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Full-Text Articles in Physical Sciences and Mathematics

Template Synthesis And Structural Characterization Of Homo Binuclear Chromium(Iii), Manganese(Iii), Iron(Iii), Cobalt(Iii), And Ruthenium(Iii) Complexes With Octaazamacrocyclic Ligands, Vinod K. Sharma, Shipra Srivastava Jan 2006

Template Synthesis And Structural Characterization Of Homo Binuclear Chromium(Iii), Manganese(Iii), Iron(Iii), Cobalt(Iii), And Ruthenium(Iii) Complexes With Octaazamacrocyclic Ligands, Vinod K. Sharma, Shipra Srivastava

Turkish Journal of Chemistry

The Schiff base octaazamacrocyclic ligands derived from primary diamines and 3,6-dimethyl/diphenyl-4,5-diazaocta-3,5-diene-2,7-dione, and their binuclear complexes [M_2LCl_4]Cl_2 [M = Cr(III), Fe(III), Co(III), or Ru(III)] and [Mn_2L(AcO)_4](AcO)_2 were synthesized by template condensation reactions. Attempts to synthesize the corresponding metal-free macrocyclic ligands did not prove successful. The overall geometry and stereochemistry of these complexes were elucidated by elemental analyses, magnetic susceptibilities, electronic spectra, infrared spectra, molar conductance measurements, ^1H NMR, and thermogravimetric analysis. All the trivalent metal ion complexes appear to be 1:2 electrolytes. An octahedral geometry is proposed for all the complexes.


The Effect Of Acid Digestion On The Recoveries Of Trace Elements: Recommended Policies For The Elimination Of Losses, Güler Somer, Arzu Nakişci Ünlü Jan 2006

The Effect Of Acid Digestion On The Recoveries Of Trace Elements: Recommended Policies For The Elimination Of Losses, Güler Somer, Arzu Nakişci Ünlü

Turkish Journal of Chemistry

Digestion of biological materials is very important for trace element determinations. Although the microwave technique is mostly used, there are cases where open wet digestion is needed. This study examined the optimum conditions for the minimum loss of trace elements during the wet digestion of a sample. The effect of acid composition and digestion time for about 21 ions was investigated. The trace element concentrations were determined by differential pulse polarography. For the digestion procedure, a HClO_4-HNO_3 mixture was used for the first step and, after its evaporation (60 min), HCl was added as the second step, since in some …


Hydrothermal And Microwave-Assisted Synthesis Of Boroarsenate, Baso_4, Abdulhadi̇ Baykal, Ayten Evren Jan 2006

Hydrothermal And Microwave-Assisted Synthesis Of Boroarsenate, Baso_4, Abdulhadi̇ Baykal, Ayten Evren

Turkish Journal of Chemistry

BAsO_4 was previously synthesized by solid-state reactions at 800 °C and was characterized by X-ray powder diffraction. Now, we succeeded in preparing BAsO_4 from H_3BO_3 and As_2O_5 using hydrothermal synthesis by heating at 160 °C for 3 days (a single-phase product) and using microwave-assisted synthesis, which takes only 5 min to transform a solid mixture of As_2O_5 and (NH_4)_2B_4O_7.4H_2O into the crystalline titled compound (a single-phase product). The crystallinity of the products is higher than that of the solid-state synthesized product given in the literature. Its X-ray powder diffraction patterns, and both Raman and IR spectra were in good agreement …


Prediction Of Acidity Constants Of Thiazolidine-4-Carboxylic Acid Derivatives Using Ab Initio And Genetic Algorithm-Partial Least Squares, Ali Niazi, Saeed Jameh Bozorghi, Davood Nori Shargh Jan 2006

Prediction Of Acidity Constants Of Thiazolidine-4-Carboxylic Acid Derivatives Using Ab Initio And Genetic Algorithm-Partial Least Squares, Ali Niazi, Saeed Jameh Bozorghi, Davood Nori Shargh

Turkish Journal of Chemistry

A quantitative structure-property relationship study is suggested for the prediction of the acidity constants of some thiazolidine-4-carboxylic acid derivatives in aqueous solution. Ab initio theory was used to calculate some quantum chemical descriptors, including electrostatic potentials and local charges at each atom, highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies, etc. Modeling of the acidity constant of thiazolidine-4-carboxylic acid derivatives as a function of molecular structures was established by means of the partial least squares algorithm. The subset of descriptors, which resulted in a low prediction error, was selected by genetic algorithm. This model was applied …


Synthesis Of 1-Cyclohept-1,2-Dien-1-Yl Benzene From 1-(2-Iodo-, Chlorocyclohept-1-En-1-Yl)Benzene And 1-(2-Iodo-, Chlorocyclohept-2-En-1-Yl)Benzene: Its Trapping With Diphenylisobenzofuran, Mustafa Ceylan, Yakup Budak, Murat Ulukaya, M. Burcu Gürdere, Esra Findik Jan 2006

Synthesis Of 1-Cyclohept-1,2-Dien-1-Yl Benzene From 1-(2-Iodo-, Chlorocyclohept-1-En-1-Yl)Benzene And 1-(2-Iodo-, Chlorocyclohept-2-En-1-Yl)Benzene: Its Trapping With Diphenylisobenzofuran, Mustafa Ceylan, Yakup Budak, Murat Ulukaya, M. Burcu Gürdere, Esra Findik

Turkish Journal of Chemistry

The key compounds vinyl iodides 12a and 13a, for the generation of 1-cyclohept-1,2-dien-1-ylbezene (1), were synthesized from cycloheptanone (5). Bromobenzene was converted to the Grignard reagent, which was condensed with 5. Dehydration of alcohol 6 gave alkene 7. Hydroboration of 7 followed by oxidation with PCC afforded ketone 9, which was converted to hydrazone 10. Treatment of 10 with iodine resulted in the formation of 12a and 13a. The other precursors, 12b and 13b, were synthesized from the reaction of 9 with PCl_5. Reactions of 12a, b and 13a, b with KOtBu in a sealed tube at 185 °C gave …


Phytochemical Studies On The Underground Parts Of Asperula Taurina Subsp. Caucasica, Ufuk Özgen, Cavi̇t Kazaz, Hasan Seçen, Maksut Coşkun Jan 2006

Phytochemical Studies On The Underground Parts Of Asperula Taurina Subsp. Caucasica, Ufuk Özgen, Cavi̇t Kazaz, Hasan Seçen, Maksut Coşkun

Turkish Journal of Chemistry

One naphthohydroquinone (mollugin) (1), 3 anthraquinones (1-hydroxy-2-methyl-9,10-anthraqinone (2), 1,3-dihydroxy-2-methoxymethyl- 9,10-anthraquinone (4) and 1,3-dihydroxy-2-carboxy-9,10-anthraquinone (7, munjistin)), \beta-sitosterol (3), 1 naphthalene glycoside (2-carbomethoxy-3-prenyl-1,4-naphtho-hydroquinone, 1,4-di-O-\beta -glucoside (5)) and 1 anthraquinone glycoside (lucidin-3-O-\beta -primeveroside (6)) were isolated from the underground parts of A. taurina subsp. caucasica. The structures of the isolates were established by MS, ^1H-NMR and ^{13}C-NMR analysis.


Cyclic Triterpenoid Saponins From Campanula Lactiflora, Nuretti̇n Yayli, Asu Usta, Ahmet Yaşar, Osman Üçüncü, Canan Güleç, Mustafa Küçükislamoğlu Jan 2006

Cyclic Triterpenoid Saponins From Campanula Lactiflora, Nuretti̇n Yayli, Asu Usta, Ahmet Yaşar, Osman Üçüncü, Canan Güleç, Mustafa Küçükislamoğlu

Turkish Journal of Chemistry

Two cyclic natural compounds, 3\beta-O-[\alpha-L-rhamnopyranosyl- (1 \to 2)-\beta-D-glucopyranosyl]-13\alpha,14\alpha-epoxy-8\alpha,12\beta, 15-trihydroxy-(17E,21E)-17,21-campanuldien-6'(30)-olide, called lactifloroside A, 1, and 3\beta-O-[\beta-D-glucopyranosyl-(1 \to 2)-\beta-D-glucopyranosyl]- 13\alpha,14\alpha-epoxy-8\alpha,12\beta-dihydroxy-(17E,21E)-17,21-campanuldien- 6'(30)-olide, called lactifloroside B, 2, were isolated for the first time from Campanula lactiflora and their structures deduced by high field 1D and 2D 400 MHz NMR, FT-IR, HPLC, GC-MS, (+/-) LC-MS/MS and (+) FAB-MS spectra. The aglycones of the 2 saponins were named 13\alpha,14\alpha-epoxy-3\beta,8\alpha,12\beta,15-tetrahydroxy-(17E,21E)- 17,21-campanuldien-30-oic acid and 13\alpha,14\alpha-epoxy-3\beta,8\alpha, 12\beta-trihydroxy-(17E,21E)-17,21-campanuldien-30-oic acid, and designated as campanuloic acid and 15-deoxycampanuloic acid, respectively.


Synthesis And Characterization Of Metal Complexes Of Cu(Ii), Ni(Ii), Zn(Ii), Co(Ii), Mn(Ii) And Cd(Ii) With Tetradentate Schiff Bases, Jianning Liu, Bo-Wan Wu, Bing Zhang, Yongchun Liu Jan 2006

Synthesis And Characterization Of Metal Complexes Of Cu(Ii), Ni(Ii), Zn(Ii), Co(Ii), Mn(Ii) And Cd(Ii) With Tetradentate Schiff Bases, Jianning Liu, Bo-Wan Wu, Bing Zhang, Yongchun Liu

Turkish Journal of Chemistry

4-(Benzeneazo)salicylaldehyde was synthesized with aniline, sodium nitrite and salicylaldehyde. Two tetradentate ligands, N,N'-bis[4-(benzeneazo) salicylaldehyde]-o-phenylenediamine (H_2L) and N,N'-bis[4-(benzeneazo) salicylaldehyde]ethylenediamine (H_2L') were formed by the 2:1 molar condensation of 4-(benzeneazo) salicylaldehyde with o-phenylenediamine or ethylenediamine. Their Cu(II), Ni(II), Zn(II), Co(II), Mn(II) and Cd(II) complexes were synthesized and characterized by elemental analysis, molar conductivity measurements, and infrared and electronic spectral data. Two ligands and their Ni(II) and Zn(II) complexes were further identified using ^1H NMR spectra. The results suggest that the metal is bonded to the ligand through the phenolic oxygen and the imino nitrogen.


First- And Second-Derivative Spectrophotometry For Simultaneous Determination Of Copper And Cobalt By 1-(2-Pyridylazo)-2-Naphthol In Tween 80 Micellar Solutions, Habibollah Eskandari, Ali Ghanbari Saghseloo, Mansour Arab Chamjangali Jan 2006

First- And Second-Derivative Spectrophotometry For Simultaneous Determination Of Copper And Cobalt By 1-(2-Pyridylazo)-2-Naphthol In Tween 80 Micellar Solutions, Habibollah Eskandari, Ali Ghanbari Saghseloo, Mansour Arab Chamjangali

Turkish Journal of Chemistry

1-(2-Pyridylazo)-2-naphthol (PAN) has been used for the simultaneous determination of copper and cobalt at trace levels. PAN at pH 1.89 forms red and green complexes with copper and cobalt, respectively, which are soluble in aqueous Tween 80 micellar media and are stable for at least 3 days. Under optimum conditions, calibration graphs were obtained for individual determination of copper and cobalt by zero- and first-derivative spectrophotometry and for simultaneous determination by first- and second-derivative spectrophotometry. Zero-crossing first-derivative spectrophotometry at 555 and 581 nm for cobalt and copper was used for the simultaneous determination, respectively. The second derivative method at 577 …


Kinetics And Mechanism Of Oxidation Of 1,3--Butylene Glycol By Dihydroxyditellutoargentate(Iii) In Alkaline Medium, Jin-Huan Shan, Shu-Ying Huo, Shi-Gang Shen, Han-Wen Sun Jan 2006

Kinetics And Mechanism Of Oxidation Of 1,3--Butylene Glycol By Dihydroxyditellutoargentate(Iii) In Alkaline Medium, Jin-Huan Shan, Shu-Ying Huo, Shi-Gang Shen, Han-Wen Sun

Turkish Journal of Chemistry

The kinetics of oxidation of 1,3--butlene glycol (\beta - BG) by dihydroxyditelluto- argentate(III) were studied spectrophotometrically between 298.2 and 313.2 K in alkaline medium. The reaction rate showed pseudo-first order dependence in oxidant and fractional order in \ss-BG. The pseudo-first order rate constant k_{obs} increased with an increase in the concentration of OH^- and a decrease in the concentration of TeO_4^{2-} . There was a negative salt effect and no free radicals were detected. Thus, the dihydroxymonotelluratoargentate(III) species is assumed to be the active species. The activation parameters along with the rate constants of the rate-determining step were calculated.


Composition And Antimicrobial Activities Of Volatile Components Of Minuartia Meyeri, Nuretti̇n Yayli, Canan Güleç, Osman Üçüncü, Ahmet Yaşar, Serdar Ülker, Kami̇l Coşkunçelebi̇, Sali̇h Terzi̇oğlu Jan 2006

Composition And Antimicrobial Activities Of Volatile Components Of Minuartia Meyeri, Nuretti̇n Yayli, Canan Güleç, Osman Üçüncü, Ahmet Yaşar, Serdar Ülker, Kami̇l Coşkunçelebi̇, Sali̇h Terzi̇oğlu

Turkish Journal of Chemistry

The essential oil of air-dried Minuartia meyeri (Boiss.) Bornm. (Caryophyllaceae) was obtained by hydrodistillation in a Clevenger-type apparatus and analyzed by GC-MS. Fifty-two components were identified in the oil. The main components in the essential oil of M. meyeri were nonacosane (6.2%), 6,10,14-trimethyl-2-pentadecanone (5.1%), nonanal (4.6%), and beta-caryophyllene (2.9%). The antimicrobial activity of the isolated essential oil of the plant was also investigated and it showed moderate antibacterial activity against Gram-positive and Gram-negative bacteria, but no antifungal activity was observed against 2 yeast-like fungi.


Chromium(Iii) Complexes With Different Chromospheres Macrocyclic Ligands: Synthesis And Spectroscopic Studies, Rajiv Kumar, Rajeev Singh Jan 2006

Chromium(Iii) Complexes With Different Chromospheres Macrocyclic Ligands: Synthesis And Spectroscopic Studies, Rajiv Kumar, Rajeev Singh

Turkish Journal of Chemistry

Symmetric tetradentate (L^1) and asymmetric pentadentate (L^2) macrocyclic ligands that possess 2 dissimilar coordination sites were prepared. One has a 4-coordinate (N_4) and the other has a 5-coordinate (N_2O_3S) donor set. Trivalent Cr(III) complexes were synthesized with L^1 and L^2 and their structures were investigated using elemental analyses and magnetic moment, electronic, IR, ^1H NMR, ^{13}C NMR and EPR spectra. All the Cr(III) complexes show magnetic moments corresponding to a high-spin configuration. \Delta values indicate the energy difference between the principle bands, which are formed due to ligand field absorption. The spin-orbit coupling parameter, z, gives no significance because the …


A Novel Alkaloid From Stapelia Hirsuta, Marwan Shabana, Mariam Gonaid, Maha Mahmoud Salama, Essam Abdel-Sattar Jan 2006

A Novel Alkaloid From Stapelia Hirsuta, Marwan Shabana, Mariam Gonaid, Maha Mahmoud Salama, Essam Abdel-Sattar

Turkish Journal of Chemistry

A novel alkaloid (1,8,8-trimethyl-5,8-dihydro-1H-pyrano[3,4-b]pyridine-4,6-dione) was isolated from the chloroformic traction obtained from the total alcoholic extract of the aerial parts of Stapelia hirsuta L. In addition, apigenin, luteolin and \beta-sitosterol-3-O-\beta-D- glucopyranoside were also isolated.


Synthesis Of A Ruthenium Complex Bound To A Polyimide Matrix: Investigating The Catalytic Properties In A Hydrosilylation Reaction, Turgay Seçki̇n, Süleyman Köytepe, İsmai̇l Özdemi̇r, Beki̇r Çeti̇nkaya Jan 2006

Synthesis Of A Ruthenium Complex Bound To A Polyimide Matrix: Investigating The Catalytic Properties In A Hydrosilylation Reaction, Turgay Seçki̇n, Süleyman Köytepe, İsmai̇l Özdemi̇r, Beki̇r Çeti̇nkaya

Turkish Journal of Chemistry

3,6-Bis(dimethylamino)acridine(hexamethylbenzene)dichlororuthenium(II) was used as a tricyclic heteroatomic monomer to prepare polyimides from the corresponding dianhyrides by solution condensation. The ruthenium complex monomer was synthesized starting from [RuCl_2(HMB)]_2 and 3-6-bis(dimethylamino)acridine. The polymers had inherent viscosities of 1.77 to 2.11 and were soluble in most polar solvents. The glass transition temperatures were in the range of 204 to 298 °C and the 10% weight loss in the range of 506-626 °C, depending upon the structure of the dianhyride monomer. The catalytic activity of the polyimides tested in a hydrosilylation reaction of acetophenone was up to 90%. Leaching of ruthenium into the reaction …


Structure Of 1-(Thiophen-2-Ylmethyl)-2-(Thiophen-2-Yl)-1h-Benzimidazole, Necmi̇ Dege, Memet Şekerci̇, Süleyman Servi̇, Muharrem Di̇nçer, Ünzi̇le Demi̇rbaş Jan 2006

Structure Of 1-(Thiophen-2-Ylmethyl)-2-(Thiophen-2-Yl)-1h-Benzimidazole, Necmi̇ Dege, Memet Şekerci̇, Süleyman Servi̇, Muharrem Di̇nçer, Ünzi̇le Demi̇rbaş

Turkish Journal of Chemistry

The title compound, C_{16}H_{12}N_2S_2, crystallizes in the monoclinic space group P2_1/n with Z = 4, a = 8.950 (5) Å, b = 9.141 (5) Å, c = 17.429 (5) Å and \beta = 93.638 (5)°. The benzimidazole ring is essentially planar. The crystal structure is stabilized by intermolecular C---H ... N and C---H ... \pi contacts.


Studies On 2-Ethyl-3-Carbmethoxy-4-Aryl-5-Oxo-1,4,5,6,7,8-Hexahydroquinoline Derivatives And Calcium Modulatory Activities, Ci̇hat Şafak, Elvan Doğan, Kevser Erol Jan 2006

Studies On 2-Ethyl-3-Carbmethoxy-4-Aryl-5-Oxo-1,4,5,6,7,8-Hexahydroquinoline Derivatives And Calcium Modulatory Activities, Ci̇hat Şafak, Elvan Doğan, Kevser Erol

Turkish Journal of Chemistry

Twelve new compounds having a 2-ethyl-3-carbmethoxy-4-aryl-5-oxo-1,4,5,6,7,8-hexahydroquinoline structure were synthesized, characterized and screened for their calcium modulatory activities. The calcium antagonistic activities of the compounds were investigated by tests performed on isolated rat ileum and lamb carotid artery. Compounds 1, 4, 8 and 9 showed considerable activity.


Heterocyclic Synthesis Using Nitrilimines: Part 5. Synthesis Of Some Novel Spiro Heterocycles, Hany M. Dalloul, Peter H. Boyle Jan 2006

Heterocyclic Synthesis Using Nitrilimines: Part 5. Synthesis Of Some Novel Spiro Heterocycles, Hany M. Dalloul, Peter H. Boyle

Turkish Journal of Chemistry

A new class of spiro-triazoles (4a-m) were synthesized from the reaction of corresponding nitrilimines 2 with substituted heterocyclic benzoylhydrazones 3 in good yields. The spectral data of the new synthesized compounds are in full agreement with their molecular structure.


Synthesis Of New 3-Pyrrolin-2-One Derivatives, Nezi̇re Saygili, Ayşegül Altunbaş, Akgül Yeşi̇lada Jan 2006

Synthesis Of New 3-Pyrrolin-2-One Derivatives, Nezi̇re Saygili, Ayşegül Altunbaş, Akgül Yeşi̇lada

Turkish Journal of Chemistry

Six new 3-pyrrolin-2-one derivatives were synthesized via the condensation reaction of amino acid esters (2a-f) with 2,5-dimethoxy-2,5-dihydrofurane (1) in acidic medium. This simple one-pot reaction furnished the corresponding pyrrolinones (3a-f) in acceptable yields.


Construction Of A Homonaphthazarin Skeleton And Synthesis Of Hydroquinone-Annelated Cycloheptatriene Derivatives, Emi̇n Şengül, Abdullah Menzek, Meti̇n Balci Jan 2006

Construction Of A Homonaphthazarin Skeleton And Synthesis Of Hydroquinone-Annelated Cycloheptatriene Derivatives, Emi̇n Şengül, Abdullah Menzek, Meti̇n Balci

Turkish Journal of Chemistry

1,4-Dihydroxy-7,8-dihydro-5H-benzo[a]cycloheptene-5,9(6H)- dione (7) was synthesised from hydroquinone and glutaric acid chloride via an acylation reaction. The reaction of dione (7) with bromine followed by treatment with NEt_3 gave homonaphthazarin 8 as well as the brominated derivatives 9 and 10. Reduction of 1,4-dimethoxy-7,8-dihydro-5H-benzo[a]cycloheptene-5,9(6H)-dione (16) with LiAlH_4 gave 2 isomeric alcohols, 17 and 18. Reaction of these alcohols with SOCl_2 followed by HCl elimination with NEt_3 afforded dimethoxybenzocycloheptatriene 19 as the sole product. For the synthesis of the isomeric cycloheptatriene 20, the double bond in 19 was isomerised with KOt-Bu.


Synthesis Of N-Alkylnaphthalenes Via Semicarbazones, Gülay Zengi̇n, John W. Huffman Jan 2006

Synthesis Of N-Alkylnaphthalenes Via Semicarbazones, Gülay Zengi̇n, John W. Huffman

Turkish Journal of Chemistry

A number of 1-n-alkylnaphthalenes were prepared via the respective semicarbazones. The semicarbazones were reduced by modified Wolff-Kishner reductions to give 1-n-alkylnaphthalenes in excellent yields as manageable yellow or orange viscous oils. The semicarbazones were prepared from ketones, which are the addition products of Grignard reagents to nitriles. This study offers an excellent preparative method for the synthesis of 1-n-alkylnaphthalenes from semicarbazones, via a 3-step procedure.


Formation Of Yttrium(Iii) Complexes With Salicylic Acid Derivatives In Aqueous Solution, Rahmi̇ye Aydin, Ulvi̇ye Özer Jan 2006

Formation Of Yttrium(Iii) Complexes With Salicylic Acid Derivatives In Aqueous Solution, Rahmi̇ye Aydin, Ulvi̇ye Özer

Turkish Journal of Chemistry

Complexes of yttrium(III) formed with 5-sulphosalicylic acid, 5-SSA (H_3L), and 5-nitrosalicylic acid, 5-NSA (H_2L), were investigated in 0.1 mol.dm^{-3} sodium perchlorate ionic medium at 25.0 \pm 0.1 °C potentiometrically for various molar ratios of Y(III) to these salicylic acid, SA (H_2L), derivatives. Y(III) forms YL and YL_2^{3-} type complexes with 5-SSA that have rather high stabilities (log \beta _1 = 7.91 \pm 0.01 and log \beta _2 = 14.56 \pm 0.06). In the Y(III):5-NSA system, YL^+ and YL_2^- type complexes appear with high stabilities (log \beta _1 = 7.39 \pm 0.02 and log \beta _2 = 13.50 \pm 0.07). Y(III):5-SSA …


Heterogeneous Electron Transfer Rate Constants Of Viologen Monocations At A Platinum Disk Electrode, Naheed Kaukab Bhatti, M. Sadiq Subhani, Ather Yaseen Khan, Rumana Qureshi, Abdur Rahman Jan 2006

Heterogeneous Electron Transfer Rate Constants Of Viologen Monocations At A Platinum Disk Electrode, Naheed Kaukab Bhatti, M. Sadiq Subhani, Ather Yaseen Khan, Rumana Qureshi, Abdur Rahman

Turkish Journal of Chemistry

Experimental values of rate constants for the heterogeneous transfer of electrons to methyl viologen, diquat viologen, benzyl viologen and n-butyl viologen monocations were determined. The process was studied at the surface of a platinum disk in mixtures of water with different aprotic solvents at different temperatures. Theoretical rate constants were evaluated using Marcus' equation, which also contains barrier crossing probability and nuclear frequency. A comparison was made between the theoretical and experimental values of rate constants.


Optimization Of The Nonaqueous Capillary Electrophoresis Separation Of Metal Ions Using Mixture Design And Response Surface Methods, Cevdet Demi̇r, Yasi̇n Yücel Jan 2006

Optimization Of The Nonaqueous Capillary Electrophoresis Separation Of Metal Ions Using Mixture Design And Response Surface Methods, Cevdet Demi̇r, Yasi̇n Yücel

Turkish Journal of Chemistry

Mixture experimental design was used to enhance the separation selectivity of metal ions in nonaqueous capillary electrophoresis. The separation of cations (Ag, Fe, Cr, Mn, Cd, Co, Pb, Ni, Zn and Cu) was achieved using imidazole as UV co-ion for indirect detection. Acetic acid was chosen as an electrolyte because its cathodic electroosmotic flow permits faster separation. The composition of organic solvents is important to achieve the best separation of all metal ions. Simplex lattice design and response surface methods have proved to be an effective tool to optimize the composition of organic solvents in nonaqueous capillary electrophoresis. Full and …


Organotin (Iv) Derivatives Of 1-Ethyl-1,4-Dihydro-7-Methyl-4-Oxo- 1,8-Naphthyridine-3-Carboxylic Acid (Nalidixic Acid): Synthesis, Structural Elucidation And Biological Activities, Sajjad Ahmed, Moazzam Hussain Bhatti, Saqib Ali, Fiaz Ahmed Jan 2006

Organotin (Iv) Derivatives Of 1-Ethyl-1,4-Dihydro-7-Methyl-4-Oxo- 1,8-Naphthyridine-3-Carboxylic Acid (Nalidixic Acid): Synthesis, Structural Elucidation And Biological Activities, Sajjad Ahmed, Moazzam Hussain Bhatti, Saqib Ali, Fiaz Ahmed

Turkish Journal of Chemistry

Organotin carboxylates of the general formulae R_2SnL_2 and R_3SnL, where R = CH_3, n-C_4H_9, C_6H_5, CH_2C_6H_5 and L = 1-ethyl-1,4-dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-carboxylic acid (nalidixic acid), have been prepared. These compounds were characterized by FT-IR, mass and multinuclear NMR (^1H, ^{13}C and ^{119}Sn) spectroscopy. The geometry around the tin atom is compared both in solution and in solid state. These compounds were also screened for their antifungal and antibacterial activities.


Surface Modification Of Glass Beads With An Aminosilane Monolayer, Gülşi̇n Arslan, Mustafa Özmen, Beni̇z Gündüz, Xunli Zhang, Mustafa Ersöz Jan 2006

Surface Modification Of Glass Beads With An Aminosilane Monolayer, Gülşi̇n Arslan, Mustafa Özmen, Beni̇z Gündüz, Xunli Zhang, Mustafa Ersöz

Turkish Journal of Chemistry

Surface modification of glass beads with a self-assembled monolayer of (3-Aminopropyl)-triethoxysilane (APTES) was investigated. Characterisation of the self-assembled monolayer was confirmed by a reaction between amine terminal groups and thionylchloride of Rhodamine-B dye using fluorescence microscopy. Quantitative 3-dimensional profiling was obtained for all modification processes by converting microscopic images to numerical values. The reaction steps were also analysed using infrared spectroscopy (FTIR).


Surface Properties And Catalytic Performance Of Pt/Prsrcoo_4 Catalysts For No Reduction By Co, Hua Zhong, Xirui Zeng Jan 2006

Surface Properties And Catalytic Performance Of Pt/Prsrcoo_4 Catalysts For No Reduction By Co, Hua Zhong, Xirui Zeng

Turkish Journal of Chemistry

Perovskite-type Pr_{2-x}Sr_xCoO_{4\pm \lambda} mixed oxides were prepared by different calcination temperatures and were investigated by XRD, BET, TPD, TPR and XPS methods. These catalysts possess high catalytic activities towards the NO reduction by CO, and the activity of the PrSrCoO_4 catalyst prepared by calcining at 750 °C is the best among these samples. This is explained in terms of its greater oxygen vacancies and larger BET surface areas. The influence of modification by a suitable amount of Pt-doping on the surface properties and catalytic activity for NO reduction by CO was studied. The results show that the Pt-modified PrSrCoO_4 catalysts …


Synthesis And Antifungal Properties Of Some Benzimidazole Derivatives, Gülgün Ayhan Kilcigi̇l, Nurten Altanlar Jan 2006

Synthesis And Antifungal Properties Of Some Benzimidazole Derivatives, Gülgün Ayhan Kilcigi̇l, Nurten Altanlar

Turkish Journal of Chemistry

Some benzimidazole derivatives were synthesized and their in vitro antifungal activities were tested against Candida albicans, Candida glabrata and Candida krusei. Compounds 6 and 9 possessed activity comparable to fluconazole against C. albicans with a minimum inhibitory concentration of 12.5 \mu g/mL.


Sesquiterpene Lactones From Centaurea Helenioides Boiss, Nuretti̇n Yayli, Cemaletti̇n Baltaci, Yaşar Gök, Ebru Aydin, Osman Üçüncü Jan 2006

Sesquiterpene Lactones From Centaurea Helenioides Boiss, Nuretti̇n Yayli, Cemaletti̇n Baltaci, Yaşar Gök, Ebru Aydin, Osman Üçüncü

Turkish Journal of Chemistry

Grosheimin (1) and cynaropicrin (3) sesquiterpenes were isolated from the flowers of Centaurea helenioides Boiss., an endemic plant of Turkey. The products are known as they occur in another species, but they were isolated and identified for the first time from C. helenioides Boiss. In order to correlate spectral data of grosheimin, its acetyl derivative, 8\alpha -acetyl grosheimin (2) was also prepared. Their structures were deduced by FT-IR, UV, 1D and 2D NMR, LC MS/MS, GC-mass spectra (EI), optical rotation, and chemical methods.


Synthesis Of Methylthionaphthalene Derivatives, Ayşegül Öncü, Nurgün Sakarya Büyükkidan, Bülent Büyükkidan, Osman Çakmak Jan 2006

Synthesis Of Methylthionaphthalene Derivatives, Ayşegül Öncü, Nurgün Sakarya Büyükkidan, Bülent Büyükkidan, Osman Çakmak

Turkish Journal of Chemistry

No abstract provided.


Gc-Ms Analysis And Antibacterial Activity Of Cultivated Satureja Cuneifolia Ten. Essential Oil, Yüksel Kan, Uçkun Sai̇t Uçan, Murat Kartal, M. Levent Altun, Si̇nem Aslan, Esi̇n Sayar, Ti̇murhan Ceyhan Jan 2006

Gc-Ms Analysis And Antibacterial Activity Of Cultivated Satureja Cuneifolia Ten. Essential Oil, Yüksel Kan, Uçkun Sai̇t Uçan, Murat Kartal, M. Levent Altun, Si̇nem Aslan, Esi̇n Sayar, Ti̇murhan Ceyhan

Turkish Journal of Chemistry

The composition of the essential oil of Satureja cuneifolia Ten. cultivated in Konya, Turkey, was investigated by capillary GC-MS. The compounds were characterized by comparison with library searches. Six main compounds were identified. Carvacrol was the dominant component, comprising 59.28% of the essential oil. The oil also contained 15.72% thymol, 9.69% p-cymene, 4.16% \gamma -terpinene, 1.70% linalool and 1.25% borneol. The antibacterial activity of the essential oil of S. cuneifolia and its components was determined by a semiquantative disc-diffusion method, and the minimum inhibitory concentration (MIC) was determined based on a micro-well dilution method against strains of Pseudomonas aeruginosa, Bacillus …