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Articles 2041 - 2070 of 2720
Full-Text Articles in Chemistry
A Concise Synthesis And The Antibacterial Activity Of 5,6-Dimethoxynaphthalene-2-Carboxylic Acid, Süleyman Göksu, Meti̇n Tansu Uğuz, Hasan Özdemi̇r, Hasan Seçen
A Concise Synthesis And The Antibacterial Activity Of 5,6-Dimethoxynaphthalene-2-Carboxylic Acid, Süleyman Göksu, Meti̇n Tansu Uğuz, Hasan Özdemi̇r, Hasan Seçen
Turkish Journal of Chemistry
5,6-Dimethoxynaphthalene-2-carboxylic acid was synthesized in 7 steps and with an overall yield of 46%. Bromination of 2-naphthol, and methylation with dimethyl sulfate followed by Friedel-Crafts acylation with AcCl gave 2-acetyl-5-bromo-6-methoxynaphthalene. 2-Acetyl-5-bromo-6-methoxynaphthalene was converted to 5-bromo-6- methoxynaphthalene-2-carboxylic acid by a haloform reaction. The esterification of the acid with methanol, methoxylation with NaOCH_3 in the presence of CuI and subsequent de-esterification with NaOH afforded 5,6-dimethoxynaphthalene-2-carboxylic acid. The 5-bromo-6-methoxynaphthalene-2-carboxylic acid and 5,6-dimethoxynaphthalene-2-carboxylic acid were found to have in vitro antibacterial activity against some pathogenic bacteria.
Synthesis And In Vitro Antimicrobial And Cytotoxicity Activities Of 2-[(2-Nitro-1-Phenylalkyl)Thio]Benzoic Acid Derivatives, Mehtap Gökçe, Semra Utku, Erdoğan Berçi̇n, Berri̇n Özçeli̇k, Taner Karaoğlu, Ni̇ngur Noyanalpan
Synthesis And In Vitro Antimicrobial And Cytotoxicity Activities Of 2-[(2-Nitro-1-Phenylalkyl)Thio]Benzoic Acid Derivatives, Mehtap Gökçe, Semra Utku, Erdoğan Berçi̇n, Berri̇n Özçeli̇k, Taner Karaoğlu, Ni̇ngur Noyanalpan
Turkish Journal of Chemistry
In this research 14 compounds were tested for their antimicrobial activity. The synthesis of 7 compounds corresponding to 2-[(2-nitro-1-phenyl-propyl)thio]benzoic acids 4 has not been reported before and 7 compounds corresponding to 2-[(2-nitro-1-phenyl-ethyl) thio]benzoic acid 3 were reported by our research group. The antibacterial activity of the title compounds was evaluated by 2 Gram (+) (Staphylococcus aureus, Bacillus subtilis) and 2 Gram (-)(Pseudomonas aeruginosa, Escherichia coli) microorganisms. The antifungal activity of the compounds was also determined against yeast-like fungi (Candida albicans, C. krusei). For antibacterial activity, ampicillin and for antifungal activity, fluconazole and ketoconazole have been used as reference compounds. All …
The Effect Of Metal Loading On Structural Characteristics And Low Temperature Co Oxidation Activity Of Coprecipitated Co/Al_2o_3, Şeyma Özkara, Ayşe Ni̇lgün Akin, Zülal Misirli, Ahmet Erhan Aksoylu
The Effect Of Metal Loading On Structural Characteristics And Low Temperature Co Oxidation Activity Of Coprecipitated Co/Al_2o_3, Şeyma Özkara, Ayşe Ni̇lgün Akin, Zülal Misirli, Ahmet Erhan Aksoylu
Turkish Journal of Chemistry
The effect of metal loading on structural properties and CO oxidation activity of coprecipitated Co/Al_2O_3 catalysts was investigated. The results indicated the participation of cobalt in the Co-Al skeleton for all coprecipitated samples. Environmental-SEM-EDXS studies showed that at loadings higher than ca. 15 wt.-%, cobalt formed layer-by-layer clusters on the surface; 16.8 wt.-% Co/Al_2O_3 displayed the highest activity and stability in CO oxidation.
Synthesis, Characterization And Primary Antimicrobial Activity Evaluation Of 3-Phenyl-6-Methyl-4(3h)-Quinazolinone-2-Yl-Mercaptoacetic Acid Arylidenehydrazides, Aysel Gürsoy, Banu Ünal, Ni̇lgün Karali, Gülten Ötük
Synthesis, Characterization And Primary Antimicrobial Activity Evaluation Of 3-Phenyl-6-Methyl-4(3h)-Quinazolinone-2-Yl-Mercaptoacetic Acid Arylidenehydrazides, Aysel Gürsoy, Banu Ünal, Ni̇lgün Karali, Gülten Ötük
Turkish Journal of Chemistry
3-Phenyl-6-methyl-4(3H)-quinazolinone-2-yl-mercaptoacetic acid hydrazide (3) was reacted with substituted aldehydes in absolute ethanol to obtain a new series, 3-phenyl-6-methyl-4(3H)-quinazolinone- 2-yl-mercaptoacetic acid arylidenehydrazides (4a-q). The structures of 4a-q were elucidated by elemental analyses and from spectrometric (UV, IR, ^1H-NMR, ^{13}C-NMR and EIMS) data. Then 4a-q were evaluated for antibacterial, antifungal and antitubercular activities. No significant activity was observed against the selected microorganisms.
Synthesis And Isolation Of New Regioisomeric 4-Thiazolidinones And Their Anticonvulsant Activity, Aysel Gürsoy, Nalan Terzi̇oğlu
Synthesis And Isolation Of New Regioisomeric 4-Thiazolidinones And Their Anticonvulsant Activity, Aysel Gürsoy, Nalan Terzi̇oğlu
Turkish Journal of Chemistry
Two regioisomer series, 2-(3-ethyl-4(3H)-quinazolinone-2- ylmercaptoacetylhydrazono)-3-alkyl/3-aryl-5-methyl-4-thiazolidinones (12-21) and 2-arylimino-3-(3-ethyl-4(3H)-quinazolinone-2-ylmercaptoacetylamino)- 5-methyl-4-thiazolidinones (22-26), were synthesized by the cyclization of 1-(3-ethyl-4(3H)-quinazolinone-2-ylmercaptoacetyl)-4-alkyl/aryl thiosemicarbazides (1-11) with ethyl 2-bromopropionate in the presence of anhydrous sodium acetate in anhydrous ethanolic medium. The structures of 12-26 were confirmed by analytical and spectral data (IR, ^1H-NMR and EIMS). Selected members of the thiosemicarbazides and thiazolidinones were subjected to anticonvulsant activity tests by the National Institute of Neurological Disorders and Stroke MD, USA.
A Novel Method For The Spectrophotometric Determination Of Thallium Using Methiomeprazine Hydrochloride, Hoskere D. Revanasiddappa, Telangusadhushetty N. Kiran Kumar
A Novel Method For The Spectrophotometric Determination Of Thallium Using Methiomeprazine Hydrochloride, Hoskere D. Revanasiddappa, Telangusadhushetty N. Kiran Kumar
Turkish Journal of Chemistry
A new, simple, sensitive, and rapid spectrophotometric method is proposed for the determination of trace amounts of thallium(III). The method is based on the oxidation of methiomeprazine hydrochloride by thallium(III) in phosphoric acid medium to give a blue radical cation, having a maximum absorption at 645 nm. Beer's law is valid over the concentration range 0.5--4.0 \mu g mL^{-1}, with molar absorptivity and Sandell's sensitivity of 3.2 \times 10^4 L mol^{-1} cm^{-1} and 0.0064 \mu g cm^{-2}, respectively. The detection limit of thallium determination is 0.01 \mu g mL^{-1}. The tolerance limits for interfering ions are discussed. All variables were …
Non-Steroidal Anti-Inflammatory Drugs (Nsaids) As Donor Ligands In Organotin(Iv) Derivatives: Synthesis, Spectroscopic Characterization And Biological Applications, Saira Shahzadi, Khadija Shahid, Saqib Ali, Mohammad Mazhar, Amin Badshah, Ejaz Ahmed, Abdul Malik
Non-Steroidal Anti-Inflammatory Drugs (Nsaids) As Donor Ligands In Organotin(Iv) Derivatives: Synthesis, Spectroscopic Characterization And Biological Applications, Saira Shahzadi, Khadija Shahid, Saqib Ali, Mohammad Mazhar, Amin Badshah, Ejaz Ahmed, Abdul Malik
Turkish Journal of Chemistry
Some new di- and tri-organotin(IV) derivatives of 4 different non-steroidal anti-inflammatory drugs (NSAIDs) with the general formulae R_2SnL_2 and R_3SnL (where R = n-C_{8}H_{17} and C_6H_5CH_2) and L = 2-[(2,3-dimethylphenyl)amino]benzoic acid, 2-(2-fluoro-4-biphenyl)propionic acid, 2-(4-isobutylphenyl) propionic acid and 2-(3-benzoylphenyl)-propionic acid were synthesized. These compounds were structurally characterized by infrared and multinuclear NMR (^1H, ^{13}C, ^{119}Sn) spectroscopies and mass spectrometry. The isotopic effect of tin was studied by comparison of experimental data with the simulated isotopic pattern using the Chemtool software package. These compounds were also screened against different animal and plant pathogens to study their biological activity. LD_{50} data show that …
Synthesis And Spectral Investigations Of Some Platinum Metals Ions Coordination Compounds Of 4[N-(Furan-2'-Carboxalidene)Amino]Antipyrine Thiosemicarbazone And 4[N-(3',4',5'-Trimethoxybenzalidene)Amino]Antipyrine Thiosemicarbazone, Ram K. Agarwal, Surendra Prasad
Synthesis And Spectral Investigations Of Some Platinum Metals Ions Coordination Compounds Of 4[N-(Furan-2'-Carboxalidene)Amino]Antipyrine Thiosemicarbazone And 4[N-(3',4',5'-Trimethoxybenzalidene)Amino]Antipyrine Thiosemicarbazone, Ram K. Agarwal, Surendra Prasad
Turkish Journal of Chemistry
The present work describes the synthesis and spectral properties of some platinum metals chlorides coordination compounds of 4[N-(-(furan-2'-carboxalidene)amino]antipyrine thiosemicarbazone (FFAAPTS) and 4[N-(3',4',5'-trimethoxybenzalidene)amino]antipyrine thiosemicarbazone (TMBAAPTS). All the compounds have the general composition MCl_2(L) (M = Pd^{2+} or Pt^{2+} ; L = FFAAPTS or TMBAAPTS) or MCl_3(L) (M = Ru^{3+} , Rh^{3+} or Ir^{3+} ; L = FFAAPTS or TMBAAPTS). All the complexes were characterized by elemental analyses, molar conductance, molecular weight, magnetic measurements, and infrared and electronic spectra. The infrared spectra suggest that both the thiosemicarbazones behave as neutral tridentate (N,N,S) ligands. The magnetic and electronic spectra suggest that Pd^{2+} and …
New Complexes Of Organotin(Iv) 2-(N-Maleoylamino)-2-Methylpropanoate: Synthesis, Spectroscopic Characterization And Biological Activity, Sajjad Ahmad, Saqib Ali, Saira Shahzadi, Fiaz Ahmed, Khalid Mohammed Khan
New Complexes Of Organotin(Iv) 2-(N-Maleoylamino)-2-Methylpropanoate: Synthesis, Spectroscopic Characterization And Biological Activity, Sajjad Ahmad, Saqib Ali, Saira Shahzadi, Fiaz Ahmed, Khalid Mohammed Khan
Turkish Journal of Chemistry
Organotin(IV) complexes of 2-(N-maleoylamino)-2-methylpropanoate were prepared by treating the ligand acid with diorganotin dichloride and triorganotin chloride in 1:2 and 1:1 molar ratios, respectively. These reactions proceeded smoothly to completion and the complexes formed were characterized by elemental analysis, infrared, multinuclear NMR (^1H, ^{13}C, ^{119}Sn) and mass spectrometry. The biological activities of the tin complexes were studied by screening the compounds against various animal and plant pathogens. These results show that triorganotin(IV) carboxylates are more active against the animal and plant pathogens tested as compared to diorganotin dicarboxylates.
Fast Oxidation Of Lactams To Cyclic Imides Using Microwave Irradiation, Avat Arman Taherpour, Hamid Reza Mansuri
Fast Oxidation Of Lactams To Cyclic Imides Using Microwave Irradiation, Avat Arman Taherpour, Hamid Reza Mansuri
Turkish Journal of Chemistry
Since polar reactants can adsorb microwave irradiation, chemists can utilize the microwave oven for some organic reactions. In this paper, we report a rapid conversion of lactams to cyclic imides using peracetic acid (CH_3-CO_3H) and manganic chloride (MnCl_2) in ethyl acetate (CH_3-COOEt) as a solvent and under microwave irradiation (90 W, 5 min) in good yields.
Synthesis Of Some New Dihalophenyl- And Dihalobenzylisocoumarins And Their (Dl)-3,4-Dihydroderivatives, Zahid Shafiq, Muhammad Arfan, Nasim Hasan Rama, Shahid Hameed, Ghulam Abbas, Muhammad Tahir Hussain
Synthesis Of Some New Dihalophenyl- And Dihalobenzylisocoumarins And Their (Dl)-3,4-Dihydroderivatives, Zahid Shafiq, Muhammad Arfan, Nasim Hasan Rama, Shahid Hameed, Ghulam Abbas, Muhammad Tahir Hussain
Turkish Journal of Chemistry
3-Dihalophenyl- and dihalobenzylisocoumarins (3a-c) were synthesized by condensation of homophthalic acid (1) with dihalobenzoyl- and dihalophenylacetyl chlorides (2a-c), respectively. The alkaline hydrolysis of these isocoumarins (2a-c) afforded keto-acids (4a-c). (dl)-3-(Dihalophenyl)- and (dl)-3-(dihalobenzyl)- 3,4-dihydroisocoumarins (6a-c) were obtained by reduction of keto-acids (4a-c) to racemic hydroxy-acids (5a-c) followed by cyclodehydration using acetic anhydride.
Pyranocoumarins From Seseli Gummiferum Subsp. Corymbosum Growing In Turkey, Alev Tosun, Nazi̇re Özkal, Masaki Baba, Toru Okuyama
Pyranocoumarins From Seseli Gummiferum Subsp. Corymbosum Growing In Turkey, Alev Tosun, Nazi̇re Özkal, Masaki Baba, Toru Okuyama
Turkish Journal of Chemistry
Seseli gummiferum Pall. ex Sm. subsp. corymbosum (Boiss. & Heldr.) P.H. Davis (Syn: S. corymbosum Boiss. & Heldr.) (Umbelliferae) collected in southern Anatolia was investigated for the presence of coumarins. A new angular-type pyranocoumarin, corymbocoumarin (1), along with 5 known coumarins (2-6) were isolated from the aerial parts of this plant. Corymbocoumarin (1) was established to be (-)-(3'S,4'S)-3' -acetoxy-4'-isovaleryloxy-3',4' -dihydroseselin (1) and coumarins 2-6 were identified as (-)-(3'S,4'S) -3'-acetoxy-4' -angeloyloxy-3' ,4' -dihydroseselin (2), (+)-(3' S,4' S)-3' -hydroxy-4' -angeloyloxy-3', 4' -dihydroseselin (d-laserpitin) (3), (-)-(3' S,4' S)-3' -angeloyloxy-4' -hydroxy-3', 4' -dihydroseselin (4), 3' -acetoxy-4' -isobutyloxy-3', 4' -dihydroseselin (5) and osthole (6), respectively, …
Determination Of Cadmium, Copper, Iron, Manganese, Lead And Zinc In Lichens And Botanic Samples By Electrothermal And Flame Atomic Absorption Spectrometry, Orhan Acar, Sümer Özvatan, Murat İli̇m
Determination Of Cadmium, Copper, Iron, Manganese, Lead And Zinc In Lichens And Botanic Samples By Electrothermal And Flame Atomic Absorption Spectrometry, Orhan Acar, Sümer Özvatan, Murat İli̇m
Turkish Journal of Chemistry
Within the framework of the International Atomic Energy Agency (IAEA) Analytical Quality Control Service (AQCS) Chemistry Unit a research program was initiated for the identification of trace elements such as Cd, Cu, Fe, Mn, Pb and Zn in IAEA lichen-338 for a proficiency test (PT). This was to evaluate the possibility of using lichens as biomonitors of trace elements in atmospheric pollution. Pyrolysis and atomization temperatures, atomization and background profiles, detection limits and characteristic masses of analytes in lichen samples with Ni, Ni + Pd and Ni + Pd + tartaric acid (TA) modifier mixture, and without any modifiers were …
Mechanism And Kinetics Of Copper(Ii) Transport Through A Liquid Membrane Containing A Dithiophosphonate Derivative As Carrier, H. Korkmaz Alpoğuz, Ahmet Kaya, Mehmet Karakuş
Mechanism And Kinetics Of Copper(Ii) Transport Through A Liquid Membrane Containing A Dithiophosphonate Derivative As Carrier, H. Korkmaz Alpoğuz, Ahmet Kaya, Mehmet Karakuş
Turkish Journal of Chemistry
The transport of Cu(II) ions from an aqueous solution into an aqueous receiving solution through a bulk liquid membrane containing a dithiophosphonate derivative (1) as a carrier was examined. The kinetic parameters were analyzed assuming 2 consecutive, irreversible first-order reactions. The influence of temperature and stirring rate on the kinetic parameters (k_1, k_2, R_m^{max}, t_{max}, J_d^{max} and J_a^{max}) was also investigated. The membrane entrance rate, k_1, and the membrane exit rate, k_2, increased with increasing temperature and stirring rate. For the maximum membrane exit flux, J_a^{max}, the activation energy was determined from the slope of the linear Arrhenius relationship to …
Anodic Stripping Voltammetric Behavior Of Mercury In Chloride Medium And Its Determination At A Gold Film Electrode, Füsun Okçu, F. Ni̇l Ertaş, H. İsmet Gökçel, Hüseyi̇n Tural
Anodic Stripping Voltammetric Behavior Of Mercury In Chloride Medium And Its Determination At A Gold Film Electrode, Füsun Okçu, F. Ni̇l Ertaş, H. İsmet Gökçel, Hüseyi̇n Tural
Turkish Journal of Chemistry
The electrochemical behavior of aqueous Hg(II) ions at a gold film electrode is described. The effects of supporting electrolyte and halide ions on the anodic stripping voltammetric behavior of Hg(II) ions was illustrated to prepare a basis for the analysis in real samples with high saline content. The concentration ratio of metallic mercury to halide ions at the electrode surface determines the resulting peak characteristics. The peak potentials in particular shift in a more negative direction as the halide concentration increases. A comparative study with Cu(II) ions revealed that a different mechanism is involved in their reoxidation steps. Mercuric ions …
Design And Characterization Of Amino And Chloro Functionalized Rhombohedral Silsesquioxanes, Ahmet Gültek, Turgay Seçki̇n, Hali̇l İbrahi̇m Adigüzel
Design And Characterization Of Amino And Chloro Functionalized Rhombohedral Silsesquioxanes, Ahmet Gültek, Turgay Seçki̇n, Hali̇l İbrahi̇m Adigüzel
Turkish Journal of Chemistry
A more rapid and a versatile synthetic approach for the preparation of polyhedral silsesquioxanes (POSS) by hydrolytic condensation of organosilicon monomers in the presence of a Pt catalyst was studied. The structural properties of POSS molecules were determined by X-ray powder diffraction analysis, yielding a rhombohedral unit cell with a = 11,52796Å and \alpha = 94,9754° for octaaminopropyl-POSS, and a rhombohedral unit cell with a = 11,51421Å, \alpha = 96,7214° for octachloropropyl-POSS. The activation energies were found to be 64.8, and 89.1 kJ/mol for octaaminopropyl-POSS and octachloropropyl-POSS, respectively. The products were also characterized by Fourier transform infrared spectroscopy, ^1H and …
Synthesis Of Novel Proponohydrazides And Their Hydrolysis Reactions, Mustafa Saçmaci, Emi̇n Saripinar, Yunus Akçamur
Synthesis Of Novel Proponohydrazides And Their Hydrolysis Reactions, Mustafa Saçmaci, Emi̇n Saripinar, Yunus Akçamur
Turkish Journal of Chemistry
4-(4-Methoxybenzoyl)-5-(4-methoxyphenyl)-2,3-furandione 1 reacted with N-aryl substituted phenylhydrazones 3a-h via the p,p'-dimethoxydibenzoylketene intermediate 2 giving the proponohydrazide derivatives 5a-h. In addition, compounds 5a-h were converted into corresponding pyrazolone derivatives 7i,j by the reactions of hydrolysis in acidic solution. The structures of these new synthesized compounds were determined by ^{13}C NMR, ^1H NMR and IR spectroscopic data and elemental analysis.
Synthesis Of Mannich Bases Of Some 2,5-Disubstituted 4-Thiazolidinones And Evaluation Of Their Antimicrobial Activities, Handan Altintaş, Öznur Ateş, Seher Bi̇rteksöz, Gülten Ötük, Meltem Uzun, Di̇lek Şanata
Synthesis Of Mannich Bases Of Some 2,5-Disubstituted 4-Thiazolidinones And Evaluation Of Their Antimicrobial Activities, Handan Altintaş, Öznur Ateş, Seher Bi̇rteksöz, Gülten Ötük, Meltem Uzun, Di̇lek Şanata
Turkish Journal of Chemistry
4-Carbethoxymethyl-2-[(\alpha -chloropropionyl/\alpha -bromobutyryl/\alpha-chloro-(\alpha-phenyl)acetyl)amino]thiazoles (2a-c) were synthesized by the reaction of 4-carbethoxymethyl-2-aminothiazole (1) with \alpha-chloropropionyl chloride, \alpha-bromobutyryl bromide and \alpha-chloro-\alpha -phenylacetyl chloride, respectively, which were then refluxed with ammonium thiocyanate to obtain 5-substituted 2-[(4-carbethoxymethylthiazol-2-yl)imino]-4-thiazolidinones (3a-c). 3a-c were stirred with formaldehyde and various secondary amines to gain 15 novel compounds with the structure 5-substituted 5-(N,N-disubstituted aminomethyl)-2-[(4-carbethoxymethylthiazol-2-yl)imino]-4- thiazolidinones (4a-o). The antibacterial activities of the compounds against S. aureus ATCC 6538, S. epidermidis ATCC 12228, E. coli ATCC 8739, K. pneumoniae ATCC 4352, P. aeruginosa ATCC 1539, S. typhi, Sh. flexneri and Pr. mirabilis ATCC 14153 were tested using disk diffusion, while the antifungal …
O-Galloyl Flavonoids From Geranium Pyrenaicum And Their In Vitro Antileishmanial Activity, Di̇lek Erci̇l, Maeki Kaloga, Oliver A. Radtke, M. Koray Sakar, Albrecht F. Kiderlen, Herbert Kolodziej
O-Galloyl Flavonoids From Geranium Pyrenaicum And Their In Vitro Antileishmanial Activity, Di̇lek Erci̇l, Maeki Kaloga, Oliver A. Radtke, M. Koray Sakar, Albrecht F. Kiderlen, Herbert Kolodziej
Turkish Journal of Chemistry
From the aerial parts of Geranium pyrenaicum Burm., a new flavonol glycoside, kaempferol 3-O-(2'',3''-di-O-galloyl)-{\ss}-D-glucopyranoside (7), along with 6 known related glycosides [kaempferol 3-O-\beta-D-glucopyranoside (1), quercetin 3-O-\beta-D-glucopyranoside (2), quercetin 3-O-\beta-D-galactopyranoside (3), kaempferol 3-O-(2''-O-galloyl)-\beta-D-glucopyranoside (4), quercetin 3-O-(2''-O-galloyl)-\beta-D-glucopyranoside (5) and quercetin 3-O-(2'',3''-di-O-galloyl)-{\ss}-D-glucopyranoside (6)] and the ellagitannins corilagin (8) and tellimagrandin I (9) were isolated. Their structures were established from spectroscopic studies (UV, FAB-MS, ^1H and ^{13}C-NMR, ^1H-^1H COSY, HETCOR, HMBC). Compounds 1-7 were evaluated for antileishmanial activity against a panel of Leishmania species (L. major, L. donovani and L. amazonensis), indicating appreciable in vitro activities (IC_{50} 4-27 nM) when compared with Pentostam (IC_{50} …
New Alkoxyzinc Salts Mediated Chemoselective Transesterification Reactions, Necdet Coşkun, Mustafa Er
New Alkoxyzinc Salts Mediated Chemoselective Transesterification Reactions, Necdet Coşkun, Mustafa Er
Turkish Journal of Chemistry
A new chemoselective method for the transesterification of alkyl esters in the presence of in situ formed alkoxyzinc salts was developed. Electron-rich esters are less reactive than electron poor ones and this is the basis for the chemoselectivity of the reaction. Suggested mechanisms of the transesterification reactions are discussed.
The Effect Of Silane Modification On The Adsorptive Properties Of Natural Pyrophyllite And Synthetic Titanium-Based Powders Prepared By The Sol-Gel Process, Şadi̇ye Şener, Murat Erdemoğlu, Meltem Asi̇ltürk, Hi̇kmet Sayilkan
The Effect Of Silane Modification On The Adsorptive Properties Of Natural Pyrophyllite And Synthetic Titanium-Based Powders Prepared By The Sol-Gel Process, Şadi̇ye Şener, Murat Erdemoğlu, Meltem Asi̇ltürk, Hi̇kmet Sayilkan
Turkish Journal of Chemistry
Our aim was to improve the relatively poor adsorption characteristics of natural pyrophyllite and those of TiO_m and Ti(OR)_x(OH)_y(O)_z obtained from titanium tetraisopropoxide (TTIP) by the sol-gel process. For this purpose, the surfaces of the above-mentioned adsorbents were coated with a surface modifier by dipping them in 1% and 50% (w/w) solutions of N-(2-aminoethyl)-3- aminopropyltrimethoxysilane (DIAMO) in methanol. Realization of the coating processes was checked by FT-IR and SEM analyses. FT-IR analyses of the coated powders heat treated at 110 °C showed that condensation took place between OH groups of prehydrolyzed silane molecules and hydroxyl groups and/or oxygen atoms on …
Miscibility Of Methylmethacrylate-Co-Methacrylic Acid Polymer With Magnesium, Zinc, And Manganese Sulfonated Polystyrene Ionomers, Cemi̇l Alkan, Nebahat Yurtseven, Leyla Aras
Miscibility Of Methylmethacrylate-Co-Methacrylic Acid Polymer With Magnesium, Zinc, And Manganese Sulfonated Polystyrene Ionomers, Cemi̇l Alkan, Nebahat Yurtseven, Leyla Aras
Turkish Journal of Chemistry
The miscibility of methyl methacrylate-co-methacrylic acid polymer (MMA-MAA) with metal neutralized sulfonated polystyrene ionomers was investigated by viscometry, differential scanning calorimetry (DSC), and Fourier transform infrared radiation spectroscopy (FTIR) techniques. Polystyrene (PS) was sulfonated by acetic anhydride and sulfuric acid and the sulfonation degree was found to be 2.6 mole percent, and 2.6 mole percent sulfonated polystyrene was neutralized by Mg, Zn, and Mn salts. The miscibility behavior of the blends of MMA-MAA with Mg neutralized 2.6 mole% sulfonated polystyrene (2.6MgSPS), Mn neutralized 2.6mole% sulfonated polystyrene (2.6MnSPS), and Zn neutralized 2.6 mole% sulfonated polystyrene (2.6ZnSPS) was investigated by dilute solution …
The Electroanalytical Determination Of Sodium Borohydride Using A Gold Electrode, Hüseyi̇n Çeli̇kkan, Hasan Aydin, M. Levent Aksu
The Electroanalytical Determination Of Sodium Borohydride Using A Gold Electrode, Hüseyi̇n Çeli̇kkan, Hasan Aydin, M. Levent Aksu
Turkish Journal of Chemistry
It was shown that square wave voltammetry, a technique with a much lower detection limit, could be successfully used in the detection of borohydride formed in alkaline medium. A Au electrode was found to be very suitable for this purpose. The detection limit was 3 x 10^{-5} M.
Analysis Of The Essential Oil Composition Of Sideritis Albiflora Using Direct Thermal Desorption And Headspace Gc-Ms Techniques, Gülaçti Topçu, Asli Barla, Ahmet C. Gören, Gökhan Bi̇lsel, Mi̇ne Bi̇lsel, Gülendam Tümen
Analysis Of The Essential Oil Composition Of Sideritis Albiflora Using Direct Thermal Desorption And Headspace Gc-Ms Techniques, Gülaçti Topçu, Asli Barla, Ahmet C. Gören, Gökhan Bi̇lsel, Mi̇ne Bi̇lsel, Gülendam Tümen
Turkish Journal of Chemistry
The main constituents of Sideritis albiflora were found to be trans-caryophyllene, \alpha-pinene, \beta-pinene, \gamma-cadinene, pulegone, and caryophyllene oxide by both thermal desorption GC/MS and headspace GC/MS techniques.
Selective Oxidation Of Thiols To Disulfides Catalyzed By Iron(Iii) -- Tetra Phenyl Porphyrin Using Urea-Hydrogen Peroxide As Oxidizing Reagent, Bahador Karimi, Morteza Montazerozohori, Majid Moghadam, Mohammad Hosein Habibi, Khodabakhsh Niknam
Selective Oxidation Of Thiols To Disulfides Catalyzed By Iron(Iii) -- Tetra Phenyl Porphyrin Using Urea-Hydrogen Peroxide As Oxidizing Reagent, Bahador Karimi, Morteza Montazerozohori, Majid Moghadam, Mohammad Hosein Habibi, Khodabakhsh Niknam
Turkish Journal of Chemistry
Oxidation of thiols to disulfides catalyzed by iron(III) -- tetra phenyl prophyrin Fe (TPP)Cl was investigated using urea-hydrogen peroxide adduct (UHP) as an oxidant in methanol as a solvent.
An Unusual Pentacyclic Dinitrogenous Alkaloid From Galanthus Gracilis, Nehi̇r Ünver, Gülen İrem Kaya
An Unusual Pentacyclic Dinitrogenous Alkaloid From Galanthus Gracilis, Nehi̇r Ünver, Gülen İrem Kaya
Turkish Journal of Chemistry
A minor alkaloid, namely gracilamine, was isolated from Galanthus gracilis. This was the first example of a pentacyclic dinitrogenous alkaloid isolated from a member of Amaryllidaceae. The structure of this alkaloid was elucidated by means of comprehensive spectroscopic methods (1D and 2D NMR, MS, UV, IR).
Polyphenolic Compounds And Antimicrobial Activity Of Quercus Aucheri Leaves, Mahmut Koray Sakar, Di̇dem Şöhretoğlu, Meral Özalp, Meli̇ke Eki̇zoğlu, Sonia Piacente, Cosimo Pizza
Polyphenolic Compounds And Antimicrobial Activity Of Quercus Aucheri Leaves, Mahmut Koray Sakar, Di̇dem Şöhretoğlu, Meral Özalp, Meli̇ke Eki̇zoğlu, Sonia Piacente, Cosimo Pizza
Turkish Journal of Chemistry
Chromatographic studies (CC, VLC, MPLC, and PTLC) on ethyl acetate extract from the leaves of Quercus aucheri yielded 2 flavonoids (quercetin 3-O-\alpha-L-arabinopyranoside (1), quercetin 3-O-\beta-D-galactopyranoside (2)) and 2 tannin precursors and a procyanidin [(isolated as peracetates of (+)-catechin (3a), (+)-gallocatechin (4a) and epicatechin-(4\beta \to 8)-catechin (5a))]. The structures of the compounds were elucidated by UV, 1D-NMR (^1H, ^{13}C, TOCSY) and 2D-NMR (COSY, HSQC, HMBC) techniques. Different extracts (80% MeOH, EtOAc, n-BuOH and H_2O) from the leaves of Q. aucheri were investigated for their antimicrobial activity against 2 Gram-positive and 2 Gram-negative bacteria and 3 yeast-like fungi by a broth microdilution …
Catalytic Oxidation Properties And Characterization Of Lasrco_{0.9}B'_{0.1}O_4 (B'= Mn, Fe, Ni, Cu) Mixed Oxides, Laitao Luo, Guangxin Shao, Zhanhui Duan
Catalytic Oxidation Properties And Characterization Of Lasrco_{0.9}B'_{0.1}O_4 (B'= Mn, Fe, Ni, Cu) Mixed Oxides, Laitao Luo, Guangxin Shao, Zhanhui Duan
Turkish Journal of Chemistry
Using a polyacrylamide gel method, a series of LaSrCo_{0.9}B'_{0.1}O_4 (B'= Mn, Fe, Ni, Cu) mixed oxides were prepared and their catalytic activity was studied with CO and C_3H_8 oxidations as a testing reaction. The results show that the specific effects of B' ions on CO and C_3H_8 oxidations depend on their category. In comparison to LaSrCoO_4 catalyst, the activity of LaSrCo_{0.9}Ni_{0.1}O_4 catalyst for CO and C_3H_8 oxidations is higher, while only lower activity is obtained for Mn, Fe or Cu-doped catalysts. The information derived from TPD, XRD and iodometry experiments shows that the increase in oxidation activity of LaSrCo_{0.9}Ni_{0.1}O_4 catalyst …
Interpretation Of Sorption Kinetics For Mixtures Of Reactive Dyes On Wool, Eli̇f Şahi̇n
Interpretation Of Sorption Kinetics For Mixtures Of Reactive Dyes On Wool, Eli̇f Şahi̇n
Turkish Journal of Chemistry
The equilibrium sorption isotherms of 3 reactive dyes (C. I. Reactive Yellow 84, C. I. Reactive Red 141, C. I. Reactive Blue 160) and their binary mixtures adsorbed on prewetted wool fiber were investigated. The kinetic studies were carried out at pH \le 7 and 80 °C in dye solutions containing 20 g/L NaCl. It was reported that binary mixtures of these reactive dyes have lower sorption values than the dyes alone, at the same dye concentration, pH and temperature. The isotherms obtained are Langmuir type. The rate parameters of adsorption kinetics decrease with increasing dye concentration.
Investigation Of Electron Transfer Reaction Between Diphenylbenzidine And Ascorbic Acid, Iftikhar Imam Naqvi, Abida Perveen
Investigation Of Electron Transfer Reaction Between Diphenylbenzidine And Ascorbic Acid, Iftikhar Imam Naqvi, Abida Perveen
Turkish Journal of Chemistry
The kinetics of the reduction of diphenylbenzidine by ascorbic acid were investigated in the pH range 3.5 to 5.0. Diphenylbenzidine was prepared by the oxidation of diphenylamine with cerium(IV) sulfate tetra hydrate. The order of the reaction with respect to each of the reactants, i.e ascorbic acid (ASC), diphenylbenzidine (DPB) and H^+ ,was found to be first. The following rate law is recommended: Rate = {k_1 [C_{12}H_{10}N_2C_{12}H_{10}] + k_2K [C_{12}H_{10}N_2C_{12}H_{10}][H^+]}[C_6H_8O_6] where k_1 and k_2 have the values of 2.0 \times 10^4 dm^3mol^{-1} s^{-1} and 6.58 \times 10^3 dm^3.mol^{-1}.s^{-1} , respectively. K is the protonation constant of DPB, having a value …