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Articles 2131 - 2160 of 2720
Full-Text Articles in Chemistry
Synthesis And Some Reactions Of 4-Benzoyl-5-Phenyl-1-Pyridin-2-Yl-1h- Pyrazole-3-Carboxylic Acid, Ahmet Şener, Esvet Akbaş, M. Kasim Şener
Synthesis And Some Reactions Of 4-Benzoyl-5-Phenyl-1-Pyridin-2-Yl-1h- Pyrazole-3-Carboxylic Acid, Ahmet Şener, Esvet Akbaş, M. Kasim Şener
Turkish Journal of Chemistry
The 1H-pyrazole-3-carboxylic acid 2, obtained from the furandione 1 and 2-hydrazinopyridine, was decarboxylated to give 4-benzoyl-5-phenyl-1-pyridin-2-yl-pyrazole derivative 3. Some ester 4 derivatives of 2 were prepared by the Fischer esterification reactions of 2 with various alcohols. Cyclocondensation reactions of 2 with phenyl hydrazine or hydrazine hydrate led to the formation of derivatives of pyrazolo[3,4-d]pyridazine 5 derivatives.
Determination Of Selenium(Iv) Using O-Phenylenediamine By Differential Pulse Polarography/Interference Of Metal Ions, Recai̇ İnam, Çi̇ğdem Toprak
Determination Of Selenium(Iv) Using O-Phenylenediamine By Differential Pulse Polarography/Interference Of Metal Ions, Recai̇ İnam, Çi̇ğdem Toprak
Turkish Journal of Chemistry
A new sensitive and selective pulse polarographic method for the determination of Se(IV) next to interfering ions is described. This method is based on the highly sensitive peak formed by the reaction of Se(IV) with o-phenylenediamine in Britton-Robinson buffer solution (pH 2.5) at --0.08 V vs. SCE. The new peak due to the Se(IV)/o-PDA complex not only prevents the interference of Pb(II), Cd(II) and Sn(II) for selenium, but also increases its sensitivity. A linear calibration graph is obtained for Se(IV) at a concentration of 5.0 x 10^{-8} to 6.8 x 10^{-5} M with a correlation coefficient of 0.9988. The proposed …
A Sensitive Spectrophotometric Assay For Tinidazole And Metronidazole Using A Pd-C And Formic Acid Reduction System, Nandipura Dyavegowda Dinesh, Padmarajaiah Nagaraja, K. Subbegowda Rangappa
A Sensitive Spectrophotometric Assay For Tinidazole And Metronidazole Using A Pd-C And Formic Acid Reduction System, Nandipura Dyavegowda Dinesh, Padmarajaiah Nagaraja, K. Subbegowda Rangappa
Turkish Journal of Chemistry
A simple, sensitive and rapid spectrophotometric method for the determination of tinidazole (TZ) and metronidazole (MZ) in pure as well as in dosage form is described. The method is based on the reduction of the nitro group of drugs using a novel and versatile reduction system comprising 10% Pd-C and formic acid. The resulting amine was then subjected to a condensation reaction with sodium 1,2-naphthaquinone-4-sulfonate (NQS) to form red Schiff base with an absorption maximum at 510 nm. Beer's law was obeyed in the concentration ranges 2.0 to 45.0 \mu g mL^{-1} and 1.5 to 37.0 \mu g mL^{-1} with …
The Kinetics Of The Photochemical Reaction Of Methylene Green With Methylamine And Ethylamine, Rehana Saeed, Fahim Uddin, Zahida Khalid
The Kinetics Of The Photochemical Reaction Of Methylene Green With Methylamine And Ethylamine, Rehana Saeed, Fahim Uddin, Zahida Khalid
Turkish Journal of Chemistry
The photochemical reduction of methylene green with methylamine and ethylamine in 50% aqueous isopropanol was studied. The photochemical reduction was carried out in a special type of optical processor associated with a deoxygenating system, a temperature controlling unit and a magnetic stirring system. A monochromatic light of 657 nm wavelength was used for irradiation of oxygen free reaction solutions in a double walled reaction cell. The transmitted light was measured and recorded in terms of electrical signals with the help of a calibrated galvanometer. Acidities of the solutions were measured with the help of a spectrophotometer based on the Hammet …
Electrocatalytic Determination Of Ascorbic Acid Using Glassy Carbon Modified With Nickel(Ii) Macrocycle Containing Dianionic Tetraazaannulene Ligand, Mozhgan Khorasai-Motlagh, Meissam Noroozifar
Electrocatalytic Determination Of Ascorbic Acid Using Glassy Carbon Modified With Nickel(Ii) Macrocycle Containing Dianionic Tetraazaannulene Ligand, Mozhgan Khorasai-Motlagh, Meissam Noroozifar
Turkish Journal of Chemistry
A symmetric Ni(II) tetraaza macrocycle modified glassy electrode shows electrocatalytic activity for the oxidation of L-ascorbic acid at pH 7. It was shown the peak potential shifted to the negative by 250 mV compared with that for the bare electrode in the cyclic voltammograms. The calibration curve was linear up to 5 mM with a detection limit of 2.5 \times 10^{-4} mM and RSD% better than 2.8%. Excipients used as additives in pharmaceutical formulations and foods did not interfere in the proposed procedure. This new modified electrode was applied to commercial pharmaceutical tablets, injections and foods. The obtained results were …
Formation Of The Monolithic Silica Gel Column With Bimodal Pore Structure, Wenhui Gao, Gegliang Yang, Jing Yang, Haiyan Liu
Formation Of The Monolithic Silica Gel Column With Bimodal Pore Structure, Wenhui Gao, Gegliang Yang, Jing Yang, Haiyan Liu
Turkish Journal of Chemistry
A biporous monolithic silica gel column possessing both micrometer sized through-pores and nanometer sized mesopores located in the silica skeletons was prepared and the high concentration porogen (e.g., 2 mol/L ammonium hydroxide solution) was use for increasing mesopore size in this work. The mechanism for the preparation of the monolithic column was investigated in detail. Moreover, the effect of the polyethylene glycol concentration in the starting solution was studied and it was found that a lower concentration range was also suitable for forming the interconnected porous structure for the monolithic silica gel column. At lower concentrations, however, the phase separation …
Synthesis, Magneto-Spectral And Thermal Characteristics Of Some 7-Coordinated Compounds Of Lanthanides(Iii) Chlorides With 4[(Furan-2-Ylmethylene)Amino]-1,5-Dimethyl-2-Phenyl Pyrazol-3-One And Isonicotinic Acid(3',4',5'-Trimethoxybenzylidene)Hydrazide, Ram K. Agarwal, Surendra Prasad, Neetu Goel
Synthesis, Magneto-Spectral And Thermal Characteristics Of Some 7-Coordinated Compounds Of Lanthanides(Iii) Chlorides With 4[(Furan-2-Ylmethylene)Amino]-1,5-Dimethyl-2-Phenyl Pyrazol-3-One And Isonicotinic Acid(3',4',5'-Trimethoxybenzylidene)Hydrazide, Ram K. Agarwal, Surendra Prasad, Neetu Goel
Turkish Journal of Chemistry
In the present work, we describe the isolation of some lanthanide(III) chlorides coordination compounds with 4[(furan-2-ylmethylene)amino]-1,5-dimethyl-2-phenyl pyrazol-3-one (FDPPO) and isonicotinic acid(3',4',5'-trimethoxybenzylidene)hydrazide (ITMBH) with the general composition [Ln(L)_2Cl_3] (Ln = La, Pr, Nd, Sm, Gd, Tb, Dy or Ho; L = FDPPO or ITMBH). All the isolated compounds were characterized through various physico-chemical studies. The coordinating ligands FDPPO or ITMBH act as neutral bidentate N and O-donors in the present compounds. The central metal ion displays the coordination number 7 in these complexes. Thermal stabilities of these complexes were also studied through thermogravimetric analysis.
Photophysical Properties And Electrochemistry Of The N,N'-Bis-N-Butyl Derivative Of Naphthalene Diimide, Yevgen Posokhov, Serap Alp, Banu Köz, Yusuf Di̇lgi̇n, Siddik İçli̇
Photophysical Properties And Electrochemistry Of The N,N'-Bis-N-Butyl Derivative Of Naphthalene Diimide, Yevgen Posokhov, Serap Alp, Banu Köz, Yusuf Di̇lgi̇n, Siddik İçli̇
Turkish Journal of Chemistry
The spectral-luminescent properties and electrochemistry of the N,N'-bis-n-butyl derivative of naphthalene diimide were studied. The main photophysical parameters (quantum yield, rate constants of fluorescence and of non-radiative deactivation and fluorescence lifetime) were determined. The LUMO value (-3.51 eV) was determined by cyclic voltammetry. The N,N'-bis-n-butyl derivative of naphthalene diimide (BBND) shows 2 reversible reduction steps (-1.19 V and -1.75 V vs. Ferrocene) in chloroform. Quenching the fluorescence emissions of aromatic donor molecules in acetonitrile revealed the electron acceptor ability of the studied naphthalene diimide derivative. It has been found that, in contrast to perylene diimide derivatives, which form \pi-electron donor-acceptor …
Synthesis And Microbiological Activity Of Some Substituted N-(2-Hydroxy-4-Nitrophenyl)Benzamides And Phenylacetamides As Possible Metabolites Of Antimicrobial Active Benzoxazoles, İlkay Yildiz Ören, Esi̇n Aki Şener, Cengi̇z Ertaş, Özlem Temi̇z Arpaci, İsmai̇l Yalçin, Nurten Altanlar
Synthesis And Microbiological Activity Of Some Substituted N-(2-Hydroxy-4-Nitrophenyl)Benzamides And Phenylacetamides As Possible Metabolites Of Antimicrobial Active Benzoxazoles, İlkay Yildiz Ören, Esi̇n Aki Şener, Cengi̇z Ertaş, Özlem Temi̇z Arpaci, İsmai̇l Yalçin, Nurten Altanlar
Turkish Journal of Chemistry
Some new antimicrobial active N-(2-hydroxy-4-nitrophenyl)- p-substituted benzamide and phenylacetamide analogues (I-II) were prepared by 2-step procedures from the corresponding carboxylic acids as possible metabolites of benzoxazoles. Their antimicrobial activities were tested against 3 Gram-positive and 2 Gram-negative bacteria with the fungus Candida albicans and were also compared with several control drugs. The compounds Ia, Id, IIa, and IIe were active at a MIC value of 12.5 \mu g/mL against the Gram-positive microorganism Bacillus subtilis. Most of the compounds exhibited antifungal activity at a MIC value of 12.5 \mu g/mL against C. albicans. On the other hand, the antimicrobial activity of …
Phenolic Compounds From Globularia Cordifolia, Hasan Kirmizibekmez, İhsan Çaliş, Sonia Piacente, Cosimo Pizza
Phenolic Compounds From Globularia Cordifolia, Hasan Kirmizibekmez, İhsan Çaliş, Sonia Piacente, Cosimo Pizza
Turkish Journal of Chemistry
From the methanolic extract of the underground parts of Globularia cordifolia, a new neolignan diglycoside, dehydrodiconiferyl alcohol 9-O-\beta -D-glucopyranosyl-(1 \to 2)-\beta -D-glucopyranoside (1) was isolated along with a known neolignan glycoside, dehydrodiconiferyl alcohol 9-O-\beta -D-glucopyranoside (2). In addition, 2 flavone glycosides, chrysoeriol 7-O-\beta -D-allopyranosyl-(1 \to 2)-\beta -D-glucopyranoside (3), stachyspinoside (4) and 5 phenylethanoid glycosides, verbascoside (5), isoverbascoside (6), leucosceptoside A (7), martynoside (8) and rossicaside A (9) were obtained and characterized. The structures of the isolates were established by 1D and 2D NMR spectroscopy in combination with IR, UV and MS analysis.
Photoinitiated Crosslinking And Grafting Of Methylmethacrylate Using N,N-Dimethyl Amino Functional Polystyrene Block Copolymers, Ali̇ Ekrem Müftüoğlu, Yusuf Yağci, Kazunori Se
Photoinitiated Crosslinking And Grafting Of Methylmethacrylate Using N,N-Dimethyl Amino Functional Polystyrene Block Copolymers, Ali̇ Ekrem Müftüoğlu, Yusuf Yağci, Kazunori Se
Turkish Journal of Chemistry
Monodisperse poly(N,N-dimethyl-4-vinylphenethylamine)-block-polystyrene was synthesized via anionic living polymerization carried out at -78 °C under a pressure of 10^{-6} torr using cumyl potassium as the initiator. Subsequent photoinduced radical polymerization of styrene through side chain-functional N,N-dimethyl amino groups yielded a crosslinked polymer and a brush type block-graft copolymer to a lesser extent. Upon irradiation at a wavelength of 350 nm, macroradicals were generated via hydrogen abstraction from amino side-chain groups by the excited benzophenone. The block-graft copolymer was characterized by ^1H-NMR, IR, and GPC analysis.
Thermally Induced Cationic Polymerization Of 2-Ethyl-2-Oxazoline By Benzyl Pyridinium And Anilinium Salts, Hali̇l Ki̇rli̇bal, Yusuf Yağci
Thermally Induced Cationic Polymerization Of 2-Ethyl-2-Oxazoline By Benzyl Pyridinium And Anilinium Salts, Hali̇l Ki̇rli̇bal, Yusuf Yağci
Turkish Journal of Chemistry
N-Benzyl pyridinium (BP), N-benzyl o-cyano pyridinium (BoCP), N-benzyl p-cyanopyridinium (BpCP), N-benzyl N, N-dimethyl anilinium (BDA) and benzyl triphenyl phosphonium (BTP) salts with bromide counter anion, thermal initiators for cationic polymerization, were synthesized and characterized. Their capability to act as initiators for the polymerization of 2-ethyl-2-oxazoline (EOZO) was examined. The postulated mechanism is based on the generation of benzyl bromide by the thermolysis of either BoCP or BDA that reacts with the monomer, EOZO. The polymerization proceeds via an oxazolonium bromide as the propagating end. BP, BoCP and BTP were found to be unreactive towards EOZO.
The Hydrodynamic Properties Of Micelles Formed By Block Copolymers Of Isoprene And Tert-Butylacrylate In N-Octane, Hali̇l İbrahi̇m Ünal, Colin Price
The Hydrodynamic Properties Of Micelles Formed By Block Copolymers Of Isoprene And Tert-Butylacrylate In N-Octane, Hali̇l İbrahi̇m Ünal, Colin Price
Turkish Journal of Chemistry
The hydrodynamic properties of micelles formed by 2 block copolymers of isoprene and tert-butylacrylate in n-octane were investigated by dynamic light scattering (DLS) over a range of temperatures and concentrations using both the cumulants and histogram methods. By means of the histogram method it was possible to determine the average hydrodynamic diameters of both micelles and unassociated-chains in the same solution. It was also used to determine the z-average fraction of unassociated-chains at a particular concentration and temperature, and it provided an alternative route when combined with static light scattering (SLS) for determining the thermodynamics of micellisation. The overall-average diffusion …
Stereoselective Photochemistry Of Methoxy Chalcones In Solution And Their Radical Scavenging Activity, Nuretti̇n Yayli, Osman Üçüncü, Ahmet Yaşar, Yaşar Gök, Murat Küçük, Sevgi̇ Kolayli
Stereoselective Photochemistry Of Methoxy Chalcones In Solution And Their Radical Scavenging Activity, Nuretti̇n Yayli, Osman Üçüncü, Ahmet Yaşar, Yaşar Gök, Murat Küçük, Sevgi̇ Kolayli
Turkish Journal of Chemistry
The photochemical dimerization of 3 known methoxy derivatives of chalcones, (2E)-1-(2-methoxy)phenyl-3-phenylpropen-1-one (1), (2E)-1-(3-methoxy)phenyl-3-phenyl-propen-1-one (2), and (2E)-1-(4-methoxy) phenyl-3-phenylpropen-1-one (3), yielded 3 new \delta -truxinic type dimers in solution: rel-(1\beta ,2\alpha)- di-(2-methoxy)-benzoyl-rel-(3\beta ,4\alpha )-diphenylcyclobutane (4), rel-(1\beta ,2\alpha )-di-(3-methoxy)benzoyl-rel-(3\beta, 4\alpha )-diphenylcyclobutane (5), and rel-(1\beta ,2\alpha)- di-(4-methoxy)benzoyl-rel-(3\beta ,4\alpha )-diphenylcyclobutane (6), stereoselectively. Precursor chalcones showed high superoxide radical scavenging activity although the dimers were inactive.
Electrochemical Detection Of Specific Dna Sequences From Pcr Amplicons On Carbon And Mercury Electrodes Using Meldola's Blue As An Intercalator, Kagan Kerman, Di̇lşat Özkan, Pinar Kara, Hakan Karadeni̇z, Zeynep Özkan, Arzum Erdem, Frantisek Jelen, Mehmet Özsöz
Electrochemical Detection Of Specific Dna Sequences From Pcr Amplicons On Carbon And Mercury Electrodes Using Meldola's Blue As An Intercalator, Kagan Kerman, Di̇lşat Özkan, Pinar Kara, Hakan Karadeni̇z, Zeynep Özkan, Arzum Erdem, Frantisek Jelen, Mehmet Özsöz
Turkish Journal of Chemistry
The electrochemical parameters for 7--dimethyl--amino--1,2-- benzophenoxazinium Meldola's Blue, (MDB) on binding to DNA at both a hanging mercury drop electrode (HMDE) and carbon paste electrode (CPE) are described. MDB, which interacts with immobilized calf thymus DNA, was detected using double stranded DNA modified HMDE or CPE (dsDNA modified HMDE or CPE), bare HMDE or CPE and single stranded DNA modified HMDE or CPE (ssDNA modified HMDE or CPE) in combination with adsorptive transfer stripping voltammetry (AdTSV) techniques and decreased peak currents were observed. The discrimination of dsDNA and ssDNA and detection of hybridization between synthetic oligonucleotides were determined from changes …
Purification And Characterization Of Pear (Pyrus Communis) Polyphenol Oxidase, Emi̇ne Zi̇yan, Şule Pekyardimci
Purification And Characterization Of Pear (Pyrus Communis) Polyphenol Oxidase, Emi̇ne Zi̇yan, Şule Pekyardimci
Turkish Journal of Chemistry
Three isoenzymes of polyphenol oxidase (PPO) were isolated from a local pear variety (Ankara Armutu) through ammonium sulfate precipitation, dialysis and gel filtration. The sample obtained from dialysis after ammonium sulfate precipitation was used for characterization of the partially purified enzyme. Optimum pH values of PPO were 8.2 for pyrogallol, 7.2 for 4-methylcatechol, 7.0 for catechol, 5.6 for D-tyrosine, 5.0 for p-cresol and 4.8 for L-dopa. The optimum temperature of PPO was 35 °C with 4-methylcatechol. Catechol was oxidized more rapidly than the other substrates; however, 4-methylcatechol, chlorogenic acid and caffeic acid were also good substrates. The effect of 6 …
Synthesis Of Novel 4-Alkylidene- And 4-Alkylamino-5-Oxo-4,5-Dihydro-[1,2,4] Triazole Derivatives And Investigation Of Their Antitumor Activities, Nesli̇han Demi̇rbaş, Reyhan Uğurluoğlu
Synthesis Of Novel 4-Alkylidene- And 4-Alkylamino-5-Oxo-4,5-Dihydro-[1,2,4] Triazole Derivatives And Investigation Of Their Antitumor Activities, Nesli̇han Demi̇rbaş, Reyhan Uğurluoğlu
Turkish Journal of Chemistry
A series of novel 3-alkyl-4-cyclohexylmethylenamino-5-oxo-4,5-dihydro-[1,2,4]triazoles (6a-e) and 3-alkyl-4-hexylidenamino-5-oxo-4,5-dihydro-[1,2,4]triazoles (7b-e) were synthesized from the reaction of corresponding 3-alkyl-4-amino-5-oxo-4,5-dihydro-[1,2,4]triazoles (1) with cyclohexancarboxaldehyde and capronaldehyde. The acetylation of compounds 6e and 7b resulted in the formation of 1-acetyl-4- cyclohexylmethylenamino-5-oxo-3-(p-tolyl)-4,5-dihydro-[1,2,4]triazole (10) and 3-benzyl-4-hexylidenamino-5-oxo-4,5-dihydro-[1,2,4]triazole (11). 3-Alkyl-4-cyclohexylmethylamino-5-oxo-4,5-dihydro-[1,2,4]triazoles (8a-e) and 3-alkyl-4-hexylamino-5-oxo-4,5-dihydro-[1,2,4]triazoles (9b-e) were obtained from the selective reduction of compounds 6a-e and 7b-e with NaBH_4. The in vitro antitumor activity of some selected compounds was screened by the National Cancer Institute (USA) against several human tumor cell lines, and compounds 8c, 9d and 11c were found to be active.
Rapid Complexometric Determination Of Mercury(Ii) Using Glutathione As A Selective Demasking Reagent, Prakash Shetty, A. Nithyananda Shetty
Rapid Complexometric Determination Of Mercury(Ii) Using Glutathione As A Selective Demasking Reagent, Prakash Shetty, A. Nithyananda Shetty
Turkish Journal of Chemistry
A simple, rapid and selective complexometric method is proposed for the determination of mercury(II) in the presence of associated metal ions. Mercury(II) is first complexed with an excess of EDTA and the surplus EDTA is titrated against standard zinc sulphate solution at pH 5-6 using xylenol orange indicator. Glutathione is then added to displace EDTA from the Hg-EDTA complex quantitatively and the EDTA released is back titrated against a standard zinc sulphate solution as before. The method works well in the range 4 to 80 mg of mercury with a relative error of less than 0.30% and a coefficient of …
Separation Of Abscisic Acid, Indole-3-Acetic Acid, Gibberellic Acid In 99 R (Vitis Berlandieri X Vitis Rupestris) And Rose Oil (Rosa Damascena Mill.) By Reversed Phase Liquid Chromatography, Mustafa Kelen, Ebru Çubuk Demi̇ralay, Songül Şen, Güleren Özkan Alsancak
Separation Of Abscisic Acid, Indole-3-Acetic Acid, Gibberellic Acid In 99 R (Vitis Berlandieri X Vitis Rupestris) And Rose Oil (Rosa Damascena Mill.) By Reversed Phase Liquid Chromatography, Mustafa Kelen, Ebru Çubuk Demi̇ralay, Songül Şen, Güleren Özkan Alsancak
Turkish Journal of Chemistry
Plant hormones, specialized chemical substances produced by plants, are the main internal factors controlling growth and development. In this study the pH and polarity of the mobile phase were taken into consideration to optimize the mobile phase for the chromatographic separation of 3 important plant hormones: abscisic acid (ABA), indole-3-acetic acid (IAA) and gibberellic acid (GA_3). pK_a values of ABA, IAA and GA_3 were determined using retention factors. These 3 hormones were extracted from 99 R (Vitis berlandieri x Vitis rupestris) and rose oil (Rosa damascena Mill.) and the chromatographic method developed was used for the separation of these hormones.
Neolignan And Phenylethanoid Glycosides From Verbascum Salviifolium Boiss, Zeli̇ha Ş. Akdemi̇r, İ. İrem Tatli, Erdal Bedi̇r, Ikhlas A. Khan
Neolignan And Phenylethanoid Glycosides From Verbascum Salviifolium Boiss, Zeli̇ha Ş. Akdemi̇r, İ. İrem Tatli, Erdal Bedi̇r, Ikhlas A. Khan
Turkish Journal of Chemistry
From the aerial parts of Verbascum salviifolium Boiss., 2 neolignan glucosides, dehydrodiconiferyl alcohol-9'-O-\beta -D-glucopyranoside (1) and dehydrodiconiferyl alcohol-9-O-\beta- D-glucopyranoside (2), along with 5 phenylethanoid glycosides, acteoside (= verbascoside) (3), \beta -hydroxyacteoside (4), forsythoside B (5), angoroside A (6) and martynoside (7), were isolated. The structure elucidation of the isolated compounds was established on the basis of spectroscopic evidence. Compounds 1-7 demonstrated scavenging properties toward the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical in TLC autographic and spectroscopic assays.
Studies On The Reactions Of 4-Ethoxycarbonyl-5-Phenyl-2,3-Dihydro-2,3- Furandione With Some Nh Nucleophiles, Ahmet Şener, Hasan Genç, İsrafi̇l Tozlu, M. Kasim Şener
Studies On The Reactions Of 4-Ethoxycarbonyl-5-Phenyl-2,3-Dihydro-2,3- Furandione With Some Nh Nucleophiles, Ahmet Şener, Hasan Genç, İsrafi̇l Tozlu, M. Kasim Şener
Turkish Journal of Chemistry
4-Ethoxycarbonyl-5-phenyl-2,3-dihydro-2,3-furandione 1 was reacted with o-phenylenediamine, substituted ureas and methylcarbamate or acetamide to give quinoxaline 2, pyrimidine 3 and benzoylmalonic acid 4 derivatives, respectively. Benzoylmalonic acid derivative 4a was converted into a new oxozinedione derivative, 5, by refluxing its solution in xylene containing a catalytic amount of p-toluene sulfonic acid. In addition, triphenylpyrazole carboxylic acid derivative 6 was obtained from the reaction of 4a with diphenylhydrazine.
Crystal And Molecular Structure Of The Yellow Form Of Chloro(2,2':6',2''-Terpyridine)Platinum (Ii)Chloride Dihydrate, [Pt(Terpy)Cl]Cl · 2h_2o, Abdurrahman Şengül
Crystal And Molecular Structure Of The Yellow Form Of Chloro(2,2':6',2''-Terpyridine)Platinum (Ii)Chloride Dihydrate, [Pt(Terpy)Cl]Cl · 2h_2o, Abdurrahman Şengül
Turkish Journal of Chemistry
The synthesis, characterization, and X-ray crystal structure of the yellow dimorph, [Pt(terpy)Cl]Cl · 2H_2O, are reported. The yellow acicular crystals are monoclinic: space group P2_1/n, a = 6.908(3) Å, b = 17.06700(11) Å, c = 13. 8390(10) Å, \beta = 98.607(4)°, and D_{calc} = 2.204 Mg m^{-3} for Z = 4. The cation consists of platinum coordinated to tridentate terpyridine ligand and to chloride ion. The coordination geometry is essentially square-planar with distortions arising from the constraints of the terpyridine ligand. Bond distances are within the acceptable limits of predicted values. The cations stack in a head-to-tail orientation with an …
Synthesis, Spectral And Thermal Properties Of Some Penta-Coordinated Complexes Of Oxovanadium(Iv) Derived From Thiosemicarbazones Of 4-Aminoantipyrine, Ram K. Agarwal, Surendra Prasad, Neetu Gahlot
Synthesis, Spectral And Thermal Properties Of Some Penta-Coordinated Complexes Of Oxovanadium(Iv) Derived From Thiosemicarbazones Of 4-Aminoantipyrine, Ram K. Agarwal, Surendra Prasad, Neetu Gahlot
Turkish Journal of Chemistry
The paper reports the synthesis of crystalline oxovanadium(IV), VO^{2+}, complexes of thiosemicarbazones, i.e. 4[N-(4'-nitrobenzalidene)amino]antipyrine thiosemicarbazone (4'-NO_2BAAPTS) and 4[N-(furan-2'-aldimine)amino]antipyrine thiosemicarbazone (FFAAPTS) with general composition VOX_2L (X = Cl, Br, I, NO_3 or NCS) and VO(ClO_4)_2(L)H_2O (L = 4'-NO_2BAAPTS or FFAAPTS). All the complexes were characterized by elemental analyses, molar mass, molar conductance, magnetic susceptibility, infrared and electronic spectra. In all the complexes, both the thiosemicarbazones behave as neutral tridentate (N, N, S) ligands. The thermal properties of the representative complexes are also reported. The most probable geometry of the complexes is proposed.
Bromination Of Tricyclo[7.2.1.0^{2,7}]Dodeca-2,4,6,10-Tetraene Derivatives: Electronic And Neighboring Group Effects On Bromination, Ari̇f Daştan
Turkish Journal of Chemistry
The bromination reaction of tricyclo[7.2.1.0^{2,7}]dodeca-2,4,6,10-tetraene derivatives was studied. The bromination of 9 gave only rearranged products 12 and 13, while the bromination of 8 with molecular bromine formed both rearranged 12 and non-rearranged products 15 and 16. The possible role of a substituent in the rearrangements was examined. All compounds were characterized properly, in particular by NMR spectra and chemical transformation.
External Mass Transfer Studies During The Adsorptions Of Some Dyestuffs And P-Nitrophenol Onto Chitosan From Aqueous Solution, İlhan Uzun, Fuat Güzel
External Mass Transfer Studies During The Adsorptions Of Some Dyestuffs And P-Nitrophenol Onto Chitosan From Aqueous Solution, İlhan Uzun, Fuat Güzel
Turkish Journal of Chemistry
The effect of temperature on the adsorptions of some dyestuffs [orange II (O-II), crystal violet (CV) and reactive blue 5 (RB5)] and an ideal adsorbate p-nitrophenol (PNP) by chitosan (Sigma C 3646) from aqueous solution was investigated. The experimental data related to adsorption isotherms were applied to linear forms of the equations that they fitted, and isotherm constants were calculated. Since the isotherm curves obtained for the adsorptions of O-II and CV by chitosan fitted the Langmuir adsorption isotherm, the Langmuir constants (q_m and b) related to the adsorption isotherms of these dyestuffs together with their kinetical data at different …
Main Flavonoids Of Tilia Argentea Desf. Ex Dc. Leaves, Gülnur Toker, Merve Memi̇şoğlu, Erdem Yeşi̇lada, Mustafa Aslan
Main Flavonoids Of Tilia Argentea Desf. Ex Dc. Leaves, Gülnur Toker, Merve Memi̇şoğlu, Erdem Yeşi̇lada, Mustafa Aslan
Turkish Journal of Chemistry
No abstract provided.
Methoxyflavonoids From Pinaropappus Roseus, Ü. Şebnem Harput, İclal Saracoğlu, Yukio Ogihara
Methoxyflavonoids From Pinaropappus Roseus, Ü. Şebnem Harput, İclal Saracoğlu, Yukio Ogihara
Turkish Journal of Chemistry
Three rare methoxyflavonoids, rhamnazin 3-O-rutinoside (1), rhamnocitrin 3-O-rutinoside (2) and isorhamnetin 3-O-rutinoside (3), were isolated from the methanolic extract of Pinaropappus roseus together with 2 well-known flavonoids, quercetin 3-O-rutinoside (=rutin) (4) and kaempferol 3-O-rutinoside (5). The structures of the isolated compounds were elucidated on the basis of UV, 1D and 2D NMR and FAB-Mass spectral analysis. Free radical scavenging activities of the isolated compounds were also demonstrated. This is the first report on the chemical composition of the genus Pinaropappus.
Secondary Metabolites From Phlomis Kotschyana, Ü. Şebnem Harput, İclal Saracoğlu, İhsan Çaliş, Ali̇ Arslan Dönmez, Akito Nagatsu
Secondary Metabolites From Phlomis Kotschyana, Ü. Şebnem Harput, İclal Saracoğlu, İhsan Çaliş, Ali̇ Arslan Dönmez, Akito Nagatsu
Turkish Journal of Chemistry
A lignan glycoside, syringaresinol-4',4''-O-di-\beta -D-glucopyranoside (1) (=liriodendrin), 4 phenylethanoid glycosides, acteoside (2), isoacteoside (3), forsythoside B (4) and leucosceptoside B (5), a caffeic acid ester, chlorogenic acid (6) and 2 iridoid glucosides, lamiide (7) and auroside (8), were isolated from the methanolic extracts of the aerial parts of Phlomis kotschyana along with an acetophenone glycoside, 4-hydroxyacetophenone 4-O-[6'-O-\beta -D-apiofuranosyl]-\beta -D-glucopyranoside (9). The structures of the isolated compounds were identified on the basis of spectroscopic (UV, IR, 1D- and 2D-NMR, and FAB-MS) methods.
Synthesis And Characterization Of Block Copolymers Using Polysiloxane Based Macroazoinitiator, Sennur Deni̇z, Ni̇l Baran, Mesut Akgün, Nalan A. Akgün, Sali̇h Di̇nçer
Synthesis And Characterization Of Block Copolymers Using Polysiloxane Based Macroazoinitiator, Sennur Deni̇z, Ni̇l Baran, Mesut Akgün, Nalan A. Akgün, Sali̇h Di̇nçer
Turkish Journal of Chemistry
Poly(dimethylsiloxane-b-styrene) (PDMS-b-PSt) and poly(dimethylsiloxane-b-methyl methacrylate) (PDMS-b-PMMA) block copolymers containing siloxane segments were studied by the radical polymerizations of vinyl monomers such as styrene (St) and methyl methacrylate (MMA) using polydimethylsiloxane based macroazoinitiator (PDM-MAI) in solution. PDM-MAI was synthesized by reacting hydroxy-terminated polydimethylsiloxane (PDMS) and 4,4'-azobis (4-cyanopentanoyl chloride) (ACPC) having a thermodegradable azo-linkage. The polycondensation reaction between PDMS and ACPC (2:1, molar ratio) was carried out at room temperature. The polymerizations of St and MMA initiated by PDM-MAI were investigated using different PDM-MAI concentrations (1, 5, 10, and 15 wt. %) for various reaction times with a methyl ethyl ketone (MEK)/ …
X-Ray Diffraction Study Of The Changes Induced During The Thermal Degradation Of Poly (Methyl Methacrylate) And Poly (Methacryloyl Chloride), Rizwan Hussain, Din Mohammad
X-Ray Diffraction Study Of The Changes Induced During The Thermal Degradation Of Poly (Methyl Methacrylate) And Poly (Methacryloyl Chloride), Rizwan Hussain, Din Mohammad
Turkish Journal of Chemistry
Poly (methyl methacrylate) -- PMMA -- and poly (methacryloyl chloride) -- PMACl -- were synthesized by free radical solution polymerization. The thermal stabilities of these polymers were determined with the help of thermogravimetry and differential thermal analysis. The structural changes in these materials at different temperatures (90, 140, 220 and 410 °C) were studied by X-ray diffraction. These studies indicate that PMACl is less amorphous than PMMA due to the presence of bulky chloride groups