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Full-Text Articles in Physical Sciences and Mathematics

Zeolite Catalyzed Efficient Synthesis Of Perimidines At Room Temperature, Akbar Mobinikhaledi, Naser Forughifar, Nemat Bassaki Jan 2009

Zeolite Catalyzed Efficient Synthesis Of Perimidines At Room Temperature, Akbar Mobinikhaledi, Naser Forughifar, Nemat Bassaki

Turkish Journal of Chemistry

Arylperimidines, 3(a-l), were synthesized in good yields by cyclocondensation reaction of 1,8-diaminonaphthalene and aromatic aldehydes in the presence of NaY zeolite as a catalyst. The simple environmentally benign nature, reusability of the catalyst, and the easy work-up reaction are some of the advantages of this protocol.


A Simple Spectrophotometric Method For The Determination Of Iron(Ii) Aqueous Solutions, M. Jamaluddin Ahmed, Uttam Kumer Roy Jan 2009

A Simple Spectrophotometric Method For The Determination Of Iron(Ii) Aqueous Solutions, M. Jamaluddin Ahmed, Uttam Kumer Roy

Turkish Journal of Chemistry

An ultra-sensitive and highly selective non-extractive spectrophotometric method is presented for the rapid determination of iron(II) at trace levels using 2', 3, 4', 5, 7-Pentahydroxyflavone (morin) as a new spectrophotometric reagent in slightly acidic solution (0.0001-0.0002 M H_2SO_4). The reaction is instantaneous and absorbance remains stable for over 24 h (\lambda_{max} = 415 nm). The molar absorptivity was found to be 6.85 \times 10^4 L mol^{-1} cm^{-1}. Linear calibration graphs were obtained for 0.01-10 \mu g mL^{-1} of Fe^{II}. The stoichiometric composition of the chelate is 1:2 (Fe:morin). Large excesses of over 50 cations, anions, and complexing agents (e.g., tartrate, …


Synthesis And Single Crystal Structure Analysis Of Three Novel Benzoylthiourea Derivatives, Gülten Kavak, Süheyla Özbey, Gün Bi̇nzet, Nevzat Külcü Jan 2009

Synthesis And Single Crystal Structure Analysis Of Three Novel Benzoylthiourea Derivatives, Gülten Kavak, Süheyla Özbey, Gün Bi̇nzet, Nevzat Külcü

Turkish Journal of Chemistry

N,N-dimethyl-N' -(2-methylbenzoyl)thiourea, C_{11}H_{14}N_2SO (HL^1), N,N-dibutyl-N' -(2-methylben\-zoyl)thiourea, C{17}H{26}N2SO (HL^2), and N,N-dihexyl-N' -(2-methylbenzoyl) thiourea, C{21}H{34}N2SO (HL^3) were synthesized and characterized by elemental analysis, spectroscopic methods (FT-IR, NMR), and single crystal X-ray diffraction. Compound HL^1 crystallizes in the monoclinic system, space group P21/c, Z = 4. Compound HL^3 also crystallizes in the monoclinic system, space group P21/n, Z = 8 with 2 independent molecules in the asymmetric unit. Compound HL^2 crystallizes in the orthorhombic system, space group Pcnn, Z = 8. In all compounds, molecules form dimers through the strong intermolecular N-H...S hydrogen bonds. Moreover, there are different types of intra- and inter-molecular …


A Convenient Synthesis Of 2-Azido And 2-Thiocyanato-2,3-Unsaturated Cyclic Ketones, Mesut Boz, Ömer Zai̇m, Hi̇lal Esen Jan 2009

A Convenient Synthesis Of 2-Azido And 2-Thiocyanato-2,3-Unsaturated Cyclic Ketones, Mesut Boz, Ömer Zai̇m, Hi̇lal Esen

Turkish Journal of Chemistry

2-Azido and 2-thiocyanato-2,3-unsaturated ketones were synthesized by utilizing functionalization of 5- or 6-membered cycloalkane-1,2-diones, namely diosphenols, with dimethylthiocarbomoyl chloride, which activates the system towards reaction with nucleophiles in acidic conditions. Replacement of the enolic oxygen of the diosphenols with azide and thiocyanate may be achieved by treating their dimethylthiocarbamates with sodium azide or potassium thiocyanate in boiling acetonitrile/acetic acid.


Synthesis Of Methyl (E)-2',4''-Thiazachalcones And Their N-Alkyl Derivatives, Photochemistry With Theoretical Calculations And Antimicrobial Activities, Asu Usta, Ahmet Yaşar, Nuran Yayli, Şengül Alpay Karaoğlu, Nuretti̇n Yayli Jan 2009

Synthesis Of Methyl (E)-2',4''-Thiazachalcones And Their N-Alkyl Derivatives, Photochemistry With Theoretical Calculations And Antimicrobial Activities, Asu Usta, Ahmet Yaşar, Nuran Yayli, Şengül Alpay Karaoğlu, Nuretti̇n Yayli

Turkish Journal of Chemistry

A series of 9 new (E)-thiazachalcones (1-3), and their N-alkyl substituted derivatives (4-6), and stereoselective dimerization products (7-9) were synthesized, then tested for antimicrobial activity against all test microorganisms except Pseudomonas aeruginosa. The new compounds (1-6) without dimerization products (7-9) showed good antimicrobial property against Staphylococcus aureus, Listeria monocitogenes, and Enterococcus faecalis. The possible dimerization products of compounds (1-3) were calculated theoretically. Experimental and theoretical calculation showed that \delta-truxinic type dimer is the most stable isomer.


Antioxidant Galloylated Flavonoids From Geranium Tuberosum L. Subsp. Tuberosum, Di̇dem Şöhretoğlu, Mahmut Koray Sakar, Suna Atasayar Sabuncuoğlu, Hi̇lal Özgüneş, Olov Sterner Jan 2009

Antioxidant Galloylated Flavonoids From Geranium Tuberosum L. Subsp. Tuberosum, Di̇dem Şöhretoğlu, Mahmut Koray Sakar, Suna Atasayar Sabuncuoğlu, Hi̇lal Özgüneş, Olov Sterner

Turkish Journal of Chemistry

Phytochemical investigations on the most active EtOAc extract led to the isolation of 9 flavonoids [quercetin (1), quercetin 3-O-\beta-glucopyranoside (2), quercetin 3-O-\beta-galactopyranoside (3), quercetin 3-O-(2''-O-galloyl)-\beta-glucopyranoside (4), quercetin 3-O-(2''-O-galloyl)-\beta-galactopyranoside (5), quercetin 3-O-(6''-O-galloyl)-\beta-glucopyranoside (6), quercetin 3-O-(6''-O-galloyl)-\beta-galactopyranoside (7), quercetin-3-O-\alpha -arabinofuranoside (8), and quercetin-3-O-\alpha-rhamnopyranosyl-(1\to 6)-\beta-glucopyranoside (9)] and a simple phenolic compound (methyl gallate) (10). The structures of the compounds were elucidated by 1- and 2-dimensional NMR techniques (^1H, ^{13}C, COSY, HMBC, and HMQC) and ESI-TOF-MS spectrometry. H_2O_2-induced lipid peroxidation inhibitor effects in human red blood cells of different extracts of G. tuberosum L. subsp. tuberosum aerial parts were also investigated. All the compounds tested …


Synthesis And Physical Studies Of Polycarbonate Of P-Tert-}Butylcalix[4]Arene: A Highly Selective Receptor For Na^+, Muhammad Ashram, Nawash Al Ghezawi, Ibrahim Abu Awaad, Gülsen Asman Jan 2009

Synthesis And Physical Studies Of Polycarbonate Of P-Tert-}Butylcalix[4]Arene: A Highly Selective Receptor For Na^+, Muhammad Ashram, Nawash Al Ghezawi, Ibrahim Abu Awaad, Gülsen Asman

Turkish Journal of Chemistry

The synthesis and characterization of a polycarbonate of p-tert-butylcalix[4]arene 4 are reported. It was synthesized by condensation of p-tert-butylcalix[4]arenetetraol derivative 3 with ethyl chloroformate. This new polymer possesses a hydrolyzable backbone and tunable hydrophobic/hydrophilic properties. The experimental results indicate that the polycarbonate was successfully synthesized with average molecular weight \overline{M}_{w}, (2.328 \times 10^4 g/mol), which was determined by static light scattering method using a Berry plot. The structure of this polymer was determined by IR spectroscopy. The thermal properties were investigated using differential scanning calorimetry (DSC). The degree of crystallinity was measured by means of XRD. The extraction ability of …


Determination Of Trace Borohydride In Basic Solutions Using Differential Pulse Polarography, Ülkü Ünal, Güler Somer Jan 2009

Determination Of Trace Borohydride In Basic Solutions Using Differential Pulse Polarography, Ülkü Ünal, Güler Somer

Turkish Journal of Chemistry

Synthesis of borohydride is important because of its use as a hydrogen energy source. The objective of this study was to develop a new and simple method for the trace determination of borohydride so that it can be used during the investigation of a new reaction for its synthesis or in some kinetic studies. A differential pulse polarographic method has been developed for this purpose since the results obtained with this method are very reproducible and the instrument used is not expensive. The optimum working condition was found to be as 0.05 M phosphate buffer (pH 9), containing 0.1 M …


A Highly Soluble Asymmetric Perylene-Bis (Dicarboximide)-Acceptor System Incorporating A Methylene Bridged Methoxybenzene-Donor: Solvent Dependence Of Charge Transfer Interactions, Rene M. Williams Jan 2009

A Highly Soluble Asymmetric Perylene-Bis (Dicarboximide)-Acceptor System Incorporating A Methylene Bridged Methoxybenzene-Donor: Solvent Dependence Of Charge Transfer Interactions, Rene M. Williams

Turkish Journal of Chemistry

The synthesis and photophysical properties of an asymmetrically substituted perylene-bis(dicarboximide), (PDI), system (1) containing a methylene bridged 4-methoxy-benzene donor and a solubilizing branched C_{13} alkyl chain are described. As compared to most PDIs, the fluorescence of 1 is strongly quenched in polar (but not in non-polar) solvents due to a photo-induced electron transfer process. Transient absorption spectroscopy and time resolved emission in e.g. acetonitrile indicates that upon excitation the radical anion of the PDI is formed with a rate of ca. 3.5 \times 10^9s^{-1}, and the charge transfer state has a lifetime of ca. 3 ns. A Frontier Molecular Orbital …


A Simple And Efficient One-Pot Multicomponent Synthesis Of \Beta-Acetamido Carbonyl Compounds With Zn(Hso_4)_2 And Co(Hso_4)_2 As Catalysts, Ahmad Reza Momeni, Maryam Sadeghi, Motahareh Hadizadeh Jan 2009

A Simple And Efficient One-Pot Multicomponent Synthesis Of \Beta-Acetamido Carbonyl Compounds With Zn(Hso_4)_2 And Co(Hso_4)_2 As Catalysts, Ahmad Reza Momeni, Maryam Sadeghi, Motahareh Hadizadeh

Turkish Journal of Chemistry

Zn(HSO_4)_2 and Co(HSO_4)_2 has been used as efficient catalysts for the preparation of \beta-acetamido carbonyl compounds by Dakin-West reaction.


Synthesis, Characterization, And Antibacterial Activity Of Some Transition Metals With The Schiff Base N-(2-Furanylmethylene)-3-Aminodibenzofuran, Aurora Reiss, Stelian Florea, Theodor Caproiu, Nicolae Stanica Jan 2009

Synthesis, Characterization, And Antibacterial Activity Of Some Transition Metals With The Schiff Base N-(2-Furanylmethylene)-3-Aminodibenzofuran, Aurora Reiss, Stelian Florea, Theodor Caproiu, Nicolae Stanica

Turkish Journal of Chemistry

This paper presents the structure and antibacterial properties of some complexes of Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Hg(II) with a new Schiff base N-(2-furanylmethylene)-3- aminodibenzofuran. The structure of each complex was characterized by spectroscopic methods (IR, UV-Vis, ^1H-NMR, and ESR), conductometric and magnetic data, and thermogravimetric and elementary analysis. According to these data, we propose an octahedral geometry for Co(II), Ni(II), and Cu(II) complexes, and a tetrahedral geometry for Zn(II), Cd(II), and Hg(II) complexes. Antibacterial activity of the ligand and its complexes was tested against selected bacteria. The ligand and all the complexes possess antimicrobial activity, and antimicrobial activity …


Antioxidant And Anticholinesterase Constituents Of Salvia Poculata, Ufuk Kolak, Işil Hacibeki̇roğlu, Mehmet Öztürk, Fevzi̇ Özgökçe, Gülaçti Topçu, Ayhan Ulubelen Jan 2009

Antioxidant And Anticholinesterase Constituents Of Salvia Poculata, Ufuk Kolak, Işil Hacibeki̇roğlu, Mehmet Öztürk, Fevzi̇ Özgökçe, Gülaçti Topçu, Ayhan Ulubelen

Turkish Journal of Chemistry

Two triterpenoids, namely 2\alpha,3\alpha-dihydroxy-24-nor- 4(23),12-oleanadien-28-oic acid (1) and ursolic acid (2); 4 flavonoids, namely 5-hydroxy-7,4'-dimethoxyflavone (3), cirsimaritin (4), eupatilin (5), and salvigenin (6); a diterpenoid, namely sclareol (7); and a steroid, namely \beta-sitosterol (8), were isolated from the aerial parts of Salvia poculata Nab., a Turkish endemic Salvia species. Total phenolic and flavonoid contents of the crude extract were determined as pyrocatechol and quercetin equivalents, respectively. The antioxidant activity of the crude extract and the isolated compounds (2-8) was established using \beta-carotene bleaching, superoxide anion radical, and ABTS cation radical scavenging activity. In addition, the anticholinesterase activity of the crude …


Partial Regeneration Of Ni-Based Catalysts For Hydrogen Production Via Methane Cracking Part Ii: Modeling And Optimization, Reyyan Koç, Erdoğan Alper, Eric Croiset, Ali Elkamel Jan 2009

Partial Regeneration Of Ni-Based Catalysts For Hydrogen Production Via Methane Cracking Part Ii: Modeling And Optimization, Reyyan Koç, Erdoğan Alper, Eric Croiset, Ali Elkamel

Turkish Journal of Chemistry

High purity, carbon monoxide-free hydrogen and filamentous carbon can be produced by thermo-catalytic cracking of methane. Carbon filaments continue to grow until the catalyst deactivates because of carbon encapsulation. Regeneration of catalyst is important to maintain a continuous process. Our work on optimization of the partial regeneration method showed that activity of the catalyst can be sustained for longer times by gasifying not all but some extent of the deposited carbon. In the previous work, a kinetic model was developed to be able to understand the reaction mechanism of deactivation of fresh catalyst at the molecular level. The objective of …


Pore Structure And Surface Acidity Evaluation Of Fe-Pilcs, Suna Balci, Eli̇f Gökçay Jan 2009

Pore Structure And Surface Acidity Evaluation Of Fe-Pilcs, Suna Balci, Eli̇f Gökçay

Turkish Journal of Chemistry

Fe-PILCs via different conditions using smectites from Hancili (Turkey) and Wyoming (USA) were synthesised. Presaturation had little effects on the basal spacing values while it had important effects on thermal stabilities of the products. Products having basal spacing (d_{001}) around 1.30 nm and surface area up to 160 m^2 g^{-1} were obtained. The thermal behaviour, X-ray diffraction (XRD) patterns, and nitrogen adsorption/desorption experiments confirmed that thermally stable and micro-mesoporous products were obtained although at elevated calcination temperature. Delaminated sample with basal spacing value of 2.79 nm was obtained. Surface acidity of clay was enhanced by pillaring. Chemically sorbed pyridine Fourier …


Three-Component Process For The Synthesis Of Some Pyrrole Derivatives Under Microwave Irradiation, Farhad Hatamjafari, Nasser Montazeri Jan 2009

Three-Component Process For The Synthesis Of Some Pyrrole Derivatives Under Microwave Irradiation, Farhad Hatamjafari, Nasser Montazeri

Turkish Journal of Chemistry

We report a short and efficient 3-component reaction for synthesis of a series of [1,2-b]pyrrole derivatives from ninhydrin, alkyl propiolates, and simple primary amines under solvent free and microwave irradiation. This method provides a new route to produce pyrrole derivatives in good to excellent yields.


Electrochemical And Optical Properties Of An Azo Dye Based Conducting Copolymer, Ati̇lla Ci̇haner, Fati̇h Algi Jan 2009

Electrochemical And Optical Properties Of An Azo Dye Based Conducting Copolymer, Ati̇lla Ci̇haner, Fati̇h Algi

Turkish Journal of Chemistry

The electrochemical and optical properties of a novel conducting copolymer called poly(2,5'-dimethyl-[4-(2,5-di-thiophen- 2-yl-pyrrol-1-yl)-phenyl]azobenzene-co-(3,4-ethylenedioxythiophene)) (poly(1-co-EDOT)) are reported. Electrochemically synthesized poly(1-co-EDOT) based on the azo dye has a well-defined and reversible redox couple (0.37 V vs. Ag/AgCl) with good cycle stability. The copolymer film exhibits high conductivity (13 S/cm) as well as electrochromic behavior (magenta when neutralized and transmissive sky blue when oxidized). Furthermore, electro-optically active copolymer film has a low band gap of 1.79 eV with a \pi-\pi* transition at 555 nm.


4h-Pyran-4-One Derivatives:; Leading Molecule For Preparation Of Compounds With Antimycobacterial Potential, Demet Us, Ece Gürdal, Barkin Berk, Si̇nem Öktem, Tanil Kocagöz, Berrak Çağlayan, Işil Aksan Kurnaz, Di̇lek Demi̇r Erol Jan 2009

4h-Pyran-4-One Derivatives:; Leading Molecule For Preparation Of Compounds With Antimycobacterial Potential, Demet Us, Ece Gürdal, Barkin Berk, Si̇nem Öktem, Tanil Kocagöz, Berrak Çağlayan, Işil Aksan Kurnaz, Di̇lek Demi̇r Erol

Turkish Journal of Chemistry

A series of 3-hydroxy-6-methyl-2-((4-substitutedpiperazin-1- yl)methyl)-4H-pyran-4-one structured compounds were synthesized by reacting 5-hydroxy-2-methyl-4H-pyran-4-one with suitable piperazine derivatives using Mannich reaction conditions. Antibacterial activities of the compounds for E. coli, S. paratyphi, S. flexneri, E. gergoviae, and M. smegmatis were assessed in vitro by using broth dilution for determination of the minimum inhibitory concentration (MIC). In addition, their inhibitory effects over DNA gyrase enzyme were evaluated using a DNA gyrase supercoiling assay. Among the synthesized compounds; compound 7 showed a 4 \mu g/mL MIC value for M. smegmatis, whereas the other compounds demonstrated moderate to high activity. Those tested in the supercoiling …


Preparation And Characterization Of Magnetic Chitosan Nanospheres, Doina Hritcu, Marcel I. Popa, Nuculina Popa, Vasile Badescu, Vera Balan Jan 2009

Preparation And Characterization Of Magnetic Chitosan Nanospheres, Doina Hritcu, Marcel I. Popa, Nuculina Popa, Vasile Badescu, Vera Balan

Turkish Journal of Chemistry

A method for the preparation of magnetite/chitosan composite nanoparticles was developed. Colloidal magnetite particles (Fe_3O_4 produced by co-precipitation and stabilized in suspension by adding a non-ionic surfactant (Pluronic F127) were subsequently covered with a layer of chitosan (CS) prepared by ionotropic gelation using sodium tripolyphosphate (STPP) as a crosslinking agent. The products were characterized in terms of the following parameters: size distribution and \zeta-potential (by laser diffraction analysis), surface morphology (TEM), composition (FTIR, elemental analysis), magnetic properties (magnetic susceptibility analysis), and concentration of surface functional groups (potentiometric titration). The synthesis parameters were optimized for obtaining uniformly distributed colloidally stable, biocompatible …


Oxorhenium(V)-Mediated Syntheses And Structures Of Oxypyridinium-Ammonium Zwitterions, Abubak'r Abrahams, Thomas Gerber, Eric Hosten, Peter Mayer Jan 2009

Oxorhenium(V)-Mediated Syntheses And Structures Of Oxypyridinium-Ammonium Zwitterions, Abubak'r Abrahams, Thomas Gerber, Eric Hosten, Peter Mayer

Turkish Journal of Chemistry

Treatment of N,N-bis(2-hydroxybenzyl)-2-(2-aminoethyl) dimethylamine (H_2had) with trans-[ReO_2(py)_4]I in acetone affords the iodide salts of the oxypyridinium-ammonium zwitterions N^1-(2-hydroxybenzyl)-N^2,N^2-dimethyl-N^1-((2-oxypyridinium)-1- methyl)ethane-1,2-diamine [Hhpd]^+ and N^2,N^2-dimethyl-N^1- bis((2-oxypyridinium)-1- methyl)ethane-1,2-diamine [dod]^+. The products were characterized by X-ray structure analysis, and NMR and IR spectroscopy.


Hydrogen Storage Via Physisorption: The Combined Role Of Adsorption Enthalpy And Entropy, Carlos Otero Arean, Barbara Bonelli, Montserrat Rodriguez Delgado, Edoardo Garrone Jan 2009

Hydrogen Storage Via Physisorption: The Combined Role Of Adsorption Enthalpy And Entropy, Carlos Otero Arean, Barbara Bonelli, Montserrat Rodriguez Delgado, Edoardo Garrone

Turkish Journal of Chemistry

Materials capable of cost-effective on-board hydrogen storage and delivery are currently being sought worldwide as a means to facilitate a hydrogen-based energy transition in the transportation sector. Among the solutions proposed, hydrogen storage by physisorption on porous solids constitutes a main avenue of research, and for intelligent design of such materials a detailed knowledge of gas adsorption thermodynamics is of the utmost importance. Analysis of the available data for hydrogen adsorption on alkali and alkaline-earth cation exchanged zeolites clearly shows that standard adsorption enthalpy (\Delta H^0) and entropy (\Delta S^0) are correlated, in the sense that larger \Delta S^0 values …


Dynamic ^1h-Nmr Demonstration Of Anomeric Effect And Structure: Conformational And Configurational Analysis Of N-2-(1,4-Dioxane)-N'-(P-Methylbenzenesulfonyl)- O-(P-Methylphenoxy) İsourea, Ali Reza Modarresi-Alam, Hossein A. Dabbagh Jan 2009

Dynamic ^1h-Nmr Demonstration Of Anomeric Effect And Structure: Conformational And Configurational Analysis Of N-2-(1,4-Dioxane)-N'-(P-Methylbenzenesulfonyl)- O-(P-Methylphenoxy) İsourea, Ali Reza Modarresi-Alam, Hossein A. Dabbagh

Turkish Journal of Chemistry

The conformational and configurational behavior and the structure of N-2-(1,4-dioxane)-N'-(p-methylbenzenesulfonyl)-O- (p-methylphenoxy) isourea (1) were studied using dynamic NMR. The endo-anomeric effect, hydrogen bonding, temperature, and polarity of solvent control the population of dioxane ring conformers or anomers but not the configuration interconversion of the imine of the imidoyl moiety. Dynamic ^1H-NMR, \Delta H°, \Delta S°, \Delta G°, and \Delta G^{\ddag} analysis of 1 demonstrates that the dioxane ring adopts the chair conformation, that the imidoyl amino group prefers axial conformation, and that the tosyl and tolyl groups about the C=N bond retain the E configuration.


Spectroscopic Studies And Hartree-Fock Ab Initio Calculations Of A Substituted Amide Of Pyrazine-2-Carboxylic Acid - C_{16}H_{18}Cln_3o, Chacko Yohannan Panicker, Hema Tresa Vanghese, Thaha Thansani Jan 2009

Spectroscopic Studies And Hartree-Fock Ab Initio Calculations Of A Substituted Amide Of Pyrazine-2-Carboxylic Acid - C_{16}H_{18}Cln_3o, Chacko Yohannan Panicker, Hema Tresa Vanghese, Thaha Thansani

Turkish Journal of Chemistry

A substituted amide of pyrazine-2-carboxylic acid was prepared and the IR spectrum was recorded and analysed. The compound prepared was identified by NMR and mass spectra. The vibrational frequencies of the title compound were computed using the Hartree-Fock level of theory using the 6-31G* basis set and compared with the experimental data. The red shift of the NH stretching frequency indicates weakening of the NH bond. The splitting of the NH stretching bond is due to Davidov coupling between neighbouring units. The first hyperpolarizability, infrared intensities, and Raman activities are reported. Methyl substitution affects all the carbon-nitrogen and carbon-carbon bond …


Secondary Metabolites From Nepeta Heliotropifolia, Zühal Güvenalp, Hi̇lal Özbek, Ayşe Kuruüzüm-Uz, Cavi̇t Kazaz, L. Ömür Demi̇rezer Jan 2009

Secondary Metabolites From Nepeta Heliotropifolia, Zühal Güvenalp, Hi̇lal Özbek, Ayşe Kuruüzüm-Uz, Cavi̇t Kazaz, L. Ömür Demi̇rezer

Turkish Journal of Chemistry

Two iridoid glycosides, ixoroside (1) and nepetanudoside B (2); 1 phenylpropanoid glycoside, coniferine (3); 2 flavone glycosides, apigenin 7-O-glucuronide (4) and apigenin 7-O-glucopyranoside (5); 2 triterpenes, oleanolic acid (6) and ursolic acid (7); and 1 sterol, \beta-sitosterol (8), were isolated from the aerial parts of Nepeta heliotropifolia Lam. (Lamiaceae). Their structures were identified by means of spectroscopic methods (1D- and 2D-NMR, UV, and EIMS).


A Facile Method For The Preparation Of Poly(4-Vinylpyridine) Nanoparticles And Their Characterization, Nurettin Sahiner Jan 2009

A Facile Method For The Preparation Of Poly(4-Vinylpyridine) Nanoparticles And Their Characterization, Nurettin Sahiner

Turkish Journal of Chemistry

Submicron size particles were synthesized from 4-vinylpyridine (4-VP) using an oil-in-water emulsion system. Divinyl benzene (DVB) and ethylene glycol dimethacrylate (EGDMA) were utilized as crosslinkers for the synthesis of p(4-VP) hydrogel nanoparticles in sodium dodecyl sulfate (SDS) surfactant systems. Characterization of the particles was made by transmission electron microscopy (TEM) and dynamic light scattering (DLS) methods. To render a positive charge, p(4-VP) particles were reacted with 1-bromo butane (1-BB).


Synthesis And Leishmanicidal Evaluation Of Novel 4-Substituted-2,2-Dimethyl-7-(Prop-2-Ynyloxy)Chromenes, Babak H. Alizadeh, Alireza Foroumadi, Susan K. Ardestani, Fatemeh Poorrajab, Abass Shafiee Jan 2009

Synthesis And Leishmanicidal Evaluation Of Novel 4-Substituted-2,2-Dimethyl-7-(Prop-2-Ynyloxy)Chromenes, Babak H. Alizadeh, Alireza Foroumadi, Susan K. Ardestani, Fatemeh Poorrajab, Abass Shafiee

Turkish Journal of Chemistry

Substituted 4-chromenes were synthesized via the Grignard coupling reaction of various substituted phenyl- and benzylmagnesium chlorides with 2,2-dimethyl-7-(prop-2-ynyloxy)chroman-4-one (1) in relatively good yield (60%-85%). The benzylic-substituted derivatives were a mixture of 2 exo and endo regioisomers, and the exo compounds were a mixture of E and Z isomers. Structural analysis of the exo and endo isomers, as well as E and Z of exo isomers were based on H-NMR, ^{13}C-NMR, and NOESY experiments. The synthetic compounds were examined for in vitro activity against Leishmania major and compound 9 (a, b) was the most active, with inhibitory activity of 36%.


Mild And Efficient Iodination Of Aromatic Compounds With Trichloroisocyanuric Acid/I_2/Wet Sio_2 System, Batool Akhlaghinia, Marzieh Rahmani Jan 2009

Mild And Efficient Iodination Of Aromatic Compounds With Trichloroisocyanuric Acid/I_2/Wet Sio_2 System, Batool Akhlaghinia, Marzieh Rahmani

Turkish Journal of Chemistry

Iodoarenes can be obtained using trichloroisocyanuric acid/I_2/wet SiO_2 system at room temperature with high yield in CH_2Cl_2.


Bromination Of Tetrachlorobenzobarrelene: Polyhalogenated Benzobicyclics, Mehmet Emi̇n Şengül, Demet Demi̇rci̇ Gülteki̇n, Selçuk Eşsi̇z, Ari̇f Daştan Jan 2009

Bromination Of Tetrachlorobenzobarrelene: Polyhalogenated Benzobicyclics, Mehmet Emi̇n Şengül, Demet Demi̇rci̇ Gülteki̇n, Selçuk Eşsi̇z, Ari̇f Daştan

Turkish Journal of Chemistry

The low and high temperature bromination reaction of tetrachlorobenzobarrelene was studied and the possible role of a neighboring group in rearrangements was investigated. New polyhalogenated benzobicyclic compounds were synthesized. All compounds were characterized properly using NMR spectroscopy.


On The Structure Sensitivity Of Co Oxidation On Alumina Supported Pd--Pt Bimetallic Catalysts, Sarp Kaya, Ebru Erunal, Riad Shaltaf, Şi̇nasi̇ Elli̇altioğlu, Deni̇z Üner Jan 2009

On The Structure Sensitivity Of Co Oxidation On Alumina Supported Pd--Pt Bimetallic Catalysts, Sarp Kaya, Ebru Erunal, Riad Shaltaf, Şi̇nasi̇ Elli̇altioğlu, Deni̇z Üner

Turkish Journal of Chemistry

CO oxidation reaction was studied over monometallic and bimetallic palladium--platinum catalysts at 25:75, 50:50, and 75:25 Pd:Pt atomic fractions co-impregnated over a \gamma -Al_2O_3 support. The size of the metal particles, measured by modified hydrogen chemisorption, increased as the Pd fractions in the catalyst increased. The surface compositions and site metal distributions of the catalysts determined from Monte Carlo simulations indicated that Pd atoms segregated to the surface: at low Pd levels, Pd occupied preferentially 6 and 7 coordinated defect-like sites. As the Pd fraction increased, first 8 coordinated (100) and then 9 coordinated (111) planes were populated. At low …


A Mild Method For The Cleavage Of Ketals Using Ibx, Abdul Rauf Raza Jan 2009

A Mild Method For The Cleavage Of Ketals Using Ibx, Abdul Rauf Raza

Turkish Journal of Chemistry

Investigation on the total synthesis of batrachotoxin 1 revealed that the cyclic ketals could be cleaved to ketone with IBX in DMSO at 70-81 °C under very mild conditions. A variety of functional groups showed no interference under these conditions except vinyl bromides, which, in fact, inhibits the single electron transfer to IBX.


The Effect Of Electrocatalytic Activity And Crystal Structure Of Pbo_2 Surfaces On Polyphenylene Oxide (Ppo) Production In Acetonitrile, Serdar Abaci, Atti̇la Yildiz Jan 2009

The Effect Of Electrocatalytic Activity And Crystal Structure Of Pbo_2 Surfaces On Polyphenylene Oxide (Ppo) Production In Acetonitrile, Serdar Abaci, Atti̇la Yildiz

Turkish Journal of Chemistry

The crystallographic nature of PbO_2 films was changed by optimizing the electrolysis conditions in an electrodeposition solution of PbO_2. These PbO_2 films were then used to prepare PPO films. It was determined that \alpha and \beta modifications, and relative degrees of crystallinity had profound effects on the electrocatalytic performance of PbO_2 films in the production PPO films.