Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 87

Full-Text Articles in Physical Sciences and Mathematics

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 …


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%.


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, …


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.


Synthesis And Cytotoxic Activity Of Some 2-(2,3-Dioxo-2,3-Dihydro-1h-Indol-1-Yl)Acetamide Derivatives, Özlem Akgül, Ayşe Hande Tari̇koğullari, Fadi̇me Aydin Köse, Petek Ballar Kirmizibayrak, Mehmet Varol Pabuççuoğlu Jan 2013

Synthesis And Cytotoxic Activity Of Some 2-(2,3-Dioxo-2,3-Dihydro-1h-Indol-1-Yl)Acetamide Derivatives, Özlem Akgül, Ayşe Hande Tari̇koğullari, Fadi̇me Aydin Köse, Petek Ballar Kirmizibayrak, Mehmet Varol Pabuççuoğlu

Turkish Journal of Chemistry

Isatin, 1H-indoline-2,3-dione, an endogenous compound, is also a synthetically versatile molecule that possesses a diversity of biological activities including anticonvulsant, antibacterial, antifungal, antiviral, anticancer, and cytotoxic properties. Based on the promising cytotoxic activity studies on N-substituted isatin derivatives, a series of 18 derivatives of 2-(2,3-dioxo-2,3-dihydro- 1H-indol-1-yl)-N-phenylacetamide were designed, synthesized, and characterized according to their analytical and spectral data. All of the compounds were evaluated for their cytotoxic activity against MCF7, A549, HeLa, and HEK293 cell lines by real time cell analyzer. Etoposide was used as a standard compound. Briefly, ortho substitutions gave better results compared to meta and para substitutions …


Ionic Liquid Mediated Synthesis, Reactions, And Insecticidal Activity Of 1-[(1h-Benzoimidazol-2-Yl)Amino]Spiro[Azetidine-4,4'-[4'H]Chroman]-2-Ones, Dr Kanti Sharma, Renuka Jain Jan 2013

Ionic Liquid Mediated Synthesis, Reactions, And Insecticidal Activity Of 1-[(1h-Benzoimidazol-2-Yl)Amino]Spiro[Azetidine-4,4'-[4'H]Chroman]-2-Ones, Dr Kanti Sharma, Renuka Jain

Turkish Journal of Chemistry

Ionic liquid mediated synthesis of novel heterocyclic compounds 1-[(1H-benzoimidazol-2-yl)amino]-2'-phenylspiro[azetidine- 4,4'-[4'H]chroman]-2-ones (3) and 1-[(1H-benzoimidazol-2-yl)amino]- 3-chloro-2'-phenylspiro[aze tidine-4,4'-[4'H] chroman]-2-ones (4) was accomplished by condensing substituted 2-hydrazino benzimidazole (1), flavanone (2), and acetyl chloride/chloroacetyl chloride in ionic liquid, [bmim]PF_6 with or without using catalyst in excellent yield (90%--95%). Further, compounds 3 and 4 were acylated with trifluoroacetic anhydride to give N-acylated products (5 and 10); 3 when treated with HCHO and (C_2H_5)_2NH gave Mannich bases (6) and with aldehydes afforded 3-arylidene-2-azetidinone (7). Compounds 4 underwent nucleophilic substitution with (i) KI (Finkelstein reaction) and (ii) phenols to give the corresponding iodo and phenoxy derivatives (8 …


A One-Pot Strategy For Regioselective Synthesis Of 6-Aryl-3-Oxo-2,3-Dihydropyridazine-4-Carbohydrazides, Mehdi Rimaz, Hossein Mousavi Jan 2013

A One-Pot Strategy For Regioselective Synthesis Of 6-Aryl-3-Oxo-2,3-Dihydropyridazine-4-Carbohydrazides, Mehdi Rimaz, Hossein Mousavi

Turkish Journal of Chemistry

A simple and efficient method for the synthesis of 6-aryl-3-oxo-2,3-dihydropyridazine-4-carbohydrazide derivatives was developed. The synthesis was achieved via one-pot multicomponent reaction of arylglyoxals, dialkylmalonates, and hydrazine hydrate in pyridine at room temperature. This procedure features high regioselectivity, generally good to excellent yields, the use of easily available starting materials, and operational simplicity. This chemistry provides an efficient and promising synthetic strategy for diversity-oriented construction of the 6-arylpyridazinone skeleton.


Potentiometric Determination Of Some Food Additives And Their Binding To A Polycationic Species Using Polyion Sensors, Nedi̇me Dürüst, Ali̇ Kayansalan Jan 2013

Potentiometric Determination Of Some Food Additives And Their Binding To A Polycationic Species Using Polyion Sensors, Nedi̇me Dürüst, Ali̇ Kayansalan

Turkish Journal of Chemistry

Polycation-sensitive membrane electrodes based on dinonylnaphthalene sulfonate (DNNS) were examined for the determination of some polyanions, namely xanthan (Xanth), alginate (Alg), carboxymethyl cellulose (CMC), and carrageenan (Carr). The potentiometric titrations of polyanionic analytes yielded sharp end points and correlative stoichiometries. After the determinations were successfully performed in saline, these polyanions were also determined in some food products consumed in Bolu (Turkey). In addition, the titration data were used to estimate the interactions between titrant and polyanionic analytes. The equilibrium constants, K_{eq}, and the number of titrant binding sites (n) per mole of analyte polyanion were calculated using Scatchard plots. The …


Electrochemistry Of 2,6-Diaminopurine On Multiwall Carbon Nanotube Modified Glassy Carbon Electrode, Ebru Mavi̇oğlu Ayan, Şükri̇ye Karabi̇beroğlu, Zekerya Dursun Jan 2013

Electrochemistry Of 2,6-Diaminopurine On Multiwall Carbon Nanotube Modified Glassy Carbon Electrode, Ebru Mavi̇oğlu Ayan, Şükri̇ye Karabi̇beroğlu, Zekerya Dursun

Turkish Journal of Chemistry

The electrochemical oxidation of 2,6-diaminopurine (2,6-DAP) was studied in pH 7.4 phosphate buffer solution on multiwall carbon nanotube modified glassy carbon electrode (MWCNT/GCE) over a temperature range of 20 to 50 °C using cyclic voltammetry. 2,6-DAP oxidation on MWCNT/GCE showed a well-defined and irreversible oxidation peak at about 0.72 V vs. Ag/AgCl at pH 7.4. The oxidation potential of 2,6-DAP linearly varied with pH over the range of 3.0 to 10.0 with a slope of --0.0547 V/pH, implying that 2 protons were accompanied by 2 electrons transferred in the electrochemical reaction. The activation energy, Ea, of oxidation reaction was found …


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 …


A Phthalocyanine--Fluorescein Conjugate, İlker Ün, Yunus Zorlu, Hani̇fe İbi̇şoğlu, Fabienne Dumoulin, Vefa Ahsen Jan 2013

A Phthalocyanine--Fluorescein Conjugate, İlker Ün, Yunus Zorlu, Hani̇fe İbi̇şoğlu, Fabienne Dumoulin, Vefa Ahsen

Turkish Journal of Chemistry

A phthalocyanine--fluorescein conjugate was designed and prepared. Its photophysical properties (electronic absorption and fluorescence) were determined and compared with those of an analogous derivative functionalized by a simple triazole without chromophore. It is likely to be used as a theranostic agent in photodynamic therapy.


Synthesis, Spectroscopic Characterization, And Genotoxicity Of A New Group Of Azo-Oxime Metal Chelates, Beyza Cabi̇r, Bariş Avar, Mehmet Gülcan, Ahmet Kayraldiz, Mükerrem Kurtoğlu Jan 2013

Synthesis, Spectroscopic Characterization, And Genotoxicity Of A New Group Of Azo-Oxime Metal Chelates, Beyza Cabi̇r, Bariş Avar, Mehmet Gülcan, Ahmet Kayraldiz, Mükerrem Kurtoğlu

Turkish Journal of Chemistry

A new azo-oxime ligand, 2-[(E)-(hydroxyimino)methyl]-4-[(E)- (4-nitrophenyl)diazenyl]phenol, (pxoxH_2) (2), was prepared by condensation of hydroxylamminehydrochloride and 2-hydroxy5- [(4-nitrophenyl)diazenyl]benzaldehyde (1) with treatment of a solution of diazonium salt of p-nitroaniline and 2-hydroxybenzaldehyde in ethanol. The 6 coordination compounds, [Mn(pxoxH)_2(H_2O)_2].H_2O (3), [Co(pxoxH)_2(H_2O)_2].4H_2O (4), [Ni(pxoxH)_2(H_2O)_2].2H_2O (5), [Cu(pxoxH)_2].H_2O (6), [Zn(pxoxH)_2].6H_2O (7), and [Cd(pxoxH)_2(H_2O)_2].H_2O (8), were prepared by reacting Mn(II), Ni(II) Cu(II), Co(II), Zn(II), and Cd(II) ions with the ligand. The structures of the compounds were elucidated from the elemental analysis data and spectroscopic studies. The azo-oxime metal complexes were also characterized by XRD, magnetic moment, molar conductivity, and thermal analyses. Elemental analyses of the chelates …


An Expedient Synthesis Of 6-Vinylfulvene, İhsan Erden, Jenny Sabol, Ana Gubeladze, Andrea Ruiz Jan 2013

An Expedient Synthesis Of 6-Vinylfulvene, İhsan Erden, Jenny Sabol, Ana Gubeladze, Andrea Ruiz

Turkish Journal of Chemistry

6-Vinylfulvenes constitute a class of fulvenes that are difficult to access due to the lack of a general method for their synthesis. In particular, the unsubstituted parent system has been very difficult to obtain by existing methods. In this communication we describe a convenient 3-step protocol for the synthesis of the title compound by way of sulfide oxidation and subsequent sulfoxide elimination.


Photo- And Electroluminescence Behavior Of Biphenyl Containing Conjugated Polymer, Tuğba Kaya Deni̇z, Doğukan Hazar Apaydin, Ali̇ Can Özelçağlayan, Levent Kami̇l Toppare, Ali̇ Çirpan Jan 2013

Photo- And Electroluminescence Behavior Of Biphenyl Containing Conjugated Polymer, Tuğba Kaya Deni̇z, Doğukan Hazar Apaydin, Ali̇ Can Özelçağlayan, Levent Kami̇l Toppare, Ali̇ Çirpan

Turkish Journal of Chemistry

Light emitting properties of poly[4-(5-(biphenyl- 4-yl)-4-hexylthiophen-2-yl)-2-dodecyl-7-(4-hexyl-thiophen-2-yl)-2H-benzo[d][1,2,3]-triazole] (PPhHTBT) and poly(9-vinylcarbazole) (PVK) blends were investigated with a configuration of ITO/PEDOT-PSS/BLEND/Ca/Al in ratios ranging from 5 to 100 wt\% in PPhHTBT. Thin film and solution spectra of all blends revealed that energy transfer was completely achieved. Device performance increased for all blends and reached 1.1 cd/A for 30 wt\% PPhHTBT.


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.


Optimization Of Synthesizing Glucose 1-Phosphate By Sodium Tripolyphosphate As A Phosphorus Acylating Agent Using Response Surface Methodology, Li 'E Jin, Fenfen Chang, Xiao Juan Wang, Qing Cao Jan 2013

Optimization Of Synthesizing Glucose 1-Phosphate By Sodium Tripolyphosphate As A Phosphorus Acylating Agent Using Response Surface Methodology, Li 'E Jin, Fenfen Chang, Xiao Juan Wang, Qing Cao

Turkish Journal of Chemistry

With glucose as the starting material, sodium tripolyphosphate as the phosphorus acylating agent, and urea as the catalyst, glucose 1-phosphate was synthesized and its properties were analyzed. The synthesis conditions were selected according to the phosphorus content and optimized through the response surface methodology (RSM), based on a 3-level, 3-variable Box--Behnken experimental design. The results showed that the phosphorus content of glucose 1-phosphate was 8.12% using a reaction temperature of 70 °C, a molar ratio of glucose to sodium tripolyphosphate of 1.54:1, and catalyst amount of 3.7 g. It coincided well with the experimental value (8.34%). The structure of the …


Determination And Evaluation Of Gross Alpha And Beta Activity Concentrations And Metal Levels In Thermal Waters From Ankara, Turkey, Orhan Acar, Orhan Murat Kalfa, Özcan Yalçinkaya, Ali̇ Rehber Türker Jan 2013

Determination And Evaluation Of Gross Alpha And Beta Activity Concentrations And Metal Levels In Thermal Waters From Ankara, Turkey, Orhan Acar, Orhan Murat Kalfa, Özcan Yalçinkaya, Ali̇ Rehber Türker

Turkish Journal of Chemistry

The gross \alpha and \beta activity concentrations in the thermal waters of Karakaya-Ayaş, İçmece-Ayaş, Beypazarı (Dutluk-Tahtalı), Haymana, and Kızılcahamam spas in Ankara Province were measured by MPC-9604 multi-detector \alpha /\beta counting system. Ranges of activity concentrations found were from 0.09 to 2.58 Bq L^{-1} for gross \alpha and from 0.25 to 2.61 Bq L^{-1} for gross \beta . The ranges of minimum detectable concentrations for gross \alpha (0.05--0.41 Bq L^{-1}) and for gross \beta (0.04--0.29 Bq L^{-1}) were obtained. Gross \alpha and \beta activity concentrations found in samples were compared with the recommended guidelines of the World Health Organization and …


Aerosol-Assisted Chemical Vapor Deposition Of Copper Sulfide Nanostructured Thin Film From Newly Synthesized Single-Source Precursor, Sohail Saeed, Naghmana Rashid, Khurram Shahzad Ahmad Jan 2013

Aerosol-Assisted Chemical Vapor Deposition Of Copper Sulfide Nanostructured Thin Film From Newly Synthesized Single-Source Precursor, Sohail Saeed, Naghmana Rashid, Khurram Shahzad Ahmad

Turkish Journal of Chemistry

The copper(II) complex of N-[ethyl(butyl)carbamothioyl]- 3,5-dinitrobenzamide (1) has been synthesized and characterized by elemental analysis, IR spectroscopy, and atmospheric pressure chemical ionization-mass spectrometry. Thermogravimetric analysis shows that complex 2 decomposes in 2 steps to form copper sulfide. The complex was used as a single-source precursor for the deposition of copper sulfide thin film by aerosol-assisted chemical vapor deposition at 350 °C. The powder X-ray diffraction pattern of thin film of the complex showed the deposition of monoclinic roxbyite Cu_7S_4 and orthorhombic anilite Cu_7S_4 phases at 350 °C with spherical crystallites. The degree of film surface roughness was determined by atomic …


Synthesis Of New N-[3-(Benzo[D]Thiazol-2-Yl)-4-Methylthiazol-2(3h)-Ylidene] Substituted Benzamides, Aamer Saeed, Hummera Rafique Jan 2013

Synthesis Of New N-[3-(Benzo[D]Thiazol-2-Yl)-4-Methylthiazol-2(3h)-Ylidene] Substituted Benzamides, Aamer Saeed, Hummera Rafique

Turkish Journal of Chemistry

A series of novel N-[3-(2-benzo[d]thiazol-2-yl)-4-methylthiazol-2(3H)-ylidene] substituted benzamides (2a--k) were efficiently synthesized by heterocyclization of the corresponding 1-(benzo[d]thiazol-2-yl)-3-aroylthioureas (1a--k). The cyclization was achieved by the reaction of \alpha-bromoacteone produced in situ using bromine in dry acetone in the presence of triethylamine.


Syntheses, Characterization, And Antibacterial Study Of Titanium Complexes, Raj Kaushal, Nitesh Kumar, Pamita Awasthi, Kiran Nehra Jan 2013

Syntheses, Characterization, And Antibacterial Study Of Titanium Complexes, Raj Kaushal, Nitesh Kumar, Pamita Awasthi, Kiran Nehra

Turkish Journal of Chemistry

Titanium(II) complexes of composition TiCl_2(L)_2 [where L = 2,2'-bipyridine (bipy), 4,4'-dimethyl-2,2'-bipyridine (bpMe), 4,4'-dimethoxy-2,2'-bipyridine (bpoMe), 6,6'-dimethyl-2,2'-bipyridine (dpMe), adamantylamine (ada)] were prepared by reacting titanium tetrachloride and N-containing bulky ligands in predetermined molar ratios. The complexes synthesized were characterized by different spectroscopic techniques, viz. UV-visible, FTIR, ^1H NMR, and mass spectrometry. The stoichiometry of the complexes was established by their elemental analysis (chlorine and titanium estimation). The unit cell parameters calculated by using the powder XRD tool confirm the monoclinic unit system and P lattice type for all complexes. Antibacterial screening of the ligands as well as the complexes was carried out …


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} …


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.


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 …


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.


New Synthetic Methodology For Construction Of The 3,4-Dihydroquinolin-2-One Skeleton, Çağatay Dengi̇z, Meti̇n Balci Jan 2013

New Synthetic Methodology For Construction Of The 3,4-Dihydroquinolin-2-One Skeleton, Çağatay Dengi̇z, Meti̇n Balci

Turkish Journal of Chemistry

We hereby report a new method for preparation of 3,4-dihydroquinolin-2(2H)-one starting from the methyl 2-(2-carboxyethyl)benzoic acid. The acid functionality, adjacent to the methylene, was regiospecifically converted to the desired methyl ester and the remaining acid functionality was transferred into acyl azide. Curtius rearrangement of acyl azide followed by trapping with aniline and alcohols provided the corresponding urea and urethane derivatives. Hydrolysis of methyl ester groups gave the acids. Ring closure in the presence of thionyl chloride resulted in the formation of the 3,4-dihydroquinolin-2(2H)-one skeleton.


Study On Crystal Transformation Process Of Magnesium Carbonate Hydrate Based On Salt Lake Magnesium Resource Utilization, Juan Du, Zhen Chen, Yulong Wu, Mingde Yang, Jie Dang, Jianjun Yuan Jan 2013

Study On Crystal Transformation Process Of Magnesium Carbonate Hydrate Based On Salt Lake Magnesium Resource Utilization, Juan Du, Zhen Chen, Yulong Wu, Mingde Yang, Jie Dang, Jianjun Yuan

Turkish Journal of Chemistry

The crystal transformation process of magnesium carbonate hydrate by the reaction of magnesium sulfate (MgSO_4) with ammonium carbonate [(NH_4)_2CO_3] was investigated. MgSO_4 is one of the main magnesium resources of the Lop Nur salt lake in the Xinjiang Autonomous Region of China. Magnesium carbonate hydrates with different chemical compositions were prepared. The transformation process of the 2 crystals, MgSO_4 and (NH_4)_2CO_3, was analyzed by Raman spectroscopy, and the associated changes in crystal morphology were observed by scanning electron microscopy. The needle-like MgCO_3 \cdot 3H_2O transformed into sheet-like 4MgCO_3 \cdot Mg(OH)_2 \cdot 4H_2O when the temperature was increased from 323 K …


Synthesis And Characterization Of New Chromogenic Substrates For Exoglycosidases: \Alpha-Glucosidase, \Alpha-Mannosidase, And \Beta-Galactosidase, Dumitru Petru Iga, Richard Schmidt, Silvia Iga, Corina Loredana Hotoleanu, Florentina Duica, Alina Nicolescu, Silvia Stefania Gitman Jan 2013

Synthesis And Characterization Of New Chromogenic Substrates For Exoglycosidases: \Alpha-Glucosidase, \Alpha-Mannosidase, And \Beta-Galactosidase, Dumitru Petru Iga, Richard Schmidt, Silvia Iga, Corina Loredana Hotoleanu, Florentina Duica, Alina Nicolescu, Silvia Stefania Gitman

Turkish Journal of Chemistry

Glycosides of 4-nitrocatechol (1,2-dihydroxy 4-nitrobenzene) with \alpha-D-glucopyranose and \alpha-D-mannopyranose were synthesized by the glycosylation of phenol with peracetylated sugars in the presence of BF_3\cdot OBu_2. The glycoside of 4-nitrocatechol with \beta-D-galactopyranose was prepared by the glycosylation of this phenol as sodium phenoxide with tetra-O-benzoyl-\alpha-D- galactopyranosyl bromide. The structure of the reaction products was confirmed by ^1 H and ^{13}C NMR spectra and by chemical analysis. The latter consisted of acidic hydrolysis, followed by ethyl ether extraction and colorimetric determination of 4-nitrocatechol in the ether phase and application of the anthrone method for the sugar in the water phase. The synthetic …


Adsorption Equilibrium Of Water Vapor On Activated Carbon And Alumina And Carbon And Alumina Impregnated With Hygroscopic Salt, Ioan Solomon, Ana Mafalda Ribeiro, Joao Carlos Santos, Jose Miguel Loureiro, Alirio E. Rodrigues, Ion Sandu, Ioan Mamaliga Jan 2013

Adsorption Equilibrium Of Water Vapor On Activated Carbon And Alumina And Carbon And Alumina Impregnated With Hygroscopic Salt, Ioan Solomon, Ana Mafalda Ribeiro, Joao Carlos Santos, Jose Miguel Loureiro, Alirio E. Rodrigues, Ion Sandu, Ioan Mamaliga

Turkish Journal of Chemistry

The adsorption equilibrium of water vapor on different adsorbent materials has been studied. Small grains of commercial activated carbon and alumina, with a diameter of d_g = 1.5 \times 10^{-3} m, were impregnated with a hygroscopic salt (calcium chloride) to improve the performance of these materials. The main characteristics of the new composite materials were obtained by adsorption/desorption of nitrogen at 77 K and salt distribution on the adsorbent surface was shown using scanning electron microscopy. The adsorption equilibrium isotherms of water vapor were measured by a gravimetric system at 2 different temperatures in the case of alumina and impregnated …


A Two-Component Protocol For Synthesis Of 3-(2-(Substituted Phenylamino)Thiazol-4-Yl)-2h-Chromen-2-Ones, Aamer Saeed, Mubeen Arif, Madiha Irfan, Michael Bolte Jan 2013

A Two-Component Protocol For Synthesis Of 3-(2-(Substituted Phenylamino)Thiazol-4-Yl)-2h-Chromen-2-Ones, Aamer Saeed, Mubeen Arif, Madiha Irfan, Michael Bolte

Turkish Journal of Chemistry

An efficient 2-component synthesis of a series of 3-(2-(substituted phenylamino)thiazol-4-yl)-2H-chromen-2-ones (3a--j) was achieved by the reaction of 3-(2-thiocyanatoacetyl)-2H-chromen-2-one (1) with a variety of suitably substituted anilines in 1:1 molar ratio in ethanol. The structures of the products were established by elemental analyses, and UV-vis, FTIR, ^1H and ^{13}C NMR, and mass spectroscopy. 3-(2-(4-Methylphenylamino)thiazol-4-yl)-2H-chromen-2-one (3j) was further characterized by single crystal X-ray diffraction study. This compound, C_{19}H_{14}N_2OS, crystallizes in the orthorhombic space group Pna21, with Z = 4, and unit cell parameters a = 13.0785(11), b = 25.746(2), c = 4.7235(3) Å, \alpha = \beta = \gamma = 90°.