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Performance Comparison Between Monolithic C18 And Conventional C18 Particle-Packed Columns In The Liquid Chromatographic Determination Of Propranolol Hcl, Sami El Deeb, Hermann Watzig Jan 2006

Performance Comparison Between Monolithic C18 And Conventional C18 Particle-Packed Columns In The Liquid Chromatographic Determination Of Propranolol Hcl, Sami El Deeb, Hermann Watzig

Turkish Journal of Chemistry

Monolithic and conventional particle-packed columns were applied for the determination of propranolol hydrochloride in the presence of its 2 main degradation products, 3-(1-naphthyloxy)-propane-1,2- diol and 4-isopropyl-1,7-bis-(1-naphthyloxy)-4-azaheptane-2,6-diol. The separations were investigated on monolithic columns at flow rates from 1 to 9 mL/min. Fast and efficient separation was obtained by monolithic columns. The analysis time was decreased by about 5-fold on monolithic columns at a flow rate of 4 mL/min, while maintaining sufficient resolution between propranolol and its degradation products. The method was validated using a set of 3 monolithic columns and compared to a conventional (Superspher) C18 column. The precision for …


Cerium(Iii) Ion-Selective Electrodes Based On 1,4,7-Trithiacyclononane, Hamid Reza Pouretedal, Abolfazl Semnani, Mohammad Hossein Keshavarz Jan 2006

Cerium(Iii) Ion-Selective Electrodes Based On 1,4,7-Trithiacyclononane, Hamid Reza Pouretedal, Abolfazl Semnani, Mohammad Hossein Keshavarz

Turkish Journal of Chemistry

Novel plasticized polymeric membrane (PPME) and coated platinum wire (CPWE) electrodes based on 1,4,7-trithiacyclononane and oleic acid, as a good lipophilic additive for highly selective determination of Ce^{3+} ions, have been developed. The electrodes exhibit a Nernstian slope of 19.4 mV/decade (for both electrodes) over a wide Ce^{3+} ion concentration range, from 5.0 \times 10^{-6}-5.0 \times 10^{-2} M and 1.0 \times 10^{-7}-1.0 \times 10^{-2} M for PPME and CPWE, respectively. The limits of detection were 3.5 \times 10^{-6} and 8.0 \times 10^{-8} M for PPME and CPWE, respectively. The electrodes possess a fast response time of 15 s, can be …


Synthesis And Anticancer Evaluation Of Some New Unsymmetrical 3,5-Diaryl-4h-1,2,4-Triazole Derivatives, Olcay Beki̇rcan, Bahi̇tti̇n Kahveci̇, Murat Küçük Jan 2006

Synthesis And Anticancer Evaluation Of Some New Unsymmetrical 3,5-Diaryl-4h-1,2,4-Triazole Derivatives, Olcay Beki̇rcan, Bahi̇tti̇n Kahveci̇, Murat Küçük

Turkish Journal of Chemistry

A series of 4-arylidenamino-4H-1,2,4-triazole derivatives (3-11) were synthesized from the treatment of 4-amino-4H-1,2,4-triazoles (2) with certain aldehydes. Compounds 3-11 were reduced with NaBH_4 to afford the corresponding 4-arylmethylenamino-4H-1,2,4-triazoles (12-20). Compounds 1-10 and 12-19 were characterized by elemental analyses and ^1H NMR, ^{13}C NMR, IR and UV spectral data. Compounds 11 and 20 were characterized by ^1H NMR, ^{13}C NMR, IR and mass spectral data. Compounds 14, 16, 17, and 18 were tested for anticancer activities. Compound 17, chosen for its higher anticancer activity in the preliminary tests with the cancer cell lines of MCF7, NCI-H460, and SF-268, exhibited remarkable anticancer …


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 …


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.


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 …


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.


Synthesis And Spectroscopic Characterization Of Biologically Active Triarylantimony(V) Carboxylates Containing Germanium, Muhammad Kaleem Khosa, Muhammad Mazhar, Saqib Ali, Khadija Shahid, Farnaz Malik Jan 2006

Synthesis And Spectroscopic Characterization Of Biologically Active Triarylantimony(V) Carboxylates Containing Germanium, Muhammad Kaleem Khosa, Muhammad Mazhar, Saqib Ali, Khadija Shahid, Farnaz Malik

Turkish Journal of Chemistry

A new series of bimetallic (Ge and Sb) compounds (1-7) was synthesized and characterized by elemental analyses, FT-IR, multinuclear NMR (^1H, ^{13}C) spectroscopy and mass spectrometry. These techniques not only confirmed the formation of the compounds, but also revealed their trigonal bipyramidal geometry around antimony(V). Selected compounds were screened against different pathogens and showed promising antibacterial and antifungal activities.


Secondary Metabolites From Phlomis Syriaca And Their Antioxidant Activities, Ü. Şebnem Harput, İhsan Çaliş, İclal Saracoğlu, Ali̇ Arslan Dönmez, Akito Nagatsu Jan 2006

Secondary Metabolites From Phlomis Syriaca And Their Antioxidant Activities, Ü. Şebnem Harput, İhsan Çaliş, İclal Saracoğlu, Ali̇ Arslan Dönmez, Akito Nagatsu

Turkish Journal of Chemistry

An iridoid glucoside, lamiide (1); 4 phenylethanoid glycosides, acteoside (2), \beta-OH acteoside (3), leucosceptoside A (4) and samioside (5); a caffeic acid ester, chlorogenic acid (6); 2 flavone glucosides, luteolin-7-O-glucopyranoside (7) and chrysoeriol-7-O-glucopyranoside (8); and a flavanone aglycone, naringenin (9), were isolated from the aerial parts of Phlomis syriaca. The structures of the isolated compounds were elucidated by means of spectroscopic (UV, IR, 1D- and 2D-NMR, and FAB-MS) methods. Free radical scavenging activity of the isolated compounds was determined using the radical 2,2-diphenyl-1-picrylhydrazyl (DPPH), spectroscopically.


Cumene Cracking On Modified Mesoporous Material Type Mcm-41, Ahmed Belhakem, Abdelkader Bengueddach Jan 2006

Cumene Cracking On Modified Mesoporous Material Type Mcm-41, Ahmed Belhakem, Abdelkader Bengueddach

Turkish Journal of Chemistry

The effect of ionic exchange degree of H(X)-AlMCM-41 materials, the method of its exchange and its grain form were investigated for mesoporous catalytic activity in the cumene cracking reaction. Benzene, propylene and xylene derivatives are the main products of this reaction. Olefins like butene and pentene appeared as the products of secondary reactions. No saturated hydrocarbons, which are typical products of secondary reactions obtained with HNaY zeolites, were formed, except for traces of butane. Generally the exchanged H(X)-AlMCM-41 materials by the substitution of Na^+ by NH_4^+ are more active than those exchanged directly with acid solution (substitution of Na^+ by …


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.


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 …


Analysis Of Nanoparticle Transmission Electron Microscopy Data Using A Public- Domain Image-Processing Program, Image, Gerd H. Woehrle, James E. Hutchison, Sai̇m Özkar, Richad G. Finke Jan 2006

Analysis Of Nanoparticle Transmission Electron Microscopy Data Using A Public- Domain Image-Processing Program, Image, Gerd H. Woehrle, James E. Hutchison, Sai̇m Özkar, Richad G. Finke

Turkish Journal of Chemistry

The need to easily and quickly count larger numbers of nanoparticles, in order to obtain statistically useful size and size-distribution data, is addressed via the use of a readily available, free, public-domain program for particle counting, NIH-Image (and 2 others derived from it, Scion Image and Image J), collectively referred to herein as Image. The best protocols that we have found useful for the use of Image are reported; both appropriate as well as problematic applications of Image are then illustrated with a series of TEM images of Ir(0), Pd(0) and Au(0) nanoclusters. Methods to detect and image nanoclusters with …


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.


Online Viscosity Measurement Of Complex Solutions Using Ultrasound Doppler Velocimetry, Volkan Köseli̇, Şeri̇fe Zeybek, Yusuf Uludağ Jan 2006

Online Viscosity Measurement Of Complex Solutions Using Ultrasound Doppler Velocimetry, Volkan Köseli̇, Şeri̇fe Zeybek, Yusuf Uludağ

Turkish Journal of Chemistry

A new method to measure the viscosity of non-Newtonian fluids over a wide range of shear rates in a short period of time is presented. The technique is based on the measurement of the velocity profile in a pipe flow using ultrasound Doppler velocimetry (UDV), which is a non-invasive method, and simultaneously determining the pressure drop. The velocity profile is used to obtain shear rate distribution, while the pressure drop is used to calculate the shear stress distribution. By taking the ratio of these quantities at a radial position, local viscosity can be obtained within the shear rate range in …


Secondary Metabolites From Euphorbia Helioscopia And Their Vasodepressor Activity, Asli Barla, Hüsni̇ye Bi̇rman, Şükran Kültür, Sevi̇l Öksüz Jan 2006

Secondary Metabolites From Euphorbia Helioscopia And Their Vasodepressor Activity, Asli Barla, Hüsni̇ye Bi̇rman, Şükran Kültür, Sevi̇l Öksüz

Turkish Journal of Chemistry

From the aerial parts of Euphorbia helioscopia L. (Euphorbiaceae), a jatrophane diterpene ester, 5,11-jatrophadiene-3-benzoyloxy-7,9,14-tri-acetyloxy-15-ol and 2 lupane derivatives, lup-20(29)-ene-3-acetate and lup-20(29)-ene-3-palmitate, together with common triterpenoids of Euphorbiaceae, 24-methylene cycloartanol, 24-methylenecycloart-3-one, cycloartanol, and stigmast-4-ene-3-one were isolated. The last compounds, lup-20(29)-ene-3-acetate, 24-methylene cycloartanol, 24-methylenecycloart-3-one, cycloartanol, and stigmast-4-ene-3-one, were isolated for the first time from E. helioscopia}. The fractions and the isolates were tested for their vasodepressor effects using Wistar Albino rats, and 5,11-jatrophadiene-3-benzoyloxy-7,9,14-tri-acetyloxy- 15-ol, lup-20(29)-ene-3-acetate, and stigmast-4-ene-3-one were found to possess relevant activity. The structures of all of the compounds were identified with high field spectroscopic methods. The detailed spectroscopic data of …


Iridoid, Flavonoid, And Phenylethanoid Glycosides From Wiedemannia Orientalis, Zühal Güvenalp, Hi̇lal Özbek, Türesi̇n Ünsalar, Cavi̇t Kazaz, L. Ömür Demi̇rezer Jan 2006

Iridoid, Flavonoid, And Phenylethanoid Glycosides From Wiedemannia Orientalis, Zühal Güvenalp, Hi̇lal Özbek, Türesi̇n Ünsalar, Cavi̇t Kazaz, L. Ömür Demi̇rezer

Turkish Journal of Chemistry

Five iridoid glycosides, lamiide, ipolamiide, ipolamiidoside, 6\beta-hydroxyipolamiide, and 5-hydroxy-8-epi-loganin; 5 flavonoid glycosides, apigenin 7-O-\beta-glucopyranoside, luteolin 5-O-\beta- glucopyranoside, isorhamnetin 3-O-rutinoside, quercetin 3-O-rutinoside, and apigenin 7-O-(6''-O-trans-p-coumaroyl) \beta-glucopyranoside; and a phenylethanoid glycoside, acteoside (= verbascoside), were isolated from the aerial parts of Wiedemannia orientalis (Lamiaceae). Their structures were identified using spectral methods (UV, 1D- and 2D-NMR, and EI-MS).


Optical Fluoride Sensing With A Bay Region Functionalized Perylenediimide Dye, Funda Yukruk Jan 2006

Optical Fluoride Sensing With A Bay Region Functionalized Perylenediimide Dye, Funda Yukruk

Turkish Journal of Chemistry

A perylenedimiide (PDI) derivative functionalized at the perylene core (bay region) to carry phenyl boronic acid groups was shown to interact with fluoride with changes in the emission and absorption spectrum. These changes are most likely due to fluoride-induced aggregation and/or quenching of the perylenediimide dye. The dye is also selective; among halide ions, fluoride anions generate a significant response. Thus, this class of PDI derivatives is likely to be useful in practical fluoride sensing.


Synthesis And Biological Activities Of N-Alkyl Derivatives Of O-, M-, And P-Nitro (E)-4-Azachalcones And Stereoselective Photochemistry In Solution, With Theoretical Calculations, Nuretti̇n Yayli, Osman Üçüncü, Ahmet Yaşar, Murat Küçük, Nuran Yayli, Emi̇ne Akyüz, Şengül Alpay Karaoğlu Jan 2006

Synthesis And Biological Activities Of N-Alkyl Derivatives Of O-, M-, And P-Nitro (E)-4-Azachalcones And Stereoselective Photochemistry In Solution, With Theoretical Calculations, Nuretti̇n Yayli, Osman Üçüncü, Ahmet Yaşar, Murat Küçük, Nuran Yayli, Emi̇ne Akyüz, Şengül Alpay Karaoğlu

Turkish Journal of Chemistry

The N-alkyl derivatisation and photochemical dimerisation of 3 o-, m-, and p-nitro substituted 4-azachalcones (1-3) yielded 3 new o-, m-, and p-nitro substituted (E)-N-decyl-4-azachalconium bromides, (2E)-1-(2-nitrophenyl)-3-(N-decyl-4-pyridinium bromide)-2-propen-1-one (4), (2E)-1-(3-nitrophenyl)-3-(N-decyl-4-pyridinium bromide)-2-propen- 1-one (5), and (2E)-1-(4-nitrophenyl)-3-(N-decyl-4-pyridinium bromide)- 2-propen-1-one (6), and 3 new dimers in solution, (1\beta, 2\alpha)-di- (3-nitrobenzoyl)-(3\beta, 4\alpha)-di-(4-pyridinyl) cyclobutane (7), (1\beta, 2\alpha)-di-(4-nitrobenzoyl)-(3\beta,4\alpha)-di-(4-pyridinyl) cyclobutane (8a), and (1\beta, 2\beta)-di-(4-nitrobenzoyl)-(3\beta, 4\alpha)-di-(4-pyridinyl)cyclobutane (8b), stereoselectively. The monomeric compounds showed good antimicrobial activity against test micro-organisms. The most sensitive micro-organisms were Gram-positive bacteria. The monomers also showed high antioxidant activity, while the dimerisation products 7-8a,b were less active. Compound 6 was found to have similar or even …


Simple Synthesis Of \Alpha -Oxime Derivatives Of 2-Ketomethyl Quinolines Under Mild And Heterogeneous Conditions, Javad Safari, Mehdi Adib, Firouzeh Sheibani, Zahra Sadeghi Jan 2006

Simple Synthesis Of \Alpha -Oxime Derivatives Of 2-Ketomethyl Quinolines Under Mild And Heterogeneous Conditions, Javad Safari, Mehdi Adib, Firouzeh Sheibani, Zahra Sadeghi

Turkish Journal of Chemistry

2-Ketomethyl quinolines are converted to their \alpha-oximinoketone derivatives in quantitative yields using sodium nitrite in the presence of silica sulfuric acid as nitrosating agent under mild and heterogeneous conditions.


A New Method For The Preparation Of Pyridazine Systems: Experimental Data And Semiempirical Pm3 Calculations, Di̇lek Ünal, Emi̇n Saripinar, Yunus Akçamur Jan 2006

A New Method For The Preparation Of Pyridazine Systems: Experimental Data And Semiempirical Pm3 Calculations, Di̇lek Ünal, Emi̇n Saripinar, Yunus Akçamur

Turkish Journal of Chemistry

The reactions of 4-benzoyl-5-phenyl-2,3-furandione (1a) and 4-(4-methoxybenzoyl)-5-(4-methoxyphenyl)-2,3-furandione (1b) with acyl hydrazines (2) (namely hydrazides) are reported. From these reactions, novel pyridazinone systems (3a-g) are obtained as well as the cyclization product of 3g at high temperature (4). The electronic properties and conformational parameters for these molecules, such as bond lengths, bond angles, torsion angles and atom charges, are calculated with a semiempirical PM3 method. In order to determine the mechanism of the reaction between the model furandion (R1) and formic hydrazide (R2), the electronic properties, conformational parameters and imaginary frequencies of the reactants, transition states and intermediates are calculated at …


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 …


Synthesis, Spectral And Thermal Characteristics Of Some Ten Coordinated Complexes Of Dioxouranium(Vi) Derived From Semicarbazones As Primary Ligand And Diphenyl Sulfoxide As Secondary Ligand, Ram K. Agarwal, Surendra Prasad Jan 2006

Synthesis, Spectral And Thermal Characteristics Of Some Ten Coordinated Complexes Of Dioxouranium(Vi) Derived From Semicarbazones As Primary Ligand And Diphenyl Sulfoxide As Secondary Ligand, Ram K. Agarwal, Surendra Prasad

Turkish Journal of Chemistry

The reactions of dioxouranium(VI) acetate with several semicarbazones derived from 4-aminoantipyrine in the presence of diphenyl sulfoxide (DPSO) led to the formation of complexes corresponding to the formulae [UO_2(CH_3COO)_2 (L).DPSO], where L = 4[N-(benzalidene)amino]antipyrinesemicarbazone (BAAPS), 4[N-(2'-hydroxybenzalidene)- amino]antipyrinesemicarbazone (HBAAPS) 4[N-(4'-methoxybenzalidene)amino] antipyrine semicarbazone (MBAAPS) 4[N-(4'-dimethylaminobenzalidene)amino]- antipyrinesemicarbazone (DABAAPS) 4[N-(2'-nitrobenzalidene)amino]antipyrine- semicarbazone (2'-NO_2 BAAPS) 4[N-(3'-nitrobenzalidene)amino]antipyrine- semicarbazone (3'-NO_2BAAPS) 4[N-(4'-nitrobenzalidene)amino]antipyrine- semicarbazone (4'-NO_2BAAPS), 4[N-(4'-hydroxy-3'-methoxybenzalidene)amino]- antipyrinesemicarbazone (HMBAAPS) 4[N-(2'-hydroxy-1'-naphthalidene)amino]- antipyrinesemicarbazone (HNAAPS) 4[N-(cinnamalidene)amino]antipyrine- semicarbazone (CAAPS)4[N-(3',4',5'-trimethoxybenzalidene)amino]antipyrine- semicarbazone (TMBAAPS) and 4[N-(furfural)amino]antipyrinesemicarbazone (FFAAPS). The complexes were characterised by means of elemental analyses, conductivity measurements, molecular weight, magnetic moments and infrared studies. The coordination number 10 is proposed for these complexes. Thermal properties of the …


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 …


Dichloride[1-(2,4,6-Trimethylbenzyl)-3-(Biphenyl-2-Ylmethyl)-Imidazolidin- 2-Ylidine (\Eta^6-Hexamethylbenzene)]Ruthenium, Hakan Arslan, Donald Van Derveer, İsmai̇l Özdemi̇r, Sedat Yaşar, Beki̇r Çeti̇nkaya Jan 2006

Dichloride[1-(2,4,6-Trimethylbenzyl)-3-(Biphenyl-2-Ylmethyl)-Imidazolidin- 2-Ylidine (\Eta^6-Hexamethylbenzene)]Ruthenium, Hakan Arslan, Donald Van Derveer, İsmai̇l Özdemi̇r, Sedat Yaşar, Beki̇r Çeti̇nkaya

Turkish Journal of Chemistry

The single crystal X-ray structure of the imidazolidin ruthenium complex, C_{38}H_{46}N_2Cl_2Ru, was determined. The complex is an orthorhombic space group Pbca with a = 17.3586(32) Å, b = 14.4447(27) Å, c = 27.4325(52) Å, and V = 6878.466(4) Å^3 with Z = 8 for D_{calc} = 1.357 g/cm^3. It exhibits the expected 3-legged piano stool geometry. There is one coordination bond of the ruthenium atom with the electrons of the \eta^6-hexamethylbenzene, 2 symmetrical Ru-Cl bonds, and one Ru-C bond involving the imidazole ring. The coordination around the ruthenium atom is 4-fold, which in this is case is pseudo-tetrahedral.


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.