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Articles 1081 - 1110 of 2720
Full-Text Articles in Chemistry
Chromium Redox Speciation In Food Samples, Krystyna Pyrzynska
Chromium Redox Speciation In Food Samples, Krystyna Pyrzynska
Turkish Journal of Chemistry
Chromium is an element with important biological characteristics, depending on its different species. Cr(III) is considered as essential; however, the Cr(VI) form is classified as carcinogenic.~For this reason, speciation analysis in food samples is a very important question. The proposed data procedures for chromium redox speciation in the literature can be divided into those with the use of online hyphenated techniques and those where appropriate sample pretreatment is necessary. The strategies for nonchromatographic speciation are mainly based on selective liquid--liquid extraction procedures, coprecipitation, selective separation of chromium species using a solid phase extraction column, or complexation reactions. In this paper, …
A Novel Ion-Imprinted Polymeric Sorbent For Separation And Determination Of Chromium(Iii) Species In Wastewater, Barbara Lesniewska, Iwona Jakubowska, Elzbieta Zambrzycka, Beata Godlewska - Zylkiewicz
A Novel Ion-Imprinted Polymeric Sorbent For Separation And Determination Of Chromium(Iii) Species In Wastewater, Barbara Lesniewska, Iwona Jakubowska, Elzbieta Zambrzycka, Beata Godlewska - Zylkiewicz
Turkish Journal of Chemistry
A new chromium(III) ion-imprinted polymer (IIP) was prepared from a Cr(III)-nicotinate complex (template), acrylamide (functional monomer), and ethylene glycol dimethacrylate (cross-linking agent) using 2,2'-azobisisobutyronitrile as the radical initiator. IIP was characterised and used as a selective sorbent for the solid-phase extraction of Cr(III) ions. The conditions for dynamic separation of Cr(III) on IIP were optimised. Cr(III) ions are selectively retained on the sorbent in a pH range from 9 to 10 and can be eluted with 4 mol L$^{-1}$ acetic acid. Cr(III) ions were determined by flame atomic absorption spectrometry (FAAS) with a detection limit of 0.08 $\mu $g mL$^{-1}$. …
Ionic Liquid Based Microextraction Combined With Derivatization For Efficient Enrichment/Determination Of Asulam And Sulfide, Habibollah Eskandari, Mahnaz Shahbazi-Raz
Ionic Liquid Based Microextraction Combined With Derivatization For Efficient Enrichment/Determination Of Asulam And Sulfide, Habibollah Eskandari, Mahnaz Shahbazi-Raz
Turkish Journal of Chemistry
This study reports 2 new simple derivatization-based dispersive liquid-liquid microextraction (DLLME) methods for spectrophotometric ultratrace determination of asulam and sulfide. 1-Naphthol (in the presence of nitrite) and N,N-diethyl-p-phenylenediamine (in the presence of Fe(III)) were used to derivatize asulam and sulfide, respectively. In the enrichment methods, the formed derivatives were preconcentrated into microdroplets of the in situ formed water insoluble ionic liquid (IL), 1-hexyl-3-methylimidazolium hexafluorophosphate. Monitoring was performed at 526 nm for asulam and at 664 nm for sulfide, after dissolution of the IL-rich phases into the basic ethanolic solution and ethanol for asulam and sulfide, respectively. Beer's law was obeyed …
Biosorption Potential Of Surface-Modified Waste Sugar Beet Pulp For The Removal Of Reactive Yellow 2 (Ry2) Anionic Dye, Si̇bel Tunali Akar, Sema Çeli̇k, Di̇lek Tunç, Yasemi̇n Yeti̇moğlu Balk, Tamer Akar
Biosorption Potential Of Surface-Modified Waste Sugar Beet Pulp For The Removal Of Reactive Yellow 2 (Ry2) Anionic Dye, Si̇bel Tunali Akar, Sema Çeli̇k, Di̇lek Tunç, Yasemi̇n Yeti̇moğlu Balk, Tamer Akar
Turkish Journal of Chemistry
Tetra-$n$-butylammonium bromide modified sugar beet pulp (TBAB-SBP) with good biosorption and regeneration potential was prepared for removal of dye from contaminated solutions. The decolorization performance of TBAB-SBP was investigated using Reactive Yellow 2 (RY2) as a model dye. The characterization of the modified biosorbent was investigated by IR, SEM, zeta potential, and BET surface area analysis to discuss the decolorization mechanism. The effects of initial pH, biosorbent amount, contact time, dye concentration, and flow rate on the treatment process were examined. The experimental kinetic data were well predicted by the pseudo-second-order kinetic model and Langmuir isotherm with a maximum monolayer …
Synthesis And Photochromism Of New Asymmetrical Diarylethenes With A Variable Heteroaryl Ring And A Quinoline Unit, Hongyan Xu, Renjie Wang, Congbin Fan, Gang Liu, Shouzhi Pu
Synthesis And Photochromism Of New Asymmetrical Diarylethenes With A Variable Heteroaryl Ring And A Quinoline Unit, Hongyan Xu, Renjie Wang, Congbin Fan, Gang Liu, Shouzhi Pu
Turkish Journal of Chemistry
Three new asymmetrical photochromic diarylethenes containing a variable heteroaryl ring and a quinoline unit were synthesized and their structures were determined by single-crystal X-ray diffraction analysis. Their properties, including photochromism, acidichromism, and fluorescence, were investigated systematically. For these diarylethenes, the one with an indole moiety had the largest absorption maximum, cyclization quantum yield, photoconversion ratio, emission peak, and fluorescent modulation efficiency. In addition, these diarylethenes exhibited an evident dual switching behavior induced by the stimulation of acid/base and UV/Vis. Addition of trifluoroacetic acid to solution of the diarylethenes produced protonated derivatives with notable changes in their absorption spectra. These results …
Density Functional Study Of The Structure And Water Adsorption Activity Of An Al$_{30}$O$_{30}$ Star-Shaped Alumina Nanocage, Mehdi Zamani
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 …
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 $-Enaminones, Said Ahmed Soliman Ghozlan, Doaa Mohmed Abdelmoniem, Amr Mohmed Abdelmoniem, Ismail Abdelshafy Abdelhamid
An Efficient One-Pot, Three-Component Synthesis Of 6-Cyano-Hexahydro-4$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.
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
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 …
Preparation And Characterization Of Zno/Mmt Nanocomposite For Photocatalytic Ozonation Of A Disperse Dye, Alireza Khataee, Murat Kiranşan, Semra Karaca, Samira Arefi- Oskoui
Preparation And Characterization Of Zno/Mmt Nanocomposite For Photocatalytic Ozonation Of A Disperse Dye, Alireza Khataee, Murat Kiranşan, Semra Karaca, Samira Arefi- Oskoui
Turkish Journal of Chemistry
ZnO was immobilized on the montmorillonite (MMT) to synthesize ZnO/MMT nanocomposite. Physicochemical properties of the as-synthesized nanocomposite were determined using X-ray diffraction, scanning electron microscopy, transmission electron microscope, Fourier transform infrared spectroscopy, N$_{2}$ adsorption/desorption, and point of zero charge pH (pH$_{pzc})$ analysis. The performance of the prepared ZnO/MMT nanocomposite was examined for the photocatalytic ozonation of Disperse Red 54 (DR54) and the highest decolorization efficiency (88.75{\%} after 60 min of reaction time) was the result for the mentioned process compared to adsorption, single ozonation, catalytic ozonation, and photolysis. The influence of various operational parameters including initial dye concentration, catalyst concentration, …
Synthesis And Computational Studies Of New Metallo-Phthalocyanines Bearing Dibenzoxanthenes And Evaluation Of Their Optical Properties In Solution And Solid Pmma/Znpc/Al Nanocomposite Films, Ali Reza Karimi, Zeinab Jafarzadeh, Meysam Sourinia, Akbar Zendehnam, Azam Khodadadi, Zeinab Dalirnasab, Mohammad Solimannejad, Peyman Zolgharnein
Synthesis And Computational Studies Of New Metallo-Phthalocyanines Bearing Dibenzoxanthenes And Evaluation Of Their Optical Properties In Solution And Solid Pmma/Znpc/Al Nanocomposite Films, Ali Reza Karimi, Zeinab Jafarzadeh, Meysam Sourinia, Akbar Zendehnam, Azam Khodadadi, Zeinab Dalirnasab, Mohammad Solimannejad, Peyman Zolgharnein
Turkish Journal of Chemistry
New thermally stable metallo-phthalocyanines bearing dibenzoxanthenes as highly organo-solubilizing aromatic hydrocarbon substituents were successfully prepared by cyclotetramerization of corresponding phthalonitriles with anhydrous metal salts [Zn(CH$_{3}$COO)$_{2}$ and NiCl$_{2}$] in the presence of a catalytic amount of DBU in 2-(dimethylamino) ethanol. All of these phthalocyanines are soluble in some organic solvents such as DMF, DMSO, THF, CH$_{2}$Cl$_{2}$, and CHCl$_{3}$. Then we successfully prepared the poly(methyl methacrylate) (PMMA)/ZnPc/Al nanocomposite films by incorporating Al nanoparticles into a transparent PMMA/ZnPc matrix. The structure and morphology of nanocomposite films were studied using X-ray diffraction and scanning electron microscopy. The optical absorption spectra of PMMA/ZnPc/Al nanocomposite films …
Synthesis, Reaction, And Evaluation Of The Anticancer Activity Of 6,7,8,9-Tetrahydro-5$H$-Cyclohepta[4,5]Selenopheno[2,3-$D$]Pyrimidine Derivatives, Kadi̇r Doğanay, Ünzi̇le Keleştemur, Sevgi̇ Balcioğlu, Burhan Ateş, Ali̇ye Altundaş
Synthesis, Reaction, And Evaluation Of The Anticancer Activity Of 6,7,8,9-Tetrahydro-5$H$-Cyclohepta[4,5]Selenopheno[2,3-$D$]Pyrimidine Derivatives, Kadi̇r Doğanay, Ünzi̇le Keleştemur, Sevgi̇ Balcioğlu, Burhan Ateş, Ali̇ye Altundaş
Turkish Journal of Chemistry
The cyclocondensation of 2-amino-5,6,7,8-tetrahydro-4$H$-cyclohepta[$b$] selenophene-3-carbonitrile (1) with formic acid and formamide gave the selenophenopyrimidine 15 and selenophenopyrimidone 6 derivatives. The reaction of 6 with phosphorus oxychloride produced 4-chloro-6,7,8,9-tetrahydro-5$H$-cyclohepta[4,5] seleno[2,3-$d$]pyrimidine (12), the key compound for our nucleophilic substitution reactions. The hydrazinoselenophenopyrimidine 19 obtained from the reaction of 12 with hydrazine hydrate was converted to its tetrazoloselenophenopyrimidine 21 and triazoloselenophenopyrimidine 26 derivatives. Moreover, the chloropyrimidine derivative was reacted with pyrrolidine and morpholine to afford 4-(1-pyrrolidinyl)-6,7,8,9-tetrahydro-5$H$-cylohepta[4,5]selenopheno[2,3-$d$]pyrimidine (27) and 4-(6,7,8,9-tetrahydro-5$H$-cyclohepta[4,5]selenopheno[2,3-$d$]pirimidin-4-yl)morpholine (28). Anticancer activities of the synthesized compounds were investigated against the MCF-7 breast cancer cell line and the IC$_{50}$ values of these compounds were …
Zr(Iv), Ti(Iv), And V(Iii) Complexes Of Some Benzimidazole, Benzothiazole, And Benzoxazole Ligands: Characterization And Catalyst Efficiency In Ethylene Polymerization, Hamdi Ali Elagab, Helmut G. Alt
Zr(Iv), Ti(Iv), And V(Iii) Complexes Of Some Benzimidazole, Benzothiazole, And Benzoxazole Ligands: Characterization And Catalyst Efficiency In Ethylene Polymerization, Hamdi Ali Elagab, Helmut G. Alt
Turkish Journal of Chemistry
Fifteen complexes of 2, 2-bis- (benzimidazole, benzothiazole, and benzoxazole) compounds with Zr(IV), Ti(IV), and V(III) metal centers were synthesized, characterized, activated with methyalumoxane (MAO), and then tested for catalytic ethylene polymerization. The activities of the various catalysts were found to be functions of the hetero atoms in the ligand frameworks. The activity of the catalyst system \textbf{6}/MAO was found to be 1372 kg PE/mol cat. h. The polyethylene produced with the catalyst system 6/MAO showed high molecular weights (1.84 $\times $ 10$^{6}$ g/mol) and broad molecular weight distributions (PD = 11). This could result from different interactions of the MAO …
Adsorption Of Cellulase On Poly(2-Hydroxyethyl Methacrylate) Cryogels Containing Phenylalanine, Murat Yavuz, Oğuz Çakir, Zübeyde Baysal
Adsorption Of Cellulase On Poly(2-Hydroxyethyl Methacrylate) Cryogels Containing Phenylalanine, Murat Yavuz, Oğuz Çakir, Zübeyde Baysal
Turkish Journal of Chemistry
The aim of this study was to prepare a supermacroporous cryogel that can be used for the adsorption of cellulase. The macroporous cryogel of poly(2-hydroxyethyl methacrylate-N-methacryloyl-l-phenylalanine) [p(HEMA-MAPA)] was prepared by copolymerization of 2-hydroxyethyl methacrylate (HEMA) with a functional monomer of N-methacryloyl-l-phenylalanine (MAPA). The cryogel was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and swelling tests. The effects of several parameters such as medium pH, temperature, ionic strength, and flow rate on cellulase adsorption were also investigated. Maximum cellulase adsorption was observed at 25 $^{\circ}$C and pH 4.0. Furthermore, adsorbed cellulase was desorbed from the cryogel by using 1.0 …
Bismuth(Iii)-Sio$_{2}$ Catalyzed Synthesis Of Polysubstituted Imidazoles With The Participation Of Azaaryl Derivatives Of Aniline In Four-Component Reactions, Zarrin Ghasemi, Ziba Zakeri, Maryam Allahvirdinesbat
Bismuth(Iii)-Sio$_{2}$ Catalyzed Synthesis Of Polysubstituted Imidazoles With The Participation Of Azaaryl Derivatives Of Aniline In Four-Component Reactions, Zarrin Ghasemi, Ziba Zakeri, Maryam Allahvirdinesbat
Turkish Journal of Chemistry
A series of novel polyaromatic derivatives of imidazole were synthesized by Bi(III) nitrate-SiO$_{2}$ catalyzed four-component reactions of benzil, ammonium acetate, aromatic aldehydes, and $N$-heterocyclic derivatives of aniline under solvent-free conditions.
Mn-Doped Zns Quantum Dots As A Room-Temperature Phosphorescent Probe For Analysis Of Glutamic Acid In Foodstuffs, Hayri̇ye Eda Şatana Kara, Burak Demi̇rhan, Buket Er Demi̇rhan
Mn-Doped Zns Quantum Dots As A Room-Temperature Phosphorescent Probe For Analysis Of Glutamic Acid In Foodstuffs, Hayri̇ye Eda Şatana Kara, Burak Demi̇rhan, Buket Er Demi̇rhan
Turkish Journal of Chemistry
L-cysteine-capped Mn-doped ZnS quantum dots (QDs) were used for the determination of glutamic acid in foodstuffs. This method is based on measurement of the quenching of the phosphorescence intensity of the QDs after interacting with glutamic acid. A linear response was observed from 50 to 500 ng mL$^{-1}$ glutamic acid with a limit of detection of 6.79 ng mL$^{-1}$. Room temperature phosphorescence (RTP) intensity of the QDs was quenched rapidly upon the addition of the quencher and the reaction reached equilibrium within 2 min. The quenching mechanism of phosphorescence of Mn-doped ZnS QDs by glutamic acid is dynamic and the …
Synthesis And Structural Properties Of $N$-3,4-(Dichlorophenyl)-3-Oxo-3- Phenyl-2-(Phenylcarbonyl)Propanamide And Its Cu(Ii) Complex, Ahmet Oral Sarioğlu, Tuğba Taşkin Tok, Mehmet Akkurt, Muhammad Nawaz Tahir, Mehmet Sönmez
Synthesis And Structural Properties Of $N$-3,4-(Dichlorophenyl)-3-Oxo-3- Phenyl-2-(Phenylcarbonyl)Propanamide And Its Cu(Ii) Complex, Ahmet Oral Sarioğlu, Tuğba Taşkin Tok, Mehmet Akkurt, Muhammad Nawaz Tahir, Mehmet Sönmez
Turkish Journal of Chemistry
A new N-carboxamide compound (3) was synthesized by the reaction of dibenzoylaceticacid-$N$-carboxyethyla\-mide (1) and 3,4-dichloroaniline (2). The $N$-(3,4-dichlorophenyl)-3-oxo-3-phenyl-2-(phenylcarbonyl) propanamide (3) subsequently reacted with Cu salt to produce its Cu(II) complex compound (4). The compounds were characterized by analytical and spectral methods. In addition, X-ray diffraction was performed to characterize and obtain detailed information about the structure of 3. The fully optimized geometries of compounds 3 and 4 were calculated at different basis sets by using the Gaussian09 (G09) software to investigate their 3D geometries and electronic structures. Comparisons between the calculated and experimental data including molecular structures, fundamental vibrational modes, …
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
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 …
Co$_{2}$ Adsorption Behavior And Kinetics On Chemically Modified Activated Carbons, Burcu Selen Çağlayan, Ahmet Erhan Aksoylu
Co$_{2}$ Adsorption Behavior And Kinetics On Chemically Modified Activated Carbons, Burcu Selen Çağlayan, Ahmet Erhan Aksoylu
Turkish Journal of Chemistry
CO$_{2}$ adsorption capacities of activated carbon-based adsorbents subjected to different treatments, such as HNO$_{3}$ oxidation, air oxidation, alkali impregnation, and heat treatment under helium gas atmosphere, were determined by gravimetric analyses and reported previously by our group. In the current work, the experimental adsorption isotherms of these modified activated carbon samples were fitted to Langmuir, Freundlich, and Dubinin--Radushkevich (D-R) models. The best fits were obtained to the D-R equation, indicating competitive or multilayer CO$_{2}$ adsorption occurring in the micropores of the adsorbents. Air oxidation followed by alkali impregnation led to the highest micropore volume, ranging between 0.259 and 0.298 g.CO$_{2}$/g.adsorbent, …
Development Of A Method For The Determination Of Cadmium Levels In Seawater By Flame Atomic Absorption Spectrometry Using An Online Cloud-Point Extraction System, Rafael Vasconcelos Oliveira, Uelber Silva Vieira, Mardson Vasconcelos Maciel, Thais Souza Neri, Graziele Santos Sales, Rebeca Moraes Menezes, Valfredo Azevedo Lemos
Development Of A Method For The Determination Of Cadmium Levels In Seawater By Flame Atomic Absorption Spectrometry Using An Online Cloud-Point Extraction System, Rafael Vasconcelos Oliveira, Uelber Silva Vieira, Mardson Vasconcelos Maciel, Thais Souza Neri, Graziele Santos Sales, Rebeca Moraes Menezes, Valfredo Azevedo Lemos
Turkish Journal of Chemistry
A new system was developed for the preconcentration and determination of cadmium levels in water following online cloud-point extraction and analysis by flame atomic absorption spectrometry. The method uses cloud-point extraction of the complex formed between Cd(II) ions and the reagent 2-(5-bromo-2'-thiazolylazo)-$p$-cresol (Br-TAC) using Triton X-114 as a surfactant. The main steps of the procedure, extraction, filtration, and detection were conducted online. Parameters that influence the experimental conditions of online preconcentration systems were examined, including pH, concentration of reagent and surfactant, and flow of sample and eluent. The limit of detection of the method is 0.2 $\mu $g L$^{-1}$. The …
Synthesis Of Novel Chiral Bisoxazoline Ligands With A Norbornadiene Backbone: Use In The Copper-Catalyzed Enantioselective Henry Reaction, Rabi̇a Deli̇kuş, Emi̇ne Çakir, Nadi̇r Demi̇rel, Meti̇n Balci, Betül Karataş
Synthesis Of Novel Chiral Bisoxazoline Ligands With A Norbornadiene Backbone: Use In The Copper-Catalyzed Enantioselective Henry Reaction, Rabi̇a Deli̇kuş, Emi̇ne Çakir, Nadi̇r Demi̇rel, Meti̇n Balci, Betül Karataş
Turkish Journal of Chemistry
Novel chiral bisoxazoline ligands based on norbornadiene were synthesized and used for the asymmetric Henry reaction. Various aromatic aldehydes were converted into chiral $\beta $-nitro alcohols with high yields and moderate to acceptable enantioselectivities under the optimized reaction conditions.
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
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 …
Simple And Rapid Voltammetric Determination Of Boron In Water And Steel Samples Using A Pencil Graphite Electrode, Lokman Li̇v, Nuri̇ Naki̇boğlu
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). …
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
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 $g/mL. A computational study for prediction of ADME and drug-like properties (solubility, drug-likeness, and drug score) as well …
Electrochemical Investigation Of2-[8-Hydroxyquinoline-5-Yl)Azo]Benzo[$C$]Cinnoline On A Platinum Electrode In Dimethysulfoxide, Funda Öztürk, Zehra Yazan, Oznur Olmez, Emi̇ne Kiliç, Esma Kiliç
Electrochemical Investigation Of2-[8-Hydroxyquinoline-5-Yl)Azo]Benzo[$C$]Cinnoline On A Platinum Electrode In Dimethysulfoxide, Funda Öztürk, Zehra Yazan, Oznur Olmez, Emi̇ne Kiliç, Esma Kiliç
Turkish Journal of Chemistry
2-[8-hydroxyquinoline-5-yl)azo]benzo[c]cinnoline was synthesized for the first time and shown to possess electrochromic characteristic, i.e. changing color during the forward and back electrolysis at --1.35 V and 0.00 V, respectively, in DMSO medium. Therefore, the electrochemical investigation of this compound appears to be worthwhile. The electrochemical reduction of 2-[8-hydroxyquinoline-5-yl)azo]benzo[c]cinnoline was investigated by cyclic voltammetry, controlled potential electrolysis, and chronoamperometry techniques in the presence of 0.10 mol L$^{-1}$ tetrabutylammonium tetrafluoroborate in dimethyl sulfoxide at platinum electrode. 2-[8-Hydroxyquinoline-5-yl)azo]benzo[c] cinnoline displays three sharp cathodic peaks and three anodic peaks in the cyclic voltammogram. The diffusion coefficients and the number of electrons transferred were calculated …
Latest Trends, Green Aspects, And Innovations In Liquid-Phase--Based Microextraction Techniques: A Review, Erkan Yilmaz, Mustafa Soylak
Latest Trends, Green Aspects, And Innovations In Liquid-Phase--Based Microextraction Techniques: A Review, Erkan Yilmaz, Mustafa Soylak
Turkish Journal of Chemistry
Liquid-phase microextraction (LPME) methods including single-drop microextraction (SDME), hollow-fiber LPME (HF-LPME), and dispersive liquid-liquid microextraction (DLLME) have in the very short time since their invention grabbed the attention of scientists. Up to now, LPME methods have shown important innovations for the extraction and preconcentration of both inorganic and organic trace analytes from different matrices. These LPME methods offer unique advantages such as high preconcentration factor for target analytes in a single step, low cost, simplicity, excellent preconcentration capability, sample cleanup and integration of steps, and combined use with almost every analytical measurement technique. We describe the milestones and the combined …
Systematic Optimization Of Chemical Deposition Conditions For Synthesis Of Vanadium(V) Oxide Xerogels, Aksu Samet, Metodija Najdoski, Igor Kuzmanovski
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, $\Delta …
Synthetic Access To Some New Benzothiazole-Based 1,3,4-Thiadiazole And 1,3-Thiazole Derivatives, Kamal M. Dawood, Eman A. Ragab, Korany A. Ali
Synthetic Access To Some New Benzothiazole-Based 1,3,4-Thiadiazole And 1,3-Thiazole Derivatives, Kamal M. Dawood, Eman A. Ragab, Korany A. Ali
Turkish Journal of Chemistry
1-(Benzothiazol-2-yl)-3-phenylthiourea\textbf{ 2} was prepared and treated with hydrazonoyl chlorides \textbf{3a}--\textbf{e }to yield the corresponding 5-(benzothiazol-2-ylimino)-1,3,4-thiadiazole derivatives \textbf{6a}--\textbf{e}, respectively. Reaction of the thiourea derivative \textbf{2} with ethyl 2-chloro-3-oxobutanoate \textbf{9} afforded the corresponding 2-(benzothiazol-2-ylimino)thiazole-5-carboxylate derivative \textbf{11}. The newly synthesized heterocyclic derivatives were confirmed from their elemental and spectral analyses.
Synthesis And Evaluation Of Some Novel Thiazoles And 1,3-Thiazines As Potent Agents Against The Rabies Virus, Magda Abdalla, Sobhi Gomha, Mohamad Abd Elaziz, Nany Serag
Synthesis And Evaluation Of Some Novel Thiazoles And 1,3-Thiazines As Potent Agents Against The Rabies Virus, Magda Abdalla, Sobhi Gomha, Mohamad Abd Elaziz, Nany Serag
Turkish Journal of Chemistry
A series of novel thiazoles and 1,3-thiazine derivatives were synthesized in good yield via reaction of ethyl 3-(1-(2-thiocarbamoylhydrazono)ethyl)-1,5-diphenyl-1$H$-pyrazole-4-carboxylate with hydrazonoyl halides and arylidenemalononitriles, respectively. The structure of the newly synthesized products was elucidated via elemental analysis, spectral data, and alternative routes whenever possible. Moreover, the antiviral screening of the products was evaluated and the results revealed that some of them have strong to moderate potency against the rabies virus compared with the reference drug.
Preparation, Characterization, And Adsorption Studies Of Core@Shell Sio$_{2}$@Ceo$_{2}$ Nanoparticles: A New Candidate To Remove Hg(Ii) From Aqueous Solutions, Ali̇ İmran Vai̇zoğullar, Ahmet Balci, İbrahi̇m Kula, Mehmet Uğurlu
Preparation, Characterization, And Adsorption Studies Of Core@Shell Sio$_{2}$@Ceo$_{2}$ Nanoparticles: A New Candidate To Remove Hg(Ii) From Aqueous Solutions, Ali̇ İmran Vai̇zoğullar, Ahmet Balci, İbrahi̇m Kula, Mehmet Uğurlu
Turkish Journal of Chemistry
SiO$_{2}$ supported core@shell nanoparticles (CSNs) have recently attracted great attention due to their unique, tunable, optical, photocatalytic, and higher adsorption properties. In this study, SiO$_{2}$@CeO$_{2}$~CSNs were synthesized using a chemical precipitation technique and characterized by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM) analysis. XRD analysis showed that SiO$_{2\, }$particles were the core while CeO$_{2}$ particles were the shell. It was seen as a new band at 961 cm$^{-1}$ of the oxygen bridge between Si and Ce atoms from FT-IR results; SiO$_{2}$ and CSNs were spherical (0.5--0.6 $\mu $m) from SEM and …
Zr(Iv) Complexes Of Some Heterocyclic Ligands: Synthesis, Characterization, And Ethylene Polymerization Activity, Hamdi Ali Elagab
Zr(Iv) Complexes Of Some Heterocyclic Ligands: Synthesis, Characterization, And Ethylene Polymerization Activity, Hamdi Ali Elagab
Turkish Journal of Chemistry
Thirty-one complexes of bis-(benzimidazole, benzothiazole, and benzoxazole) compounds with Zr(IV) metal centers were synthesized, characterized, activated with methylaluminoxane (MAO), and then tested for catalytic ethylene polymerization. The activities of the various catalysts were found to be functions of the heteroatoms in the ligand frameworks and the structure around the active metal center. The highest activity was obtained with 38/MAO (424 kg E/mol cat. h). The produced polyethylenes showed high molecular weights (41/MAO, 1.9 $\times$ 10$^{6}$ g/mol) and broad molecular weight distributions (38/MAO, M$_{w}$ = 9.64 $\times $ 10$^{5}$ g/mol, PD = 23). This could result from different interactions of the …