Yazar "Turac, Ersen" seçeneğine göre listele
Listeleniyor 1 - 18 / 18
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe A facile synthesis of heterotricycles from furfurylbromoalkenes using thermal IMDA cycloaddition(FREUND PUBLISHING HOUSE LTD, 2006) Demircan, Aydm; Karaarslan, Muhsin; Turac, ErsenA variety of key precursors to the IMDA reaction of furan diene have been prepared via facile alkylation. Subsequently, rigid tricyclic compounds (2a-g) possessing oxygen, nitrogen, and sulfur has been synthesized by employing thermal intramolecular Diels-Alder reactions. These heterocyclic fused tricycles include a bromo quaternary carbon centre obtained stereoselectively with moderate yields (32-44 overall).Öğe Chemoenzymatic polycondensation of para-benzylamino phenol(SPRINGER INTERNATIONAL PUBLISHING AG, 2016) Yildirim, Pinar; Gokturk, Ersen; Turac, Ersen; Demir, Haci O.; Sahmetlioglu, Ertugrulpara-Benzylamine substituted oligophenol was synthesized via enzymatic oxidative polycondensation of 4-(benzylamino) phenol (BAP). Polymerization involved only the phenolic moiety without oxidizing the sec-amine (benzylamine) group. Chemoselective polycondensation of BAP monomer using HRP enzyme yielded oligophenol with sec-amine functionality on the side-chain. Effects of various factors including solvent system, reaction pH and temperature on the polycondensation were studied. Optimum polymerization process with the highest yield (63 %) and molecular weight (M-n = 5000, degree of polymerization approximate to 25) was achieved using the EtOH/buffer (pH 5.0; 1 : 1 vol. ratio) at 25 degrees C in 24 h under air. Characterization of the oligomer was accomplished by H-1 NMR and C-13 NMR, Fourier transform infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), ultraviolet-visible spectroscopy (UV-Vis), cyclic voltammetry (CV) and thermogravimetric analysis (TGA). The polymerization process involved the elimination of hydrogen from BAP, and phenolic -OH end groups of the oligo(BAP), confirmed using H-1 NMR and FT-IR analyses. The oligomer backbone possessed phenylene and oxyphenylene repeat units, and the resulting oligomer was highly soluble in common organic solvents such as acetone, CHCl3, 1,4-dioxane, N, N-dimethylformamide (DMF), tetrahydrofurane (THF) and dimethylsulfoxide (DMSO). Oligo(BAP) was thermally stable and exhibited 5 % and 50 % mass loss determined by thermogravimetric analysis at 247 degrees C and 852 degrees C, respectively. (c) 2015 Institute of Chemistry, Slovak Academy of SciencesÖğe Chemoenzymatic Polymerization of Hydrazone Functionalized Phenol(MAIK NAUKA/INTERPERIODICA/SPRINGER, 2016) Isci, Irfan; Gokturk, Ersen; Turac, Ersen; Sahmetlioglu, ErtugrulHydrazone substituted oligophenol was synthesized via enzymatic oxidative polymerization of (E)-2-((2-phenylhydrazono) methyl) phenol. Enzymatic polymerization catalyzed by Horseradish peroxidase (HRP) enzyme and H2O2 oxidizer yielded oligophenol with hydrazone functionality on the side-chain. Effects of various factors including solvent system, reaction pH and temperature on the polymerization were studied. Optimum polymerization conditions with the highest yield (84%) and molecular weight (M-n = 8 x 103, DP approximate to 37, PDI - 1.11) was achieved using MeOH/pH 6.0 buffer (1 : 1 vol %) at 25 degrees C in 24 h under air. Synthesized oligomer was characterized by H-1 and C-13 NMR, FTIR, UV-Vis spectroscopy, GPC, cyclic voltammetry and thermo-gravimetric analyses. The polymerization involved hydrogen elimination from the monomer, and terminal units of the oligomer structure consisted of phenolic hydroxyl (-OH) end groups. The oligomer backbone possessed phenylene and oxyphenylene repeat units. The resulting oligomer was completely soluble in common organic solvents. The oligomer was thermally robust and exhibited 5% mass loss at 375 degrees C and 50% mass loss at 440 degrees C.Öğe Electrochemical Synthesis of a Water-Soluble and Self-Doped Polythiophene Derivative(VSP BV, 2008) Turac, Ersen; Varol, Ramazan; Ak, Metin; Sahmetlioglu, Ertugrul; Toppare, LeventA new monomer, 4-(thiophen-3-yl methyleneamino)benzene sulfonate) (ThSA), was synthesized and characterized. Electrochemical polymerization of ThSA yields a water-soluble and self-doped polymer (PThSA). This polymer was characterized by FT-IR, NMR, DSC, XRD and conductivity measurements. (C) Koninklijke Brill NV, Leiden, 2008Öğe Electropolymerizations of two novel EDOT-BODIPY zinc oxide nanocomposites and evaluation of their in vitro antibacterial activities(Wiley, 2021) Kilavuz, Esra; Turac, Ersen; Ilk, Sedef; Sahmetlioglu, ErtugrulBoron containing materials as novel classes of antibacterial agents have been widely used in coating or medical applications due to their excellent functionality against microorganisms. In this study, two different boron dipyrromethene (BODIPY)/zinc oxide based P(M1-co-Edot)/ZnO and P(M2-co-Edot)/ZnO nanocomposite copolymer materials were prepared. The BODIPY/ZnO nanocomposite films were synthesized using potentiostat. ZnO nanoparticles were used to increase the strength and conductivity of the obtained semiconducting materials. Spectroelectrochemical analysis show that the copolymers, P(M1-co-Edot)/ZnO and P(M2-co-Edot)/ZnO, have electronic band gaps at 1.56 and 2.51 eV and optical band gaps at 2.11 and 2.00 eV, respectively. The synthesized nanocomposite films were characterized by Raman, nuclear magnetic resonance (NMR) and FT-IR spectroscopies. The optical properties of the synthesized monomers and their nanocomposite copolymers were demonstrated using UV-Vis and fluorescence spectroscopy. SEM and AFM images show the surface morphologies of nanocomposite copolymer films and surface roughness of P(M1-co-Edot)/ZnO and P(M2-co-Edot)/ZnO were calculated as Ra = 84.6 nm Rq = 106 nm and 120 nm, respectively. Antibacterial activities of the obtained nanocomposite films prepared in ultrapure water with different concentrations (2.5-0.25 mg/mL) were discovered against Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli) bacteria by using disc diffusion method. The antibacterial activities of obtained films were found to be higher against Gram negative bacteria compared to that of Gram positives. Obtained results show that synthesized nanocomposites with easy production and nontoxic properties can be used as functional bioengineering materials for antibacterial electrochromical materials.Öğe ENVIRONMENTALLY FRIENDLY ENZYME-CATALYZED POLYMERIZATION OF A NOVEL PHENOXY-KETIMINE(Gh Asachi Technical Univ Iasi, 2017) Tapan, Senem; Sahmetlioglu, Ertugrul; Demir, Haci Okkes; Turac, Ersen; Sahin, ElifThe monomer with ketimine side group, 2-(1-(benzylimino) ethyl) phenol (2-BEP), was synthesized from the condensation of 2-hydroxyacetophenone and benzyl amine. The enzymatic oxidative polymerization of 2-BEP was performed in the presence of hydrogen peroxide using horseradish peroxidase (HRP) as catalyst. The oxidation reaction was carried out in various solvents and phosphate buffers at room temperature. These studies have shown that a dark brown polymer was successfully synthesized by utilizing aqueous methanol as the cosolvent at pH 7.0. Poly(2-BEP) shows good solubility in DMF and DMSO, but it is insoluble in THF, methanol, water, acetone and chloroform. Characterization of poly(2-BEP) was carried out via UV-vis, FT-IR, H-1-NMR, C-13-NMR and GPC techniques. The number-average molecular weight (M-n), weight-average molecular weight (M-w) and polydispersity index (PDI) of the polymer were determined to be 1157.4 g mol(-1), 2039.6 g mol(-1) and 1.76, respectively. FTIR and H-1-NMR studies confirmed the presence of phenylene and oxyphenylene units within the polymer backbone. The optical band gaps (E-g) of 2-BEP and poly(2-BEP) were calculated as 4.10 eV and 3.86 eV, respectively.Öğe Enzymatic oxidative polymerization of para-imine functionalized phenol catalyzed by horseradish peroxidase(WILEY-BLACKWELL, 2015) Kumbul, Altug; Gokturk, Ersen; Turac, Ersen; Sahmetlioglu, ErtugrulEnzymatic oxidative polymerization of a new para-imine functionalized phenol derivative, 4-(4-hydroxybenzylideneamino)benzoic acid (HBBA), using horseradish peroxidase enzyme and hydrogen peroxide oxidizer has been investigated in an equivolume mixture of an organic solvent (acetone, methanol, ethanol, dimethylformamide, 1,4-dioxane, and tetrahydrofuran) and phosphate buffer (pH=5.0, 6.0, 6.8, 7.0, 7.2, 8.0, and 9.0) at different temperatures under air for 24h. The resulting oligomer, oligo(4-(4-hydroxybenzylideneamino)benzoic acid) [oligo(HBBA)], was characterized using ultraviolet-visible, Fourier transform infrared (FT-IR), H-1 nuclear magnetic resonance (NMR), cyclic voltammetry, size exclusion chromatography, differential scanning calorimetry, and thermogravimetric analyses. Polymerization involved carbon dioxide and hydrogen elimination from the monomer, and terminal units of the oligomer structure consisted of phenolic hydroxyl (-OH) groups at the ends. The polymer is mainly composed of a mixture of phenylene and oxyphenylene units according to H-1 NMR and FT-IR analyses. Effects of solvent system, temperature and buffer pH on the polymerization have been investigated in respect to the yield and molecular weight (M-n) of the product. The best condition in terms of the highest molecular weight (M-n=3000g/mol, DP similar to 15) was achieved in an equivolume mixture of 1,4-dioxane/pH 5.0 phosphate buffer condition at 35 degrees C. Electrochemical characterization of oligo(HBBA) was investigated at different scan rates. The resulting oligomer has also shown relatively high thermal stability according to thermogravimetric analysis. Copyright (c) 2015 John Wiley & Sons, Ltd.Öğe Horseradish peroxidase-based hybrid nanoflowers with enhanced catalytical activities for polymerization reactions of phenol derivatives(Wiley, 2020) Gokturk, Ersen; Ocsoy, Ismail; Turac, Ersen; Sahmetlioglu, ErtugrulCatalytic activity and stability of HRP-Cu2+ hybrid nanoflowers (hCu-NFs) in the polymerization reactions of phenol derivatives was investigated. It was observed that the catalytic activity and stability of hybrid nanoflowers on the polymerization of the phenol derivatives was considerably higher compared to free Horseradish peroxidase (HRP) enzyme. The hCu-NFs effectively polymerized phenolic compounds as a novel nanobiocatalyst and led to polymers having quite high yields, molecular weights, and thermal stabilities compared to free HRP enzyme. The hCu-NFs provide substantial repeated use and showed some degree of catalytic activity even after fourth cycle experiment in the polymerization reactions.Öğe Oxidative polymerization of 4-[(4-phenylazo-phenyimino)-methyl]-phenol catalyzed by horseradish peroxidase(ELSEVIER SCIENCE SA, 2010) Turac, Ersen; Sahmetlioglu, ErtugrulSchiff base derivate 4-[(4-phenylazo-phenyimino)-methyl]-phenol (4-PPMP) monomer was synthesized by condensation reaction and the chemical structure of the monomer has been characterized by UV-vis, FT-IR, H-1 NMR spectroscopies. 4-PPMP readily dissolves in 1,4-dioxane, THF, DMF, diethyl ether, chloroform and DMSO. Its solubility in methanol and ethanol is much lower. Enzymatic oxidative polymerization of azobenzene derivate 4-[(4-phenylazo-phenyimino)-methyl]-phenol using horseradish peroxidase (HRP) in the presence of hydrogen peroxide as catalyst and oxidizing agent was carried out in various solvents (acetone, methanol, ethanol, N,N-DMF, and 1,4-dioxane) and phosphate buffers (pH 6, 6.8, 7, and 7.2) at room temperature. Studies have shown that a black polymer having a melting point of 290 degrees C was successfully produced in good yields by utilizing aqueous 1,4-dioxane as the solvent at pH 6. Poly(4-[(4-phenylazo-phenyimino)-methyl]-phenol) P(4-PPMP) shows good solubility in 1,4-dioxane, DMF and DMSO but it is only sparingly soluble in chloroform, THF, methanol and ethanol. P-(4-PPMP) is insoluble in diethyl ether. Characterization of P-(4-PPMP) was carried out via UV-vis, FT-IR, H-1 NMR, elemental analysis and SEC measurements. The number-average molecular weight (M-n), weight-average molecular weight (M-w) and polydispersity index (PDI) of the polymer were determined to be 7970.4, 8146.2 and 1.02 g mol(-1), respectively. FT-IR and H-1 NMR studies confirmed the presence of phenylene and oxyphenylene units with in the polymer backbone. The optical band gaps (E-g) of 4-PPMP and P-(4-PPMP) were calculated as 3.69 and 3.36eV, respectively. (C) 2009 Elsevier B.V. All rights reserved.Öğe Synthesis and characterization of conducting copolymer of (N (1),N (3)-bis(thiophene-3-ylmethylene)benzene-1,3-diamine-co-3,4-ethylenedioxythiophene)(VERSITA, 2010) Kumbul, Altug; Turac, Ersen; Dursun, Tugba; Sahmetlioglu, ErtugrulElectrochemical copolymerization of N (1),N (3)-bis(thiophene-3-ylmethylene)benzene-1,3-diamine (TMBA) with 3,4-ethylenedioxythiophene (EDOT) was carried out in a CH3CN/LiClO4 (0.1 M) solvent-electrolyte via potentiodynamic electrolysis. Chemical structure of the monomer was determined by nuclear magnetic resonance (H-1 NMR) and Fourier transform infrared (FTIR) spectroscopy. The resulting copolymer was characterized by cyclic voltammetry (CV), FTIR, scanning electron microscopy (SEM), and thermogravimetry analyses (TGA). Conductivity measurements of the copolymer and PEDOT (poly(3,4-ethylenedioxythiophene)) were carried out by the four-probe technique.Öğe Synthesis and characterization of conducting copolymer of Trans-1-(4-methyl-3'-thienyl)-2-(ferrocenyl)ethene with EDOT(WILEY-BLACKWELL, 2012) Turac, Ersen; Sahmetlioglu, Ertugrul; Demircan, Aydin; Toppare, LeventFerrocene-substituted conducting polymer namely poly(trans-1-(4-methyl-3'-thienyl)-2-(ferrocenyl)ethene-co-3,4-ethylenedioxythiophene) [P(MTFE-co-EDOT)] was synthesized and its electrochromic properties were studied. Monomer, MTFE, was obtained using 2-(ferrocenyl)ethene and 3-methyl-4-bromothiophene. The structure of monomer was determined via Fourier transform infrared spectroscopy (FTIR), 1H-NMR, and 13C-NMR techniques. The copolymer was synthesized using this monomer and EDOT. The resulting copolymer P(MTFE-co-EDOT) was characterized by cyclic voltammetry, FTIR, scanning electron microscopy, atomic force microscopy, and UVvis spectroscopy. The conductivity measurements of copolymer and PEDOT were accomplished by the four-probe technique. Although poly(trans-1-(4-methyl-3'-thienyl)-2-(ferrocenyl)ethene) [P(MTFE)] reveals no electrochromic activity, its copolymer with EDOT has two different colors (violet and gray). Band gap (Eg) and ?max of P(MTFE-co-EDOT) were determined. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012Öğe Synthesis and Characterization of Conducting Copolymers of Quinoxaline Derivatives(WILEY, 2011) Turac, Ersen; Sahmetlioglu, Ertugrul; Toppare, Levent; Yuruk, HuseyinElectrochemical copolymerizations of 2,3-di(2-thienyl)quinoxaline (M1), 6-methyl-2,3-di(2-thienyl)quinoxaline (M2), and 2,3-di(2-thienyl)quinoxaline-6-yl)(phenyl)methanone (M3) with 3,4-ethylenedioxy thiophene (EDOT) were carried out in CH3CN/TBABF(4) (0.1M) solvent-electrolyte couple via potentiodynamic electrolysis. The obtained copolymers were characterized by cyclic voltammetry (CV), Fourier transform-infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetry analyses (TGA). The conductivity measurements of copolymers and PEDOT were performed by the four-probe technique. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120: 1713-1719, 2011Öğe Synthesis and Characterization of Conducting Copolymers of Thiophene Derivatives(TAYLOR & FRANCIS INC, 2014) Turac, Ersen; Sahmetlioglu, Ertugrul; Toppare, LeventElectrochemical copolymerizations of N1,N2-bis(thiophen-3-ylmethylene)benzene-1,2-diamine (TMBD), 4-methyl-N1,N2-bis (thiophen-3-ylmethylene)benzene-1,2-diamine (MTMBD) and 4-nitro-N1,N2-bis(thiophen-3-ylmethylene)benzene-1,2-diamine (NTMBD) with 3,4-ethylenedioxy thiophene (EDOT) were carried out in CH3CN/LiClO4 (0.1M) solvent-electrolyte couple via potentiodynamic electrolysis. The resulting copolymers were characterized by cyclic voltammetry (CV), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The conductivity measurements of copolymers and PEDOT were carried out by the four-probe technique.Öğe Synthesis and Characterization of Polyaniline/Zinc Sulfite Composite Films and Investigation of Properties(WILEY-BLACKWELL, 2013) Tuncer, Ebru; Turac, ErsenIn the present work, we explore the opportunity to deposit zinc sulfide (ZnS)/polyaniline (PANI) composite films through an electrochemical route. The structural and the optical characterization showed the interaction between ZnS nanoparticular and PANI. The structure of the PANI-ZnS composite films was characterized by scanning electron microscopy, atomic force microscopy, and UV-vis spectroscopy. Cyclic voltammetry was used to investigate the electrochemical behavior of the resulting material. The existence of Zn and S on PANI-ZnS composite films was proved by the EDX-mapping method. The conductivity measurements of PANI-ZnS composite films and PANI were accomplished by the four-probe technique. (c) 2013 Wiley Periodicals, Inc. Adv Polym Technol 2013, 32, 21373; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21373Öğe Synthesis and characterization of poly{2-[3-(1H-pyrrol-2-yl)phenyl]-1H-pyrrole} and its copolymer with EDOT(MAIK NAUKA/INTERPERIODICA/SPRINGER, 2011) Turac, Ersen; Ak, Metin; Sahmetlioglu, Ertugrul; Sener, M. Kasim; Kaya, Mehmet ArifA pyrrole-functionalized monomer 2-[3-(1H-pyrrol-2-yl)phenyl]-1H-pyrrole (PyPhPy) was synthesized. The structure of monomer was investigated by Nuclear Magnetic Resonance (H-1 NMR) and Fourier Transform Infrared (FTIR) spectroscopy. The chemical polymerization of PyPhPy (CPyPhPy) was realized using FeCl3 as the oxidant. The electrochemical oxidative polymerization of polymer P(PyPhPy) and its copolymer with 3,4-ethylenedioxythiophene poly(2-[3-(1H-pyrrol-2-yl)phenyl]-1H-pyrrole-co-3,4-ethylenedioxythiophene) [P(PyPhPy-co-EDOT)] were achieved via potentiodynamic method by using NaClO4/LiClO4 as the supporting electrolyte in CH3CN. Characterizations of the resulting polymers were performed by cyclic voltammetry (CV), FTIR, scanning electron microscopy (SEM), UV-Visible spectrophotometry (UV-Vis) and thermogravimetry analyses (TGA). Electrical conductivity of CPyPhPy, P(PyPhPy), and P(PyPhPyco-EDOT) were measured by four-probe technique.Öğe Synthesis and characterization of water-soluble oligosalicylaldehyde-sulfanilic acid and its Cu(II), Co(II), Pb(II) complexes(JOHN WILEY & SONS INC, 2008) Turac, Ersen; Surme, Yavuz; Sahmetlioglu, Ertugrul; Varol, Ramazan; Narin, Ibrahim; Toppare, LeventThis work presents the synthesis and characterization of a new water-soluble oligophenol derivative, 4-(2-hydroxybenzylideneamino)benzenesulfanic acid (OSAL-SA) and its metal complexes. The chemical structure of the water-soluble polymer was characterized by nuclear magnetic resonance (H-1 NMR) and Fourier transform infrared (FTIR) spectroscopies and thermogravimetric analyses (TGAs). Pb(II), Cu(II), Co(II) complexes of the polymer were also synthesized in methanol. Characterizations of water insoluble polymer-metal complexes were performed by FTIR, flame atomic absorption spectroscopy, and TGA. he conductivity measurements of OSAL-SA and polymer-metal complexes were carried out by the four-probe technique. (c) 2008 Wiley Periodicals, Inc.Öğe Synthesis of Conducting Polymer/Zinc Sulfide Nanocomposite Films and Investigation of Their Electrochemical and Morphological Properties(WILEY-HINDAWI, 2015) Turac, Ersen; Sahmetlioglu, Ertugrul; Gokturk, ErsenPolypyrrole-zinc sulfide (PPy-ZnS) and poly(3,4-ethylenedioxythiophene)-zinc sulfide (PEDOT-ZnS) composite films were synthesized and characterized. Their electrochemical behaviors were investigated. The synthesis of PPy-ZnS and PEDOT-ZnS composite films was carried out by electropolymerization of pyrrole and 3,4-ethylenedioxythiophene in the presence of ZnS nanoparticles dispersed in the electrolytic solution. The structures of the PPy-ZnS and PEDOT-ZnS composite films were characterized by the use of scanning electron microscopy, atomic force microscopy, and UV-vis spectroscopy. Cyclic voltammetry was used to determine the electrochemical behavior of the resulting materials. The Energy Dispersive X-Ray mapping (EDX mapping) method was used to detect the existence of Zn and S ions on PPy-ZnS and the Zn ion on PEDOT-ZnS composite films. A four-probe technique was used to measure the conductivity of PPy-ZnS and PEDOT-ZnS composite films along with PPy and PEDOT.Öğe Synthesis, Characterization and Optoelectrochemical Properties of Poly(2,5-di(thiophen-2-yl)-1-(4-(thiophen-3-yl)phenyl)-1H-pyrrole-co-EDOT)(TAYLOR & FRANCIS LTD, 2010) Turac, Ersen; Sahmetlioglu, Ertugrul; Toppare, Levent; Yuruk, HuseyinA new polythiophene derivative was synthesized by electrochemical oxidative polymerization of 2,5-di( thiophen-2-yl)-1-(4-(thiophen-3-yl) phenyl)-1H-pyrrole (TTPP). The structure of the monomer was evaluated by H-1-NMR and FT-IR. The polymer (P(TTPP)) and its co-polymer with 3,4-ethylenedioxythiophene (P(TTPP-co-EDOT)) were synthesized via potentiostatic electrochemical polymerization. The resulting polymers were characterized by cyclic voltammetry (CV), FT-IR, SEM and UV-Vis spectroscopy, and conductivity measurements. Also, the spectroelectrochemical and electrochromic properties of P(TTPP-co- EDOT) were investigated. While P(TTPP) reveals no electrochromic activity, its co-polymer with EDOT has two different colours (yellow and blue). Optical contrast, switching time, lambda(max) and band gap (E-g) of (P(TTPP-co-EDOT)) were determined. (C) Koninklijke Brill NV, Leiden, 2010
