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2009

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Articles 11161 - 11190 of 14103

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Nitric Oxide Releasing Derivatives Of [(2-Chloroethyl)Ureido] Benzoic Acid Esters As Potential Antineoplastic Agents, Hülya Akgün, Barkin Berk, Di̇lek Demi̇r Erol, Güldem Mercanoğlu, Ömer Faruk Bayrak, Berrak Çağlayan, Asli Dedeağaç, Işil Aksan Kurnaz Jan 2009

Nitric Oxide Releasing Derivatives Of [(2-Chloroethyl)Ureido] Benzoic Acid Esters As Potential Antineoplastic Agents, Hülya Akgün, Barkin Berk, Di̇lek Demi̇r Erol, Güldem Mercanoğlu, Ömer Faruk Bayrak, Berrak Çağlayan, Asli Dedeağaç, Işil Aksan Kurnaz

Turkish Journal of Chemistry

New series of [(2-chloroethyl)ureido] benzoic acids (compounds 3-8) and nitric oxide releasing derivatives of [(2-chloroethyl)ureido] benzoic acid esters (compounds 9-14) were synthesized as potential anti-cancer agents. These compounds were screened for their anti-proliferative activities on A549 (human lung carcinoma) cells and for their cytotoxic effects on L929 (mouse fibroblast) cells. The compounds 3-8 exhibited mild cytotoxic effects on L929 cells (cell viability from 100% to 85% -- 90% only) whereas they had very little anti-proliferative activities towards A549 lung carcinoma cells. On the other hand, compounds 10, 11, and 13 had some growth inhibition activity in A549 (human lung carcinoma) …

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Microwave-Assisted Synthesis Of Some Metal-Free Phthalocyanine Derivatives And A Comparison With Conventional Methods Of Their Synthesis, Özlem Seven, Bi̇rcan Di̇ndar, Burak Gülteki̇n Jan 2009

Microwave-Assisted Synthesis Of Some Metal-Free Phthalocyanine Derivatives And A Comparison With Conventional Methods Of Their Synthesis, Özlem Seven, Bi̇rcan Di̇ndar, Burak Gülteki̇n

Turkish Journal of Chemistry

Synthesis of metal-free 2,9(10),16(17),23(24)-tetra(3,5- dimethylphenoxy) phthalocyanine, 2,9(10),16(17), 23(24)-tetra(4- tert-butylphenoxy) phthalocyanine, and 2,9(10),16(17),23(24)-tetra(3,5- di-tert-butyl-4-hydroxyphenyl) phthalocyanine was carried out via microwave irradiation. Furthermore, pentanol and lithium were used for the first time in the synthesis of metal-free phthalocyanine under microwave irradiation as a solvent and a base-catalyst, respectively. The microwave irradiation experiments were performed in a MARS5 with a CEM XP-1500 vessel. In addition, these compounds were obtained with conventional heating procedures to compare them with those obtained with microwave irradiation. The compounds were characterized by elemental and spectroscopic analysis, including UV-Vis, H NMR, FT-IR, and MALDI-TOF mass data. In particular, both …

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Synthesis And Antimicrobial And Antitumor Activity Of Some New [1,2,4] Triazole-5-One Derivatives, Yasemi̇n Ünver, Esra Düğdü, Kemal Sancak, Mustafa Er, Sengül Alpay Karaoğlu Jan 2009

Synthesis And Antimicrobial And Antitumor Activity Of Some New [1,2,4] Triazole-5-One Derivatives, Yasemi̇n Ünver, Esra Düğdü, Kemal Sancak, Mustafa Er, Sengül Alpay Karaoğlu

Turkish Journal of Chemistry

4-[Arylidene-amino]-3-thiophen-2-ylmethyl-4,5-dihydro[1,2,4]triazole-5-one compounds (3a-g) with Schiff base character were obtained from the reaction of 4-amino-3-thiophen-2-ylmethyl-4,5-dihydro-1H-[1,2,4]triazole-5-one (2) with various aldehydes. 1-(2-Oxo-2-phenyl-ethyl)-4-[arylidene-amino]-3-thiophen-2-ylmethyl-4,5- dihydro-1H-[1,2,4]triazole-5-ones (4a-g) were synthesized from the reaction of corresponding compounds 3a-g with bromoacetophenone. 1-(2-Hydroxy-2-phenyl-ethyl)- 3-thiophen-2-ylmethyl-4-[aryl-amino]4,5-dihydro-1H-[1,2,4]triazole-5-ones (5a-g) and 1-(2-hydroxy-2-phenyl-ethyl)-3-thiophen-2-ylmethyl-4-[arylidene-amino] 4,5-dihydro-1H-[1,2,4]triazole-5-ones (6b,d,e) were obtained from the selective reduction of 1-(2-oxo-2-phenyl-ethyl)-4-[arylidene-amino]-3-thiophen-2ylmethyl- 4,5-dihydro-1H-[1,2,4] triazole-5-ones (4) with NaBH_4. They were characterized by IR, H-NMR,^{13}C-NMR, and elemental analyses. Compounds 2, 3a, 3c, 3g, 4f, 5b, and 5g showed good antifungal activity against yeast-like fungi. Compounds selected by the National Cancer Institute (NCI, USA) were investigated for antitumor activity.

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Quantitative Structure--Retention Study Of Some 2,4-Dioksotetrahydro- 1,3--Thiazole Derivatives Using The Partial Least Squares Method, Tatjana Djakovic-Sekulic, Costel Sarbu, Nada Perisic-Janjic, Zagorka Lozanov-Crvenkovic Jan 2009

Quantitative Structure--Retention Study Of Some 2,4-Dioksotetrahydro- 1,3--Thiazole Derivatives Using The Partial Least Squares Method, Tatjana Djakovic-Sekulic, Costel Sarbu, Nada Perisic-Janjic, Zagorka Lozanov-Crvenkovic

Turkish Journal of Chemistry

Thin-layer chromatography on rice starch support and aqueous ammonia--organic modifier (methanol, dioxane, and acetone) mobile phases was used to study the effect on retention of the chromatographic system and the physicochemical properties of twelve 2,4-dioxotetrahydro-1,3-thiazoles. A multivariate approach to the retention behaviour of the investigated compounds with 3 quite different organic solvents was used to explain the interactions between the 1,3-thiazoles and the mobile phases. Partial least-squares (PLS) regression was used to quantify differences between the observed data and recognize the molecular properties with the greatest effect on retention for each modifier. Good correlation was obtained between experimental and calculated …

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Cover And Contents Jan 2009

Cover And Contents

Turkish Journal of Chemistry

No abstract provided.

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Chiral Calixarenes, Abdulkadi̇r Sirit, Mustafa Yilmaz Jan 2009

Chiral Calixarenes, Abdulkadi̇r Sirit, Mustafa Yilmaz

Turkish Journal of Chemistry

No abstract provided.

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Study Of The Polymerization Of Methyl Methacrylate Initiated By Thioxanthone Derivatives: A Magnetic Field Effect, Sevnur Keski̇n, Meral Aydin, Igor Khudyakov, Nergi̇z Arsu Jan 2009

Study Of The Polymerization Of Methyl Methacrylate Initiated By Thioxanthone Derivatives: A Magnetic Field Effect, Sevnur Keski̇n, Meral Aydin, Igor Khudyakov, Nergi̇z Arsu

Turkish Journal of Chemistry

Free radical photopolymerization of methyl methacrylate (MMA) initiated by 2-mercaptothioxanthone (TX-SH), thioxanthone-thioacetic acid (TXSCH_2COOH), and thioxanthone-carboxymethoxy acetic acid (TXOCH_2COOH) as so called one-component initiators was performed with and without an external magnetic field (MF). These initiators contain light-absorbing and electron/hydrogen-donating fragments in one molecule and do not require an additional hydrogen donor, and initiate the polymerization of MMA in the air. Polymerization experiments were performed in solutions with 3 different optical densities at \lambda 365 nm, where the photoinitiator absorbs. It was observed that application of MF leads to both larger conversion and higher molecular weight of the prepared PMMA, …

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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.

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Voltammetric Determination Of Ascorbic Acid And Dopamine Simultaneously At A Single Crystal Au(111) Electrode, Zekerya Dursun, Levent Peli̇t, Isao Taniguchi Jan 2009

Voltammetric Determination Of Ascorbic Acid And Dopamine Simultaneously At A Single Crystal Au(111) Electrode, Zekerya Dursun, Levent Peli̇t, Isao Taniguchi

Turkish Journal of Chemistry

A single-crystal Au(111) electrode was used for the simultaneous determination of dopamine (DA) and ascorbic acid (AA) in a phosphate buffer solution at pH 6.9. The single-crystal Au(111) electrode displayed excellent electrocatalytic activity for DA and AA oxidation in comparison to a Au disk electrode. Although the anodic peaks of both reagents overlapped on the Au disk electrode, the anodic peak potentials of DA and AA in their mixture were well separated since the peak potential of AA was shifted to more negative values by cyclic and differential pulse voltammetry. The oxidation peak current increased linearly with the concentration of …

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Ferric Hydrogen Sulfate As An Efficient Heterogeneous Catalyst For Environmentally Friendly Greener Synthesis Of 1,8-Dioxo-Octahydroxanthenes, Hamid Reza Shaterian, Asghar Hosseinian, Majid Ghashang Jan 2009

Ferric Hydrogen Sulfate As An Efficient Heterogeneous Catalyst For Environmentally Friendly Greener Synthesis Of 1,8-Dioxo-Octahydroxanthenes, Hamid Reza Shaterian, Asghar Hosseinian, Majid Ghashang

Turkish Journal of Chemistry

Ferric hydrogen sulfate was used as an environmentally friendly heterogeneous acidic catalyst for the greener, 1-pot, 3-component synthesis of 1,8-dioxo-octahydroxanthene via condensation reactions between aromatic aldehydes and dimedone under solvent-free thermal and microwave irradiation as well as in aqueous media conditions in short periods of times with excellent yields. The catalyst was easily separated in simple work-up and was recycled several times without loss of reactivity under the described reaction conditions.

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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.

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The Role Of The Entropy Factor On The Adsorption Of An Optical Brightener On Pulp, Greta Radeva, Eva Valcheva, Stefka Veleva Jan 2009

The Role Of The Entropy Factor On The Adsorption Of An Optical Brightener On Pulp, Greta Radeva, Eva Valcheva, Stefka Veleva

Turkish Journal of Chemistry

The present paper reports results of the thermodynamic study of adsorption of 2 optical brighteners (Tinopal UP and Leucophor AP) on pulp. The entropy non-homogeneity of the pulp surface was confirmed and the coefficients of entropy non-homogeneity were determined. The entropy effect on the variation of Gibbs free energy of the process studied was followed.

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Water-Gas Shift Reaction Over Bimetallic Pt-Ni/Al_2o_3 Catalysts, Burcu Selen Çağlayan, Ahmet Erhan Aksoylu Jan 2009

Water-Gas Shift Reaction Over Bimetallic Pt-Ni/Al_2o_3 Catalysts, Burcu Selen Çağlayan, Ahmet Erhan Aksoylu

Turkish Journal of Chemistry

The water-gas shift (WGS) activity of bimetallic Pt-Ni/Al_2O_3 catalysts was investigated in the temperature range 200-450 °C using an idealized feed composition consisting of 3% CO and 6%-10% H_2O. The effects of the Ni content, space velocity, and H_2O/CO ratio on the catalytic performance of the catalysts were studied. An increase in the Ni content and H_2O/CO ratio shifted the carbon monoxide conversion--temperature curve toward lower reaction temperatures. No detectable methane formation was observed in the catalytic reaction tests. The results indicate that Pt-Ni/Al_2O_3 catalysts are highly selective and active for water-gas shift reactions under idealized conditions.

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Synthesis, Spectral Characterization, And Antimicrobial Activity Of Arsenic(Iii) And Bismuth(Iii) Tri[3(2´-Hydroxyphenyl)-5-(4-Subsituted Phenyl)Pyrazolinates], Umesh Nath Tripathi, Afshan Siddqui, Jeeven Singh Solanki, Mohammad Safi Ahmad, Arpan Bhardwaj, Tulsi Ram Thapak Jan 2009

Synthesis, Spectral Characterization, And Antimicrobial Activity Of Arsenic(Iii) And Bismuth(Iii) Tri[3(2´-Hydroxyphenyl)-5-(4-Subsituted Phenyl)Pyrazolinates], Umesh Nath Tripathi, Afshan Siddqui, Jeeven Singh Solanki, Mohammad Safi Ahmad, Arpan Bhardwaj, Tulsi Ram Thapak

Turkish Journal of Chemistry

Arsenic(III) tripyrazolinates and bismuth(III) tripyrazolinates of the type M(C_{15}H_{12}N_2OX)_3 [where C_{15}H_{12}N_2OX = 3(2'-hydroxyphenyl)-5-(4-substituted phenyl)pyrazoline] have been synthesized by the reaction of MCl_3 and sodium salt of pyrazolines in 1:3 molar ratio in anhydrous benzene at elevated temperature. These newly synthesized derivatives have been characterized by elemental analysis (C, H, N, As, and Bi), molecular weight measurement, spectral [IR and multinuclear NMR (^1H & ^{13}C)] and x-ray diffraction studies. The bonding mode of pyrazolines and coordination no. of arsenic(III) and bismuth(III) in these derivatives have been discussed. Antibacterial and antifungal potential of free pyrazoline and some arsenic(III) tripyrazolinates and bismuth(III) tripyrazolinates …

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Development Of Alumina Supported Alkaline Catalysts Used For Biodiesel Production, Oğuzhan İlgen, Ayşe Ni̇lgün Akin Jan 2009

Development Of Alumina Supported Alkaline Catalysts Used For Biodiesel Production, Oğuzhan İlgen, Ayşe Ni̇lgün Akin

Turkish Journal of Chemistry

The transesterification of canola oil with methanol was studied in a heterogeneous system, using \gamma-Al_2O_3 supported alkaline catalysts. All the catalysts were prepared by incipient-wetness impregnation of an aqueous solution of alkaline compounds on \gamma-Al_2O_3 support. The effects of alkaline compound, methanol/canola oil molar ratio, reaction temperature, catalyst amount, and reaction time in biodiesel production were investigated. The catalyst with KOH loaded on \gamma-Al_2O_3 gave the highest basicity and the best catalytic activity for this reaction. The highest FAME yield obtained was 89.40%.

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Synthesis Of 5-Arylamino-1h (2h)-Tetrazoles And 5-Amino-1-Aryl-1h-Tetrazoles From Secondary Arylcyanamides In Glacial Acetic Acid: A Simple And Efficient Method, Ali Reza Modarresi-Alam, Mahmoud Nasrollahzadeh Jan 2009

Synthesis Of 5-Arylamino-1h (2h)-Tetrazoles And 5-Amino-1-Aryl-1h-Tetrazoles From Secondary Arylcyanamides In Glacial Acetic Acid: A Simple And Efficient Method, Ali Reza Modarresi-Alam, Mahmoud Nasrollahzadeh

Turkish Journal of Chemistry

A simple and efficient method for the preparation of 5-arylamino-1H (2H)-tetrazoles (3a-i) and 5-amino-1-ary-1H-tetrazoles (4a-i), with excellent yields and high purity, from secondary arylcyanamides (1a-i) at room temperature in glacial acetic acid is described. Tautomers 3a-i were separated from tautomers 4a-i by crystallization in ethanol. A mechanism was introduced in glacial acetic acid. The ratio of isomers is described based on the electronic and steric effects of various substituents. The electron withdrawing group (-NO_2) increased the ratio of 4:3. The rate of product formation was enhanced by introducing electron donating substituents. ^1H-NMR and ^{13}C-NMR chemical shifts and multiplicities are also …

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Investigation Of Biodiesel Production From Canola Oil Using Amberlyst-26 As A Catalyst, Oğuzhan İlgen, Ayşe Ni̇lgün Akin, Nezahat Boz Jan 2009

Investigation Of Biodiesel Production From Canola Oil Using Amberlyst-26 As A Catalyst, Oğuzhan İlgen, Ayşe Ni̇lgün Akin, Nezahat Boz

Turkish Journal of Chemistry

The transesterification of canola oil to fatty acid methyl esters was studied using Amberlyst-26 as a solid catalyst. The influence of reaction conditions, such as the reaction time, methanol to oil molar ratio, amount of catalyst, effect of co-solvent, and alcohol and oil types, were determined. When the reaction was carried out at 45 °C with a canola oil to methanol molar ratio of 6:1, a reaction time of 1.5 h, and 3 wt.% of catalyst, oil conversion was about 67%. Methanol was much more reactive than ethanol and isopropyl alcohol (IPA) in the transesterification reaction. The conversion of canola …

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[Pd(Me-Xanthate)_2]: Synthesis, Characterization, And X-Ray Structure, Saira Shahzadi, Saqib Ali, Rehana Jabeen, Muhammad Kaleem Khosa Jan 2009

[Pd(Me-Xanthate)_2]: Synthesis, Characterization, And X-Ray Structure, Saira Shahzadi, Saqib Ali, Rehana Jabeen, Muhammad Kaleem Khosa

Turkish Journal of Chemistry

Potassium methyl xanthate and its complex [Pd(Me-Xanthate)_2] were synthesized at room temperature under stirring conditions. The ligand and the complex were characterized by elemental analysis, IR, NMR (^1H, ^{13}C) and XRD. NMR data revealed that potassium methyl xanthate acts as a bidentate specie and the complex exhibits 4-coordinated geometry in solution. In solid state, the palladium atom is coordinated to the 2 sulfur atoms of the xanthate ligand and the complex exhibits distorted square planar geometry.

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A Density Functional Theory Study Of Oxidation Of Benzene To Phenol By N_2o On Fe- And Co-Zsm-5 Clusters, Mehmet Ferdi̇ Fellah, Işik Önal Jan 2009

A Density Functional Theory Study Of Oxidation Of Benzene To Phenol By N_2o On Fe- And Co-Zsm-5 Clusters, Mehmet Ferdi̇ Fellah, Işik Önal

Turkish Journal of Chemistry

Density functional theory (DFT) calculations were carried out in the study of oxidation of benzene to phenol by N_2O on relaxed [(SiH_3)_4AlO_4M] (where M=Fe, Co) cluster models representing Fe- and Co-ZSM-5 surfaces. The catalytic cycle steps are completed for both Fe-ZSM-5 and Co-ZSM-5 clusters. The general trend of the results that were obtained in terms of activation barriers for the Fe-ZSM-5 cluster is in agreement with the experimental and theoretical literature. It was observed that the phenol formation step is the rate-limiting step for both clusters and Co-ZSM-5 surface has a lower activation barrier than the Fe-ZSM-5 surface (i.e. 35.82 …

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Cover And Contents Jan 2009

Cover And Contents

Turkish Journal of Chemistry

No abstract provided.

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Synthesis And Biological Activity Of 4-(4-Hydroxybenzylidene)-2- (Substituted Styryl) Oxazol-5-Ones And Their O-Glucosides, Vijay Taile, Kishor Hatzade, Pravin Gaidhane, Vishwas Ingle Jan 2009

Synthesis And Biological Activity Of 4-(4-Hydroxybenzylidene)-2- (Substituted Styryl) Oxazol-5-Ones And Their O-Glucosides, Vijay Taile, Kishor Hatzade, Pravin Gaidhane, Vishwas Ingle

Turkish Journal of Chemistry

The 4-(4-hydroxybenzylidene)-2-methyl oxazol-5-ones 1 were treated with various aldehydes in the presence of acetic acid to form 4-(4-hydroxybenzylidene)-2-(substituted styryl) oxazol-5-ones 2a-i, which were glucosylated using \alpha-acetobromoglucose as a glucosyl donor to afford 4-(4-o-\beta-d-tetra-o-acetyl-glucoxybenzylidene)-2- (substituted styryl) oxazol-5-ones 3a-i, which were deacetylated using zinc acetate in absolute methanol to form 4-(4-o-\beta-d-glucoxybenzylidene)- 2-(substituted styryl) oxazol-5-ones 4a-i. The compounds showed good antimicrobial and antifungal activity.

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The Synthesis, Characterization And Energy Transfer Efficiency Of A Dithienylpyrrole And Bodipy Based Donor-Acceptor System, Taner Atalar, Ati̇lla Ci̇haner, Fati̇h Algi Jan 2009

The Synthesis, Characterization And Energy Transfer Efficiency Of A Dithienylpyrrole And Bodipy Based Donor-Acceptor System, Taner Atalar, Ati̇lla Ci̇haner, Fati̇h Algi

Turkish Journal of Chemistry

A dithienylpyrrole-BODIPY based donor-acceptor system with 1,4-phenylene spacer as a model system for energy transfer was designed and synthesized. Absorption and emission spectra have revealed an efficient resonance energy transfer from dithienylpyrrole as donor to BODIPY as acceptor.

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Synthesis, Characterization, And Antibacterial Effect Of 4-Methoxy-2-(5-H/Me/Cl/No_2-1h-Benzimidazol-2-Yl)- Phenols And Some Transition Metal Complexes, Aydin Tavman, Serkan İki̇z, Arzu Funda Bağcigi̇l, N. Yakut Özgür, Seyyal Ak Jan 2009

Synthesis, Characterization, And Antibacterial Effect Of 4-Methoxy-2-(5-H/Me/Cl/No_2-1h-Benzimidazol-2-Yl)- Phenols And Some Transition Metal Complexes, Aydin Tavman, Serkan İki̇z, Arzu Funda Bağcigi̇l, N. Yakut Özgür, Seyyal Ak

Turkish Journal of Chemistry

4-Methoxy-2-(5-H/methyl/chloro/nitro-1H-benzimidazol-2-yl)-phenol(HL_X; X=1-4) ligands and HL_1 complexes with Fe(NO_3)_3, Cu(NO_3)_2, AgNO_3, and Zn(NO_3)_2 were synthesized and characterized. The structures of the compounds were confirmed on the basis of elemental analysis, molar conductivity, magnetic moment, FT-IR, UV-visible, and ^1H- and ^{13}C-NMR. Antibacterial activity of the free ligands, their hydrochloride salts, and the complexes was evaluated using the disk diffusion method in dimethyl sulfoxide (DMSO) as well as the minimum inhibitory concentration (MIC) dilution method, against 9 bacteria, and the results were compared with penicillin-G and oxytetracycline. It was observed that HL_1, [Ag(HL_1)](NO_3), and [Cu(L_1)_2](H_2O)_2 are effective on S. epidermidis, S. aureus, and …

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Spectroscopic And Structural Study Of Ni(Ii) Dipicolinate Complex With 2-Amino-4-Methylpyrimidine, İclal Bulut, İbrahi̇m Uçar, Canan Kazak Jan 2009

Spectroscopic And Structural Study Of Ni(Ii) Dipicolinate Complex With 2-Amino-4-Methylpyrimidine, İclal Bulut, İbrahi̇m Uçar, Canan Kazak

Turkish Journal of Chemistry

Nickel(II) dipicolinate complex containing 2-amino-4- methylpyrimidine (2A-4Mpy), [Ni(2A-4Mpy)(dpc) (H_2O)_2] . 2H_2O was synthesized in solid state and its structural and spectroscopic properties were determined by XRD, IR, and UV-Vis techniques. The crystal data revealed that the Ni complex is in triclinic crystal systems with space group P-1 and Z = 2. The Ni(II) ion is bonded to dipicolinate ligand through pyridine N atom together with one O atom of each carboxylate group, 2 aqua ligands, and the N atom of 2-amino-4-methylpyrimidine, forming distorted octahedral geometry. IR and UV-Vis spectra of the complexes all agree with the observed crystal structure.

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Methanol Dehydration Reaction To Produce Clean Diesel Alternative Dimethylether Over Mesoporous Aluminosilicate-Based Catalysts, Di̇lek Varişli, Kenan Cem Tokay, Ayşegül Çi̇ftçi̇, Ti̇mur Doğu, Gülsen Doğu Jan 2009

Methanol Dehydration Reaction To Produce Clean Diesel Alternative Dimethylether Over Mesoporous Aluminosilicate-Based Catalysts, Di̇lek Varişli, Kenan Cem Tokay, Ayşegül Çi̇ftçi̇, Ti̇mur Doğu, Gülsen Doğu

Turkish Journal of Chemistry

Due to its good burning characteristics and high cetane number, dimethylether (DME) is considered as a highly attractive and clean alternative to diesel fuel. This ether can be produced by methanol dehydration reaction over solid acid catalysts. In the present study, activities of mesoporous aluminosilicate catalysts prepared by the hydrothermal synthesis route and containing Al/Si atomic ratios ranging between 0.03 and 0.18 were tested in methanol dehydration. The optimum Al/Si ratio was 0.09 for DME synthesis. Activity of silicotungstic acid (STA) impregnated aluminosilicate was also tested. This STA impregnated catalyst showed very high DME yield values at temperatures as low …

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Synthesis And Antimicrobial Activity Of Dinaphtho[2,1-B]Furan-2-Yl-Methanone And Their Oxime Derivatives, Cumhur Kirilmiş, Murat Koca, Süleyman Servi̇, Seher Gür Jan 2009

Synthesis And Antimicrobial Activity Of Dinaphtho[2,1-B]Furan-2-Yl-Methanone And Their Oxime Derivatives, Cumhur Kirilmiş, Murat Koca, Süleyman Servi̇, Seher Gür

Turkish Journal of Chemistry

The reaction of 2-hydroxy-1-naphthaldehyde with 1,3-dichloroacetone and potassium carbonate was used to prepare dinaphtho[2,1-b]furan-2-yl-methanone (1) as starting reagents. In order to obtain dinaphtho[2,1-b]furan-2-yl-methanole (2), compound 1 was reduced with NaBH_4. N-oxime derivative of this compound (3) was synthesized by the reaction of the compound 1 with hydroxylamine. Alkyl and acyl substituted N-oxime ethers (4-11) were obtained by the reaction compound 3 with various halogen containing compounds. Compound 12 was obtained by reflux of the compound 11 with hydrazine monohydrate in ethanol. Compound 13 was synthesized by the reaction of the compound 11 with NaOH. The synthesized compounds were tested for …

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Synthesis And Evaluation Of Phenytoin Derivatives As Anticonvulsant Agents, Meenakshi Deodhar, Pravin Sable, Ashok Bhosale, Kapil Juvale, Rahul Dumbare, Pramod Sakpal Jan 2009

Synthesis And Evaluation Of Phenytoin Derivatives As Anticonvulsant Agents, Meenakshi Deodhar, Pravin Sable, Ashok Bhosale, Kapil Juvale, Rahul Dumbare, Pramod Sakpal

Turkish Journal of Chemistry

2,5-Dioxo-4,4-diphenylimidazolidine-1-carboxylic acid (2) was reacted with methyl ester of different amino acids (1a-c) and substituted benzhydrols (3a-b) in pyridine and in the presence of N,N dicyclohexyl carbodiimide (DCC) to yield a series of the title compounds, methyl 2-(2,5-dioxo-4,4-diphenylimidazolidine-1-carboxamido) substituted propanoate (4a-c) and benzhydryl 2,5-dioxo-4,4-diphenyl imidazolidine-1-carboxylate (5a-b). The structures of these compounds were established on the basis of their spectral (IR, ^1H-NMR) data. These newly synthesized derivatives of phenytoin were evaluated in terms of anticonvulsant activity.

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Improved Photostability Of Pvc Films In The Presence Of 2-Thioacetic Acid-5-Phenyl-1,3,4-Oxadiazole Complexes, Emad A. Yousif, Salah A. Aliwi, Ameer A. Ameer, Jaleel R. Ukal Jan 2009

Improved Photostability Of Pvc Films In The Presence Of 2-Thioacetic Acid-5-Phenyl-1,3,4-Oxadiazole Complexes, Emad A. Yousif, Salah A. Aliwi, Ameer A. Ameer, Jaleel R. Ukal

Turkish Journal of Chemistry

The photostabilization of poly(vinyl chloride) (PVC) films by 2-thioacetic acid-5-phenyl-1,3,4-oxadiazole with Sn(II), Ba(II), Ni(II), Zn(II), Cu(II), and Ca(II) complexes was investigated. PVC films containing different concentrations of complexes ranging from 0.1% to 0.5% by weight were produced by the same casting method from THF solvent. The photostabilization activities of these compounds were determined by monitoring the carbonyl and polyene indices with irradiation time. The changes in viscosity average molecular weight of PVC with irradiation time were also tracked (using THF as a solvent). The quantum yield of the chain scission (\Phi _{cs}) of these complexes in PVC films was evaluated …

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H_2{So}_4-Silica As An Efficient And Chemoselective Catalyst For The Synthesis Of Acylal From Aldehydes Under Solvent-Free Conditions, Seied Ali Pourmousavi, Zahra Zinati Jan 2009

H_2{So}_4-Silica As An Efficient And Chemoselective Catalyst For The Synthesis Of Acylal From Aldehydes Under Solvent-Free Conditions, Seied Ali Pourmousavi, Zahra Zinati

Turkish Journal of Chemistry

A variety of aldehydes react with acetic anhydride in the presence of a catalytic amount of H_2SO_4-silica to afford the corresponding 1,1-diacetates (acylals) in excellent yields. Ketones are not affected under the reaction conditions. The advantages are the simplicity of the acylation procedure, and the relatively non-toxic nature of the catalyst as well as its easy availability and low cost.

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Synthesis, Characterization, And Optical Properties Of Novel 2,5-Bis[4-(2-(-Arylvinyl)Phenyl]-1,3,4-Oxadiazoles, Dao-Hang He, Yong-Chuang Zhu, Zhuo-Ru Yang, Ai-Xi Hu, Gao Cao Jan 2009

Synthesis, Characterization, And Optical Properties Of Novel 2,5-Bis[4-(2-(-Arylvinyl)Phenyl]-1,3,4-Oxadiazoles, Dao-Hang He, Yong-Chuang Zhu, Zhuo-Ru Yang, Ai-Xi Hu, Gao Cao

Turkish Journal of Chemistry

Six novel 2,5-bis[4-(2-arylvinyl)phenyl]-1,3,4-oxadiazoles were synthesized by introducing 1,3,4-oxadiazole moiety into the stilbene skeleton. The synthesis route included the cyclization of p-toluic acid and hydrazine hydrate catalyzed by polyphosphoric acid (PPA), bromination of 1,3-dibromo-5,5-dimethylhydantoin (DBDMH), esterification, and the Wittig-Horner reaction. All the title compounds were characterized by ^1H-NMR, MS, and elemental analysis. UV-Vis absorption and fluorescence emission spectra in THF solution were investigated; the compounds may have potential for use in organic optical materials.

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