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Full-Text Articles in Physical Sciences and Mathematics

Advances In The Chemistry Of Pyrazolopyrazoles, Rizk Elsyad Khidre, Hanan Ahmed Mohamed, Bakr Fathy Abdelwahab Jan 2013

Advances In The Chemistry Of Pyrazolopyrazoles, Rizk Elsyad Khidre, Hanan Ahmed Mohamed, Bakr Fathy Abdelwahab

Turkish Journal of Chemistry

Published data on the methods of preparation of pyrazolopyrazoles are summarized and described systematically. The title compounds are subdivided according to the position of fusion between the 2 pyrazole rings.


A New Anthracene Derivative Of Calix[4]Arene As A Fluorescent Chemosensor, Özlem Şahi̇n, Mustafa Şahi̇n, Nuri̇ye Koçak, Mustafa Yilmaz Jan 2013

A New Anthracene Derivative Of Calix[4]Arene As A Fluorescent Chemosensor, Özlem Şahi̇n, Mustafa Şahi̇n, Nuri̇ye Koçak, Mustafa Yilmaz

Turkish Journal of Chemistry

A new anthracene derivative of calix[4]arene was synthesized as a highly fluorescent compound. This compound was examined for its fluorescent properties towards different metal ions (Li^+, Na^+, Mg^{2+}, Ca^{2+}, Ba^{2+}, Ni^{2+}, Cu^{2+}, Zn^{2+}, Pb^{2+}) by UV and fluorescence spectroscopy. On complexation by alkaline earth metal cations and transition metal cations, the fluorescence spectrum was quenched. In particular, Ca^{2+} caused greater than 98% quenching of the anthracene derivative of calix[4]arene.


Spectrophotometric Determination Of 3-Hydroxy-3-Methylglutaryl Coenzyme-A Reductase Inhibitors In Pharmaceutical Preparations, Gamze Ergi̇n, Sena Çağlar, Armağan Önal, Sidika Ertürk Toker Jan 2013

Spectrophotometric Determination Of 3-Hydroxy-3-Methylglutaryl Coenzyme-A Reductase Inhibitors In Pharmaceutical Preparations, Gamze Ergi̇n, Sena Çağlar, Armağan Önal, Sidika Ertürk Toker

Turkish Journal of Chemistry

Simple and accurate spectrophotometric methods are presented for the determination of five 3-hydroxy-3-methylglutaryl coenzyme-A (HMG-CoA) reductase inhibitors (statins), namely atorvastatin, fluvastatin, pitavastatin, rosuvastatin, and simvastatin, in pharmaceutical preparations. The methods are based on the reaction of drugs as n-electron donor with 7,7,8,8-tetracyanoquinodimethane as \pi-acceptors to give highly colored complex species. All variables were studied in order to optimize the reaction conditions. Beer's law was obeyed in the concentration ranges 4--20 \mu g mL^{-1}, 4--12 \mu g mL^{-1}, 0.8--2.4 \mu g mL^{-1}, 4--14 \mu g mL^{-1}, and 2.5--20 \mu g mL^{-1} for atorvastatin, fluvastatin, pitavastatin, rosuvastatin, and simvastatin, respectively. The proposed …


Electrochemical Properties Of 1,3-Disubstituted Methyl Methoxy Phenyl-5-Phenylformazans And Comparison With Spectral Properties, Habi̇be Tezcan, Güler Ekmekci̇, Mehmet Levent Aksu Jan 2013

Electrochemical Properties Of 1,3-Disubstituted Methyl Methoxy Phenyl-5-Phenylformazans And Comparison With Spectral Properties, Habi̇be Tezcan, Güler Ekmekci̇, Mehmet Levent Aksu

Turkish Journal of Chemistry

In this study, electrochemical behaviors of formazans were investigated. The compounds contained CH_3 and OCH_3 groups at the o-, m-, and p-positions of the 1-phenyl ring and an OCH_3 group at the p-position of the 3-phenyl ring. Their electrochemical behaviors, such as the number of electrons transferred, diffusion coefficients, and heterogeneous rate constants, were studied by cyclic voltammetry, ultramicrodisk electrode, and chronoamperometry. Possible mechanisms were proposed based upon the data obtained. There was a correlation between the absorption and electrochemical properties. A linear correlation was obtained between \lambda_{\max} and E_{red2} and Hammett substituent coefficients with E_{red2} and k_s values.


A New Method For Calculating The Vibration-Rotation-Tunneling Spectra Of Molecular Clusters And Its Application To The Water Dimer, Mahi̇r Erteki̇n Ocak Jan 2013

A New Method For Calculating The Vibration-Rotation-Tunneling Spectra Of Molecular Clusters And Its Application To The Water Dimer, Mahi̇r Erteki̇n Ocak

Turkish Journal of Chemistry

A new method is developed for calculating the vibration-rotation-tunneling spectra of molecular clusters consisting of rigid monomers. The method is based on generation of optimized bases for each monomer. First, a sequential symmetry adaptation procedure is developed for relating the symmetries of monomer basis functions with the symmetries of the eigenstates of the cluster. Then this symmetry adaptation procedure is used in the generation of optimized bases and combining them for finding the eigenstates. Symmetry adaptation problems related to the generation of optimized bases are identified and solutions are suggested. The method is applied to the water dimer by using …


Disposable Carbon Electrodes As An Alternative For The Direct Voltammetric Determination Of Alkyl Phenols From Water Samples, Iulia Gabriela David, Irinel Adriana Badea, Gabriel Lucian Radu Jan 2013

Disposable Carbon Electrodes As An Alternative For The Direct Voltammetric Determination Of Alkyl Phenols From Water Samples, Iulia Gabriela David, Irinel Adriana Badea, Gabriel Lucian Radu

Turkish Journal of Chemistry

Disposable sensors based on a pencil graphite electrode were described for detection of alkyl phenols. The performances of the disposable bare pencil graphite electrode (PGE) and PGE modified with carbon nanotubes, regarding the cyclic and differential pulse voltammetric determination of 4-nonylphenol, 4-octylphenol, and 4-tert-octylphenol, were compared. Some experimental variables of the electrode surface pretreatment and measurement parameters were optimized. Using a phosphate buffer solution (pH 7.40) as the supporting electrolyte, alkyl phenols gave a well-defined oxidation peak at about 700 mV vs. Ag/AgCl. The detection limits established for each alkyl phenol were: 0.25 \muM for 4-octylphenol, 0.42 \muM for 4-nonylphenol, …


Synthesis And Characterization Of Thermally Stable Camphor-Based Polyimide--Clay Nanocomposites, Murat Yi̇ği̇t, Turgay Seçki̇n, Beyhan Yi̇ği̇t, Süleyman Köytepe Jan 2013

Synthesis And Characterization Of Thermally Stable Camphor-Based Polyimide--Clay Nanocomposites, Murat Yi̇ği̇t, Turgay Seçki̇n, Beyhan Yi̇ği̇t, Süleyman Köytepe

Turkish Journal of Chemistry

A new monomer was prepared from (1R,3S)-(+)-camphoric acid. Novel polyimide and polyimide--clay hybrid composites were developed from one-pot condensation reactions of this monomer and pyromellitic dianhyride. Polyimide-montmorillonite nanocomposites were prepared from solution of polyimide and with different weight percentages (1, 5, 10 wt %) of organo-modified montmorillonite (OM-MMT) using N-methyl-2-pyrrolidone (NMP) as aprotic solvent. The reactive organoclay was formed by using hexadecylpyridinium chloride as a swelling agent for silicate layers of montmorillonite. The polyimide--clay composites films (PI--MMT) were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD). All composites were subjected to differential scanning calorimetry …


Synthesis And Antimicrobial Investigation Of Some 5h-Pyridazino[4,5-B]Indoles, İlker Avan, Alaetti̇n Güven, Kiymet Güven Jan 2013

Synthesis And Antimicrobial Investigation Of Some 5h-Pyridazino[4,5-B]Indoles, İlker Avan, Alaetti̇n Güven, Kiymet Güven

Turkish Journal of Chemistry

Synthesis and in vitro antimicrobial activities are reported for a series of 1,3,5-substituted 4-oxo-3,4-dihydro-5H-pyridazino[4,5-b]indole derivatives. Corresponding pyridazino[4,5-b]indoles were prepared from ethyl 3-formyl-1H-indole-2-carboxylate precursors and the functional group in question was installed with hydrazine and its derivatives. The purity and primary structures of pyridazino[4,5-b]indole were confirmed by IR, ^1 H NMR, and ^{13}C NMR spectroscopy and elemental analyses. All of the indoles were tested for in vitro antimicrobial activity against 8 isolates of bacteria and a fungus including Staphylococcus aureus NRRL B-767, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Proteus vulgaris NRRL-B123, Salmonella typhimurium NRRL B-4420, Bacillus subtilis NRRL 744, …


Spectral, Electrochemical, Luminescence, And Dye-Sensitized Solar Cell Studies Of Mono And D-F Hetero Binuclear Cryptates, Arunachalam Vijayaraj, Raju Prabu, Ranganathan Suresh, Subbaiah Manoharan, Sambandam Anandan, Vengidusamy Narayanan Jan 2013

Spectral, Electrochemical, Luminescence, And Dye-Sensitized Solar Cell Studies Of Mono And D-F Hetero Binuclear Cryptates, Arunachalam Vijayaraj, Raju Prabu, Ranganathan Suresh, Subbaiah Manoharan, Sambandam Anandan, Vengidusamy Narayanan

Turkish Journal of Chemistry

Mono and hetero binuclear cryptates, [Gd(III)ML]^+ [M = VO(IV), Co(II), Ni(II), Cu(II)], were synthesized by a 2-step method. The ligand L represents the deprotonated anionic cryptate obtained by the 2+3 condensation of tris-(2-aminoethyl)amine with 2,6-diformyl-4-nitrophenol. The complexes were characterized by elemental analysis, spectral, magnetic, and electrochemical studies. Fluorescence of Gd(III) ion in the cavity was quenched by the encapsulated Cu(II) and Ni(II) ions. [GdCoL(NO_3)]^+ cryptate had a high lifetime value compared to other cryptates. The cyclic voltammogram showed that the reduction potential values of [Gd(M)L] M = VO(IV), Co(II), Ni(II), and Cu(II) complexes were in the following order: Cu(II) > Ni(II) …


Establishment Of An Electrochemical Rna Aptamer-Based Biosensor To Trace Nanomolar Concentrations Of Codeine, Mehdi Saberian, Davoud Asgari, Yadollah Omidi, Jaleh Barar, Hossein Hamzeiy Jan 2013

Establishment Of An Electrochemical Rna Aptamer-Based Biosensor To Trace Nanomolar Concentrations Of Codeine, Mehdi Saberian, Davoud Asgari, Yadollah Omidi, Jaleh Barar, Hossein Hamzeiy

Turkish Journal of Chemistry

Codeine is an opium alkaloid with a great potential of abuse among opioid consumers. Detection of codeine is a routine procedure in the military and government of some countries for personnel recruitment. Therefore, a specific, selective, and easy to use method would be an important improvement in such detection procedures. According to previous reports, short single-stranded DNA or RNA sequences with high affinity and specificity to their targets, aptamers, could be used for designing an accurate and specific biosensor for codeine. This study introduces an aptamer-based biosensor for codeine detection in nanomolar concentrations by an electrochemical method, and ferrocene carboxylic …


C_2-Symmetric Chiral Diamine Ligands For Enantiomeric Recognition Of Amino Acid Esters And Mandelic Acid By Proton Nmr Titration Method, Hayri̇ye Aral, Tarik Aral, Mehmet Çolak, Berri̇n Zi̇yadanoğullari, Recep Zi̇yadanoğullari Jan 2013

C_2-Symmetric Chiral Diamine Ligands For Enantiomeric Recognition Of Amino Acid Esters And Mandelic Acid By Proton Nmr Titration Method, Hayri̇ye Aral, Tarik Aral, Mehmet Çolak, Berri̇n Zi̇yadanoğullari, Recep Zi̇yadanoğullari

Turkish Journal of Chemistry

Two novel C_2-symmetric chiral diamines containing \alpha -phenylethyl and \alpha -(1-naphthyl)ethyl chiral subunits were prepared with quantitative yields. Enantiomeric recognition properties of these simple structured diamine ligands towards D- and L-amino acid esters and D- and L-mandelic acid were examined by the ^1H NMR titration method. These ligands exhibited strong complexation (with K_f up to 2481 M^{-1}) and good enantioselectivity (up to K_L/K_D = 4.08) towards the mandelic acid enantiomers. The results show that simple structured and easily accessible acyclic C_2-symmetrical compounds can also be used for enantiomeric recognition of racemic amino acids and mandelic acid in addition to complex …


New Synthetic Strategy For Novel 6-Arylazo-5-Methyl-3-Aryl-Thiazolo[2,3-C]- [1,2,4]Triazoles And Study Of Their Solvatochromic Properties, Ahmad Sami Shawali, Mohie Eldin Moustafa Zayed Jan 2013

New Synthetic Strategy For Novel 6-Arylazo-5-Methyl-3-Aryl-Thiazolo[2,3-C]- [1,2,4]Triazoles And Study Of Their Solvatochromic Properties, Ahmad Sami Shawali, Mohie Eldin Moustafa Zayed

Turkish Journal of Chemistry

Two series of 6-arylazothiazol[2,3-c][1,2,4]triazoles were prepared via oxidative cyclization of the respective aldehyde N-(5-arylazo-4-methylthiazol-2-yl)-hydrazones. The structures of the latter hydrazone precursors and the azo compounds were confirmed by spectral and elemental analyses. The solvatochromism of the title azo dyes is evaluated by means of the Kamlet--Taft equation and discussed.


Flavonoid Constituents Of Sideritis Caesarea, Belkis Halfon, Ece Çi̇ftçi̇, Gülaçti Topçu Jan 2013

Flavonoid Constituents Of Sideritis Caesarea, Belkis Halfon, Ece Çi̇ftçi̇, Gülaçti Topçu

Turkish Journal of Chemistry

The acetone extract of the aerial parts of Sideritis caesarea Duman, Aytaç & Başer (Lamiaceae) afforded the flavonoids penduletin (1) and apigenin (2) and 6 glycosylated flavonoids, 4'-O-methyl-isoscutellarein-7-O-[6'''-O-acetyl-\beta-D-allopyranosyl- (1 \to 2)]-6\"-O-acetyl-\beta -D-glucopyranoside (3), 4'-O-methylhypolaetin- 7-O-[6'''-O-acetyl-\beta -D-allopyranosyl-(1 \to 2)]-6\"-O-acetyl-\beta- D-glucopyranoside (4), isoscutellarein-7-O-[6'''-O-acetyl-\beta- D-allopyranosyl-(1 \to 2)]-6\"-O-acetyl-\beta -D-glucopyranoside (5), isoscutellarein-7-O-[6'''-O-acetyl-\beta -D-allopyranosyl-(1 \to 2)]- \beta-D-glucopyranoside (6), 4'-O-methylhypolaetin-7-O- [6'''-O-acetyl-\beta -D-allopyranosyl-(1 \to 2)]-\beta-D- glucopyranoside (7), and hypolaetin-7-O-[6'''-O-acetyl-\beta- D-allopyranosyl-(1 \to 2)]-\beta -D-glucopyranoside (8). The compounds were identified by the use of 1D- and 2D-NMR and UV spectroscopic techniques and by comparisons with the reported data. The acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of the acetone, methanol, …


Exploring Distinct Binding Site Regions Of \Beta_2-Adrenergic Receptor Via Coarse-Grained Molecular Dynamics Simulations, Si̇bel Çakan, Ebru Demet Akdoğan Jan 2013

Exploring Distinct Binding Site Regions Of \Beta_2-Adrenergic Receptor Via Coarse-Grained Molecular Dynamics Simulations, Si̇bel Çakan, Ebru Demet Akdoğan

Turkish Journal of Chemistry

\beta_2-Adrenergic receptor (\beta_2AR) is a G protein- coupled receptor that is highly flexible and able to recognize a wide range of ligands through its conformational variations. Active and inactive conformations revealed by recent crystallographic experiments do not provide a complete dynamic picture of the receptor, especially in the binding site. In this study, molecular dynamics (MD) simulation through a residue-based coarse-grained model is used as an alternative and efficient method to explore a wider conformational search space. The system was composed of \beta_2AR embedded into a 1-palmitoyl-2-oleoyl-phosphatidylcholine membrane bilayer with surrounding water. A total of 6 \mu s of simulation …


Dft Study Of Tautomerism In Aklavinone, Burhan Lemi̇ Türker Jan 2013

Dft Study Of Tautomerism In Aklavinone, Burhan Lemi̇ Türker

Turkish Journal of Chemistry

Aklavinone has an anthraquinone-based chromophore and its backbone highly resembles the kernel of some anthracycline antibiotics that possess anticancer activity, e.g., daunomycin. Since aklavinone's structure possesses many --OH groups and 2 keto groups, it is quite probable that certain tautomeric equilibria may occur. Presently, aklavinone prototropic tautomers possessing embedded anthraquinone moiety have been investigated quantum chemically by using density functional theory at the levels of RB3LYP/6-31G(d) and RB3LYP/6-31G(d,p). Additionally, IR spectra of the tautomers were calculated. Moreover, the phenolate ions obtained from the most stable tautomer in water were considered, and the protonation of this tautomer at various possible sites …


Calixarene-Based Receptors For Molecular Recognition, Mustafa Yilmaz, Serkan Erdemi̇r Jan 2013

Calixarene-Based Receptors For Molecular Recognition, Mustafa Yilmaz, Serkan Erdemi̇r

Turkish Journal of Chemistry

Calixarene-based molecular receptors have been a widely developing area in material science and technology for the last few decades. Due to their bowl-shaped geometry, calixarene macrocycles are used as hosts allowing organic and inorganic guests to coordinate/sorb onto their cavity. This work briefly reviews the recent development of calixarenes.


Synthesis Of Fused Tetrazolone Derivatives, Sevi̇l Özcan, Zeynep Ekmekçi̇, Berk Müjde, Meti̇n Balci Jan 2013

Synthesis Of Fused Tetrazolone Derivatives, Sevi̇l Özcan, Zeynep Ekmekçi̇, Berk Müjde, Meti̇n Balci

Turkish Journal of Chemistry

New fused tetrazolone derivatives were synthesized using homophthalic and maleic anhydrides. Treatment of anhydrides with trimethylsilyl azide opened the lactone rings and formed the corresponding intermediates, which bore 1,3-dipole and dipolarophile functionalities in ortho positions. The intermediates partially underwent internal 1,3-dipolar cycloaddition to produce fused tetrazolone derivatives. When the carbonyl groups in anhydride were not conjugated with any double bond, then a triazine-fused tetrazolone derivative was formed.


Anticholinesterase Furocoumarins From Heracleum Platytaenium, A Species Endemic To The Ida Mountains, Demet Di̇ncel, Seda Damla Hatipoğlu, Ahmet Ceyhan Gören, Gülaçti Topçu Jan 2013

Anticholinesterase Furocoumarins From Heracleum Platytaenium, A Species Endemic To The Ida Mountains, Demet Di̇ncel, Seda Damla Hatipoğlu, Ahmet Ceyhan Gören, Gülaçti Topçu

Turkish Journal of Chemistry

The petroleum ether extract of Heracleum platytaenium afforded 8 furocoumarins (psoralen, bergapten, xanthotoxin, pimpinellin, isopimpinellin, sphondin, byakangelicin, and heraclenol) and the methanol extract of H. platytaenium gave only 1 glycosylated dihydrofurocoumarin, apterin. In addition, stigmasterol was also obtained from petroleum ether extract. Structure identification of the isolated compounds has been achieved by using spectroscopic methods, namely 1D and 2D NMR experiments and mass spectral analyses. The antioxidant activity of the extracts and pure compounds was investigated by 2 methods, including DPPH free radical scavenging activity and lipid peroxidation inhibitory activity by \beta-carotene-linoleic acid assays. The anticholinesterase activity of petroleum ether …


Synthesis Of Novel Benzimidazole Salts And Microwave-Assisted Catalytic Activity Of In Situ Generated Pd Nanoparticles From A Catalyst System Consisting Of Benzimidazol Salt, Pd(Oac)_2, And Base In A Suzuki-Miyaura Reaction, Ülkü Yilmaz, Hasan Küçükbay, Sevi̇m Türkteki̇n Çeli̇kesi̇r, Mehmet Akkurt, Orhan Büyükgüngör Jan 2013

Synthesis Of Novel Benzimidazole Salts And Microwave-Assisted Catalytic Activity Of In Situ Generated Pd Nanoparticles From A Catalyst System Consisting Of Benzimidazol Salt, Pd(Oac)_2, And Base In A Suzuki-Miyaura Reaction, Ülkü Yilmaz, Hasan Küçükbay, Sevi̇m Türkteki̇n Çeli̇kesi̇r, Mehmet Akkurt, Orhan Büyükgüngör

Turkish Journal of Chemistry

Novel benzimidazolium salts having N-benzyl or N-(4-substitutedbenzyl) groups were synthesized and their microwave-promoted catalytic activity for the Suzuki--Miyaura cross-coupling reaction were determined using in situ formed palladium(0) nanoparticles (PdNPs) from a catalytic system consisting of Pd(OAc)_2/K2CO_3 in DMF/H_2O. PdNPs were characterized by X-ray diffraction (XRD) pattern and particle size of in situ generated PdNPs from the Pd(111) plane was determined to be of diameter 19.6 nm by the Debye--Scherrer equation. Moreover, the yield of the Suzuki--Miyaura reactions with aryl iodides and aryl bromides was found to be nearly quantitative. The synthesized benzimidazole salts (1--5) were identified by ^1H and ^{13}C …


Optimization Of A Gas Chromatography--Mass Spectrometry Method Using Chemometric Techniques For The Determination Of Ezetimibe In Human Plasma, Ebru Uçaktürk, Nuran Özaltin Jan 2013

Optimization Of A Gas Chromatography--Mass Spectrometry Method Using Chemometric Techniques For The Determination Of Ezetimibe In Human Plasma, Ebru Uçaktürk, Nuran Özaltin

Turkish Journal of Chemistry

A new, rapid, and sensitive gas chromatography--mass spectrometry (GC-MS) method was developed for the determination of ezetimibe (EZE) in human plasma. EZE was derivatized prior to GC-MS analysis. Various derivatization techniques such as acetylation, methylation, and silylation were tried. EZE was extracted from plasma with high recovery (94.39%--97.57%) using methyl tertbutyl ether and carbonate buffer (pH 9). Chromatographic conditions were optimized using chemometric methods. In the first step, optimization with factorial design, chromatographic variables (initial and final column temperature, oven ramp rate, and flow rate of gas) were screened to select important variables for the retention of EZE. In the …


Synthesis, Characterization, And Fluorescence Study Of Phthalhydrazidylazo Derivative Of An Unsaturated Diketone And Its Metal Complexes, Radhika Pallikkavil, Muhammed Basheer Ummathur, Krishnannair Krishnankutty Jan 2013

Synthesis, Characterization, And Fluorescence Study Of Phthalhydrazidylazo Derivative Of An Unsaturated Diketone And Its Metal Complexes, Radhika Pallikkavil, Muhammed Basheer Ummathur, Krishnannair Krishnankutty

Turkish Journal of Chemistry

The coupling of diazotized luminol with the unsaturated diketone 1,7-diphenylhepta-4,6-diene-1,3-dione yielded a new type of tridentate ligand (H_2L). Analytical, IR, ^1H NMR, and mass spectral data indicate the existence of the compound in the intramolecularly hydrogen-bonded keto-hydrazone tautomeric form. Dibasic tridentate coordination of the compound in its [ML(H_2O)] complexes [M = Cu(II), Ni(II) and Zn(II)] was established on the basis of analytical and spectral data. The Ni(II) and Zn(II) chelates are diamagnetic while Cu(II) complex showed normal paramagnetic moment. The fluorescence maxima of the compound in different solvents show that the emission wavelength increases with increases in the polarity of …


Electrochemical Determination Of Sudan Iv In Food Samples By Using Graphene-Modified Glassy Carbon Electrodes, Meifeng Chen, Xinying Ma, Xia Li Jan 2013

Electrochemical Determination Of Sudan Iv In Food Samples By Using Graphene-Modified Glassy Carbon Electrodes, Meifeng Chen, Xinying Ma, Xia Li

Turkish Journal of Chemistry

A simple and sensitive modified electrode was fabricated with graphene via the drop-casting method and applied for the electrochemical detection of Sudan IV. Cyclic voltammetry (CV) was used to investigate the electrochemical behaviors of Sudan IV in phosphate buffer solution (PBS). The experimental conditions such as determining medium, scan rate, and accumulation time were optimized for the determination of Sudan IV. The sensor has excellent performance associated with high sensitivity, a low detection limit (6.00 \times 10^{-8} M), and a wide linear range of 2.00 \times 10^{-7} M to 8.00 \times 10^{-5} M with a correlation coefficient as follows: i_{pc} …


Asymmetric Henry Reaction Catalyzed By Cu(I)-Based Chiral Amino Alcohol Complex, Tianhua Shen, Quan Qin, Hang Ni, Ting Xia, Xiaocong Zhou, Funa Cui, Junqi Li, Deqiang Ran, Qingbao Song Jan 2013

Asymmetric Henry Reaction Catalyzed By Cu(I)-Based Chiral Amino Alcohol Complex, Tianhua Shen, Quan Qin, Hang Ni, Ting Xia, Xiaocong Zhou, Funa Cui, Junqi Li, Deqiang Ran, Qingbao Song

Turkish Journal of Chemistry

The Cu(I)-based complex prepared from (S)-2-(furan-2-yl-methylamino)-2-phenylethanol (5c) and CuCl was used as catalyst in enantioselective Henry reactions of arylaldehydes and nitromethane, which gave 89% ee and 95% yield at ambient temperature. The proposed catalytic cycle of an asymmetric Henry reaction was suggested.


Mechanochemical Modification Method Used In The Development Of New Composite Materials Based On Epoxy Binder And Natural Minerals, Umida Ziyamukhamedova, Dilshod Djumabaev, Botirali Shaymardanov Jan 2013

Mechanochemical Modification Method Used In The Development Of New Composite Materials Based On Epoxy Binder And Natural Minerals, Umida Ziyamukhamedova, Dilshod Djumabaev, Botirali Shaymardanov

Turkish Journal of Chemistry

This article highlights the results of a mechanochemical modification method of epoxy composite materials and coatings on their base. It proves the mechanochemical activated components of composition to be the most acceptable for structuring when producing composite materials. It also states the increase of mechanical properties of epoxy heterocomposite coatings with mechanically activated particles by 25%-40%.


Fabrication Of Layer-By-Layer Deposited Films Containing Carbon Nanotubes And Poly(Malachite Green) As A Sensor For Simultaneous Determination Of Ascorbic Acid, Epinephrine, And Uric Acid, Jahan Bakhsh Raoof, Reza Ojani, Mehdi Baghayeri Jan 2013

Fabrication Of Layer-By-Layer Deposited Films Containing Carbon Nanotubes And Poly(Malachite Green) As A Sensor For Simultaneous Determination Of Ascorbic Acid, Epinephrine, And Uric Acid, Jahan Bakhsh Raoof, Reza Ojani, Mehdi Baghayeri

Turkish Journal of Chemistry

A simple approach to constructing a double-layer voltammetric sensor is described. The poly(malachite green) (PMG) and multiwalled carbon nanotubes (MWCNTs) were coimmobilized at the surface of the glassy carbon electrode (GCE) for fabrication of PMG/MWCNT/GCE. The modified electrode was characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), differential pulse voltammetry (DPV), and chronoamperometric techniques. Using DPV, the obtained catalytic peak current was linearly dependent on the ascorbic acid (AA), epinephrine (EP), and uric acid (UA) concentrations in the ranges of 0.4-100.0, 0.1-100.0, and 0.3-90.0 \muM, respectively. The resultant detection limits for AA, EP, and UA were 0.23, 0.0820, and …


Synthesis, Characterization, And Swelling Behaviors Of A Ph-Responsive Cmc-G-Poly(Aa-Co-Amps) Superabsorbent Hydrogel, Yizhe Wang, Xiaoning Shi, Wenbo Wang, Aiqin Wang Jan 2013

Synthesis, Characterization, And Swelling Behaviors Of A Ph-Responsive Cmc-G-Poly(Aa-Co-Amps) Superabsorbent Hydrogel, Yizhe Wang, Xiaoning Shi, Wenbo Wang, Aiqin Wang

Turkish Journal of Chemistry

New superabsorbent hydrogels were synthesized through free radical graft copolymerization of partially neutralized acrylic acid (AA) and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) onto carboxymethyl cellulose (CMC) backbones. The structure and morphology of the synthesized superabsorbent hydrogels were characterized by Fourier transform infrared spectroscopy and scanning electron microscope. The effect of the molar ratio of AMPS to AA, the APS concentration, and the CMC content on swelling ratio was optimized. The swelling properties in various pH solutions and saline solutions as well as the swelling kinetics were also evaluated. Results showed that the introduction of AMPS enhanced the swelling capacity, swelling rate, and …


Synthesis And Characterization Of Ni(Ii) And Cu(Ii) Complexes Derived From Novel Phenolic Mannich Bases, Nurgün Büyükkidan, Sali̇h Özer Jan 2013

Synthesis And Characterization Of Ni(Ii) And Cu(Ii) Complexes Derived From Novel Phenolic Mannich Bases, Nurgün Büyükkidan, Sali̇h Özer

Turkish Journal of Chemistry

The novel phenolic Mannich bases 2,2'-(2-hydroxy-4,5- dimethylbenzylazanediyl)diethanol (1) and 2-((2-(4-(2-hydroxy-4,5- dimethylbenzyl)piperazin-1-yl)ethylamino)methyl)-4,5-dimethylphenol (2) have been synthesized in good yield by using a microwave-induced technique from 3,4-dimethylphenol and corresponding amines in the presence of formaldehyde. Metal complexes of 1 and 2 for Ni(II) (3 and 5) and for Cu(II) (4 and 6) have also been prepared and all compounds have been characterized by elemental and spectral analyses. Thermal, magnetic, and electronic studies have also been reported for metal complexes. Electronic spectra and magnetic susceptibility measurements suggested tetrahedral geometry for Ni(II) (3), square planar geometry for Cu(II) (4) complexes of 1, and octahedral …


Molecular Docking And Qsar Study On Imidazole Derivatives As 14 /Alpha -Demethylase Inhibitors, Asghar Davood, Maryam Iman Jan 2013

Molecular Docking And Qsar Study On Imidazole Derivatives As 14 /Alpha -Demethylase Inhibitors, Asghar Davood, Maryam Iman

Turkish Journal of Chemistry

14\alpha-Demethylase (CYP51) inhibitors have been widely used in the treatment of fungal infections. In this study, a series of imidazole derivatives with CYP51 inhibitory activity were subjected to a molecular docking study followed by quantitative structure-activity relationship (QSAR) analyses in search of the ideal physicochemical characteristics of potential CYP51 inhibitors. Desired imidazoles were built using the HyperChem program, and conformational studies were performed through a semiempirical method followed by the PM3 method. Docking study was performed using the AutoDock program on all of the compounds. Different QSAR descriptors were calculated using DRAGON, AutoDock, and HyperChem. Multilinear regression was used as …


New Secondary Metabolites From Croton Sparsiflorus Morong, Rashad Mehmood, Amna Bibi, Abdul Malik Jan 2013

New Secondary Metabolites From Croton Sparsiflorus Morong, Rashad Mehmood, Amna Bibi, Abdul Malik

Turkish Journal of Chemistry

Sparsifloamide (1), a new sphingolipid, and sparsifloside (2), a new diglyceride galactoside, have been isolated from the ethyl acetate soluble fraction of the 80% ethanolic extract of the whole plant of Croton sparsiflorus Morong. Their structures were assigned by ^1H- and ^{13}C-NMR spectra and DEPT, COSY, NOESY, HMQC, HMBC, and ESI-MS experiments.


Enaminonitriles In Heterocyclic Synthesis: Synthesis And Biological Evaluation Of Novel Indeno[2,1-B]Thiophene Derivatives, Ahmed A. Fadda, Abd El Galil M. Khalil, Eman H. Tawfik Jan 2013

Enaminonitriles In Heterocyclic Synthesis: Synthesis And Biological Evaluation Of Novel Indeno[2,1-B]Thiophene Derivatives, Ahmed A. Fadda, Abd El Galil M. Khalil, Eman H. Tawfik

Turkish Journal of Chemistry

No abstract provided.