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Full-Text Articles in Physical Sciences and Mathematics

Zinc Perchlorate Hexahydrate Catalyzed Mono- And Bis-Transesterification Of Malonic Esters, Servet Tural Jan 2008

Zinc Perchlorate Hexahydrate Catalyzed Mono- And Bis-Transesterification Of Malonic Esters, Servet Tural

Turkish Journal of Chemistry

Commercially available zinc perchlorate hexahydrate [Zn(ClO_4)_2.6H_2O] was found to be a highly effective catalyst for the transesterification of malonic esters with alcohols. The treatment of methyl-, ethyl-, or \alpha-substituted malonic esters with primary or secondary alcohols in the presence of a catalytic amount of zinc perchlorate results in good to high yields of the corresponding esters (68%-99%). Mono-transesterification products are also obtained in moderate to good yields (22%-42%). The reaction was also carried out with 2-mono- and di-substituted malonic esters, and in the case of 2-mono- and di-substituted malonic esters, the reaction time is, in some cases, shorter, in which …


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.


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 …


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 …


Synthesis And Characterization Of Novel Azole Heterocycles Based On 2,5-Disubstituted Thiadiazole, Nadia A. Salih Jan 2008

Synthesis And Characterization Of Novel Azole Heterocycles Based On 2,5-Disubstituted Thiadiazole, Nadia A. Salih

Turkish Journal of Chemistry

Starting from 2-amino-5-mercapto-1,3,4-thiadiazole (1), a variety of new 1,2,4-triazino[5,4-b][1,3,4] thiadiazole (3), pyrazole (4), [1,2,4]triazolo[3,4-b] [1,3,4]thiadiazole (5), phthalazine-3,6-dione (6), azo derivatives (9), pyrimidine -2,4,6-trione (11), Schiff base (12) and pyrrolidine (13) derivatives have been synthesized. All proposed structures were supported by FT-IR, ^1H-NMR, ^{13}C-NMR elemental analysis, and MS spectroscopic data.


Cyanoacetamide Derivatives As Synthons In Heterocyclic Synthesis, Ahmed Ali Fadda, Samir Bondock, Ramy Rabie, Hassan Ali Etman Jan 2008

Cyanoacetamide Derivatives As Synthons In Heterocyclic Synthesis, Ahmed Ali Fadda, Samir Bondock, Ramy Rabie, Hassan Ali Etman

Turkish Journal of Chemistry

This review presents a systematic and comprehensive survey of the methods of preparation and the chemical reactivity of cyanoacetamide derivatives. These compounds are important intermediates for the synthesis of a variety of otherwise difficult to obtain synthetically useful and novel heterocyclic systems.


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 …


Behaviour Of Salicylaldehyde And Some Of Its Derivatives In The Biginelli Reaction For The Preparation Of Aryl Tetrahydropyrimidines, Eman M. H. Abbas, Shadia M. Abdallah, Mervat H. Abdoh, Hanaa A. Tawfik, Wageeh S. El-Hamouly Jan 2008

Behaviour Of Salicylaldehyde And Some Of Its Derivatives In The Biginelli Reaction For The Preparation Of Aryl Tetrahydropyrimidines, Eman M. H. Abbas, Shadia M. Abdallah, Mervat H. Abdoh, Hanaa A. Tawfik, Wageeh S. El-Hamouly

Turkish Journal of Chemistry

Salicylaldehyde and some of its derivatives react with urea (or thiourea) and ethyl acetoacetate (the Biginelli reaction) to give products that depend on the type of the substituent in the ortho-position to the hydroxyl group. Aldehydes having oxygen-bearing substituents ortho to the hydroxyl group (e.g., OCH_3, NO_2, COOH) undergo chelation with the hydroxyl proton and lead to 4-aryl-6-methyl-4-aryl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-ethyl carboxylate (the classical Biginelli product). Compounds not having such a property give oxacyclic products formed by addition of the hydroxyl proton to the C5-C6 double bond of the pyrimidine ring. This study also includes compounds having an amino group instead of the …


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 …


A Hydrogen Ion-Selective Poly(Vinyl Chloride) Membrane Electrode Based On Calix[4]Arene As A Perchlorate Ion-Selective Electrode, Esi̇n Canel, Sevcan Erden, Ayça Demi̇rel Özel, Sahahabuddin Memon, Mustafa Yilmaz, Esma Kiliç Jan 2008

A Hydrogen Ion-Selective Poly(Vinyl Chloride) Membrane Electrode Based On Calix[4]Arene As A Perchlorate Ion-Selective Electrode, Esi̇n Canel, Sevcan Erden, Ayça Demi̇rel Özel, Sahahabuddin Memon, Mustafa Yilmaz, Esma Kiliç

Turkish Journal of Chemistry

A hydrogen ion-selective electrode was prepared using 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetracyanometoxy-calix[4]arene and the possibility of its use as a perchlorate ion-selective electrode was investigated using its characteristic of becoming perchlorate sensitive in acidic regions. The electrode of the optimum characteristic had a composition of 1% ionophore, 66% o-NPOE, and 33% PVC. This electrode exhibited a linear response over the range 1.0 \times 10^{-1}-1.0 \times 10^{-5} M of perchlorate with a slope of 48.7 \pm 0.5 mV per p[ClO_4]. The effects of the pH and the membrane composition were also investigated. The lifetime of the electrode was at least 4 months and its response …


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 …


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).


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.


Synthesis And Swelling Behavior Of Starch-Poly (Sodium Acrylate-Co-Acrylamide) Superabsorbent Hydrogel, Mohammad Sadeghi, Hossein Hosseinzadeh Jan 2008

Synthesis And Swelling Behavior Of Starch-Poly (Sodium Acrylate-Co-Acrylamide) Superabsorbent Hydrogel, Mohammad Sadeghi, Hossein Hosseinzadeh

Turkish Journal of Chemistry

Superabsorbent polymers based on starch (St) and polyacrylonitrile (PAN) were prepared by alkaline hydrolysis of the physical mixture of St and PAN in aqueous solution. The nitrile groups of PAN were completely converted to a mixture of hydrophilic carboxamide and carboxylate groups during alkaline hydrolysis, followed by in situ cross-linking of the PAN chains by the alkoxide ions of St. A proposed mechanism for hydrogel formation was suggested and the structure of the product was established using FTIR spectroscopy. Moreover, morphology of the samples was examined by scanning electron microscopy. The factors that influenced the swelling capacity of the hydrogels …


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.


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.


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 …


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 …


Synthesis And Antimicrobial Evaluation Of Novel Di-Triazoles And 4-Arylidene Amino 4,5 Dihydro-1h-[1,2,4] Triazole-5-One Derivatives, Yasemi̇n Ünver, Esra Düğdü, Kemal Sancak, Mustafa Er, Şengül Alpay Karaoğlu Jan 2008

Synthesis And Antimicrobial Evaluation Of Novel Di-Triazoles And 4-Arylidene Amino 4,5 Dihydro-1h-[1,2,4] Triazole-5-One Derivatives, Yasemi̇n Ünver, Esra Düğdü, Kemal Sancak, Mustafa Er, Şengül Alpay Karaoğlu

Turkish Journal of Chemistry

A series of novel di-[3(thiophen-2-yl-methyl)-4,5-dihydro-1H- [1,2,4]triazole-5-one-4yl]n-alkanes (2a-h) were obtained by the reaction of N'-1-ethoxy-2-thiophen-2-yl-ethylydene hydrazino carboxylic acid ethyl ester (1) and diamines. Compound 3 was reacted with aldehydes and 4-(arylidene-amino)-3-thiophen-2-yl-methyl-4,5-dihydro-1H-[1,2,4] triazole-5-ones (4, 5, and 8) with Schiff base character were synthesized. (4-(arylidene-amino)-5-oxo-3-thiophen-2-yl-methyl-4,5- dihydro-1H-[1,2,4]triazole-1-yl)-acetic acid ethyl esters (6, 7, and 9) were obtained by the reaction of 4-(arylidene-amino)-3-thiophen-2-yl- methyl-4,5-dihydro-1H-[1,2,4]triazole-5-ones (4, 5, and 8) and ethyl bromoacetate. The structures of the new compounds were inferred through IR, ^1H/^{13}C NMR, elemental analyses, and mass spectral data. Compound 8i was characterized by IR, ^1H/^{13}C NMR, elemental analyses, mass, and X-ray spectral techniques. Geometry optimization …


Determination Of Iridoid Glycosides From Four Turkish Lamium Species By Hplc-Esi/Ms, Funda Nuray Yalçin, Duygu Kaya, İhsan Çaliş, Tayfun Ersöz, Erhan Palaska Jan 2008

Determination Of Iridoid Glycosides From Four Turkish Lamium Species By Hplc-Esi/Ms, Funda Nuray Yalçin, Duygu Kaya, İhsan Çaliş, Tayfun Ersöz, Erhan Palaska

Turkish Journal of Chemistry

An HPLC-ESI/MS method that enables fast detection and identification of iridoid glycosides is described. Eleven iridoid glycosides known to occur in the genus Lamium-lamalbide, sesamoside, 6-\beta-OH ipolamiide, shanzhiside methyl ester, dehydropenstemoside, barlerin (= 8-O-acetylshanzhiside methyl ester), 6-O-syringyl-8-O- acetylshanzhiside methyl ester, lamerioside, lamiide, eriobioside, and ipolamiide, were identified by means of their retention time and ESI/MS data. This method was successfully applied to the identification of the iridoid composition of the n-butanol extracts of Lamium eriocephalum Bentham subsp. eriocephalum, L. garganicum L. subsp. pulchrum R. Mill, L. garganicum L. subsp. laevigatum Arcangeli, and L. purpureum L. var. purpureum from the Turkish …


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.


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 …


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 …


Potentiometric Utility Of The New Solid-State Sensor Based On Crowned Ionophore For The Determination Of K^+, Bariş Kemer, Mustafa Özdemi̇r Jan 2008

Potentiometric Utility Of The New Solid-State Sensor Based On Crowned Ionophore For The Determination Of K^+, Bariş Kemer, Mustafa Özdemi̇r

Turkish Journal of Chemistry

All solid-state contact poly vinyl chloride (PVC) membrane potassium-selective electrode has been developed. The construction of the ion selective electrode membrane was organized using ionophore 4,4'-bis[4''-phenoxy(15-crown-5) methyl]benzyl in PVC cocktail. The potentiometric performance characteristics of the electrode were investigated by a computerized system. The electrode was found highly selective to K^+ ions over a wide variety of other cations. The electrode almost exhibited a Nernstian response (\ge 55 (\pm15) mV/decade of K activity) to K^+ within the concentration range 1.5 x 10^{-1} - 1.0 \times 10^{-5} M. The operational pH range of the electrode was 5--7. The response time of …


Preparation And Potentiometric Study Of Promethazine Hydrochloride Selective Electrodes And Their Use In Determining Some Drugs, Nabil S. Nassory, Shahbaz A. Maki, Bashaer A. Al-Phalahy Jan 2008

Preparation And Potentiometric Study Of Promethazine Hydrochloride Selective Electrodes And Their Use In Determining Some Drugs, Nabil S. Nassory, Shahbaz A. Maki, Bashaer A. Al-Phalahy

Turkish Journal of Chemistry

Promethazine hydrochloride selective electrodes were constructed based on promethazine-phosphotun- gstic acid ion pair in PVC matrix membrane. The plasticizers used were di-butyl phosphate (DBP), tri-n-butyl phosphate (TBP), o-nitro phenyl octyl ether (ONPOE), and di-n-butyl phthalate (DBPH). The electrodes based on DBP, TBP, and ONPOE gave the same linear range between 1 x 10^{-4} and 1 x 10^{-1} M, while the one based on DBPH ranged between 5 x 10^{-4} and 1 x 10^{-1}M. The slopes for linear range ranged from 40 to 56 mV/decade with correlation coefficients lying between 0.9984 and 0.9993. The best detection limit was 2 x 10^{-5}M …


Langmuir Aggregation Of Congo Red On Cpc And Its Application, Xiang-Hu Liu, Jiao-Rong Ren, Ya-Nan Huang, Jing Bai, Hong-Wen Gao Jan 2008

Langmuir Aggregation Of Congo Red On Cpc And Its Application, Xiang-Hu Liu, Jiao-Rong Ren, Ya-Nan Huang, Jing Bai, Hong-Wen Gao

Turkish Journal of Chemistry

In this paper, microsurface adsorption-spectral correction technique (MASCT) was used to research the interaction between negatively charged sodium diphenyl diazo-bis-\alpha -naphthylamine-4-sulfonate (Congo Red, CR) and positively charged cetylpyridinium chloride (CPC) in a pH 2.03 BR buffer solution. The experiment results indicate that CR was absorbed on the surface of CPC mainly through electrostatic attraction. This aggregation obeys the Langmuir isothermal adsorption equation. The maximal binding number of CR to CPC was calculated to be 1.2 and the adsorption constant was about 2.03 \times 10^5 L/mol. This CR-CPC binding product is insensitive to a concentrated electrolyte solution, but higher temperature influences …


On-Line Incorporation Of Cloud Point Extraction In Flame Atomic Absorption Spectrometric Determination Of Silver, Nasser Dalali, Nasrin Javadi, Yadvendra Kumar Agawal Jan 2008

On-Line Incorporation Of Cloud Point Extraction In Flame Atomic Absorption Spectrometric Determination Of Silver, Nasser Dalali, Nasrin Javadi, Yadvendra Kumar Agawal

Turkish Journal of Chemistry

A cloud point extraction method was incorporated into a flow injection system, coupled with flame atomic absorption spectrometry, for determination of trace amounts of silver. The analyte in the aqueous solution was acidified with 0.2 mol L^{-1} sulfuric acid and complexed with dithizone. The cloud point extraction was performed using the non-ionic surfactant Triton X-114. After obtaining the cloud point, the surfactant-rich phase containing the dithizonate complex was collected in a mini-column packed with cotton wool. Then the complex was eluted by passing THF through the column and silver content was determined by flame atomic absorption spectrometry. All the chemical …


Electrocatalytic Oxidation Of Hydroxylamine At A Quinizarine Modified Glassy Carbon Electrode: Application To Differential Pulse Voltammetry Detection Of Hydroxylamine, Mohammad Mazloumardakani, Payam Ebrahimi Karami, Hossein Naeimi, Bibifatemeh Mirjalili Jan 2008

Electrocatalytic Oxidation Of Hydroxylamine At A Quinizarine Modified Glassy Carbon Electrode: Application To Differential Pulse Voltammetry Detection Of Hydroxylamine, Mohammad Mazloumardakani, Payam Ebrahimi Karami, Hossein Naeimi, Bibifatemeh Mirjalili

Turkish Journal of Chemistry

The electrocatalytic behavior of hydroxylamine was studied on a glassy carbon electrode modified by electrodeposition of quinizarine, using cyclic voltammetry, chronoamperometry, and rotating disk voltammetry as diagnostic techniques. Cyclic voltammetry showed that the catalytic current of the system depends on the concentration of hydroxylamine. The magnitude of the peak current for quinizarine increased sharply in the presence of hydroxylamine and proportional to hydroxylamine concentration. The diffusion coefficient of hydroxylamine and the catalytic rate constant for the catalytic reaction of quinizarine with hydroxylamine were also estimated using a rotating disk electrode experiment. The kinetics parameters of this process were calculated, and …


Thermal Decomposition Of Metal Complexes Of Type Mlx_2 (M = Co(Ii), Cu(Ii), Zn(Ii), And Cd(Ii); L = Die; X = No_3^{1-}) By Tg-Dta-Dtg Techniques In Air Atmosphere, Muhammad Arshad, Saeed Ur-Rehman, Ammad Hussain Qureshi, Khalid Masud, Muhammad Arif, Aamer Saeed, Riaz Ahmed Jan 2008

Thermal Decomposition Of Metal Complexes Of Type Mlx_2 (M = Co(Ii), Cu(Ii), Zn(Ii), And Cd(Ii); L = Die; X = No_3^{1-}) By Tg-Dta-Dtg Techniques In Air Atmosphere, Muhammad Arshad, Saeed Ur-Rehman, Ammad Hussain Qureshi, Khalid Masud, Muhammad Arif, Aamer Saeed, Riaz Ahmed

Turkish Journal of Chemistry

The nitrate complexes of transition metals with 1,2-diimidazoloethane (DIE) of the general formula M(DIE)(NO_3)_2, where M = Co(II), Cu(II), Zn(II), and Cd(II), were synthesized. The compositions of metal complexes and ligand were investigated by elemental analysis in order to ensure their purity and the structure elucidations were based on conductivity measurements, room temperature magnetic moment studies, proton NMR, and electronic and IR spectra. The thermal behavior of these complexes possessing distorted tetrahedral geometry and their ligand was studied by means of thermoanalytical techniques in static air atmosphere in order to determine their mode of decomposition and thermal stability. All these …


Studies On The Chemical Constituents Of Thymus Serpyllum, Shahid Aziz, . Habib-Ur-Rehman Jan 2008

Studies On The Chemical Constituents Of Thymus Serpyllum, Shahid Aziz, . Habib-Ur-Rehman

Turkish Journal of Chemistry

Phytochemical investigations on the methanolic extract of Thymus serpyllum resulted in the isolation of 2 new compounds, 3-ketopentatriacontanoic acid (1) and 27-ketotriacontanol (2). The extract also afforded 3 known compounds, 3 \beta-hydroxyolean-12-en- 28-oic acid (3), 3-O-\beta-D-glucopyranosyl-sitosterol (4), and dihydroursonic acid (5), detected for the first time from Thymus serpyllum. The structures of the new compounds were elucidated by spectroscopic methods, while the known compounds were identified on the basis of their spectral data and literature evidence. The hexane and ethyl acetate soluble portions of the methanolic extract showed significant antifungal activity, whereas the chloroform soluble portion and the remaining methanol …