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Full-Text Articles in Physical Sciences and Mathematics

Anionic Polymerization Of Methyl Methacrylate As Promoted By A N-Butyl Lithium-Pyridazine-Polyether Alkoxide Based Complex Initiator System, Z. Tim Hamaudi, Ni̇han Nugay, Turgut Nugay Jan 2004

Anionic Polymerization Of Methyl Methacrylate As Promoted By A N-Butyl Lithium-Pyridazine-Polyether Alkoxide Based Complex Initiator System, Z. Tim Hamaudi, Ni̇han Nugay, Turgut Nugay

Turkish Journal of Chemistry

Polymerization of methyl methacrylate was conducted using a n-butyl lithium/pyridazine system as initiator in tetrahydrofuran (THF) and toluene. Special attention was focused on using some lithium polyether alkoxides as polymerization is promoted at ambient temperatures. The positive effects of these \mu /\sigma -type ligands such as lithium 2-(2-methoxyethoxy)ethoxide and lithium 2-(methoxy)ethoxide on controlling the living character, molecular weight, stereoregularity and yield of the produced polymers were all demonstrated. It was found that initiator/lithium-2-(methoxy)ethoxide in a 1/10 ratio gives the most controlled polymerization. All products were then characterized by size exclusion chromatography (SEC), proton nuclear magnetic resonance (^1H NMR) and differential …


An Efficient Synthesis Of Substituted 4-Aryl-3-Cyano-2-Amino Thiophenes By A Stepwise Gewald Reaction, Ferhan Tümer, Duygu Eki̇nci̇, Kani̇ Zi̇lbeyaz, Ümi̇t Demi̇r Jan 2004

An Efficient Synthesis Of Substituted 4-Aryl-3-Cyano-2-Amino Thiophenes By A Stepwise Gewald Reaction, Ferhan Tümer, Duygu Eki̇nci̇, Kani̇ Zi̇lbeyaz, Ümi̇t Demi̇r

Turkish Journal of Chemistry

The title compounds were efficiently synthesised starting from aryl methyl ketones in 3 steps. Knoevenagel condensation of aryl methyl ketones with malononitrile gave the corresponding crotonitriles (5a-f). Methyl groups of the crotonitriles (5a-f) were then efficiently brominated by refluxing and lightening the reaction media to give bromocrotonitriles (6a-f). The bromocrotonitriles (6a-f) were finally cyclised by treatment with NaSH to give the title compounds.


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 Jan 2004

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 …


Naphthoquinones From The Roots Of Onosma Argentatum Hub.-Mor. (Boraginaceae), Ufuk Özgen, Maksut Coşkun, Cavi̇t Kazaz, Hasan Seçen Jan 2004

Naphthoquinones From The Roots Of Onosma Argentatum Hub.-Mor. (Boraginaceae), Ufuk Özgen, Maksut Coşkun, Cavi̇t Kazaz, Hasan Seçen

Turkish Journal of Chemistry

Onosma argentatum Hub.-Mor. is an endemic species growing in Turkey. In this study, the roots of O. argentatum were extracted with n-hexane-dichloromethane (1:1). The extract was separated on a silica gel column eluting with n-hexane-ethyl acetate by gradient elution. New naphthoquinone compounds (3 known and 1 new) were isolated and their structures were elucidated by spectroscopic methods as deoxyshikonin, acetyl shikonin, 3-hydroxy-isovaleryl shikonin, and 5,8-O-dimethyl acetyl shikonin.


Phenolic Compounds From Globularia Cordifolia, Hasan Kirmizibekmez, İhsan Çaliş, Sonia Piacente, Cosimo Pizza Jan 2004

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 Jan 2004

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 Jan 2004

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.


Genetic Multivariate Calibration Methods For Near Infrared (Nir) Spectroscopic Determination Of Complex Mixtures, Durmuş Özdemi̇r, Betül Öztürk Jan 2004

Genetic Multivariate Calibration Methods For Near Infrared (Nir) Spectroscopic Determination Of Complex Mixtures, Durmuş Özdemi̇r, Betül Öztürk

Turkish Journal of Chemistry

The simultaneous determination of ternary mixtures of methylene chloride, ethyl acetate, and methanol using near infrared (NIR) spectroscopy and 4 different genetic algorithms based multivariate calibration methods was demonstrated. The 4 genetic multivariate calibration methods are genetic partial least squares (GPLS), genetic regression (GR), genetic classical least squares (GCLS) and genetic inverse least squares (GILS). The sample data set contains the NIR spectra of 63 ternary mixtures and covers the range from 900 to 2000 nm in 2 nm intervals. Of these 63 spectra, 42 were used as the calibration set, and 21 were reserved for the prediction purposes. Several …


Stereoselective Photochemistry Of Methoxy Chalcones In Solution And Their Radical Scavenging Activity, Nuretti̇n Yayli, Osman Üçüncü, Ahmet Yaşar, Yaşar Gök, Murat Küçük, Sevgi̇ Kolayli Jan 2004

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 Jan 2004

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 …


Defect Structure And Properties Of Sr-Doped La Cr O_{3-\Delta}, Mahmoud Omari, Ilhem Chadli, Salah Belaidi Jan 2004

Defect Structure And Properties Of Sr-Doped La Cr O_{3-\Delta}, Mahmoud Omari, Ilhem Chadli, Salah Belaidi

Turkish Journal of Chemistry

A defect chemical model for the behavior of acceptor-doped LaCrO_3 as a function of oxygen pressure is proposed. This is considered within the regime that corresponds to oxygen deficit oxygen. The mathematical approach allows us to calculate the oxygen partial pressure dependant properties of La_{1-x} Sr_x Cr O_{3-\delta} in the range 0.10 \le x \le 0.30. The results show that the conductivity was independent of pO_2 and was proportional to the dopant concentration at high pO_2. Therefore, under reducing conditions, the conductivity decreased exponentially with decreasing pO_2 and asymptotically approached a pO_2^{1/4} relationship. Stability regimes and compensation mechanisms at various …


Purification And Characterization Of Pear (Pyrus Communis) Polyphenol Oxidase, Emi̇ne Zi̇yan, Şule Pekyardimci Jan 2004

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 Jan 2004

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 Jan 2004

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 …


Direct Dyes Derived From 4,4'-Diaminobenzanilide Synthesis, Characterization And Toxicity Evaluation Of A Disazo Symmetric Direct Dye, Georgeta Maria Simu, Sergiu Adrian Chicu, Nicole Morin, Walter Schmidt, Eugen Şişu Jan 2004

Direct Dyes Derived From 4,4'-Diaminobenzanilide Synthesis, Characterization And Toxicity Evaluation Of A Disazo Symmetric Direct Dye, Georgeta Maria Simu, Sergiu Adrian Chicu, Nicole Morin, Walter Schmidt, Eugen Şişu

Turkish Journal of Chemistry

The synthesis of a new symmetric disazo direct dye containing the non--carcinogenic 4,4'-diaminobenzanilide as the middle component and salicylic acid as the coupling component is presented. The synthesized dye is an analog of the benzidine based dye C. I. Direct Yellow 1 (C. I. 22,250) and was analyzed by thin layer chromatography (TLC), electronic spectra (VIS) and mass spectroscopy (FAB-MS). The coloristic and fastness properties of the synthesized dye were determined and compared with those of C. I. Direct Yellow 1. The toxicities of the dye and of its precursors were evaluated by biological tests, using the process of metamorphosis …


Electrorheological Properties Of Suspensions Prepared From Poly(Li-Tert-Butyl Methacrylate) Ionomer, Mustafa Yavuz, Hali̇l İbrahi̇m Ünal Jan 2004

Electrorheological Properties Of Suspensions Prepared From Poly(Li-Tert-Butyl Methacrylate) Ionomer, Mustafa Yavuz, Hali̇l İbrahi̇m Ünal

Turkish Journal of Chemistry

The synthesis, characterisation and partial hydrolysis of poly(tert-butylmethacrylate), (PTBMA), and the electrorheological (ER) properties of its suspensions were investigated. The polymer was synthesised by radical polymerisation and partially hydrolysed by para-toluenesulphonic acid monohydrate (PTSA.H_2O), and then converted to a lithium salt (PTBMA-Li) by washing with a LiOH_{(aq)} solution. From particle size measurements, the average particle size of PTBMA-Li was determined to be 74 \mu m. Colloidal suspensions of ionomer were prepared in various insulating oils [silicone oil (SO), mineral oil (MO), threeoctylthreemellitate (TOTM) and dioctylphatalete (DOP)] at a series of concentrations (c = 5-33 m/m, %). The sedimentation stabilities 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 Jan 2004

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.


Study On The Solid Phase Extraction And Spectrophotometric Determination Of Cobalt With 2-(2-Quinolylazo)-5-Diethylaminoaniline, Qiufen Hu, Guangyu Yang, Xuechang Dong, Jiayuan Yin Jan 2004

Study On The Solid Phase Extraction And Spectrophotometric Determination Of Cobalt With 2-(2-Quinolylazo)-5-Diethylaminoaniline, Qiufen Hu, Guangyu Yang, Xuechang Dong, Jiayuan Yin

Turkish Journal of Chemistry

A sensitive, selective and rapid method for the determination of cobalt based on the rapid reaction of cobalt(II) with QADEAA and the solid phase extraction of the Co(II)-QADEAA chelate with C_{18} membrane disks was developed. In the presence of pH = 5.5 buffer solution and cetyl trimethylammonium bromide (CTMAB) medium, QADEAA reacts with cobalt to form a violet complex with a molar ratio of 1:2 (cobalt to QADEAA). This chelate was enriched by the solid phase extraction with C_{18} membrane disks. An enrichment factor of 50 was obtained by elution of the chelate from the disks with a minimal amount …


Neolignan And Phenylethanoid Glycosides From Verbascum Salviifolium Boiss, Zeli̇ha Ş. Akdemi̇r, İ. İrem Tatli, Erdal Bedi̇r, Ikhlas A. Khan Jan 2004

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.


Preparation, Spectroscopic Studies And Biological Activity Of Mono-Organotin(Iv) Derivatives Of Non-Steroidal Anti-Inflammatory Drugs, Azra Jalal, Saira Shahzadi, Khadiji Shahid, Saqib Ali, Amin Badshah, Mohammad Mazhar, Khalid Mohammed Khan Jan 2004

Preparation, Spectroscopic Studies And Biological Activity Of Mono-Organotin(Iv) Derivatives Of Non-Steroidal Anti-Inflammatory Drugs, Azra Jalal, Saira Shahzadi, Khadiji Shahid, Saqib Ali, Amin Badshah, Mohammad Mazhar, Khalid Mohammed Khan

Turkish Journal of Chemistry

A set of 14 mono-organotin(IV) derivatives of general formulae n-BuSnClL_2 and n-BuSnL_3, where `L' are various non-steroidal anti-inflammatory drugs (NSAIDs), were synthesized and structurally characterized by vibrational, ^1H, ^{13}C and ^{119}Sn spectroscopies and mass spectrometry to propose their structure. Biological activity data (antibacterial, antifungal and cytotoxicity) of the synthesized complexes were compared with the precursors to establish the significance of the complexes.


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 Jan 2004

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 And Antitumor Activities Of Some New 4-(1-Naphthylidenamino)- And 4-(1-Naphthylmethylamino)-1,2,4-Triazol-5-One Derivatives, Nesli̇han Demi̇rbaş, Reyhan Uğurluoğlu Jan 2004

Synthesis And Antitumor Activities Of Some New 4-(1-Naphthylidenamino)- And 4-(1-Naphthylmethylamino)-1,2,4-Triazol-5-One Derivatives, Nesli̇han Demi̇rbaş, Reyhan Uğurluoğlu

Turkish Journal of Chemistry

A series of 4-(1-naphthylidenamino)-1,2,4-triazol-5-one derivatives (3a-e) were synthesized by condensation of corresponding 3-alkyl-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones with 1-naphthaldehyde. Acetylation and alkylation of these compounds gave 4a-e and 5a-e, respectively. Sodium borohydride reduction of 1-naphthylidenamino derivatives afforded naphthylmethylamino derivatives, which were subsequently acetylated. Depending on the duration of the acetylation, mono or bis acetamide derivatives were obtained. The in vitro antitumor activities of some selected compounds were screened and compounds 3e, 5c, 6e and 9c} were found to be active.


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 Jan 2004

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.


An Atropisomeric Chiral 2,2'-Bipyridyl-3,3'-Dicarboxylic Acid And Corresponding Platinum(Ii) Complex, Abdurrahman Şengül Jan 2004

An Atropisomeric Chiral 2,2'-Bipyridyl-3,3'-Dicarboxylic Acid And Corresponding Platinum(Ii) Complex, Abdurrahman Şengül

Turkish Journal of Chemistry

2,2'-Bipyridyl-3,3'-dicarboxylic acid (H_2BDC) spontaneously resolves on crystallization from water, giving monohydrated crystals of the space group P2_12_12_1. In any individual crystal, all the atropisomeric-skewed molecules are of one hand; however, on dissolution in water, optical activity is lost. Strong hydrogen bonding leads to a helical structure, via O--H ... N links, and 3 further strong bonds between water and carboxylate groups produce a framework structure. The pK_a values measured for H_2BDC (3.18 \pm 0.04 and 4.59 \pm 0.02 at 20 \pm 1 °C, in dilute aqueous solution) agree with the zwitterionic form. The reaction of H_2BDC with potassium tetrachloroplatinate(II) in …


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 Jan 2004

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.


X-Ray Diffraction Study Of The Changes Induced During The Thermal Degradation Of Poly (Methyl Methacrylate) And Poly (Methacryloyl Chloride), Rizwan Hussain, Din Mohammad Jan 2004

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


External Mass Transfer Studies During The Adsorptions Of Some Dyestuffs And P-Nitrophenol Onto Chitosan From Aqueous Solution, İlhan Uzun, Fuat Güzel Jan 2004

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 …


Phenylpropanoid Glycosides From Linum Olympicum (Linaceae), Belma Konuklugi̇l, Özlem Bahadir Jan 2004

Phenylpropanoid Glycosides From Linum Olympicum (Linaceae), Belma Konuklugi̇l, Özlem Bahadir

Turkish Journal of Chemistry

The lignan content of Linum olympicum Boiss. was investigated by HPLC and GC-MS in comparison with standards, and 2 phenylpropanoid glycosides, syringin (1) and coniferin (2), were isolated from the aerial parts. Identification of the 2 compounds was achieved by comparison with standards using TLC and HPLC and the structures of the isolated compounds were established by UV and ^1H-NMR analysis.


Main Flavonoids Of Tilia Argentea Desf. Ex Dc. Leaves, Gülnur Toker, Merve Memi̇şoğlu, Erdem Yeşi̇lada, Mustafa Aslan Jan 2004

Main Flavonoids Of Tilia Argentea Desf. Ex Dc. Leaves, Gülnur Toker, Merve Memi̇şoğlu, Erdem Yeşi̇lada, Mustafa Aslan

Turkish Journal of Chemistry

No abstract provided.


Acylated Flavone Glycosides From Veronica Pectinata Var. Glandulosa And V. Persica, İclal Saracoğlu, Ü. Şebnem Harput, Yukio Ogihara Jan 2004

Acylated Flavone Glycosides From Veronica Pectinata Var. Glandulosa And V. Persica, İclal Saracoğlu, Ü. Şebnem Harput, Yukio Ogihara

Turkish Journal of Chemistry

This study deals with the isolation of a new acylated 5,6,7,3',4'-pentahydroxy-flavone glycoside (1) and 3 known allose-containing acylated flavone glycosides (2-4) as well as a known flavone aglycone (5) from the aerial parts of Veronica pectinata var. glandulosa and V. persica. The structures of the isolated compounds were determined to be 3' -hydroxy-4'-O-methylscutellarein-7-O-[2''-O-\alpha -L-rhamnopyranosyl-3''-O-(6''''-O-acetyl-\beta -D-glucopyranosyl)]-\beta- D-glucopyranoside, named sarachoside (1), 4' -O-methylisoscutellarein-7-O-2''- O-(6''' -O-acetyl-\beta -D-allopyranosyl)-\beta -D-glucopyranoside (2), isos\-cutellarein-7-O-2''-O-(6'''-O-acetyl-\beta-D-allopyranosyl)-\beta- D-glucopyranoside (3), 3'-hydroxy-4'-O-methy\-lisoscutellarein-7-O-2'' -O-(6'''-O-acetyl-\beta -D-allopyranosyl)-\beta -D-glucopyranoside (4) and 5,4'-dihydroxy-6,7,3' -trimethoxyflavone, named circilineol (5) by extensive 1-D and 2D-NMR spectroscopy. Sarachoside (1) exhibited potent radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical.