimani, Nima Hosseini Jazani

Turkish Journal of Chemistry

A series of new tetrazolic azo dyes based on (thio)barbiturate and electron-rich aromatics were synthesized in excellent yield. The electron-donor and tetrazole ring moieties were linked by a $p$-phenylazo bridge and the structural characterizations were achieved by FT IR, $^{1}$H and $^{13}$C NMR, and UV-visible spectrometry. The antibacterial activity of the synthesized compounds was tested against gram-positive and gram-negative bacterial strains, namely \textit{Acinetobacter calcoaceticus} (ATCC23055), \textit{Escherichia coli} (ATCC2592), \textit{Pseudomonas aeruginosa} (ATCC27853), and \textit{Staphylococcus aureus} (ATCC25923). As a result, potential antimicrobial effects were seen for some of the synthesized compounds.

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Preparation And Physicochemical Characterizations Of Solid Lipid Nanoparticles Containing Dotap$^®$ For Dna Delivery, Gülay Büyükköroğlu, Emi̇ne Yasemi̇n Yazan, Ayşe Fi̇li̇z Öner Jan 2015

Preparation And Physicochemical Characterizations Of Solid Lipid Nanoparticles Containing Dotap$^®$ For Dna Delivery, Gülay Büyükköroğlu, Emi̇ne Yasemi̇n Yazan, Ayşe Fi̇li̇z Öner

Turkish Journal of Chemistry

The aim of this study was to prepare and evaluate stable cationic solid lipid nanoparticles (SLNs) as colloidal carriers for gene therapy. SLNs were mainly composed of three different biocompatible and biodegradable matrix lipids called tripalmitin, glyceryl dibehenate, and triglyceride, all containing the cationic lipid $N$-(1-(2,3-dioleoyloxy)propyl)-$N,N,N$-trimethylammonium (DOTAP$^®$). Each of these SLNs were divided into three parts and characterized by applying different processes: Part I was autoclaved (121 $^{\circ}$C, 15 min), Part II was lyophilized (5 mbar, --50 $^{\circ}$C), and Part III was kept in its intact form. These parts were stored at 4 $^{\circ}$C, 25 $^{\circ}$C (room temp.), and 40 …

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Synthesis, Characterization, And Electrical And Optical Properties Of Magnesium-Type Boracite, Tuğba İbroşka, Azmi̇ Seyhun Kipçak, Süreyya Aydin Yüksel, Emek Derun, Sabri̇ye Pi̇şki̇n Jan 2015

Synthesis, Characterization, And Electrical And Optical Properties Of Magnesium-Type Boracite, Tuğba İbroşka, Azmi̇ Seyhun Kipçak, Süreyya Aydin Yüksel, Emek Derun, Sabri̇ye Pi̇şki̇n

Turkish Journal of Chemistry

Synthesis of the magnesium type of the mineral boracite (Mg$_{3}$B$_{7}$O$_{13}$Cl) was studied. Several parameters affecting boracite synthesis were investigated. The raw materials selected were magnesium chloride hexahydrate (MgCl$_{2}$.6H$_{2}$O), magnesium oxide (MgO), and boron oxide (B$_{2}$O$_{3})$. Reaction temperatures were selected between 600~$^{\circ}$C and 900 $^{\circ}$C. Moreover, three different reaction times of 4, 1, and 0.5 h were studied with the determined optimum molar ratio, reaction temperature, and reaction medium. Synthesized boracite characterization analyses were done by the techniques of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscope (SEM). Reaction yields were also calculated. From the results of …

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Separation And Preconcentration Of Lead(Ii), Cobalt(Ii), And Nickel(Ii) On Edta Immobilized Activated Carbon Cloth Prior To Flame Atomic Absorption Spectrometric Determination In Environmental Samples, Zeid Abdullah Alothman, Erkan Yilmaz, Mohamed Habi̇la, Mustafa Soylak Jan 2015

Separation And Preconcentration Of Lead(Ii), Cobalt(Ii), And Nickel(Ii) On Edta Immobilized Activated Carbon Cloth Prior To Flame Atomic Absorption Spectrometric Determination In Environmental Samples, Zeid Abdullah Alothman, Erkan Yilmaz, Mohamed Habi̇la, Mustafa Soylak

Turkish Journal of Chemistry

The synthesis and characterization of ethylenediaminetetraacetic acid immobilized activated carbon cloth was performed in the present work. It was used for preconcentration-separation of lead(II), cobalt(II), and nickel(II) at trace levels as an adsorbent. Factors including pH, concentration and volume of eluent, sample and eluent flow rates, sample volume, and effect of coexisting ions on the solid phase extraction of analytes were examined. The preconcentration factor was 50. The detection limits for Pb(II), Co(II), and Ni(II) were 4.39, 0.99 and 0.91 $\mu $g L$^{-1}$, respectively. The adsorption capacity for Pb(II), Co(II), and Ni(II) ions was found as 11.0, 11.2, and 10.2 …

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Properties And Some In Vitro Studies Of 6-Phosphogluconate Dehydrogenase Purified From The Liver Of Chalcalburnus Tarichi, The Only Fish Living In Lake Van's Highly Alkaline Water (Ph 9.8), Muhammet Güler, Vedat Türkoğlu, Mehmet Riza Kivanç Jan 2015

Properties And Some In Vitro Studies Of 6-Phosphogluconate Dehydrogenase Purified From The Liver Of Chalcalburnus Tarichi, The Only Fish Living In Lake Van's Highly Alkaline Water (Ph 9.8), Muhammet Güler, Vedat Türkoğlu, Mehmet Riza Kivanç

Turkish Journal of Chemistry

In this study, some enzymology parameters and some antibiotics affecting the enzyme activity of 6-phosphogluconate dehydrogenase (6PGD) extracted from t the livers of fish from Lake Van (\textit{Chalcalburnus tarichi}) were investigated because it is an important enzyme-producing NADPH, a reductive power, protecting the cell against the oxidative agents by producing reduced glutathione. The crude enzyme solution was obtained by using the affinity chromatography method. The native molecular weight of the enzyme is $\sim $90,000 $\pm $ 3000 Da and it is composed of two subunits with identical molecular weights of $\sim $46,000 Da as exhibited on sodium dodecyl sulfate-polyacrylamide gel …

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Spectrophotometric Determination Of Iron Species Using Ionic Liquid Ultrasound Assisted Dispersive Liquid--Liquid Microextraction, Alireza Bazmandegan, Ali Mohammad Haji Shabani, Sayessteh Dadfarnia, Mahboubeh Saeidi, Masoud Rohani Moghadam Jan 2015

Spectrophotometric Determination Of Iron Species Using Ionic Liquid Ultrasound Assisted Dispersive Liquid--Liquid Microextraction, Alireza Bazmandegan, Ali Mohammad Haji Shabani, Sayessteh Dadfarnia, Mahboubeh Saeidi, Masoud Rohani Moghadam

Turkish Journal of Chemistry

A simple and efficient method for speciation and determination of iron in different water samples was developed. The method is based on ionic liquid ultrasound assisted dispersive liquid--liquid microextraction (IL-USA-DLLME) followed by spectrophotometric determination. Fe(II) is complexed with 2,4,6-tri(2'-pyridyl)-l,3,5-triazine (TPTZ{)}, neutralized through ion pair formation with sodium dodecyl sulfate (SDS) and extracted into 1-hexyl-3-methylimidazolium hexafluorophosphate [C$_{6}$MIM][PF$_{6}$]. Total iron amount was determined after reduction of Fe(III) to Fe(II) with hydroxylamine hydrochloride. The concentration of Fe(III) was determined from the difference of concentration of total iron and Fe(II). The important parameters such as the type and volume of the extraction solvent, pH, …

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Green And Efficient Synthesis Of Novel Bispyrazoles Through A Tandem Knoevenagel And Michael Type Reaction Using Nanowire Zinc Oxide As A Powerful And Recyclable Catalyst, Khalil Eskandari, Bahador Karami, Saeed Khodabakhshi, Seyyed Jafar Hoseini Jan 2015

Green And Efficient Synthesis Of Novel Bispyrazoles Through A Tandem Knoevenagel And Michael Type Reaction Using Nanowire Zinc Oxide As A Powerful And Recyclable Catalyst, Khalil Eskandari, Bahador Karami, Saeed Khodabakhshi, Seyyed Jafar Hoseini

Turkish Journal of Chemistry

Zinc oxide nanowires (ZnO NWs) were prepared and characterized by scanning electron microscopy, powder X-ray diffraction, and transmission electron microscopy analyses. ZnO NWs were then employed as heterogeneous and recyclable catalyst for green synthesis of some new and known bispyrazole derivatives through a tandem Knoevenagel and Michael type addition reaction of aromatic aldehyde and pyrazolone. The synthetic method is operationally simple and affords product with high yields in short reaction times.

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Corrosion Inhibition By Naturally Occurring Hibiscus Sabdariffa Plant Extract On A Mild Steel Alloy In Hcl Solution, Magda Abdo Mahmoud Ameer, Amany Mohamed Fekry Jan 2015

Corrosion Inhibition By Naturally Occurring Hibiscus Sabdariffa Plant Extract On A Mild Steel Alloy In Hcl Solution, Magda Abdo Mahmoud Ameer, Amany Mohamed Fekry

Turkish Journal of Chemistry

The corrosion inhibition of mild steel alloys is of tremendous technological importance due to their increased industrial applications. Potentiodynamic polarization and electrochemical impedance spectroscopy techniques were used to establish the effect of different concentrations of HCl on the corrosion behavior of mild steel. A study was conducted on the inhibition of dissolution for a mild steel alloy in the most corrosive concentration of HCl (5 M) by adding different concentrations of aqueous extract of \textit{Hibiscus sabdariffa} plant (named karkade or rosselle) as an ecofriendly inhibitor. The extent of corrosion inhibition as measured by the two techniques was comparable. The results …

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Contribution Of Heterobifunctional Ligands To Transition Metal-Catalysed C--C Coupling Reactions, Agnes Labande, Eric Deydier, Eric Manoury, Jean-Claude Daran, Catherine Audin, Rinaldo Poli Jan 2015

Contribution Of Heterobifunctional Ligands To Transition Metal-Catalysed C--C Coupling Reactions, Agnes Labande, Eric Deydier, Eric Manoury, Jean-Claude Daran, Catherine Audin, Rinaldo Poli

Turkish Journal of Chemistry

In this account the authors' latest results in C-C coupling catalysis are reviewed. First, an efficient catalytic system for the Kumada-Tamao-Corriu coupling reaction based on NHC-phosphine (NHC = N-heterocyclic carbene) nickel complexes is presented. Then the use of palladium complexes of chiral ferrocenyl NHC-phosphines in the asymmetric Suzuki-Miyaura coupling reaction is reported. High catalytic activities and moderate enantioselectivities (ee up to 46%) were obtained. Chiral ferrocenyl phosphine-ethers were also tested in the asymmetric Suzuki-Miyaura reaction yielding good activities and moderate enantioselectivities (ee up to 37%). Finally, the original synthesis of a ferrocenyl rhodium(III) complex and its successful use as catalyst …

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