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2016

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Articles 11521 - 11550 of 12690

Full-Text Articles in Physical Sciences and Mathematics

Synthesis And Photochromism Of New Asymmetrical Diarylethenes With A Variable Heteroaryl Ring And A Quinoline Unit, Hongyan Xu, Renjie Wang, Congbin Fan, Gang Liu, Shouzhi Pu Jan 2016

Synthesis And Photochromism Of New Asymmetrical Diarylethenes With A Variable Heteroaryl Ring And A Quinoline Unit, Hongyan Xu, Renjie Wang, Congbin Fan, Gang Liu, Shouzhi Pu

Turkish Journal of Chemistry

Three new asymmetrical photochromic diarylethenes containing a variable heteroaryl ring and a quinoline unit were synthesized and their structures were determined by single-crystal X-ray diffraction analysis. Their properties, including photochromism, acidichromism, and fluorescence, were investigated systematically. For these diarylethenes, the one with an indole moiety had the largest absorption maximum, cyclization quantum yield, photoconversion ratio, emission peak, and fluorescent modulation efficiency. In addition, these diarylethenes exhibited an evident dual switching behavior induced by the stimulation of acid/base and UV/Vis. Addition of trifluoroacetic acid to solution of the diarylethenes produced protonated derivatives with notable changes in their absorption spectra. These results …

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Density Functional Study Of The Structure And Water Adsorption Activity Of An Al$_{30}$O$_{30}$ Star-Shaped Alumina Nanocage, Mehdi Zamani Jan 2016

Density Functional Study Of The Structure And Water Adsorption Activity Of An Al$_{30}$O$_{30}$ Star-Shaped Alumina Nanocage, Mehdi Zamani

Turkish Journal of Chemistry

Molecular and electronic structures of a novel Al$_{30}$O$_{30}$ star-shaped alumina nanocage (SANC) were studied using the recently developed CAM-B3LYP density functional method. Comparison of the stretching vibrational modes of this compound with the corresponding modes related to an Al$_{20}$O$_{30}$ perfect cage and Al$_{50}$O$_{75}$ tubular alumina nanomaterials showed a shift to lower frequencies, while the bending modes moved to higher frequencies. The highest occupied molecular orbital (HOMO) of the SANC had 65% nonbonding character, whereas the lowest unoccupied molecular orbital (LUMO) was 72% antibonding. The HOMO and LUMO of the SANC arose mostly from Al 3s and 2p atomic orbitals. The …

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Synthesis And Evaluation Of A Novel N--P-Containing Oil-Based Fire-Retardant Plasticizer For Poly(Vinyl Chloride), Pu-You Jia, Guo-Dong Feng, Yun Hu, Yong-Hong Zhou Jan 2016

Synthesis And Evaluation Of A Novel N--P-Containing Oil-Based Fire-Retardant Plasticizer For Poly(Vinyl Chloride), Pu-You Jia, Guo-Dong Feng, Yun Hu, Yong-Hong Zhou

Turkish Journal of Chemistry

A novel N--P-containing soybean-oil-based fire-retardant plasticizer was synthesized using soybean oil methyl ester, 9,10-dihydro-9-oxa-phosphaphenanthrene-10-oxide (DOPO), and tris(2-hydroxyethyl) isocyanurate (THEIC). The structure was verified by Fourier transform infrared (FTIR) spectrometry and nuclear magnetic resonance (NMR) spectroscopy. The blends were characterized by thermogravimetric analysis (TGA), FTIR spectrometry, scanning electron microscopy (SEM), and dynamic mechanical analysis (DMA). TGA showed that the thermal stability of the blends were acceptable. DMA indicated that the plasticizer had good plasticity for PVC. The limiting oxygen index (LOI) of the blends ranged from 21.3 to 29.6. The flammability and thermal stability of PVC/THEIC-DOPO-ESOME was better than that of …

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Comparative Study For The Separation, Preconcentration, And Determination Of Copper And Cadmium In Real Samples By Using Two Different Ligands, Hami̇de Elvan Bayrak, Volkan Numan Bulut, Mehmet Tüfekçi̇, Hacer Bayrak, Celal Duran, Mustafa Soylak Jan 2016

Comparative Study For The Separation, Preconcentration, And Determination Of Copper And Cadmium In Real Samples By Using Two Different Ligands, Hami̇de Elvan Bayrak, Volkan Numan Bulut, Mehmet Tüfekçi̇, Hacer Bayrak, Celal Duran, Mustafa Soylak

Turkish Journal of Chemistry

Two new solid phase extraction methods have been developed for simultaneous separation and preconcentration of Cu(II) and Cd(II) in some food and environmental samples before their determination by flame atomic absorption spectrometry (FAAS). One of these methods is based on the absorption of the Cu(II) and Cd(II) complexes with [3-(cyanomethyl)-5-(4-methylphenyl)-4$H$-1,2,4-triazol-4-yl]carbamate (L1) and the other is based on the absorption of the Cu(II) and Cd(II) complexes with 4-(4-methylphenyl)-5-{[pyridine-4-yl-4$H$-1,2,4-triazole-3-yl)thio]methyl}-4$H$-1,2,4-triazole-3-thiol (L2) on Amberlite XAD-1180 resin. The metal complexes are retained on resin at pH 6.0 and eluted with 1.0 mol L$^{-1}$ HCl in acetone in both methods. After the optimum conditions were determined, …

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Square Wave Voltammetric Determination Of Valproic Acid In Pharmaceutical Preparations, Ebru Türköz Acar, Ati̇ye Nur Onar Jan 2016

Square Wave Voltammetric Determination Of Valproic Acid In Pharmaceutical Preparations, Ebru Türköz Acar, Ati̇ye Nur Onar

Turkish Journal of Chemistry

The electrochemical behavior of valproic acid (VAL) was investigated using square wave voltammetry, cyclic voltammetry, and sampled direct current polarography and a new square wave voltammetric method was developed for determination of VAL in pharmaceutical preparations. VAL showed two reduction peaks at about --0.2 V and --0.8 V vs. Ag/AgCl 3 M KCl with a hanging mercury drop electrode in 0.05 M pH 3.3 Britton--Robinson (BR) buffer. These peaks were named peak I and peak II, respectively. The types of limiting current of both peaks were determined as diffusion controlled based on cyclic voltammetry studies. A linear calibration graph was …

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Durability Of Carbon/Conducting Polymer Composite Supported Pt Catalysts Prepared By Supercritical Carbon Dioxide Deposition, Gamze Bozkurt, Fulya Memi̇oğlu, Ayşe Bayrakçeken Yurtcan Jan 2016

Durability Of Carbon/Conducting Polymer Composite Supported Pt Catalysts Prepared By Supercritical Carbon Dioxide Deposition, Gamze Bozkurt, Fulya Memi̇oğlu, Ayşe Bayrakçeken Yurtcan

Turkish Journal of Chemistry

Polypyrrole (PPy)/carbon (C) composites were synthesized by oxidative chemical polymerization and used as support material for Pt nanoparticles. PPy/C supported Pt nanoparticles were prepared by using a promising catalyst preparation method, supercritical carbon dioxide (scCO$_{2})$ deposition. The prepared materials were characterized by using BET, TGA, XRD, and TEM techniques. Cyclic voltammetry was used in order to determine the electrocatalytic activity of the prepared catalyst for hydrogen oxidation and oxygen reduction reactions that occur in proton exchange membrane fuel cells (PEMFCs). The Pt loading obtained over the composite material was around 10{\%}. TEM results showed highly dispersed and small nanoparticles over …

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Voltammetric Determination Of Famotidine On A Disposable Pencil Graphite Electrode, Iulia Gabriela David, Dana Elena Popa, Andreea-Alexandra Calin, Mihaela Buleandra, Emilia-Elena Iorgulescu Jan 2016

Voltammetric Determination Of Famotidine On A Disposable Pencil Graphite Electrode, Iulia Gabriela David, Dana Elena Popa, Andreea-Alexandra Calin, Mihaela Buleandra, Emilia-Elena Iorgulescu

Turkish Journal of Chemistry

The present paper describes the use of a disposable pencil graphite electrode (PGE) for the voltammetric determination of famotidine. Cyclic voltammetric studies using different supporting electrolytes emphasized an irreversible oxidation of famotidine on the PGE. The electrode process is diffusion-controlled and pH-dependent. Differential pulse voltammetry (DPV) in phosphate buffer solution of pH 6.81 was employed for famotidine's quantitative determination. The anodic peak current of famotidine varies linearly with the analyte concentration in the range 4.72 $\times $ 10$^{-7}$--4.95 $\times $ 10$^{-4}$ M. Detection and quantification limits were 1.51 $\times $ 10$^{-7}$ M and 5.04 $\times $ 10$^{-7}$ M famotidine, respectively. …

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Systematic Optimization Of Chemical Deposition Conditions For Synthesis Of Vanadium(V) Oxide Xerogels, Aksu Samet, Metodija Najdoski, Igor Kuzmanovski Jan 2016

Systematic Optimization Of Chemical Deposition Conditions For Synthesis Of Vanadium(V) Oxide Xerogels, Aksu Samet, Metodija Najdoski, Igor Kuzmanovski

Turkish Journal of Chemistry

We performed the optimization of conditions in chemical bath deposition using the design of experimental methodology. Factorial design (2$^{3})$ was used for finding the optimal conditions of preparing vanadium(V) oxide xerogel thin films with better electrochromic properties suitable for electrochemical applications. The thin films were prepared by acidification of NH$_{4}$VO$_{3}$ aqueous solution with chemical bath deposition. The factors and selected values we considered were as follows: the deposition time (10 and 20 min), the deposition temperature (70 and 80 $^{\circ}$C), and the mass of ammonium metavanadate (0.3 and 0.5 g). UV-vis spectrometry was used for recording the transmittance variance, $\Delta …

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Adsorptive Features Of Polyacrylamide--Aluminosilicate Composites For Methylene Blue, Demet Baybaş, Ulvi̇ Ulusoy Jan 2016

Adsorptive Features Of Polyacrylamide--Aluminosilicate Composites For Methylene Blue, Demet Baybaş, Ulvi̇ Ulusoy

Turkish Journal of Chemistry

Polyacrylamide--montmorillonite (PAAm-Mt) and polyacrylamide--clinoptilolite (PAAm-Z) composites were prepared by cross-linked polymerization of acrylamide in dispersions of Mt and Z. The composites were characterized by FT-IR, SEM, XRD, CEC, and PZC analysis. The adsorptive features of PAAm-Mt and PAAm-Z for methylene blue (MB) were investigated by their relevance to initial dye concentration, temperature, contact time, PZC, and pH. The monolayer adsorption capacities were 0.14 and 0.08 mol kg$^{-1}$ for PAAm-Z and PAAm-Mt, respectively. The changes in pH of MB solution had an insignificant influence on their adsorption capacities. The values of enthalpy and entropy changes were positive ($\Delta $H$_{PAAm-Mt}$ = 7.6 …

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Liquid State $^{15}$N Nmr Studies Of $^{15}$N Isotope Labeled Phthalocyanines, Armağan Atsay, Ahmet Gül, Makbule Koçak Jan 2016

Liquid State $^{15}$N Nmr Studies Of $^{15}$N Isotope Labeled Phthalocyanines, Armağan Atsay, Ahmet Gül, Makbule Koçak

Turkish Journal of Chemistry

$^{15}$N labeled soluble metallo- and metal-free phthalocyanines are described for the first time. The complexes were synthesized starting from phthalic anhydride derivatives using 98{\%} $^{15}$N enriched urea. The effects of the substitution pattern, aggregation, and coordinated metal on $^{15}$N chemical shifts in liquid state NMR were studied.

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Purification And Characterization Of Mitochondrial Thioredoxin Reductase Enzyme From Rainbow Trout (Oncorhynchus Mykiss) Liver And Investigation Of The In Vitro Effects Of Some Metal Ions On The Enzyme, İlknur Özgençli̇, Mehmet Çi̇ftci̇ Jan 2016

Purification And Characterization Of Mitochondrial Thioredoxin Reductase Enzyme From Rainbow Trout (Oncorhynchus Mykiss) Liver And Investigation Of The In Vitro Effects Of Some Metal Ions On The Enzyme, İlknur Özgençli̇, Mehmet Çi̇ftci̇

Turkish Journal of Chemistry

Thioredoxin reductase (E.C 1.6.4.5.; TrxR) is an enzyme belonging to the flavoprotein family of pyridine nucleotide-disulfide oxidoreductases. In this study, mitochondrial TrxR enzyme was purified from rainbow trout mitochondria. Thanks to the 2 consecutive procedures (preparation of homogenate and 2',5'-ADP Sepharose 4B affinity chromatography), the enzyme, having the specific activity of 11.9 EU mg protein-1, was purified with a yield of 2.38{\%} and 672-fold. The purity of the enzyme was monitored and the molecular weight of its subunits was calculated as 70 kDa by SDS-PAGE. The native molecular mass of the enzyme was found to be approximately 151 kDa by …

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A Convenient Route For The Synthesis Of New Thiadiazoles, Abdelwahed Sayed, Yasser Zaki, Emad Aish Jan 2016

A Convenient Route For The Synthesis Of New Thiadiazoles, Abdelwahed Sayed, Yasser Zaki, Emad Aish

Turkish Journal of Chemistry

The present work describes the preparation of new thiadiazoles through a simple intramolecular reaction of mono- and bis-hydrazonoyl halides with methyl hydrogen phenyl carbonimidodithioate or methyl-2-arylidene hydrazinecarbodithioate. The synthetic method involves nucleophilic substitution followed by intramolecular cyclization reactions mediated by evolution of methanethiol. The structures of the title compounds were elucidated by elemental analyses, and FTIR, MS and NMR spectra.

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Synthetic Approaches Towards The Synthesis Of Beta-Blockers (Betaxolol, Metoprolol, Sotalol, And Timolol), Furqan Ahmad Saddique, Ameer Fawad Zahoor, Muhammmad Yousaf, Muhammmad Irfan, Matloob Ahmad, Asim Mansha, Zulfiqar Ali Khan, Syed Ali Raza Naqvi Jan 2016

Synthetic Approaches Towards The Synthesis Of Beta-Blockers (Betaxolol, Metoprolol, Sotalol, And Timolol), Furqan Ahmad Saddique, Ameer Fawad Zahoor, Muhammmad Yousaf, Muhammmad Irfan, Matloob Ahmad, Asim Mansha, Zulfiqar Ali Khan, Syed Ali Raza Naqvi

Turkish Journal of Chemistry

Numerous efficient synthetic methodologies have been elaborated for the synthesis of $\beta $-blockers since the introduction of propranolol (a beta-blocker) in 1968. In this review, focus is placed on the more concise asymmetric and bioenzymatic synthetic approaches attempted towards the synthesis of beta-blockers (betaxolol, metoprolol, sotalol, and timolol).

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Immobilization Of Laccase Onto A Porous Nanocomposite: Application For Textile Dye Degradation, Sedef İlk, Deni̇z Demi̇rcan, Semran Sağlam, Necdet Sağlam, Zakir M. O. Rzayev Jan 2016

Immobilization Of Laccase Onto A Porous Nanocomposite: Application For Textile Dye Degradation, Sedef İlk, Deni̇z Demi̇rcan, Semran Sağlam, Necdet Sağlam, Zakir M. O. Rzayev

Turkish Journal of Chemistry

Poly(MA-\textit{alt}-MVE)-$g$-PLA/ODA-MMT nanocomposite was prepared by self-catalytic interlamellar graft copolymerization of L-lactic acid (LA) onto poly(maleic anhydride-\textit{alt}-methyl vinyl ether) copolymer in the presence of octadecyl amine-montmorillonite (ODA-MMT) organoclay. FTIR, $^{1}$H ($^{13}$C) NMR, XRD, and SEM-TEM were utilized for characterizing the resultant nanocomposite. Laccase from \textit{Trametes versicolor} was immobilized onto the prepared nanocomposite by adsorption or covalent coupling. Decolorization of Reactive Red 3 from aqueous solution by laccase immobilized on the nanocomposite was studied in different conditions (pH, temperature, dye concentration, and reaction time) to investigate the decolorization activity with repeated use and storage. The results indicated that more than 77{\%} of …

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Synthesis Of Graft Copolymer Of Kappa-Carrageenan Using Microwave Energy And Studies Of Swelling Capacity, Flocculation Properties, And Preliminary Acute Toxicity, Tapan Kumar Giri, Minakshi Pradhan, Dulal Krishna Tripathi Jan 2016

Synthesis Of Graft Copolymer Of Kappa-Carrageenan Using Microwave Energy And Studies Of Swelling Capacity, Flocculation Properties, And Preliminary Acute Toxicity, Tapan Kumar Giri, Minakshi Pradhan, Dulal Krishna Tripathi

Turkish Journal of Chemistry

Grafting of acrylamide (AAm) onto kappa-carrageenan (KC) was carried out using microwave irradiation in the presence of ammonium persulfate (APS) as initiator. The effect of reaction variables including the concentration of APS, AAm, and KC; time duration; and microwave power was studied. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) were carried out to characterize the graft copolymer. The graft copolymer possesses slightly sensitive activities to external pH and shows reversible on--off switching swelling characteristics. Flocculation efficacy of the graft copolymer was studied in coal fine suspension toward potential application as …

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The Role Of N-Heterocyclic Carbene Substituents On Ruthenium(Ii) Complexes In The Catalytic Transfer Hydrogenation Of Acetophenone, Muhammet Emi̇n Günay, Gülcan Gençay Çoğaşlioğlu Jan 2016

The Role Of N-Heterocyclic Carbene Substituents On Ruthenium(Ii) Complexes In The Catalytic Transfer Hydrogenation Of Acetophenone, Muhammet Emi̇n Günay, Gülcan Gençay Çoğaşlioğlu

Turkish Journal of Chemistry

The novel ruthenium(II) complexes [RuCl$_{2}$(NHC)($p$-cymene)], \textbf{3a}--\textbf{e}, containing 1-alkyl-3-benzylimidazol-2-ylidene ligands were prepared. All synthesized compounds were characterized by NMR spectroscopy and elemental analyses. Ru(II)-NHC complexes were tested as catalysts for the transfer hydrogenation of acetophenone, showing modest to high activity in this reaction. The results revealed that efficiencies depend on the substituents of the benzene ring of the benzyl on the N atom of the NHC ring.

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Investigation Of Long-Term Water Absorption Behavior Of Carbon Fabric Reinforced Epoxy Composites Containing Hydrophobic Nanosilica, Nurten Eki̇n, Mehmet Gali̇p İçduygu, Ahmet Gültek Jan 2016

Investigation Of Long-Term Water Absorption Behavior Of Carbon Fabric Reinforced Epoxy Composites Containing Hydrophobic Nanosilica, Nurten Eki̇n, Mehmet Gali̇p İçduygu, Ahmet Gültek

Turkish Journal of Chemistry

hydrophobic filler containing epoxy matrix composites was investigated by keeping them in distilled water for 9 months. Aerosil R812 (8 nm) and Aerosil R972 (12 nm) were utilized at 3{\%} and 5{\%} w/w filler to resin ratio and the resin/filler mixture was combined with 12-ply carbon fabric to get 15 $\times $ 15 cm samples. Samples were molded under a hot press and for each sample 50 test samples obtained by cutting them with a water jet. The obtained samples were characterized by TG, FTIR, and SEM. The effect of water absorption was evaluated by measuring percentage water absorption and …

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Polybrominated Methoxy- And Hydroxynaphthalenes, Kiymet Berki̇l Akar, Osman Çakmak, Tuncay Tunç Jan 2016

Polybrominated Methoxy- And Hydroxynaphthalenes, Kiymet Berki̇l Akar, Osman Çakmak, Tuncay Tunç

Turkish Journal of Chemistry

Regio- and stereoselective synthesis are described for convenient preparation of hydroxy- and methoxynaphthalenes starting from naphthalene (\textbf{1}). \textit{cis,cis,trans}-2,3,5,8-Tetrabromo-4-methoxy-1,2,3,4-tetrahydronaphthalen-1-ol (\textbf{6}), \textit{cis,cis,trans}-2,3,5,8-tetrabromo-1,4-dimethoxy-1,2,3,4-tetrahydronaphthalene (\textbf{7}), and \textit{cis,cis,cis}-2,3,5,8-tetrabromo-1,4-dimethoxy-1,2,3,4-tetrahydronaphthalene (\textbf{8}) were obtained with silver-induced substitution of \textit{trans,cis,trans}-1,2,3,4, 5,8-hexabromo-1,2,3,4-tetrahydronaphthalene (\textbf{3}). Base-promoted aromatization of dimethoxides \textbf{7} and \textbf{8} afforded 3,5,8-tribromo-1-methoxynaphthalene (\textbf{9}) and 2,5,8-tribromo-1-methoxynaphthalene (\textbf{10}). The reaction of \textbf{6 }with sodium methoxide formed compounds \textbf{10 }and 3,5,8-tribromonaphthalen-1-ol (\textbf{16}). Bromination of \textbf{9} and\textbf{ 16} with Br$_{2}$ in dichloromethane at room temperature produced 2,3,5,8-tetrabromo-1-methoxynaphthalene (\textbf{14}) and 2,3,4,5,8-pentabromonaphthalen-1-ol (\textbf{18}), respectively, while compound \textbf{10} did not react in the same conditions. Pyridine-induced elimination of hexabromide \textbf{3} afforded 1,4,6\textbf{-}tribromnaphthalene (\textbf{21}) in 99{\%} yield and …

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Heterogeneous Fenton-Like Degradation Of Acid Red 17 Using Fe-Impregnated Nanoporous Clinoptilolite: Artificial Neural Network Modeling And Phytotoxicological Studies, Alireza Khataee, Mehrangiz Fathinia, Soghra Bozorg Jan 2016

Heterogeneous Fenton-Like Degradation Of Acid Red 17 Using Fe-Impregnated Nanoporous Clinoptilolite: Artificial Neural Network Modeling And Phytotoxicological Studies, Alireza Khataee, Mehrangiz Fathinia, Soghra Bozorg

Turkish Journal of Chemistry

Heterogeneous Fenton-like removal of Acid Red 17 (AR17) from aqueous solution was investigated. Fe-impregnated nanoporous clinoptilolite (Fe-NP-Clin) was prepared by an impregnation method and used as a catalyst. A complete characterization including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), inductively coupled plasma (ICP), and Brunauer--Emmett--Teller (BET) analyses was done to describe the physical and chemical properties of NP-Clin and Fe-NP-Clin samples. The effects of five operational parameters, i.e. solution pH, H$_{2}$O$_{2}$ dosage, catalyst loading, AR17 concentration, and reaction time, on the removal efficiency of AR17 were studied. For the first time, an artificial neural network …

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Impregnation Of Different Ionic Liquids Onto Cationic Starch And Their Comparison In The Extraction Of Th(Iv), Eli̇f Ant Bursali, Serap Seyhan Bozkurt, Mürüvvet Yurdakoç Jan 2016

Impregnation Of Different Ionic Liquids Onto Cationic Starch And Their Comparison In The Extraction Of Th(Iv), Eli̇f Ant Bursali, Serap Seyhan Bozkurt, Mürüvvet Yurdakoç

Turkish Journal of Chemistry

Cationic starch (CS) was prepared by using epichlorohydrin (EPI) and 3-chloro-2-hydroxypropyltrimethy- lammonium chloride (CHPTMA) and ionic liquids (ILs) having different anionic groups [1-butyl-3-methyl imidazolium tetrafluoroborate (BMI$^{+}$BF$_{4}^{-})$, 1-butyl-3-methyl imidazolium bromide (BMI$^{+}$Br$^{-})$, 1-butyl-3-methyl imidazolium hexafluorophosphate (BMI$^{+}$PF$_{6}^{-})$, and 1-butyl-3-methyl imidazolium bis-[(trifluoromethyl)sulfonyl]imide (BMI$^{+}$ [(TF)$_{2}$N]$^{-})$] were impregnated onto CS. Thorium(IV) ions were preconcentrated by using IL impregnated CS. The effects of ILs were investigated for extraction of Th(IV) by CS and the results were compared. Th(IV) was preconcentrated with approximately 73{\%} sorption capacity by CS and increased up to 98{\%}--100{\%} for IL impregnated sorbents at pH 7.0. The sorption capacities of Th(IV) were 0.453 mmol …

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New Antimicrobial Biscembrane Hydrocarbon And Cembranoid Diterpenes From The Soft Coral Sarcophyton Trocheliophorum, Muhammad Zubair, Walied Alarif, Khalid Al-Footy, Mohamed Ph, Magda Ali, Salim Basaif, Sultan Al-Lihaibi, Seif-Eldin Ayyad Jan 2016

New Antimicrobial Biscembrane Hydrocarbon And Cembranoid Diterpenes From The Soft Coral Sarcophyton Trocheliophorum, Muhammad Zubair, Walied Alarif, Khalid Al-Footy, Mohamed Ph, Magda Ali, Salim Basaif, Sultan Al-Lihaibi, Seif-Eldin Ayyad

Turkish Journal of Chemistry

A new tetracyclic biscembrane hydrocarbon, trocheliane (1), along with two new cembranoid diterpenes, sarcotrocheldiol A (2) and B (3), and the known diterpene cembrene-C (4), were isolated from the Red Sea soft coral Sarcophyton trocheliophorum. The structures and relative stereochemistry of the compounds were elucidated by interpretation of MS, 1 D NMR, and 2 D NMR experiments. The sensitivity of some pathogenic bacteria used as test organisms to the new compounds 1-3 was determined. 1 showed appreciable antimicrobial activity with the diameter of inhibition zones ranging from 11 to 18 mm. 1 was active against the two multidrug resistant bacteria …

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Synthesis And Evaluation Of Novel $N,N'$-Disubstituted Benzimidazolium Bromides Salts As Antitumor Agents, Hasan Küçükbay, Akin Mumcu, Suat Teki̇n, Süleyman Sandal Jan 2016

Synthesis And Evaluation Of Novel $N,N'$-Disubstituted Benzimidazolium Bromides Salts As Antitumor Agents, Hasan Küçükbay, Akin Mumcu, Suat Teki̇n, Süleyman Sandal

Turkish Journal of Chemistry

Novel benzimidazolium bromides salts having (4-methoxyphenyl)ethyl, (phthalimide-2-yl)methyl, 4-nitro- benzyl, 2-phenylethyl, penthyl, or allyl groups were synthesized and their characterizations were conducted by $^{1}$H and $^{13}$C NMR and IR spectroscopic methods, and microanalysis. In vitro antitumor activities of the novel benzimidazole compounds (1-7) were determined by using ovarian (A2780) and prostate (PC-3) cancer cell lines. Antitumor properties of all compounds were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. A time-dependent cell viability assay for the tested benzimidazole compounds was performed and the IC$_{50}$ values of the compounds were calculated after treatment for 24 and 48 h. Our results indicate that the tested …

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Simple And Rapid Voltammetric Determination Of Boron In Water And Steel Samples Using A Pencil Graphite Electrode, Lokman Li̇v, Nuri̇ Naki̇boğlu Jan 2016

Simple And Rapid Voltammetric Determination Of Boron In Water And Steel Samples Using A Pencil Graphite Electrode, Lokman Li̇v, Nuri̇ Naki̇boğlu

Turkish Journal of Chemistry

This paper presents a simple, rapid, and accurate voltammetric method for determination of boron in water and steel samples using a disposable pencil graphite electrode. The oxidation of Tiron in the boron-Tiron complex in phosphate buffer at pH 7.5 was measured as a response. Type and concentration of supporting electrolyte, pH, ionic strength, Tiron concentration, scan rate, step amplitude, pulse amplitude, and pencil grade were investigated as the parameters affecting the peak current. The limit of detection (3s) was estimated as 84 $\mu $g/L. The relative standard deviation of the method was 4.6 for 1 mg B/L (N = 7). …

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Synthesis And Application Of Polyvinylimidazole-Based Bronsted Acidic Ionic Liquid Grafted Silica As An Efficient Heterogeneous Catalyst In The Preparation Of Quinoxaline Derivatives, Bahman Tamami, Alireza Sardarian, Elaheh Ataollahi Jan 2016

Synthesis And Application Of Polyvinylimidazole-Based Bronsted Acidic Ionic Liquid Grafted Silica As An Efficient Heterogeneous Catalyst In The Preparation Of Quinoxaline Derivatives, Bahman Tamami, Alireza Sardarian, Elaheh Ataollahi

Turkish Journal of Chemistry

Two types of polymer-grafted silica based on polyvinylimidazole Bronsted acidic ionic liquids were prepared and used as new heterogeneous catalysts for the preparation of pharmaceutically important quinoxaline derivatives. These catalysts were characterized by thermogravimetric analysis, FT-IR spectroscopy, and titration. They could be recycled without considerable loss in their catalytic activity. High efficiency of the catalysts along with short reaction times, high yields, easy purification, recyclability, and simple procedure are among the advantages of these catalytic systems.

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An Efficient One-Pot, Three-Component Synthesis Of 6-Cyano-Hexahydro-4$H$-Thieno[3',2':5,6]Pyrimido[1,2-$A$]Quinoline-2-Carboxylates And Their Spiro Derivatives From $\Beta $-Enaminones, Said Ahmed Soliman Ghozlan, Doaa Mohmed Abdelmoniem, Amr Mohmed Abdelmoniem, Ismail Abdelshafy Abdelhamid Jan 2016

An Efficient One-Pot, Three-Component Synthesis Of 6-Cyano-Hexahydro-4$H$-Thieno[3',2':5,6]Pyrimido[1,2-$A$]Quinoline-2-Carboxylates And Their Spiro Derivatives From $\Beta $-Enaminones, Said Ahmed Soliman Ghozlan, Doaa Mohmed Abdelmoniem, Amr Mohmed Abdelmoniem, Ismail Abdelshafy Abdelhamid

Turkish Journal of Chemistry

A simple and efficient one-pot synthesis of novel thieno[3',2':5,6]pyrimido[1,2-a]quinoline-2-carboxylates (5a-d) and their spirooxindole derivatives (12a-d) was accomplished. Thus, the Michael addition reaction of the cyclic $\beta $-enaminone 3 with the corresponding $\alpha ,\beta $-unsaturated nitrile derivatives 4a-d in refluxing EtOH in the presence of piperidine afforded 5a-d in good yields. On the other hand, spirooxindole derivatives 12a-d were synthesized by the reaction of cyclic $\beta $-enaminone 3 with the corresponding 3-cyanomethylidene-2-oxoindoles 11a-d in refluxing EtOH.

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Synthesis And Evaluation Of Some Novel Thiazoles And 1,3-Thiazines As Potent Agents Against The Rabies Virus, Magda Abdalla, Sobhi Gomha, Mohamad Abd Elaziz, Nany Serag Jan 2016

Synthesis And Evaluation Of Some Novel Thiazoles And 1,3-Thiazines As Potent Agents Against The Rabies Virus, Magda Abdalla, Sobhi Gomha, Mohamad Abd Elaziz, Nany Serag

Turkish Journal of Chemistry

A series of novel thiazoles and 1,3-thiazine derivatives were synthesized in good yield via reaction of ethyl 3-(1-(2-thiocarbamoylhydrazono)ethyl)-1,5-diphenyl-1$H$-pyrazole-4-carboxylate with hydrazonoyl halides and arylidenemalononitriles, respectively. The structure of the newly synthesized products was elucidated via elemental analysis, spectral data, and alternative routes whenever possible. Moreover, the antiviral screening of the products was evaluated and the results revealed that some of them have strong to moderate potency against the rabies virus compared with the reference drug.

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Visible Light Photocatalysis Of A Textile Dye Over Zno Nanostructures Covered On Natural Diatomite, Reza Darvishi Cheshmeh Soltani, Zohreh Haghighat Jan 2016

Visible Light Photocatalysis Of A Textile Dye Over Zno Nanostructures Covered On Natural Diatomite, Reza Darvishi Cheshmeh Soltani, Zohreh Haghighat

Turkish Journal of Chemistry

In the present study, ZnO nanostructures were ultrasonically synthesized and immobilized on the surface of diatomite and used for visible light photocatalysis of Acid Red 88 (AR88) in the aqueous phase. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses were employed for characterization of the samples. The process was optimized via response surface methodology (RSM) on the basis of central composite design (CCD). Based on numerical optimization, for the maximized color removal of 96% the initial dye concentration, the catalyst dosage, the reaction time, and the initial pH were 13 mg/L, 1.5 g/L, 85 min, and 4, respectively. The …

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Experimental And Theoretical Approaches For Structural And Mechanical Properties Of Novel Side Chain Lcp-Pp Graft Coproducts, Sedat Çeti̇n, Behi̇ye Öztürk Şen, Uğur Soykan, Eli̇f Esra Firat, Gürcan Yildirim Jan 2016

Experimental And Theoretical Approaches For Structural And Mechanical Properties Of Novel Side Chain Lcp-Pp Graft Coproducts, Sedat Çeti̇n, Behi̇ye Öztürk Şen, Uğur Soykan, Eli̇f Esra Firat, Gürcan Yildirim

Turkish Journal of Chemistry

The monomers p-biphenyloxycarbonylphenyl acrylate (BPCPA) and p-biphenyloxycarbonylphenyl methacrylate (BPCPMA) were synthesized by the reaction of p-acryloyloxybenzoyl chloride and p-methacryloyloxybenzoyl chloride with 4-hydroxybiphenyl, respectively, and polymerized by bulk polymerization in vacuum by using dicumyl peroxide. The graft copolymerization of the monomers onto polypropylene were carried out by bulk melt polymerization at 170 $^{\circ}$C with various concentration levels of the monomers and the initiator in reaction mixtures. The content of monomers in their graft coproducts increased with monomer-initiator percentage in the reaction medium. The graft coproducts were characterized by several available experimental techniques including differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared …

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Comparative Density Functional Study Of Antioxidative Activity Of The Hydroxybenzoic Acids And Their Anions, Zoran Markovic, Jelena Djorovic, Jasmina M. Dimitric Markovic, Radomir Biocanin, Dragan Amic Jan 2016

Comparative Density Functional Study Of Antioxidative Activity Of The Hydroxybenzoic Acids And Their Anions, Zoran Markovic, Jelena Djorovic, Jasmina M. Dimitric Markovic, Radomir Biocanin, Dragan Amic

Turkish Journal of Chemistry

Hydroxybenzoic acids (HBAs) and their anions play an important role in the food and pharmaceutical industries because of their antioxidant activity. In this study, we examined the mechanisms of the free radical scavenging action of HBAs and their anions using density functional theory (DFT) methods. Reaction enthalpies related to the mechanisms of free radical scavenging by the investigated species were calculated by DFT methods in water, DMSO, pentylethanoate, and benzene. Hydrogen atom transfer (HAT) is a preferred reaction pathway in benzene, while sequential proton loss electron transfer (SPLET) is a predominant reaction pathway in polar solvents, water, and DMSO for …

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Synthesis, And Prediction Of Molecular Properties And Antimicrobial Activity Of Some Acylhydrazones Derived From $N$-(Arylsulfonyl)Methionine, Esra Tatar, Sevi̇l Şenkardeş, Hasan Erdi̇nç Selli̇tepe, Şükri̇ye Güni̇z Küçükgüzel, Şengül Alpay Karaoğlu, Ari̇f Bozdeveci̇, Erik De Clercq, Christophe Pannecouque, Tai̇bi̇ Ben Hadda, İlkay Küçükgüzel Jan 2016

Synthesis, And Prediction Of Molecular Properties And Antimicrobial Activity Of Some Acylhydrazones Derived From $N$-(Arylsulfonyl)Methionine, Esra Tatar, Sevi̇l Şenkardeş, Hasan Erdi̇nç Selli̇tepe, Şükri̇ye Güni̇z Küçükgüzel, Şengül Alpay Karaoğlu, Ari̇f Bozdeveci̇, Erik De Clercq, Christophe Pannecouque, Tai̇bi̇ Ben Hadda, İlkay Küçükgüzel

Turkish Journal of Chemistry

A series of 38 new acylhydrazones [3-40], derived from (2$S)$-4-(methylsulfanyl)-2-[[(4-methylphenyl)sulfonyl] amino]butanoic acid hydrazide [2], were synthesized and evaluated for their anti-HIV and antimicrobial activity with the further aim to develop acylhydrazones carrying an amino acid side chain. All tested compounds possess stronger activity against gram (+) bacteria. Compound 23 was found active against methicillin-resistant Staphylococcus aureus (MRSA) with a MIC value of 3.9 $\mu $g/mL. The MIC value of compound 30 against Enterococcus faecalis, Listeria monocytogenes, and Bacillus cereus was 8 $\mu $g/mL. A computational study for prediction of ADME and drug-like properties (solubility, drug-likeness, and drug score) as well …

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