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Full-Text Articles in Physical Sciences and Mathematics

The Synthesis And Antimicrobial Activity Of \\\\Gamma-Butyrolactone Derivatives, Slobodan Sukdolak, Slavica Solujic-Sukdolak, Nenad Vukovic, Tanja Milosevic Jan 2008

The Synthesis And Antimicrobial Activity Of \\\\Gamma-Butyrolactone Derivatives, Slobodan Sukdolak, Slavica Solujic-Sukdolak, Nenad Vukovic, Tanja Milosevic

Turkish Journal of Chemistry

This paper examines the synthesis of \gamma-butyrolactone compounds 2, 3, 4, 5, and 9, and their potential antimicrobial nature and ability. The structures of all the compounds mentioned above were determined and confirmed with elemental analyses, and IR, ^1H-NMR, and ^{13}C-NMR spectroscopy. The in vitro antimicrobial activity of compounds 2, 3, 4, 5, and 9 was examined and evaluated against the following pathogens: Enterobacter aerogenes, Enterobacter cloacae, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus agalactiae, Aspergillus niger, and Candida albicans. Compound 5 (20 mg/mL) demonstrated high antimicrobial activity against S. epidermidis, which was closely comparable to the antimicrobial …


Hydrogenation Of Citral Over Ni And Ni-Sn Catalysts, Hi̇lal Aykaç, Selahatti̇n Yilmaz Jan 2008

Hydrogenation Of Citral Over Ni And Ni-Sn Catalysts, Hi̇lal Aykaç, Selahatti̇n Yilmaz

Turkish Journal of Chemistry

Liquid phase citral hydrogenation over zeolite-supported monometallic Ni and bimetallic Ni-Sn catalysts was studied. The zeolite support materials were Na-Y, Na-mordenite, and clinoptilolite. Ni and Sn contents of the monometallic and bimetallic catalysts were 8.1-9.2 wt% and 0.46 wt%, respectively. The type of the zeolite support affected the activity and selectivity of the catalysts differently. The main product of the citral hydrogenation reaction was citronellal, for both monometallic (84.5% yield) and bimetallic (44.5% yield) catalysts. The addition of promoter increased the selectivity to unsaturated alcohols (geraniol+nerol), i.e. it changed from 0.9% to 6.3% over mordenite and from 0.9% to 2.1% …


Synthesis And Selective Extractant Properties Of A Calixarene Thioether Derivative And Its Oligomeric Analogue, Gülderen Uysal Akkuş, Selma Aslan, F. Fulya Taktak, Shahabuddin Memon Jan 2008

Synthesis And Selective Extractant Properties Of A Calixarene Thioether Derivative And Its Oligomeric Analogue, Gülderen Uysal Akkuş, Selma Aslan, F. Fulya Taktak, Shahabuddin Memon

Turkish Journal of Chemistry

Herein we report the synthesis of a novel calix[4]arene thioether derivative (4) and its oligomeric analogue (5). The liquid-liquid extraction properties of these compounds towards the selected metal cations were evaluated, and it was concluded, based on our observations, that these compounds demonstrated remarkable affinity towards the selected metal cations. Nevertheless, is a good extractant and very selective for Hg^{2+} ions, whereas, in the case of its oligomeric analogue 5, the situation is quiet different. It was observed that 5 could not efficiently retain the parent selective behavior by extracting all of the selected metal ions from the aqueous to …


Co Oxidation Over Mono And Bi-Metallic Sequentially Impregnated Pd-Pt Catalysts, Sarp Kaya, Deni̇z Üner Jan 2008

Co Oxidation Over Mono And Bi-Metallic Sequentially Impregnated Pd-Pt Catalysts, Sarp Kaya, Deni̇z Üner

Turkish Journal of Chemistry

The CO oxidation capability of sequentially impregnated Pd-Pt/\gamma -Al_2O_3 bimetallic catalysts was tested. The CO oxidation light-off curves were hierarchically spaced between monometallic Pd and monometallic Pt, which showed the highest and lowest activity, respectively, indicating that sequential impregnation did not result in the formation of bimetallic particles, but that the catalysts remained as monometallic entities over the support surface. An investigation of the effect of CO partial pressure on the reaction rates over monometallic catalysts indicated that in the presence of excess CO the surface of Pt was poisoned. On the other hand, in the presence of excess CO …


Synthesis And Properties Of Novel Photosensitive Poly(Amide-Imide)S Containing Chalcone Moiety And Aromatic Diamines In The Main Chain, Khalil Faghihi, Zohreh Mozafari Jan 2008

Synthesis And Properties Of Novel Photosensitive Poly(Amide-Imide)S Containing Chalcone Moiety And Aromatic Diamines In The Main Chain, Khalil Faghihi, Zohreh Mozafari

Turkish Journal of Chemistry

Six new poly(amide-imide)s were synthesized by the polycondensation reaction of 1,3-bis[4,4'-bis(trimellityimido) phenyl]-2-propenone (6) with 3,3'-diamino diphenyl sulfone (7a), 4,4'-diamino diphenyl sulfone (7b), 4,4'-diamino diphenyl ether (7c), 1,5-diamino naphthalene (7d), 6-phenyl-1,3,5-triazine (7e), and 6-choloro-1,3-diazine (7f) in a medium consisting of N-methyl-2- pyrrolidone, triphenyl phosphite, calcium chloride, and pyridine. The polycondensation reaction produced a series of novel poly(amide-imide)s (8a-f) in high yield and with inherent viscosities between 0.42 and 0.62 dL/g. The resulting polymers were characterized by elemental analysis, viscosity measurement, solubility testing, thermo-gravimetric analysis (TGA & DTG), FT-IR, and UV-VIS spectroscopy.


Production Of (S)-(-)-1-(1´-Napthyl) Ethanol By Rhodotorula Glutinis Isolate Using Ram Horn Peptone, Esabi̇ Başaran Kurbanoğlu, Kani̇ Zi̇lbeyaz, Namudar I. Kurbanoğlu, Mesut Taşkin, Hamdullah Kiliç Jan 2008

Production Of (S)-(-)-1-(1´-Napthyl) Ethanol By Rhodotorula Glutinis Isolate Using Ram Horn Peptone, Esabi̇ Başaran Kurbanoğlu, Kani̇ Zi̇lbeyaz, Namudar I. Kurbanoğlu, Mesut Taşkin, Hamdullah Kiliç

Turkish Journal of Chemistry

The bioreduction of 1-acetonaphthone 1 by locally isolated Rhodotorula glutinis strains using ram horn peptone (RHP) gave (S)-(-)-1-(1´-naphthyl) ethanol (2), an important pharmaceutical intermediate. R. glutinis strains were isolated from the water of fermented Salix leaves. Optimum fermentation conditions for the production of 2 were 200 rpm, 32 °C, and pH 6.5. The production of 2 with excellent enantiomeric excess (>99%), and good conversion (100%) and yield (78%) under optimum conditions was achieved up to preparative scale via a fermenter. Wide temperature, pH, time, and agitation ranges did not affect the enantiomeric excess (ee) of the bioreduction product. A …


High Yielding Oxidative Deprotection Of Silyl And Pyranyl Ethers To Their Corresponding Carbonyl Compounds With Strontium Manganate In The Presence Of Aluminium Chloride In Solution And Under Solvent-Free Conditions, Mostafa Gholizadeh, I. Mohmmadpoor Baltork Jan 2008

High Yielding Oxidative Deprotection Of Silyl And Pyranyl Ethers To Their Corresponding Carbonyl Compounds With Strontium Manganate In The Presence Of Aluminium Chloride In Solution And Under Solvent-Free Conditions, Mostafa Gholizadeh, I. Mohmmadpoor Baltork

Turkish Journal of Chemistry

Strontium manganate (SrMnO_4) in the presence of aluminium chloride (AlCl_3) is an efficient reagent for the high yielding oxidative deprotection of aromatic and aliphatic silyl and pyranyl ethers into their corresponding carbonyl compounds, in solution and under solvent-free conditions.


Preparation Of Palladium Composite Membranes On Pore Structure Modified And Non-Modified Supports By Electroless Plating Procedure, Sali̇ha Kiliçarslan, Osman Muzaffer Afyon, Meltem Doğan Jan 2008

Preparation Of Palladium Composite Membranes On Pore Structure Modified And Non-Modified Supports By Electroless Plating Procedure, Sali̇ha Kiliçarslan, Osman Muzaffer Afyon, Meltem Doğan

Turkish Journal of Chemistry

The effects of pore structure of the support on the plating morphology, thickness, and composition were investigated in an electroless plating procedure. Some of the plating studies were carried out directly on commercially available porous glass supports, while others were performed on modified supports. Two modification steps with alumina were applied on tubular supports. Formation of a 60-\mu m-thick layer on the modified support was detected by SEM analysis after the first 2 plating steps, while layer formation was not observed on the non-modified support. It was shown that the formation of a new layer started on the modified support, …


Examination Of The Electroanalytic Performance Of Carbon Nanotube (Cnt) Modified Carbon Paste Electrodes As Xanthine Biosensor Transducers, Ülkü Anik, Meli̇ha Çubukçu Jan 2008

Examination Of The Electroanalytic Performance Of Carbon Nanotube (Cnt) Modified Carbon Paste Electrodes As Xanthine Biosensor Transducers, Ülkü Anik, Meli̇ha Çubukçu

Turkish Journal of Chemistry

The effect of multi-walled carbon nanotube (MWCNT) and single-wall carbon nanotube (SWCNT) on carbon paste electrode (CPE) electrochemical response was examined by introducing various portions of CNT into the CPE. The optimum electrode structure was determined by comparing the prepared electrodes´ electroanalytical performance towards ferricyanide. Then these optimum compositions were modified with xanthine oxidase (XO) enzyme for obtaining a xanthine biosensor. After the optimization of biosensor working conditions, the developed systems were characterized for xanthine. Linearity was obtained in the concentration range between 1 and 100 \mu M xanthine with an RSD value of 3.35% for MWCNT-CPE, while with SWCNT-CPE …


Potentiometric Determination Of The Stability Constants Of Lanthanide Complexes With Iminodiacetic Acid In Water And Dioxane-Water Mixtures, Sevgi̇ Arzik, Ebru Mavi̇oğlu Ayan, A. Sedat Çelebi̇ Jan 2008

Potentiometric Determination Of The Stability Constants Of Lanthanide Complexes With Iminodiacetic Acid In Water And Dioxane-Water Mixtures, Sevgi̇ Arzik, Ebru Mavi̇oğlu Ayan, A. Sedat Çelebi̇

Turkish Journal of Chemistry

The protonation constants of iminodiacetic acid (H_2 ida) and the stability constants of its complexes with Nd(III), Sm(III), Gd(III), Dy(III), and Er(III) ions at metal/ligand mole ratios of 1:1, 1:2, and 1:3 at 25 °C and 0.1 M ionic strength in aqueous medium and 20%, 45%, and 70% w/w dioxane-water mixtures were determined by the potentiometric method using the BEST computer program. The stability constants of the complexes that formed increased as the dioxane content increased. The stability of all the analogues' complexes, both in aqueous medium and in dioxane-water mixtures, were in the order of Nd(III) < Sm(III) < Gd(III) < Dy(III) < Er(III).


Synthesis And Cloning Of A Small Bacillus Pheromone Gene (Comx_{Ro-B-2}) By Primer-Dimer Formation With Pcr, Devri̇m Demi̇r Dora, Tanil Kocagöz, Fi̇li̇z Öner Jan 2008

Synthesis And Cloning Of A Small Bacillus Pheromone Gene (Comx_{Ro-B-2}) By Primer-Dimer Formation With Pcr, Devri̇m Demi̇r Dora, Tanil Kocagöz, Fi̇li̇z Öner

Turkish Journal of Chemistry

ComX pheromone is the major extracellular signaling peptide stimulating transformation in response to high cell density in Bacillus species. In this study, Bacillus mojavensis ComX_{(RO-B-2)} pheromone gene was cloned to pGEMT-Easy vector based on TA cloning of PCR products. The gene encoding 11 amino acid peptides of Bacillus mojavensis RO-B-2 strain ComX pheromone (GLQIYTNWVPS) was obtained by PCR amplification of 2 primers complementary to each other at their 3' end. This eliminated the need for the original bacterial gene as DNA template for PCR. The amplified PCR products were ligated directly without any modification by T4 DNA ligase into pGEMT-Easy …


Preparation, Characterization, And Potentiometric Titrations Of Some New Di-[3-(3-Alkyl/Aryl-4,5-Dihydro-1h-1,2,4-Triazol-5-One-4-Yl)-Azomethinphenyl] Isophthalate/Terephthalate Derivatives, Haydar Yüksek, Özlem Gürsoy Kol Jan 2008

Preparation, Characterization, And Potentiometric Titrations Of Some New Di-[3-(3-Alkyl/Aryl-4,5-Dihydro-1h-1,2,4-Triazol-5-One-4-Yl)-Azomethinphenyl] Isophthalate/Terephthalate Derivatives, Haydar Yüksek, Özlem Gürsoy Kol

Turkish Journal of Chemistry

3-Alkyl(Aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) reacted with di-(3-formylphenyl) isophthalate (3) and di-(3-formylphenyl) terephthalate (6) to afford the corresponding 6 novel di-[3-(3-alkyl/aryl-4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl)- azomethinphenyl] isophthalates (4) and 6 novel di-[3-(3-alkyl/aryl-4,5- dihydro-1H-1,2,4-triazol-5-one-4-yl)-azomethinphenyl] terephthalates (7), respectively. The acetylation reactions of compounds 4 and 7 were investigated, and 5 and 8 type compounds were obtained, respectively. The new compounds synthesized were characterized by using IR, ^1H-NMR, ^{13}C-NMR, and UV spectral data together with elemental analysis. In addition, to investigate the effects of solvents and molecular structure upon acidity, compounds 4 and 7 were titrated potentiometrically with tetrabutylammonium hydroxide in 5 non-aqueous solvents (isopropyl alcohol, tert-butyl alcohol, N,N-dimethylformamide, acetone, …


Microwave-Assisted Synthesis Of 1,4´-Diazaflavone And N-Alkyl Derivative Pigments With Anti-Microbial Activity, Nuran Yayli, Osman Üçüncü, Nuretti̇n Yayli, Emi̇ne Demi̇r, Zi̇hni̇ Demi̇rbağ Jan 2008

Microwave-Assisted Synthesis Of 1,4´-Diazaflavone And N-Alkyl Derivative Pigments With Anti-Microbial Activity, Nuran Yayli, Osman Üçüncü, Nuretti̇n Yayli, Emi̇ne Demi̇r, Zi̇hni̇ Demi̇rbağ

Turkish Journal of Chemistry

1,4'-Diazaflavone pigment (2) was synthesized by a simple environmentally friendly microwave-assisted one-pot method for the cyclization of 2'-amino (E)-4''-aza-chalcone (1) under solventless conditions using K-10 clay. In addition, 10 new N-alkyl (C_{5-12, 14-15}) substituted 1,4' -diazaflavonium bromide pigments (3-12) were prepared from compound 2 or directly from compound 1, with corresponding alkyl halides in acetonitrile under reflux. The anti-microbial activity of compounds 1-12 was tested. The N-alkyl substituted 1,4' -diazaflavonium bromides (3-12) showed good antimicrobial activity against the gram-positive bacteria tested with minimal bactericidal concentration (MBC) values for the reference antibiotic kanamycin. The optimum length of the alkyl chain for …


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.


One Step Synthesis Of Some 2,5,6-Trisubstituted-1,3-Dioxin-4-Ones, Ahmet Şener, İshak Bi̇ldi̇ri̇ci̇, Hasan Genç, Nuretti̇n Mengeş, Siddik Eski̇noba Jan 2008

One Step Synthesis Of Some 2,5,6-Trisubstituted-1,3-Dioxin-4-Ones, Ahmet Şener, İshak Bi̇ldi̇ri̇ci̇, Hasan Genç, Nuretti̇n Mengeş, Siddik Eski̇noba

Turkish Journal of Chemistry

A number of novel 2,5,6-trisubstituted-1,3-dioxin-4-one derivatives were synthesized via one step reactions between dibenzoylmethane or benzoylacetone and oxalyl chloride in refluxing solvents containing various aldehydes.


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 …


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 …


Synthesis And X-Ray Structural Studies Of Amino Acids Half Sandwich Complexes Of Osmium(Ii), Raja A. Sarfraz, Tasneem Gul Kazi, Shahid Iqbal, Hassan I. Afridi, Mohammad K. Jamali, Nusrat Jalbani, Mohammad Bilal Arain Jan 2008

Synthesis And X-Ray Structural Studies Of Amino Acids Half Sandwich Complexes Of Osmium(Ii), Raja A. Sarfraz, Tasneem Gul Kazi, Shahid Iqbal, Hassan I. Afridi, Mohammad K. Jamali, Nusrat Jalbani, Mohammad Bilal Arain

Turkish Journal of Chemistry

The amino acids complexes of osmium(II), i.e. [Os(\eta 6-p-cymene)(\eta1-N-(rac)-phenylglycine methyl ester)Cl_2] (A) and [Os(\eta 6-p-cymene) (\eta1-N,N'-(S)-phenylalanine amido) Cl] (B), were prepared by an ultrasound energy-assisted method at room temperature. The solid structures of the newly synthesized complexes were determined by single crystal X-ray analysis. In A, osmium is bonded to 2 chloride ligands, the \eta 6-coordinated p-cymene molecule, and to a nitrogen atom of the corresponding amino acid derived ligand, whereas in the case of B the central osmium is surrounded by an N, N' bidentate amino amide ligand, by an \eta 6-coordinated p-cymene molecule, and a chloride ligand. Both …


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.


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.


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 …


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 …


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 …


The Kinetics And Mechanism Of Ruthenium(Iii)-Catalyzed Oxidation Of Tris(2-Amino Ethyl)Amine By Hexacyanoferrate(Iii) In Aqueous Alkaline Medium, Radhey Mohan Naik, Abhishek Srivastava, Amit Kumar Verma Jan 2008

The Kinetics And Mechanism Of Ruthenium(Iii)-Catalyzed Oxidation Of Tris(2-Amino Ethyl)Amine By Hexacyanoferrate(Iii) In Aqueous Alkaline Medium, Radhey Mohan Naik, Abhishek Srivastava, Amit Kumar Verma

Turkish Journal of Chemistry

The kinetics of ruthenium(III)-catalyzed oxidation of TREN, i.e. tris(2-amino ethyl)amine(3-hydrochloride) by an outer sphere electron transfer oxidant, potassium hexacyanoferrate(III), was investigated spectrophotometrically in aqueous alkaline medium. The extent of the reaction was followed by registering a decrease in absorbance at 420 nm (\lambda_{max} of Fe(CN)_6^{3-}) due to its consumption as a function of [OH^-], ionic strength, [Fe(CN)_6^{3-}], [TREN], and temperature by varying only one variable at a time and keeping all other variables constant. The rate data indicate that the reaction exhibited first order dependence in [oxidant] and at a lower concentrations of reductant. The overall reaction follows second order …


Novel Analogues Of 2-Pyrazoline: Synthesis, Characterization, And Antimycobacterial Evaluation, Ahmet Özdemi̇r, Gülhan Turan Zitouni, Zafer Asim Kaplancikli Jan 2008

Novel Analogues Of 2-Pyrazoline: Synthesis, Characterization, And Antimycobacterial Evaluation, Ahmet Özdemi̇r, Gülhan Turan Zitouni, Zafer Asim Kaplancikli

Turkish Journal of Chemistry

Fourteen new 1-[(N,N-disubstitutedthiocarbamoylthio)acetyl]- 3-(2-thienyl)-5-aryl-2-pyrazoline derivatives were synthesized by reacting 1-(chloroacetyl)-3-(2-thienyl)-5-aryl-2-pyrazolines and appropriate sodium salts of N,N-disubstituted dithiocarbamoic acids in acetone. The structures of the synthesized compounds were confirmed by UV, IR, ^1H-NMR, and FAB^+-MS spectral data. The compounds were evaluated for in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv using the BACTEC 460 radiometric system and BACTEC 12B medium. The preliminary results showed that all of the tested compounds were inactive against the test organism.


Synthesis And Antifungal Activity Of Some Novel N-(4-Phenyl-3-Aroylthiazol-2(3h)-Ylidene) Substituted Benzamides, Aamer Saeed, Sabah Zaman, Maryam Jamil, Bushra Mirza Jan 2008

Synthesis And Antifungal Activity Of Some Novel N-(4-Phenyl-3-Aroylthiazol-2(3h)-Ylidene) Substituted Benzamides, Aamer Saeed, Sabah Zaman, Maryam Jamil, Bushra Mirza

Turkish Journal of Chemistry

Variously substituted N-(4-phenyl-3-aroylthiazol-2(3H)-ylidene)benzamides (2a-t) were prepared by base-catalyzed cyclization of corresponding 1-aroyl-3-aryl thioureas with acetophenone in the presence of bromine. Some of the synthesized compounds were assayed in vitro for their antifungal activity and were found to exhibit low to moderate activity.


Hydrogenation Of Citral Over Pt And Pt-Sn Catalysts, Hi̇lal Aykaç, Selahatti̇n Yilmaz Jan 2008

Hydrogenation Of Citral Over Pt And Pt-Sn Catalysts, Hi̇lal Aykaç, Selahatti̇n Yilmaz

Turkish Journal of Chemistry

Hydrogenation of citral on monometallic (Pt) and bimetallic (Pt-Sn) catalysts was investigated. It was found that the catalyst activities and product distributions were different over Na-Y and Clino supports. Among monometallic catalysts, Pt/Na-Y was more selective to citronellol (3.9%) and unsaturated alcohols, geraniol and nerol, (14.1%). Sn addition increased the catalyst activities. However, its effect on product distribution differed. Yield of geraniol+nerol changed from 5.1% to 19.7% over Clino. However, selectivity to unsaturated alcohols over Na-Y decreased when it was prepared as a bimetallic catalyst support. Unsaturated alcohol formation was favored when there was a metal support interaction over monometallic …


New Flame-Retardant Poly(Ester-Imide)S Containing Phosphine Oxide Moieties In The Main Chain: Synthesis And Properties, Khalil Faghihi Jan 2008

New Flame-Retardant Poly(Ester-Imide)S Containing Phosphine Oxide Moieties In The Main Chain: Synthesis And Properties, Khalil Faghihi

Turkish Journal of Chemistry

Six new flame-retardant poly(ester-imide)s (9a-f) with high inherent viscosity and containing phosphine oxide moieties in the main chain were synthesized from the polycondensation reaction of N,N-(3,3-diphenylphenyl phosphine oxide) bistrimellitimide diacid chloride (7) with 6 aromatic diols (8a-f) by 2 different methods:--solution and microwave-assisted polycondensation. The results showed that compared to solution polycondensation, the microwave-assisted polycondensation reaction using a domestic microwave oven proceeded rapidly and was completed within about 9-12 min. All of the obtained polymers were fully characterized by means of elemental analysis, viscosity measurement, solubility testing, and FT-IR spectroscopy. Thermal properties and flame retardant behavior of the PEIs (9a-f) …


Synthesis And Characterization Of New Tridentate Iminooxime Ligands And Their Co(Iii) Complexes, Hasene Mutlu, Gazi̇ İrez Jan 2008

Synthesis And Characterization Of New Tridentate Iminooxime Ligands And Their Co(Iii) Complexes, Hasene Mutlu, Gazi̇ İrez

Turkish Journal of Chemistry

In this study, (hydroxyimino)(2-phenyl(1,2,3,4-tetrahydroquinazolin- 2-yl))methane (H_2L^1) and (hydroxyimino)(2-(2-thienyl)(1,2,3,4- tetrahydroquinazolin-2-yl))methane (H_2L^2) were synthesized by the condensation of 2-(hydroxyimino)-1-phenylethan-1-one (INAP) and 2-(hydroxyimino)-1-(2-thienyl)ethan-1-one (INAT) with 2-aminobenzylamine (2-ABA). Complexes of these ligands with Co^{3+} were prepared with a metal:ligand ratio of 1:2. The ligands and their complexes were elucidated on the basis of elemental analyses, AAS, FT-IR, ^1H- and ^{13}C-NMR spectra, mass spectra, magnetic susceptibility measurements, and molar conductivity.


Comparison Of Catalytic Activities Of Carbon Supported Pt And Pt-Ru Catalysts For Methanol Oxidation In Neutral And Basic Media By Cyclic Voltammetry, Abdul Sattar Ali Khan, Riaz Ahmed, Muhammad Latif Mirza Jan 2008

Comparison Of Catalytic Activities Of Carbon Supported Pt And Pt-Ru Catalysts For Methanol Oxidation In Neutral And Basic Media By Cyclic Voltammetry, Abdul Sattar Ali Khan, Riaz Ahmed, Muhammad Latif Mirza

Turkish Journal of Chemistry

The catalytic activities of an equal amount of 3 different carbon supported catalysts containing 10% Pt, 20% Pt + 10% Ru, and 30% Pt were evaluated in neutral and basic media for methanol oxidation by cyclic voltammetry. The prominent oxidation peak for methanol appeared in the forward anodic sweep at around 1.0 V in neutral medium, while in basic medium it appeared at significantly lower potential close to 0.2 V. The peak current for methanol oxidation was higher on a catalyst containing higher Pt loading. The comparison of polarization behavior of 20% Pt + 10% Ru and 30% Pt catalysts …