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Articles 16141 - 16170 of 17310
Full-Text Articles in Entire DC Network
Zno Nanoflake Arrays Prepared Via Anodization And Their Performance In The Photodegradation Of Methyl Orange, Huey-Shya Goh, Rohana Adnan, Muhammad Akhyar Farrukh
Zno Nanoflake Arrays Prepared Via Anodization And Their Performance In The Photodegradation Of Methyl Orange, Huey-Shya Goh, Rohana Adnan, Muhammad Akhyar Farrukh
Turkish Journal of Chemistry
In the present work, anodization of zinc foil was investigated in a mixed electrolyte of ammonium sulfate and sodium hydroxide under the influence of different anodization times and concentrations of the electrolyte while the temperature and voltage were kept constant. The ZnO nanoflake arrays formed on Zn foil were characterized using a field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX) analysis, and X-ray diffraction (XRD). The size of the nanoflakes increased as the anodization time increased, while increasing the concentration of (NH_4)_2SO_4 increased the dissolution of the nanoflakes. Upon stirring, the nanoflakes that formed were more uniform …
One Pot Synthesis Of Pyridophenanthroline And Pyrrolophenanthroline Derivatives By Regioselective Reaction Between 1,7-Phenanthroline And Dialkyl Acetylenedicarboxylate: New Fused Heterocyclic Compounds, Malek Taher Maghsoodlou, Reza Heydari, Sayyed Mostafa Habibi Khorassani, Batool Tahami Pour, Ghasem Marandi, Farhad Maghfuri
One Pot Synthesis Of Pyridophenanthroline And Pyrrolophenanthroline Derivatives By Regioselective Reaction Between 1,7-Phenanthroline And Dialkyl Acetylenedicarboxylate: New Fused Heterocyclic Compounds, Malek Taher Maghsoodlou, Reza Heydari, Sayyed Mostafa Habibi Khorassani, Batool Tahami Pour, Ghasem Marandi, Farhad Maghfuri
Turkish Journal of Chemistry
1,7-Phenanthroline reacts with dialkyl acetylenedicarboxylate in a regioselective manner to give new macromolecules such as tetramethyl- 6aH-pyrido[1,2-i][1,7]phenanthroline-7,8,9,10-tetracarboxylate and trialkyl pyrrolo[1,2-i][1,7]phenanthroline-7,8,9-tricarboxylate derivatives.
Voltammetric Behavior Of Indole-3-Acetic Acid And Kinetin At Pencil-Lead Graphite Electrode And Their Simultaneous Determination In The Presence Of Anionic Surfactant, Yavuz Yardim, Zühre Şentürk
Voltammetric Behavior Of Indole-3-Acetic Acid And Kinetin At Pencil-Lead Graphite Electrode And Their Simultaneous Determination In The Presence Of Anionic Surfactant, Yavuz Yardim, Zühre Şentürk
Turkish Journal of Chemistry
A method was developed for the simultaneous determination of indole-3-acetic acid (IAA) and kinetin, based on the oxidation of both phytohormones at a pencil-lead graphite electrode. The electrochemical behaviors were examined by cyclic, linear sweep, and square-wave voltammetry in the pH range of 2-12. In Britton-Robinson buffer solution (pH 6), the oxidation peaks of IAA and kinetin are well separated by square-wave voltammetry. By adding an anionic surfactant (sodium dodecylsulfate) in a concentration of 50 \mu M, the sensitivity of kinetin was increased significantly without reducing the resolution. The detection limits were 0.14 and 0.11 \mu M (24.53 and 23.67 …
Stable Ester And Amide Conjugates Of Some Nsaids As Analgesic And Antiinflammatory Compounds With Improved Biological Activity, Meci̇t Orhan Uludağ, Burcu Çalişkan Ergün, Duygu Asli Alkan, Ni̇lüfer Ercan, Güler Yağmur Özkan, Erden Banoğlu
Stable Ester And Amide Conjugates Of Some Nsaids As Analgesic And Antiinflammatory Compounds With Improved Biological Activity, Meci̇t Orhan Uludağ, Burcu Çalişkan Ergün, Duygu Asli Alkan, Ni̇lüfer Ercan, Güler Yağmur Özkan, Erden Banoğlu
Turkish Journal of Chemistry
A set of ester and amide derivatives of some acidic NSAIDs, including ibuprofen, ketoprofen, and mefenamic acid (1-3), were synthesized and evaluated for their in vivo analgesic and antiinflammatory activity using the p-benzoquinone-induced writhing test and the carrageenan-induced paw edema model, respectively. Among the synthesized compounds, ester derivatives of ketoprofen showed especially potent analgesic and antiinflammatory activity as compared to the parent drug. In vitro chemical stability studies revealed that ester and amide derivatives were chemically stable in simulated gastric (pH 1.2) and intestinal fluids (pH 6.8). In 80\% human plasma, the ester derivatives were found to be relatively stable …
Synthesis And Characterization Of New Symmetrical 3,6-Bis[(25,26,27- Tripropoxy-28-(3-(4-Iodophenyl) Propoxy)-P-Tert-Butyl Calix[4]Arene Ethynyl]-9h- Fluoren-9-One By Sonogashira Coupling As A Novel Precursor For Synthesis Of Quinodimethane (Qdm), Karim Akbari Dilmaghani, Fazel Nasuhi Pur
Synthesis And Characterization Of New Symmetrical 3,6-Bis[(25,26,27- Tripropoxy-28-(3-(4-Iodophenyl) Propoxy)-P-Tert-Butyl Calix[4]Arene Ethynyl]-9h- Fluoren-9-One By Sonogashira Coupling As A Novel Precursor For Synthesis Of Quinodimethane (Qdm), Karim Akbari Dilmaghani, Fazel Nasuhi Pur
Turkish Journal of Chemistry
Novel symmetrical 3,6-bis[(25,26,27-tripropoxy-28-(3-(4-iodophenyl)propoxy)-p-tert-butyl calix[4]arene ethynyl]-9H-fluoren-9-one with a cone conformation was synthesized by palladium-catalyzed coupling of (25,26,27-tripropoxy- 28-(3-(4-iodophenyl)propoxy)-p-tert-butyl calix[4]arene and 3,6-diethynyl-9H-fluoren-9-one. Its structure was confirmed by FT-IR, ^1H-NMR, and ^{13}C-NMR spectroscopy, and elemental analysis and positive ion FAB mass spectrometry.
Qsar And Docking Studies Of Inhibition Activity Of 5,6-Dihydro 11-Alkylbenzo[\Alpha]Carbazole Derivatives Against Estrogen Receptor, Tuğba Taşkin, Fatma Sevi̇n
Qsar And Docking Studies Of Inhibition Activity Of 5,6-Dihydro 11-Alkylbenzo[\Alpha]Carbazole Derivatives Against Estrogen Receptor, Tuğba Taşkin, Fatma Sevi̇n
Turkish Journal of Chemistry
In the present study, QSAR and docking studies were applied to understand the nature of 5,6-dihydro 11-alkylbenzo[\alpha]carbazole derivatives and to investigate the interactions of homolog series with binding sites on selected a-chains of human estrogen receptors (hER). The best QSAR model was selected, having the correlation coefficient r = 0.924, squared correlation coefficient r^2 = 0.854, standard deviation s = 0.357, and cross-validated squared correlation coefficient Q^2 = 0.755. The QSAR model indicated that the descriptors E-HOMO and heat of formation play an important role in human estrogen receptor inhibitor activities. A docking study was also utilized to visualize the …
Electrocatalytic Oxidation Of Ethanol On Various Metal Ad-Layer Modified Au(111) Electrodes In Alkaline Solution, Zekerya Dursun, Şükri̇ye Ulubay Karabi̇beroğlu, Buket Gelmez, Aydan Başaran
Electrocatalytic Oxidation Of Ethanol On Various Metal Ad-Layer Modified Au(111) Electrodes In Alkaline Solution, Zekerya Dursun, Şükri̇ye Ulubay Karabi̇beroğlu, Buket Gelmez, Aydan Başaran
Turkish Journal of Chemistry
Ethanol oxidation was studied on single-crystal Au(111) electrodes that were modified by platinum, palladium, and cadmium metal ad-layers. The metal ad-layer modification was carried out by the underpotential deposition process, in which controlled amounts of Pt, Pd, and Cd were electrodeposited onto the substrate as submonolayer or monolayer coverage. The activity of the metal ad-layer modified Au(111) electrodes toward ethanol oxidation was studied in alkaline media, and recorded voltammograms were compared to those of bare single crystal Au(111) and polycrystalline gold and platinum disk electrodes. In terms of the desired shift in reduction potential and increased current density, the best …
Chemical Composition And Antimicrobial Activity Of The Essential Oils Of Geranium Columbinum L. And G. Lucidum L. (Geraniaceae), Niko Radulovic, Milan Dekic, Zorica Stojanovic-Radic, Radosav Palic
Chemical Composition And Antimicrobial Activity Of The Essential Oils Of Geranium Columbinum L. And G. Lucidum L. (Geraniaceae), Niko Radulovic, Milan Dekic, Zorica Stojanovic-Radic, Radosav Palic
Turkish Journal of Chemistry
The chemistry of Geranium columbinum and G. lucidum volatiles has been studied here for the first time. The essential oils were obtained by hydrodistillation, analyzed by GC and GC-MS, and screened for their in vitro antibacterial and antifungal activity in a microdilution assay. In total, 172 constituents were identified, accounting for 88.1%-96.7% of the detected GC peak areas. The essential oils consisted mainly of fatty acids and fatty acid-derived compounds (65.0%-86.3%). The major compounds of the essential oils were hexadecanoic acid, hexahydrofarnesyl acetone, and tetracosane. The antimicrobial assay showed a strong activity of the oil from aerial parts of G. …
In Silico Design Of Novel And Highly Selective Lysine-Specific Histone Demethylase Inhibitors, Ebru Demet Akdoğan, Burak Erman, Kemal Yelekçi̇
In Silico Design Of Novel And Highly Selective Lysine-Specific Histone Demethylase Inhibitors, Ebru Demet Akdoğan, Burak Erman, Kemal Yelekçi̇
Turkish Journal of Chemistry
Histone lysine-specific demethylase (LSD1) is involved in a wide range of epigenetic processes and plays important roles in gene silencing, DNA transcription, DNA replication, DNA repair, and heterochromatin formation. Its active site shows a resemblance to those of 2 homologous enzymes, monamine oxidase A and B (MAO-A and MAO-B.) In the present work, starting from suitable scaffolds and generating thousands of structures from them, 10 potential inhibitors were obtained with structural and physicochemical properties selectively suitable for inhibiting LSD1. iLib Diverse software was used to generate the diverse structures and 3 docking tools, CDOCKER, GOLD, and AutoDock, were used to …
Bromination Of 2,3-Dihydrobenzobarrelene And Synthesis Of Its Mono- And Dibromide Derivatives: Unexpected Wagner-Meerwein Rearrangement On Silica Gel, Selçuk Eşsi̇z, Mehmet Emi̇n Şengül, Ertan Şahi̇n, Ari̇f Daştan
Bromination Of 2,3-Dihydrobenzobarrelene And Synthesis Of Its Mono- And Dibromide Derivatives: Unexpected Wagner-Meerwein Rearrangement On Silica Gel, Selçuk Eşsi̇z, Mehmet Emi̇n Şengül, Ertan Şahi̇n, Ari̇f Daştan
Turkish Journal of Chemistry
The bromination reaction of dihydrobenzobarrelene under different conditions was studied. The bromination reaction of dihydrobenzobarrelene with molecular bromine gave only a Wagner-Meerwein rearrangement product by aryl and alkyl migration. Its high-temperature bromination reaction resulted in the formation of normal addition products besides rearrangement products. The bromination reaction of the alkene with 1,2- dibromotetrachloroethane (DBTCE) gave a non-rearrangement product as the sole product. The synthesis and bromination reaction of 2-bromodihydrobenzobarrelene was also studied. An unexpected Wagner-Meerwein rearrangement was observed on silica gel during the column chromatography of isomeric tribromides. Herein, we report the results of the synthesis, and the X-ray crystal …
Synthesis Of Novel Tetraoxime Derivative With Hydrazone Side Groups And Its Metal Complexes, İlknur Babahan, Hüseyi̇n Anil, Nursabah Sarikavakli
Synthesis Of Novel Tetraoxime Derivative With Hydrazone Side Groups And Its Metal Complexes, İlknur Babahan, Hüseyi̇n Anil, Nursabah Sarikavakli
Turkish Journal of Chemistry
In this study, the synthesis of a novel tetraoxime (LH_4) derivative containing hydrazone side groups, and its transition metal complexes with Ni(II), Cu(II), Co(II), and Zn(II) ions, were reported. The ligand was synthesized by reacting anti-glyoximehydrazine (GH_2) with terephthaldialdehyde. Polymeric complexes with Ni(II) and Co(II) and binuclear complexes with Cu(II) and Zn(II) of this tetraoxime were isolated. Structural assignments were supported by a combination of ^1H-NMR, ^{13}C-NMR, HMQC, FT-IR, UV-Vis, thermogravimetric analysis (TGA), molar conductances, elemental analyses, and magnetic susceptibility.
Enantioselective Henry Reaction Catalyzed By A Novel L-(+)-Aspartic Acid-Derived Schiff Base Ligand And Cu(Ii) Ion, Gamze Koz, Demet Astley, Stephen Thomas Astley
Enantioselective Henry Reaction Catalyzed By A Novel L-(+)-Aspartic Acid-Derived Schiff Base Ligand And Cu(Ii) Ion, Gamze Koz, Demet Astley, Stephen Thomas Astley
Turkish Journal of Chemistry
Mild and efficient enantioselective Henry reactions of nitromethane with various aldehydes were catalyzed by a novel L-(+)-aspartic acid-derived Schiff base ligand in the presence of Cu(II) ions, affording the corresponding adducts in high yields (up to 96%) and enantioselectivities (up to 92% ee).
Constituents Of Plantago Major Subsp. Intermedia With Antioxidant And Anticholinesterase Capacities, Ufuk Kolak, Mehmet Boğa, Emi̇ne Akalin Uruşak, Ayhan Ulubelen
Constituents Of Plantago Major Subsp. Intermedia With Antioxidant And Anticholinesterase Capacities, Ufuk Kolak, Mehmet Boğa, Emi̇ne Akalin Uruşak, Ayhan Ulubelen
Turkish Journal of Chemistry
The methanol extract of Plantago major subsp. intermedia (Gilib.) Lange afforded 4 known compounds, namely isomartynoside (1), 10-hydroxymajoroside (2), \beta -sitosterol (3), and ursolic acid (4). Their structures were established by spectroscopic methods. After determination of the total phenolic and flavonoid contents of the methanol extract, the antioxidant potentials of the crude extract and isolated compounds 1-4 were determined by \beta -carotene bleaching, DPPH free radical and ABTS cation radical scavenging, and cupric reducing antioxidant capacity methods. The methanol extract, rich in phenolic contents, indicated the same DPPH free radical scavenging activity (72\% inhibition) as a standard compound, butylated hydroxytoluene, …
Synthesis Of New Substituted 2,2-Bis-(3,5-Di-T-Butyl-4-Hydroxybenzyl)Benzocycloalkanones, Bromopropiophenones, And Their Alcohol Analogs, Jabbar Khalafy, Mehdi Rimaz, Sara Taghinejhad, Mirzagha Babazadeh
Synthesis Of New Substituted 2,2-Bis-(3,5-Di-T-Butyl-4-Hydroxybenzyl)Benzocycloalkanones, Bromopropiophenones, And Their Alcohol Analogs, Jabbar Khalafy, Mehdi Rimaz, Sara Taghinejhad, Mirzagha Babazadeh
Turkish Journal of Chemistry
A new series of substituted 2,2-bis-(3,5-di-t-butyl-4-hydroxybenzyl) benzocycloalkanones, bromopropiophenones, and their alcohol analogs were synthesized. The corresponding alcohols may act as potential allosteric modulators of GABA_B receptors.
Antioxidant Phenolics From Lobaria Pulmonaria (L.) Hoffm. And Usnea Longissima Ach. Lichen Species, Fadi̇me Atalay, Mesut Bünyami̇ Halici, Ahmet Mavi̇, Ahmet Çakir, Fehmi̇ Odabaşoğlu, Cavi̇t Kazaz, Ali̇ Aslan, Ömer İrfan Küfrevi̇oğlu
Antioxidant Phenolics From Lobaria Pulmonaria (L.) Hoffm. And Usnea Longissima Ach. Lichen Species, Fadi̇me Atalay, Mesut Bünyami̇ Halici, Ahmet Mavi̇, Ahmet Çakir, Fehmi̇ Odabaşoğlu, Cavi̇t Kazaz, Ali̇ Aslan, Ömer İrfan Küfrevi̇oğlu
Turkish Journal of Chemistry
In this study, 1 steroidal and 8 phenolic compounds from Lobaria pulmonaria (L.) Hoffm. and Usnea longissima Ach. were isolated and their chemical structures were characterized by ^1H-NMR, ^{13}C-NMR, DEPT, ^1H-^1H COSY, HMQC, HMBC, IR, UV, and MS spectroscopic methods as stictic acid, isidiophorin, rhizonaldehyde, rhizonyl alcohol, pulmonarianin, vesuvianic acid, ergosterol peroxide, usnic acid, and diffractaic acid. Among these compounds, pulmonarianin, isolated from L. pulmonaria, was characterized for the first time as a natural compound. In addition to isolation and characterization, the lipid peroxidation inhibition and DPPH radical scavenging activities of the isolated compounds were investigated. Among these compounds, isidiophorin, …
Solidified Floating Organic Drop Microextraction And Spectrophotometric Determination Of Vanadium In Water Samples, Shayessteh Dadfarnia, Ali Mohammad Haji Shabani, Akram Mirshamsi
Solidified Floating Organic Drop Microextraction And Spectrophotometric Determination Of Vanadium In Water Samples, Shayessteh Dadfarnia, Ali Mohammad Haji Shabani, Akram Mirshamsi
Turkish Journal of Chemistry
Solidified floating organic drop microextraction (SFODME) was used as a sample preparation method prior to spectrophotometric determination of trace amounts of vanadium in water samples. 8-Hydroxyquinoline (oxine) was used as the chelating agent. The main parameters affecting the performance of SFODME, such as pH, concentration of oxine, extraction time, sample and organic phase volume, extraction temperature, and the nature of the organic solvent, were optimized. Under the optimized conditions, an enhancement factor of 38, detection limit of 0.97 \mu g L^{-1}, and good relative standard deviation of \pm 3.9% at 10 \mu g L^{-1} were obtained. The method was successfully …
Chemistry Of Dibenzobarallene, Moustafa A. Gouda, Moged A. Berghot, Khaled M. Elattar, Abd El Galil M. Khalil
Chemistry Of Dibenzobarallene, Moustafa A. Gouda, Moged A. Berghot, Khaled M. Elattar, Abd El Galil M. Khalil
Turkish Journal of Chemistry
This review represents a systematic and comprehensive survey of the methods of syntheses and chemical reactivity of dibenzobarallene. This compound is an important intermediate for the synthesis of useful and novel heterocycle systems.
In Situ Catalytic Activities Of 1,3-Dialkyltetrahydropyrimidinium Salts/[Rucl_2(P-Cymene)]_2 System For Transfer Hydrogenation Reactions, Emi̇ne Özge Özcan, Deni̇z Mercan, Nevi̇n Gürbüz, Engi̇n Çeti̇nkaya, Beki̇r Çeti̇nkaya, İsmai̇l Özdemi̇r
In Situ Catalytic Activities Of 1,3-Dialkyltetrahydropyrimidinium Salts/[Rucl_2(P-Cymene)]_2 System For Transfer Hydrogenation Reactions, Emi̇ne Özge Özcan, Deni̇z Mercan, Nevi̇n Gürbüz, Engi̇n Çeti̇nkaya, Beki̇r Çeti̇nkaya, İsmai̇l Özdemi̇r
Turkish Journal of Chemistry
Hydrogen-transfer reduction processes are attracting increasing interest from synthetic chemists in view of their operational simplicity. In the present study novel ruthenium carbene complexes were generated in situ and tested for their transfer hydrogenation reactions. The in situ prepared 3 component 1,3-dialkyltetrahydropyrimidinium salts (LHX)/[RuCl_2(p-cymene)]_2 and KOH catalyzed quantitatively the transfer hydrogenation of ketones under mild reaction conditions in 2-propanol.
Electrochemical Impedance Spectroscopy Study On Intercalation And Anomalous Diffusion Of Alcl_4^- Ions Into Graphite In Basic Molten Salt, Ali Ehsani, Mohammad Ghasem Mahjani, Majid Jafarian
Electrochemical Impedance Spectroscopy Study On Intercalation And Anomalous Diffusion Of Alcl_4^- Ions Into Graphite In Basic Molten Salt, Ali Ehsani, Mohammad Ghasem Mahjani, Majid Jafarian
Turkish Journal of Chemistry
Electrochemical impedance spectroscopy (EIS) was employed to investigate diffusion of AlCl_4^- ions in basic (AlCl_3-NaCl-KCl) molten salt. Nyquist plots in different DC offset potentials showed finite and restricted aluminum ion diffusion due to insertion and blocking in the graphite electrode. The general Warburg, open Warburg, and short Warburg impedance in the complex Nyquist plot of this system showed the anomalous diffusion behavior of the ions in the graphite electrode. The diffusion coefficient of the AlCl_4^- ions was calculated from the slope of the Warburg line in a totally blocking film in the graphite electrode and was found to be 2.8 …
Studies On The Mechanism Of Phosphazene Ring-Opening Polymerization (Rop), Selen Bi̇lge
Studies On The Mechanism Of Phosphazene Ring-Opening Polymerization (Rop), Selen Bi̇lge
Turkish Journal of Chemistry
In this study, the ring-opening polymerization (ROP) of cyclic trimer N_3P_3Cl_6 catalyzed by [Et_3Si(N_3 P_3Cl_6)][CHB_{11}H_5Br_6] (3) obtained from the reaction of N_3P_3Cl_6 (1) and Et_3Si(CHB_{11}H_5Br_6) (2) at room temperature was investigated. This provided a unique opportunity to explore the polymerization mechanism. The coordinatively unsaturated cation [N_3P_3Cl_5]^+ is responsible for the ROP of N_3P_3Cl_6, and is formed by the intramolecular elimination of Et_3SiCl from 3. The detection of Et_3SiCl by ^1H-NMR as the catalysis proceeded offers new evidence for the formation of [N_3P_3Cl_5]^+. The progress of the catalysis was followed using ^{31} P-NMR and revealed the build-up of a polymer. Cyclic …
Preparation And Characterization Of A Series Of Thiourea Derivatives As Phase Change Materials For Thermal Energy Storage, Cemi̇l Alkan, Yusuf Tek, Derya Kahraman
Preparation And Characterization Of A Series Of Thiourea Derivatives As Phase Change Materials For Thermal Energy Storage, Cemi̇l Alkan, Yusuf Tek, Derya Kahraman
Turkish Journal of Chemistry
A series of solid-liquid phase change materials, thiourea derivatives, were prepared via condensation of thiourea with the respective carboxyl chlorides (lauroyl chloride, myristoyl chloride, and palmitoyl chloride) and were then characterized by using FT-IR, ^1H-NMR, differential scanning calorimetry (DSC), and thermogravimetric (TG) analysis. The thiourea derivatives (1,3-didodecanoyl thiourea, 1,3-ditetradecanoyl thiourea, and 1,3-dihexadecanoyl thiourea) were structurally symmetric and had long alkyl groups to crystallize. Thermal analysis by DSC and spectroscopic investigation by FT-IR spectroscopy were performed on the samples before and after thermal cycling tests to determine thermal reliability. The maximum latent heats of melting and freezing of the thiourea derivatives …
Synthesis Of Starch-G-Poly(Acrylic Acid-Co-2-Hydroxy Ethyl Methacrylate) As A Potential Ph-Sensitive Hydrogel-Based Drug Delivery System, Mohammad Sadeghi
Synthesis Of Starch-G-Poly(Acrylic Acid-Co-2-Hydroxy Ethyl Methacrylate) As A Potential Ph-Sensitive Hydrogel-Based Drug Delivery System, Mohammad Sadeghi
Turkish Journal of Chemistry
The present work focused on the design of a drug delivery system (DDS) based on pH-sensitive hydrogel. The hydrogels were prepared via graft copolymerization of mixtures of acrylic acid (AA) and 2-hydroxy ethyl methacrylate (HEMA) onto starch backbones by a free radical polymerization technique. Sodium bicarbonate (NaHCO_3) was added to function as a foaming agent under acidic conditions, rendering the hydrogels to be porous. The porous structure of the hydrogel was essential in this system to yield a large surface area so that 5-fluorouracil (5-FU) release could be facilitated. The hydrogel, thus prepared, possessed a porous structure as determined by …
Electrocatalytic Oxidation Of Methanol At Pd And Pt Ad-Layer Modified Au(111) Electrodes In Alkaline Solution, Süleyman Koçak, Zekerya Dursun, Fatma Ni̇l Ertaş
Electrocatalytic Oxidation Of Methanol At Pd And Pt Ad-Layer Modified Au(111) Electrodes In Alkaline Solution, Süleyman Koçak, Zekerya Dursun, Fatma Ni̇l Ertaş
Turkish Journal of Chemistry
The electrochemical oxidation of methanol was investigated by using various ad-layer modified Au(111) electrodes in alkaline media in comparison to Au(111), polycrystalline Pd, and polycrystalline Pt electrodes. Catalytic activity of gold toward methanol oxidation has tended to increase in more alkaline media, as reflected in the oxidation peak in the concentration range of NaOH (0.1-3.0 M) studied here. The oxidation peak potential of methanol shifted to more negative potentials, indicating a pH-dependent surface reaction. Among the electrodes studied, single-crystal gold electrode surfaces modified with Pd and Pt ad-layers displayed the highest catalytic activity for methanol oxidation. Additional shifts of about …
A New And Simple Procedure For The Polarographic Speciation And Determination Of Trace Inorganic As(Iii) And As(V) Species, Ülkü Ünal, Güler Somer
A New And Simple Procedure For The Polarographic Speciation And Determination Of Trace Inorganic As(Iii) And As(V) Species, Ülkü Ünal, Güler Somer
Turkish Journal of Chemistry
A new and simple differential pulse polarographic method was developed for the trace determination of As(III) and As(V) species in the same sample. Among several electrolytes, 0.1 M HCl was found to be the most suitable. As(III) had 3 peaks in this medium, and the peak at --0.82 V was chosen because of its peak shape and response to standard additions. In this medium, the limit of detection for As(III) was found to be 1.5 \times 10^{-7} M. Since As(V) is not electroactive, it had to be reduced first into As(III). For this purpose, KI in an acidic and hot …
A Computational Study On Substituted Diazabenzenes, Selçuk Gümüş
A Computational Study On Substituted Diazabenzenes, Selçuk Gümüş
Turkish Journal of Chemistry
The results of computational calculations on the aromaticity of the monosubstituted diazabenzenes (pyridazine, pyrimidine, and pyrazine) are reported herein. The aromaticity of the parent heterocycle was enhanced by substitution of strong electron-withdrawing groups. The effects of the position of the substituent on the aromaticity and the stability of the system were also investigated by studying all possible derivatives of the systems.
Polyphenolic Compounds From Geranium Purpureum Vill. Growing In Turkey, Di̇dem Şöhretoğlu, Mahmut Koray Sakar, Olov Sterner
Polyphenolic Compounds From Geranium Purpureum Vill. Growing In Turkey, Di̇dem Şöhretoğlu, Mahmut Koray Sakar, Olov Sterner
Turkish Journal of Chemistry
Two new flavonol derivatives, Geranioside A (kaempferol 3-[3-(\alpha-rhamnopyranosyl)-4-oxy-5-hydroxy-6-methyl-3,4-dihyropyran-2H- 2-pyranoside]) (1) and Geranioside B (quercetin 3-[3-(\alpha-rhamnopyranosyl)- 4-oxy-5-hydroxy-6-methyl-3,4-dihyropyran-2H-2-pyranoside]) (2), along with 5 known flavonols (quercetin (3), kaempferol (4), quercetin 4'-O-\beta -glucopyranoside (5), quercetin 3-O-\beta -glucopyranoside (6), and kaemferol-3-O-\beta -glucopyranoside (7)), a gallic acid derivative (methyl gallate (8)), and a hydrolysable tannin (pusilagin (9)), were isolated from the aerial parts of Geranium purpureum. The structures of the isolated compounds were elucidated on the basis of UV, IR, and 1D- and 2D-NMR experiments as well as TOF-MS.
Amphiphilic And Chiral Unsymmetrical Perylene Dye For Solid-State Dye-Sensitized Solar Cells, Hurmus Refiker, Hüri̇ye İci̇l
Amphiphilic And Chiral Unsymmetrical Perylene Dye For Solid-State Dye-Sensitized Solar Cells, Hurmus Refiker, Hüri̇ye İci̇l
Turkish Journal of Chemistry
A novel amphiphilic, unsymmetrically substituted N-((2S)-2-aminohexanoic acid)-N'-[(S)-1-phenylethyl]-3,4,9,10- perylenetetracarboxydiimide with 2 different chiral centers was synthesized and characterized. Chiral amphiphilicity, which can be tunable between hydrophilic and hydrophobic parts, is responsible for controlled self-assembly through intermolecular hydrogen bonding (N-H \cdots O). The product showed high thermal stability but partial solubility in common organic solvents. We observed 2 isosbestic points at 533 and 611 nm, confirming the presence of overlapped monomer and excimer emissions in the temperature range of 10-80 °C. Fluorescence quenching in m-cresol was attributed to charge-transfer interactions. Importantly, the excited state of the chiral dye can decay only by …