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Article Citation - WoS: 18Citation - Scopus: 19Effect of Furan, Thiophene and Selenophene Donor Groups on Benzoselenadiazole Based Donor-Acceptor Systems(Elsevier Science Sa, 2016) Karabay, Lutfiye Canan; Karabay, Bads; Karakoy, Merve Serife; Cihaner, AtillaA series of the monomers called 4,7-di(furan-2-yl)benzo[c][1,2,5]selenadiazole (OSeO), 4,7-di(thiophen-2-yl)benzo[c]11,2,5]selenadiazole (SSeS) and 4,7-di(selenophen-2-yl)benzo[c][1,2,5]selenadiazole (SeSeSe) was synthesized via a donor-acceptor-donor (D-A-D) approach. Benzoselenadiazole was used as an acceptor unit and furan, thiophene and selenophene were used as donor units. The effects of chalcogen atoms (0, S, and Se) in furan, thiophene and selenophene were investigated systematically on the properties of the monomers and their corresponding polymers (POSeO, PSSeS and PSeSeSe, respectively), which were polymerized electrochemically via potentiodynamic or potentiostatic methods. The monomers OSeO, SSeS and SeSeSe exhibited low oxidation potentials of 1.15, 1.25 and 1.19 V vs. Ag/AgCl, respectively. Intramolecular charge transfer interaction between donor and acceptor units was demonstrated from the emission spectra of the monomers. Also, the optical studies showed that the ambipolar and electrochromic polymers POSeO, PSSeS and PSeSeSe have low band gaps of 1.57, 1.47 and 1.45 eV, respectively. (C) 2016 Elsevier B.V. All rights reserved.Article Citation - WoS: 16Citation - Scopus: 16A New Carborane Based Polymeric Electrochrome(Elsevier Science Sa, 2013) Cansu-Ergun, Emine Gul; Cihaner, AtillaNew electrochromic copolymers of 3,4-ethylenedioxythiophene and di(m-carboranyl thiophene) were synthesized, characterized and their electro-optical properties were reported. The copolymers were successfully prepared from various monomer feed ratios using electrochemical polymerization technique. It can be conjectured that electrochemical and optical properties of the copolymers can be adjusted by playing with monomer feed ratios. For example, the maximum wavelength of poly(3,4-ethylenedioxythiophene) at 600 nm can be shifted to lower values (i.e., 522 nm) by increasing the ratio of di(m-carboranyl thiophene) in the monomer mixture. The copolymer films also have low band gap values between 1.69 and 1.82 eV and showed electrochromic properties; purple when neutralized and transparent sky blue when oxidized. Also, during redox switching the films exhibited a percent transmittance change between 32% and 46% with a switching time between 1.0 s and 1.3 s. (C) 2013 Elsevier B.V. All rights reserved.Article Citation - WoS: 27Citation - Scopus: 27Electrochromic performance and ion sensitivity of a terthienyl based fluorescent polymer(Elsevier, 2010) Atilgan, Nurdan; Cihaner, Atilla; Onal, Ahmet M.A novel terthienyl based fluorescent polymer bearing strong electron-withdrawing substituents directly attached to the 3,4-positions of the central thiophene ring was synthesized by electrochemical polymerization of diethyl 2,5-di(3,4-ethylenedioxythiophen-2-yl)thiophene-3,4-dicarboxylate. The corresponding polymer was characterized by cyclic voltammetry, FT-IR and UV-vis spectroscopy. The polymer has a well-defined redox process (E-p,E-1/2 = 0.74 V) and demonstrates a reversible electrochromic behavior; lilac in the neutral state and transparent sky blue in the oxidized state. Also, the polymer had low band gap (E-g = 1.82 eV) and high redox stability (retaining 94.0% of its electro-activity after 500th switch). Moreover, the sensitivity of both the monomer and its polymer towards metal cations was investigated by monitoring the change in the fluorescence intensity. Among various common ions both the monomer and its polymer were found to be selective towards Cu2+ and Cu+ ions by quenching the fluorescence efficiency with a Stern-Volmer constant (K-sv) of (1.4-1.6 x 10(3) M-1) and (1.5-1.8 x 10(2) M-1) for monomer and polymer solutions, respectively. (c) 2010 Elsevier Ltd. All rights reserved.
