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2008

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Articles 481 - 510 of 713

Full-Text Articles in Chemistry

Synthesis Of New Azo Dyes And Copper(Ii) Complexes Derived From Barbituric Acid And 4-Aminobenzoylhydrazone, Bülent Kirkan, Ramazan Gup Jan 2008

Synthesis Of New Azo Dyes And Copper(Ii) Complexes Derived From Barbituric Acid And 4-Aminobenzoylhydrazone, Bülent Kirkan, Ramazan Gup

Turkish Journal of Chemistry

Four new azo dyes, L^1, L^2, L^3, and L^4, were prepared by linking benzaldehyde p-aminobenzoylhydrazone (3) and p-hydroxybenzaldehyede p--aminobenzoylhydrazone (4) to barbituric acid and 1,3-dimethylbarbituric acid through diazo-coupling reactions. Reactions of the azo-dyes with copper chloride and bidentate ligand, 1,10-phenanthroline, produced mixed-ligand dinuclear complexes with general stoichiometry [Cu_2L(phen)_2]Cl_2 (7, 8, 9, and 10). The structures of both azo dyes and their complexes were identified by elemental analyses, FT-IR, ^1H-NMR, UV-VIS, magnetic susceptibility, and mass spectral data.

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Investigation Of Solid State Synthesis And Characterizations Of Novel Sodium Rare-Earth Oxyphosphates, Semi̇h Seyyi̇doğlu, Maci̇t Özenbaş, Ayşen Yilmaz Jan 2008

Investigation Of Solid State Synthesis And Characterizations Of Novel Sodium Rare-Earth Oxyphosphates, Semi̇h Seyyi̇doğlu, Maci̇t Özenbaş, Ayşen Yilmaz

Turkish Journal of Chemistry

A new orthorhombic phase of Na_2LaOPO_4 (sodium lanthanum oxyphosphate), and novel Na_2NdOPO_4 (sodium neodymium oxyphosphate), Na_2SmOPO_4 (sodium samarium oxyphosphate) were synthesized by solid state reactions of Na_2CO_3, NH_4H_2PO_4, and Ln_2O_3 (Ln = La, Nd, and Sm). The unit cell dimensions were calculated using their X-ray powder diffraction data, which were a = 13.60(1), b = 12.71(1), and c = 6.96(1) Å, a = 13.466(5), b = 12.547(6), and c = 6.932(5) Å, and a = 13.54(1), b = 12.577(8), and c = 7.047(5) Å, respectively, and the probable space group was Pmm2. Using the same procedure orthorhombic Na_2DyOPO_4 (sodium dysprosium …

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Preparation Of 1,5-Diketones By Addition Of Cyclohexanone To Chalcones Under Solvent-Free Phase Transfer Catalyst Condition, Mustafa Ceylan, Hayretti̇n Gezegen Jan 2008

Preparation Of 1,5-Diketones By Addition Of Cyclohexanone To Chalcones Under Solvent-Free Phase Transfer Catalyst Condition, Mustafa Ceylan, Hayretti̇n Gezegen

Turkish Journal of Chemistry

Eight different chalcone-1,5-diketone derivatives (5a-h) were prepared by the reaction of chalcone derivatives (3a-h) with cyclohexanone under the solvent-free phase transfer catalyst condition with modarate to high yields. The mechanistic pathway of the reaction can be explained by the Michael-type addition of cyclohexanone to chalcone derivatives (3a-h).

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Synthesis And Crystal Structure Of Pilloin, Hong-Bing Yang, Yan-Chang Wang, Zun-Ting Zhang, Yong Chang Jan 2008

Synthesis And Crystal Structure Of Pilloin, Hong-Bing Yang, Yan-Chang Wang, Zun-Ting Zhang, Yong Chang

Turkish Journal of Chemistry

Pilloin was synthesized by methylation of luteolin and its structure was characterized by element analysis, ^1H-NMR, IR, and single-crystal X-ray diffraction analysis. It crystallizes in the monoclinic crystal system, space group P2_1/n, with a = 7.336(3) Å, b = 14.257(5) Å, c = 13.298(5) Å, \beta = 93.516(5)°. The flavone molecules of pilloin are linked into puckering sheets via R_3^3(14) and R_2^2(9) graph-set ring motifs defined by the C-H...O and O-H...O hydrogen bonds. \pi -\pi stacking interactions lead to the flavone skeletons of columns that are held together through centrosymmetric R_2^2(8) motifs. Hydrogen bonding and aromatic \pi -\pi stacking interactions …

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A New Approach To The Calculation Of N-15 Chemical Shifts Of Cyclic Compounds, Emad A. S. Al-Hyali Jan 2008

A New Approach To The Calculation Of N-15 Chemical Shifts Of Cyclic Compounds, Emad A. S. Al-Hyali

Turkish Journal of Chemistry

Two sets of additive parameters used previously for the calculation of C-13 chemical shifts of mono and poly six-membered cycloalkanes were applied for the prediction of N-15 chemical shifts of some methyl piperidine derivatives. These sets are based on 2 principles: the p-character (substituents electronic effect) of the atom under consideration and the steric effect that reflects the spatial arrangement of the molecule. An additional parameter, namely the ring angle of the studied atom, was added to the other parameters to define the structural distortion that is due to large steric interactions. The p-character in set (1) is represented by …

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Synthesis Of New Bengazole Analogues And Their Antimicrobial Activity, Jurgen Krauss, Sandra Kalkbrenner, Angela Schuster, Anne Obainoke, Franz Bracher Jan 2008

Synthesis Of New Bengazole Analogues And Their Antimicrobial Activity, Jurgen Krauss, Sandra Kalkbrenner, Angela Schuster, Anne Obainoke, Franz Bracher

Turkish Journal of Chemistry

Bengazole A and bengazole B are 2 representatives out of a large family of marine metabolites isolated from a Jaspis sponge and display potent anti-fungal and anthelmintic activity as well as modest cytotoxic activity. This paper reports a short and efficient synthesis and microbiological evaluation of some new bengazole analogues.

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New Polyamides Derived From 2,5-Bis[(4-Carboxyanilino) Carbonyl] Pyridine And Hydantoin Derivatives: Synthesis And Characterization, Khalil Faghihi, Zohreh Mozaffari Jan 2008

New Polyamides Derived From 2,5-Bis[(4-Carboxyanilino) Carbonyl] Pyridine And Hydantoin Derivatives: Synthesis And Characterization, Khalil Faghihi, Zohreh Mozaffari

Turkish Journal of Chemistry

We synthesized 2,5-bis[(4-carboxyanilino) carbonyl] pyridine (4) as a new monomer containing pyridyl moiety by using a 2-step reaction. At first 2,5-pyridine dicarboxylic acid (1) was converted to 2,5-pyridine dicarbonyl dichloride (2). Then, diacid 4 was prepared by a condensation reaction of diacid chloride (2) with p-aminobenzoic acid (3). Then, 6 new polyamides (6a-f) were synthesized through the polycondensation reaction of 2,5-bis[(4-carboxyanilino) carbonyl] pyridine (4) with 6 different derivatives of hydantoins (5a-f) in a medium consisting of N-methyl-2-pyrrolidone, triphenyl phosphite, calcium chloride, and pyridine. The polycondensation reaction produced a series of novel polyamides containing pyridyl moiety in the main chain in …

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Synthesis And Antimicrobial Activities Of 1,2,4-Oxadiazin-5-One, 6-One And 5-Thiones, Nevi̇n Arikan, Doğan Sümengen, Başaran Dülger Jan 2008

Synthesis And Antimicrobial Activities Of 1,2,4-Oxadiazin-5-One, 6-One And 5-Thiones, Nevi̇n Arikan, Doğan Sümengen, Başaran Dülger

Turkish Journal of Chemistry

N-Substituted pyridine carboxamide oximes (2) were obtained from the reactions of pyridine hydroxamic acid chloride hydrochlorides (1) with primary amines. The reactions of carboxamide oximes with chloroacetyl chloride in the presence of triethylamine gave the corresponding 3,4-disubstituted-1,2,4-oxadiazin-5-ones (3), which on treatment with P_2S_5 gave in moderate yielded the corresponding 3,4-disubstituted-1,2,4-oxadiazin-5-thiones (4). The reaction of pyridine carboxamide oximes with \alpha-aminoacid ester led to the formation of 3,5-disubstituted-1,2,4-oxadiazin-6-ones (5) in moderate yields. The structures of the prepared compound were evaluated by spectroscopy. Some of the representatives of 3,4-disubstituted-1,2,4- oxadiazin-5-ones, thiones, and 3,5-disubstituted-1,2,4-oxadiazin-6-ones were screened for antibacterial activity using disc diffusion. It was …

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Partial Regeneration Of Ni-Based Catalysts For Hydrogen Production Via Methane Cracking, Reyyan Koç, Erdoğan Alper, Eric Croiset, Ali Elkamel Jan 2008

Partial Regeneration Of Ni-Based Catalysts For Hydrogen Production Via Methane Cracking, Reyyan Koç, Erdoğan Alper, Eric Croiset, Ali Elkamel

Turkish Journal of Chemistry

Methane cracking has the potential to produce high purity, carbon monoxide-free hydrogen suitable for application in PEM fuel cells. The 2 products of the reaction are molecular hydrogen and solid carbon. The carbon appears in the form of carbon filaments whose growth is hindered by carbon encapsulation leading to total deactivation of the catalyst. Several attempts have been made to regenerate the catalyst, mainly by gasifying the carbon filament in air or steam. Our work on 5-wt% Ni/\gamma-Al_2O_3 indicated that after complete gasification of the carbon the catalyst lost nearly all its activity toward methane cracking. However, if the gasification …

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The Synthesis And Anticonvulsant Activity Of 1-Substituted-7-Methoxy-1,2,4-Triazolo [4,~3-A]Quinoline, Li-Ping Guan, Xian-Yu Sun, Guan-Rong Tian, Kyu-Yun Chai, Zhe-Shan Quan Jan 2008

The Synthesis And Anticonvulsant Activity Of 1-Substituted-7-Methoxy-1,2,4-Triazolo [4,~3-A]Quinoline, Li-Ping Guan, Xian-Yu Sun, Guan-Rong Tian, Kyu-Yun Chai, Zhe-Shan Quan

Turkish Journal of Chemistry

A new series of 1-substituted-7-methoxy-5-phenyl-1,2,4-triazolo [4,3-a]quinolines were synthesized using ethyl-3-oxo-3-phenylpropanoate and 4-methoxybenzenamine as the starting material. Their anticonvulsant activity was evaluated by the maximal electroshock (MES) test and 7-methoxy-5-phenyl-1,2,4-triazolo[4,3-a]quinoline (4a) was identified as the most potent compound, with an ED_{50} value of 9.2 mg kg^{-1}, which is comparable to the reference drug phenytoin (ED_{50} = 9.9 mg kg^{-1}). To explore the possible mechanism of its anticonvulsant activity, compound 4a was tested with the rotarod neurotoxicity test, pentylenetetrazole (sc-PTZ) test, and isoniazid test. Compound 4a had a higher protective index (PI = TD_{50}/ED_{50}) value (16.6) than phenytoin (PI = 7.0), and …

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Synthesis And Properties Of New Polyamides Based On 4-Phenylenediacrylic Acid And Hydantoin Derivatives In The Main Chain, Khalil Faghihi Jan 2008

Synthesis And Properties Of New Polyamides Based On 4-Phenylenediacrylic Acid And Hydantoin Derivatives In The Main Chain, Khalil Faghihi

Turkish Journal of Chemistry

Six new polyamides (5a-f) containing p-phenylenediacrylic and hydantoin moieties in the main chain were prepared by direct polycondensation reaction of 4-phenylenediacrylic acid (3) with 6 different hydantoin derivatives (4a-f) using thionyl chloride and pyridine as condensing agents and N-methyl-2-pyrolidone as solvent. These new polymers (5a-f) were obtained in high yield and inherent viscosity between 0.35-0.55 dL/g. The resulting polyamides were characterized by elemental analysis, viscosity measurements, thermal gravimetric analysis (TGA and DTG), solubility test, and FT-IR and UV-vis spectroscopy. 4-Phenylenediacrylic acid (3) was prepared by the reaction of terephthal aldehyde (1) with malonic acid (2) in the presence of pyridine.

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Compounds Isolated From Tannacetum Polycephalum, . Azizuddin, Muhammad Iqbal Choudhary Jan 2008

Compounds Isolated From Tannacetum Polycephalum, . Azizuddin, Muhammad Iqbal Choudhary

Turkish Journal of Chemistry

Several known secondary metabolites, namely lupeol (1), \beta-sitosterol (2), stigmasterol (3), and 2,6-dimethoxy-4-hydroxy acetophenone (4) were isolated from a folkloric medicinal plant, Tannacetum polycephalum. The structures of these compounds were elucidated on the basis of various spectroscopic methods.

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Synthesis, Spectroscopic And Biological Investigation Of Cyclic Octapeptide: Cherimolacyclopeptide G, Rajiv Dahiya Jan 2008

Synthesis, Spectroscopic And Biological Investigation Of Cyclic Octapeptide: Cherimolacyclopeptide G, Rajiv Dahiya

Turkish Journal of Chemistry

A natural cyclic octapeptide cherimolacyclopeptide G (8) was synthesized by coupling of tetrapeptide units Boc-Gly-Ala-Val-Pro-OMe (5) and Boc-Ile-Tyr-Ala-Pro-OMe (6) after proper deprotection at carboxyl and amino terminals followed by cyclization of the linear peptide segment. The structure was elucidated by IR, ^1H-NMR, ^{13}C-NMR, FAB MS spectral data, and elemental analyses. The newly synthesized cyclopeptide was also evaluated for its antimicrobial, anthelmintic, and cytotoxic activities and found to exhibit potent anthelmintic and cytotoxic activity against earthworms, Megascoplex konkanensis, Pontoscotex corethruses, and Eudrilus species, and Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines. In addition, compound 8 possessed moderate …

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Orthogonal Signal Correction -- Partial Least Squares Method For Simultaneous Spectrophotometric Determination Of Nickel, Cobalt, And Zinc, Ali Niazi, Amir Azizi Jan 2008

Orthogonal Signal Correction -- Partial Least Squares Method For Simultaneous Spectrophotometric Determination Of Nickel, Cobalt, And Zinc, Ali Niazi, Amir Azizi

Turkish Journal of Chemistry

The simultaneous determination of nickel, cobalt, and zinc mixtures by spectrophotometric method is a difficult problem in analytical chemistry, due to spectral interferences. By multivariate calibration methods, such as partial least squares (PLS) regression, it is possible to obtain a model adjusted to the concentration values of the mixtures used in the calibration range. Orthogonal signal correction (OSC) is a preprocessing technique used for removing the information unrelated to the target variables based on constrained principal component analysis. OSC is a suitable preprocessing method for partial least squares calibration of mixtures without loss of prediction capacity using spectrophotometric method. In …

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Diphenylthiocarbazone Immobilized On The Triacetyl Cellulose Membrane As An Optical Silver Sensor, Meissam Noroozifar, Mozhgan Khorasani-Motlagh, Aboozer Taheri, Rohhollah Zare-Dorabei Jan 2008

Diphenylthiocarbazone Immobilized On The Triacetyl Cellulose Membrane As An Optical Silver Sensor, Meissam Noroozifar, Mozhgan Khorasani-Motlagh, Aboozer Taheri, Rohhollah Zare-Dorabei

Turkish Journal of Chemistry

An optical sensor for the direct measurement of silver was developed. The basic element of this optode is the immobilization of diphenylthiocarbazone on a triacetyl cellulose membrane. This optode has a linear range of up to 40 \mu g mL^{-1} of Ag^+ ions, with a limit of detection of 0.01 \mu g mL^{-1}. The response time of the optode was 4-7 min, depending on the concentration of Ag^+ ions.

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Synthesis Of Vertilecanin C And Two New Derivatives Of Vertilecanin A Via Nicotinic Acid, Serpi̇l Demi̇rci̇, Süleyman Göksu, Murat Boztaş, Ferhan Tümer, Hasan Seçen Jan 2008

Synthesis Of Vertilecanin C And Two New Derivatives Of Vertilecanin A Via Nicotinic Acid, Serpi̇l Demi̇rci̇, Süleyman Göksu, Murat Boztaş, Ferhan Tümer, Hasan Seçen

Turkish Journal of Chemistry

Vertilecanin C and 2 new phenyl-substituted derivatives of vertilecanin A were synthesized. Lithiation of 5-benzoylpicolinamide with BuLi at -78 °C followed by treatment with methyl bromoacetate gave vertilecanin C [methyl 2-(3-benzoylpicolinamido)acetate], a natural product. Vertilecanin A type phenopicolinic acid derivatives were synthesized starting from nicotinic acid in 4 steps. Chlorination of nicotinic acid with SOCl_2 followed by treatment with anisole in the presence of AlCl_3 gave (4-methoxyphenyl)(pyridin-3-yl)methanone. The Minisci reaction of the ketone afforded 5-(4-methoxybenzoyl)picolinamide. TiCl_4-catalyzed acidic hydrolysis of the picolinamide gave 5-(4-methoxybenzoyl) picolinic acid, from which 5-(hydroxy(4-methoxyphenyl) methyl)picolinic acid was obtained by selective reduction with NaBH_4. The same reaction …

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Synthesis And Characterization Of 4-(Alkylaminoisonitrosoacetyl)Diphenyl Ether And Some Of Their Metal Complexes, Ahmet Coşkun, Funda Yilmaz Jan 2008

Synthesis And Characterization Of 4-(Alkylaminoisonitrosoacetyl)Diphenyl Ether And Some Of Their Metal Complexes, Ahmet Coşkun, Funda Yilmaz

Turkish Journal of Chemistry

4-(Chloroacetyl)diphenyl ether (I) was synthesized from chloroacetyl chloride and diphenyl ether in the presence of AlCl_3 as catalyst in a Friedel-Crafts reaction. Subsequently, its keto oxime (II) derivative was prepared. Then 3 new substituted 4-(alkylaminoisonitrosoacetyl)diphenyl ether ligands derived from 4-(phenoxy)phenyloxylohydroxymoyl chloride and corresponding amines were synthesized. The following aromatic and aliphatic amines were used for the ligands ethanolamine, 2-amino-4-methylphenol, and 2-(aminomethyl) pyridine. Mononuclear or binuclear Co(II), Ni(II), Cu(II), and Cd(II) complexes of the ligands were synthesized. The structures of these ligands were identified by FT-IR, ^1H-NMR, and ^{13}C-NMR spectral data and elemental analysis, and the structures of the complexes were …

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Microcontact Printing Of An Alkylsilane Monolayer On The Surface Of Glass, Gülşi̇n Arslan, Mustafa Özmen, İmren Hatay, İlkay Hi̇lal Gübbük, Mustafa Ersöz Jan 2008

Microcontact Printing Of An Alkylsilane Monolayer On The Surface Of Glass, Gülşi̇n Arslan, Mustafa Özmen, İmren Hatay, İlkay Hi̇lal Gübbük, Mustafa Ersöz

Turkish Journal of Chemistry

This paper describes the use of microcontact printing (\mu CP) for patterning of self-assembled monolayers (SAMs) of (3-aminopropyl)-triethoxysilane (APTES) and octadecyltrichloro silane (OTS) on the surface of glass and functionalization of alkylsilane monolayers. After activation of the glass surface, which was patterned with OTS using a poly(dimethylsiloxane) (PDMS) stamp, the remaining bars of the surfaces were treated with APTES and then treated with a dye solution. The characterization of printed silane compounds was confirmed using fluorescence microscopy on the basis of the reaction between terminal amine groups of APTES and thionylchloride of Rhodamine-B dye. Quantitative 3-dimensional profiling was performed for …

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Characterization And Antimicrobial Activity Of Organotin(Iv) Complexes Of 2-[(2´,6´-Diethylphenylamido)]Benzoates And 3-[(2´,6´-Diethylphenylamido)]Propanoates, Saira Shahzadi, Khadija Shahid, Saqib Ali, Mohammad Bakhtiar Jan 2008

Characterization And Antimicrobial Activity Of Organotin(Iv) Complexes Of 2-[(2´,6´-Diethylphenylamido)]Benzoates And 3-[(2´,6´-Diethylphenylamido)]Propanoates, Saira Shahzadi, Khadija Shahid, Saqib Ali, Mohammad Bakhtiar

Turkish Journal of Chemistry

New organotin(IV) complexes with 2-[(2',6'-diethylphenylamido)] benzoic acid (HL^1) and 3-[(2',6' -diethylphenylamido)]propanoic acid (HL^2) were synthesized by the reaction of di- and triorganotin salts in the presence of triethylamine as base or dioctyltin oxide using a Dean and Stark trap for the removal of azeotropic water. All complexes were characterized by elemental analysis, IR, NMR, and mass spectral studies, and proof that tin-ligand coordination involves only the carboxylate group and complexes show hexa-coordinated geometry in solid state. Multinuclear NMR data show that triorganotin complexes exhibit 4-coordinated geometry while diorganotin complexes show a coordination number greater than 4, probably 5 or 6 …

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Synthesis And Characterization Of Novel Polyamide And Polyhydrazides Based On The 6,6´-Disubstituted-2,2´-Bipyridine, Abdurrahman Şengül, Hülya Arslan Jan 2008

Synthesis And Characterization Of Novel Polyamide And Polyhydrazides Based On The 6,6´-Disubstituted-2,2´-Bipyridine, Abdurrahman Şengül, Hülya Arslan

Turkish Journal of Chemistry

The monomers namely 6,6'-dicarbonylchloride-2,2'-bipyridine (1) and 6,6'-dihydrazine-2,2'-bipyridine (2) were synthesized and characterized thoroughly. The polyhydrazides (PHZ1 and PHZ2) were obtained by direct polycondensation of 2 with terephtaloylchloride (TPCl}), and novel polyamide (PA1) by direct polycondensation of 1 with hexametyhlenediamine (HMDA}). Polymers with low PDIs were generated in all cases (PD \sim 1.02-1.3). The polymers were characterized by ^1H and ^{13}C NMR, FT-IR, and Gel Permission Chromatography (GPC).

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Synthesis Of Some New 4-Oxo-4h-Chromene Derivatives Bearing Nitrogen Heterocyclic Systems As Antifungal Agents, Tarik El-Sayed Ali, Salah Abdel-Aghfaar Abdel-Aziz, Hafez Metwali El-Shaaer, Faten Ismail Hanafy, Ali Zaky El-Fauomy Jan 2008

Synthesis Of Some New 4-Oxo-4h-Chromene Derivatives Bearing Nitrogen Heterocyclic Systems As Antifungal Agents, Tarik El-Sayed Ali, Salah Abdel-Aghfaar Abdel-Aziz, Hafez Metwali El-Shaaer, Faten Ismail Hanafy, Ali Zaky El-Fauomy

Turkish Journal of Chemistry

Some new 4-oxo-4H-chromone derivatives bearing nitrogen heterocyclic systems were achieved by treatment of 3-[(4-aminophenylimino) methyl]-6-chloro-4-oxo-4H-chromene (2) with some aldehydes, cyclic oxygen, and halogen compounds, followed by heterocyclization. Significant antifungal activities were observed for some of the prepared compounds. Structures of all products were confirmed by elemental analysis, IR, ^1H-NMR, and mass spectra.

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Efficient Synthesis Of Imidazole Derivatives: An Important Synthon For The Preparation Of Biologically Active Compounds, Asghar Davood, Eskandar Alipour, Abbas Shafiee Jan 2008

Efficient Synthesis Of Imidazole Derivatives: An Important Synthon For The Preparation Of Biologically Active Compounds, Asghar Davood, Eskandar Alipour, Abbas Shafiee

Turkish Journal of Chemistry

4(5)-Chloro-imidazole-5(4)-carboxaldehyde derivatives are important precursors for the preparation of biologically active compounds. We developed a simple, novel, and efficient method for the synthesis of these compounds. The chemistry described is amenable to large-scale use and is flexible enough to allow the preparation of analogs.

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One-Step Synthesis Of Hyaluronic Acid-Based (Sub)Micron Hydrogel Particles: Process Optimization And Preliminary Characterization, Nurettin Sahiner, Xinqiao Jia Jan 2008

One-Step Synthesis Of Hyaluronic Acid-Based (Sub)Micron Hydrogel Particles: Process Optimization And Preliminary Characterization, Nurettin Sahiner, Xinqiao Jia

Turkish Journal of Chemistry

Hyaluronic acid (HA)-based (sub)micron hydrogel particles were synthesized by crosslinking virgin HA with divinyl sulfone (DVS) in sodium bis(2-ethylhexyl)sulfosuccinate (AOT) reverse micelle systems under basic conditions. Experimental parameters including HA molecular weight, solution concentration, and reaction time were systematically varied in order to obtain well defined hydrogel particles. The use of a cosurfactant, 1-heptanol (1-HP), had a profound effect on the reaction kinetics and the particle morphology. The resulting particles exhibit negative charges on their surfaces. In vitro biocompatibility study indicates that these particles do not cause severe death to the cultured fibroblasts. These HA-based hydrogel particles are promising candidates …

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Oxidative Cyclisation Of 3-Oxopropanenitriles Mediated Manganese(Iii) Acetate With 2-Thienyl Substituted Alkenes, Mehmet Yilmaz, Neşe Uzunali̇oğlu, Mehtap Yakut, A. Tarik Pekel Jan 2008

Oxidative Cyclisation Of 3-Oxopropanenitriles Mediated Manganese(Iii) Acetate With 2-Thienyl Substituted Alkenes, Mehmet Yilmaz, Neşe Uzunali̇oğlu, Mehtap Yakut, A. Tarik Pekel

Turkish Journal of Chemistry

The oxidative cyclisation of 3-oxopropanenitriles 1a-g with alkenes 2a-c containing 2-thienyl group by manganese(III) acetate was studied. Treatment of 3-oxopropanenitriles 1a-d with 2-[(E)-2-phenylvinyl] thiophene 2a gave 4-phenyl-5-(2-thienyl)-4,5-dihydrofuran-3-carbonitriles 3a-d in moderate yields (52%-60%). 5-(2-thienyl) substituted 4,5-dihydrofuran-3-carbonitriles 3e-i were obtained by the oxidative cyclisation of these 3-oxopropanenitriles with 2-[(E)-1-methyl-2- phenylvinyl]thiophene 2b in good yields (54%-68%). In addition, the reactions of 2-(1-phenylvinyl)thiophene 2c with various 3-oxopropanenitriles produced 4,5-dihydrofurans 3j-n containing heterocycle in 77%-91% yields.

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Electrocatalytic Oxidation Of D-Glucose Using A Cd Ad-Atom-Modified Au(111) Electrode In Alkaline Solution, Zekerya Dursun, Sami Ben Aoun, Isao Taniguchi Jan 2008

Electrocatalytic Oxidation Of D-Glucose Using A Cd Ad-Atom-Modified Au(111) Electrode In Alkaline Solution, Zekerya Dursun, Sami Ben Aoun, Isao Taniguchi

Turkish Journal of Chemistry

Au(111) single crystal electrodes were modified by underpotential deposition (UPD) of Cd ad-atoms with different coverages, which were used for the electrocatalytic oxidation of glucose in alkaline media. The catalytic activity of the electrodes was dependent on how the Cd ad-atoms covered the surface. Under the presented experimental conditions the monolayer (ML) Cd ad-atom-covered Au(111) electrode had the best catalytic activity on D-glucose oxidation, in terms of both potential shifts and peak current increases, as compared to the 0.11, 0.5, and 2 ML covered and bare Au(111) electrodes. Double layer capacity measurements revealed that the shifts of the potential of …

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Solid Phase Extraction Of Cadmium In Edible Oils Using Zinc Piperazinedithiocarbamate And Its Determination By Flame Atomic Absorption Spectrometry, Mehtap Yağan Aşci, Ayşegül Efendi̇oğlu, Beki̇r Bati Jan 2008

Solid Phase Extraction Of Cadmium In Edible Oils Using Zinc Piperazinedithiocarbamate And Its Determination By Flame Atomic Absorption Spectrometry, Mehtap Yağan Aşci, Ayşegül Efendi̇oğlu, Beki̇r Bati

Turkish Journal of Chemistry

A method was developed for preconcentration of cadmium with zinc-piperazinedithiocarbamate (ZnPDC) in edible oils and its determination by flame atomic absorption spectrometer (FAAS). The preconcentration method is based on the adsorption of the Cd(II) on to ZnPDC and the elution of them with mercury(II) nitrate. The accuracy of the method was tested with standard reference material (CONOSTAN S-21) and Cd added samples. Under optimum conditions, the recovery and the detection limit for cadmium were 99.67% (\pm 0.67) and 0.028 mg/L, respectively. The calibration curve was linear over the concentration range 0.1-3.0 mg/L (r^2 = 0.9979). The proposed method was applied …

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Synthesis And Antimicrobial Activity Of Some 3(2h)-Pyridazinone And 1(2h)-Phthalazinone Derivatives, Deni̇z S. Doğruer, Ti̇jen Önkol, Semi̇ha Özkan, Selda Özgen, M. Fethi̇ Şahi̇n Jan 2008

Synthesis And Antimicrobial Activity Of Some 3(2h)-Pyridazinone And 1(2h)-Phthalazinone Derivatives, Deni̇z S. Doğruer, Ti̇jen Önkol, Semi̇ha Özkan, Selda Özgen, M. Fethi̇ Şahi̇n

Turkish Journal of Chemistry

Some 3(2H)-pyridazinone and 1(2H)-phthalazinone derivatives were synthesized. The structures of these new compounds were confirmed by IR, ^1H-NMR, mass spectrum, and elemental analysis. The synthesized compounds were evaluated for their antibacterial activity against various gram-positive and gram-negative strains of bacteria and their clinical isolates and for their antimycobacterial activity against M. tuberculosis H37Rv. The results showed that the synthesized compounds were generally active against B. subtilis and its clinical isolate. Among the target compounds, compound 14c exhibited the best antibacterial activity, with a MIC value of 15.62 \mu g/mL against B. subtilis. Compound 15e had the highest antimycobacterial activity.

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The Crystal Structure Of 2-Nitro-N-(4-Nitrophenyl)Benzamide, Aamer Saeed, Shahid Hussain, Ulrich Flörke Jan 2008

The Crystal Structure Of 2-Nitro-N-(4-Nitrophenyl)Benzamide, Aamer Saeed, Shahid Hussain, Ulrich Flörke

Turkish Journal of Chemistry

2-Nitro-N-(4-nitrophenyl)benzamide was synthesized and characterized by spectroscopy and elemental analysis. The crystal structure was determined from single-crystal X-ray diffraction data. It crystallizes in the orthorhombic space group, P 2_12_12_1, with unit cell dimensions a = 8.9443(10) Å, b = 9.7147(11) Å, and c = 13.8016(16) Å. The dihedral angle between the 2 aromatic rings is 82.32(4)^{\circ}. The N2 and N3 nitro groups are oriented with respect to their attached phenyl rings at dihedral angles of 1.97(3)^{\circ} and 15.73(3)^{\circ}, respectively. The intramolecular C-H{\ldots}O hydrogen bond results in the formation of a non-planar 6-membered ring. In the crystal structure, intermolecular N-H...O hydrogen …

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Biologically Active Transition Metal Chelates With A 2-Thiophenecarboxaldehyde-Derived Schiff Base: Synthesis, Characterization, And Antibacterial Properties, Cezar Spinu, Maria Pleniceanu, Cristian Tigae Jan 2008

Biologically Active Transition Metal Chelates With A 2-Thiophenecarboxaldehyde-Derived Schiff Base: Synthesis, Characterization, And Antibacterial Properties, Cezar Spinu, Maria Pleniceanu, Cristian Tigae

Turkish Journal of Chemistry

Metal complexes, ML_2Cl_2, where M is Fe(II), Co(II), Ni(II), Cu(II), Zn(II), or Cd(II), and L is the Schiff base formed by condensation of 2-thiophenecarboxaldehyde with 2-aminopyridine, N-(2-thienylmethylidene)-2-aminopyridine (TNAPY) have been prepared and characterized by elemental analysis, and magnetic and spectroscopic measurements. Elemental analysis of the chelates suggests the stoichiometry is 1:2 (metal-ligand). Infrared and NMR spectra of the complexes agree with the coordination to the central metal atom through the nitrogen of the azomethine (-HC=N-) group and the sulfur atom of the thiophene ring. Magnetic susceptibility data coupled with electronic and ESR spectra suggest a distorted octahedral structure for the …

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Interaction Of Mefenamic Acid With Cobalt(Ii) Ions In Aqueous Media: Evaluation Via Classic And Response Surface Methods, Mohammad Edrissi, Nima Razzaghi Asl, Behrooz Madjidi Jan 2008

Interaction Of Mefenamic Acid With Cobalt(Ii) Ions In Aqueous Media: Evaluation Via Classic And Response Surface Methods, Mohammad Edrissi, Nima Razzaghi Asl, Behrooz Madjidi

Turkish Journal of Chemistry

Mefenamic acid reacts with cobalt(II) ions in aqueous alkaline medium to form a highly stable deep brown complex at ambient temperature. The complexation process was optimized in terms of pH, temperature, agitation rate, and contact time using classical studies. A response surface method based on Box-Behnken design was used to statistically model the complexation reaction and investigate factor effects along with their interactions. A quadratic model was developed using experimental data with a correlation coefficient of 0.9609. Numerical optimization was performed to achieve the optimum solutions of factor combinations. The results of the classical investigation and statistical method were in …

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