Browsing by Author "Gokce, Gurcan"

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[1,2,5]thiadiazolo[3,4-G]quinoxaline Acceptor-Based Donor-Acceptor Polymers: Effect of Strength and Size of Donors on the Band Gap
(Wiley, 2017) Gokce, Gurcan; Karabay, Baris; Cihaner, Atilla; Ozkut, Merve Icli
Electrochromic polymers based on [1,2,5]thiadiazolo[3,4-g]quinoxaline acceptor and thiophene, 3,4-ethylenedioxythiophene and 3,3-didecyl-3,4-proylenedioxythiophene donors, namely poly(6,7-diphenyl-4,9-di(thiophen-2-yl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline) (P1), poly(4-(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-9-(2,3-dihydrothieno[3,4-b][1,4]dioxin-7-yl)-6,7-diphenyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline) (P2), and poly(4-(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-6-yl)-9-(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-8-yl)-6,7-diphenyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline) (P3), respectively, were electrochemically and/or chemically synthesized and characterized. Electrochemical and optical properties of the polymers were then investigated. The results, which were obtained electrochemically and optically, indicate that the polymers bearing the same acceptor and different donor units have a band gap range of 0.59-1.24 eV depending on the strength and size of the donor units and band gap determination method. A significant finding in this study was the phenomenon that when the acceptor is physically huge, the general rule that a weak donor would have a high band gap whereas a strong donor would have low band gap can be broken due to the torsional angles/steric hindrances involved with physically large donor molecules. (c) 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3483-3493
Acid/ Base Doped/ Dedoped Low Band Gap Polymer
(Amer Chemical Soc, 2016) Karabay, Baris; Gokce, Gurcan; Cihaner, Atilla; Icli Ozkut, Merve
Electrochemical Synthesis of Poly(6,7-Diphenyl and Its Electrochemical and Optical Characterizations
(Springer, 2024) Smail, Sardar Kareem; Gokce, Gurcan; Ozkut, Merve Icli
In this study, electrochemical copolymerization of 6,7-diphenyl-4,9-di(selenophen-2-yl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline and 3,3'-didecyl-3,4-propylenedioxythiophene is carried out to obtain a copolymer namely poly(6,7-diphenyl-4,9-di(selenophen-2-yl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline-co-3,3'-didecyl-3,4-propylenedioxythiophene). Two distinct copolymers, PC1 and PC2, were produced as a result of the utilization of two different feed ratios. Copolymers were examined electrochemically and spectroelectrochemically after the copolymerization procedure. This study's major goal is to combine the exceptional characteristics of homopolymers P1 and P2 (P1 has a low band gap but is not soluble, and P2 is soluble and has a larger band gap) into a single copolymeric material.
From Narrow To Narrower: a Very Low Band Gap [1,2,5]thiadiazolo[3,4-G]quinoxaline Donor-Acceptor Type Electrochromic Polymer
(Electrochemical Soc inc, 2017) Gokce, Gurcan; Karabay, Baris; Cihaner, Atilla; Ozkut, Merve Icli
The development of low bandgap polymers (or zero bandgap polymers) is still one of the main goals of scientists and many viable paths have been formulated in order to accomplish this. In this study, a donor-acceptor-donor type electrochromic polymer based on [1,2,5]thiadiazolo[3,4-g]quinoxaline acceptor and selenophene donor units with extremely low bandgap (ranging from 0.21 to 0.60 eV depending on bandgap determination method) is synthesized and characterized electrochemically, optically and colorimetrically. Electrochemical and optical studies showed that the polymer film was susceptible to both n- and p-type doping and has a mustard color in its neutral state, and upon oxidation its color changed to brown, and upon reduction the color is light purple. (C) 2017 The Electrochemical Society. All rights reserved.
An Indolocarbazole Based Yellow-To Soluble Electrochromic Polymer
(Elsevier Science Bv, 2018) Gokce, Gurcan; Ozkut, Merve Icli
A new donor-acceptor-donor type polymer called poly(3,9-(3,3-didecyl-3,4-propylenedioxythiophene)-5,11-di-hydroindolo[3,2-b] carbazole) (P1) was synthesized and characterized electrochemically, spectro-electrochemically and colorimetrically. P1 shows multielectrochromic property; it is yellow in neutral state, and it changes color from yellow to khaki upon oxidation. Further oxidation causes the khaki color to turn green and then green to cyan, and upon reduction, the color changes from yellow to orange. P1 also has capacitance property and is soluble in common organic solvents. Its band gap was also electrochemically determined as 1.38 eV from cyclic voltammetry and 1.50 eV from differential pulse voltammetry, while optically, it was determined as 1.56 eV.
A Low Band Gap Polymer Based on Selenophene and Benzobis (Thiadiazole)
(Pergamon-elsevier Science Ltd, 2017) Abdulrazzaq, Mohammed; Ozkut, Merve Icli; Gokce, Gurcan; Ertan, Salih; Tutuncu, Esra; Cihaner, Atilla
A new derivative of benzobis(thiadiazole) based donor-acceptor-donor type monomers, namely 4,7-di (selenophen-2-yl)benzo[1,2-c;4,5-c']bis[1,2,5]thiadiazole (SeBTSe), was synthesized and its polymerization was carried out successfully via electrochemical polymerization in an electrolyte solution of 0.1 M tetrabutylammonium hexafluorophosphate dissolved in dichloromethane. The monomer SeBTSe is a deep red chromophore and it has four redox states: one oxidation, one neutral and two reduction states. The electrochemical behaviour of the corresponding polymer called PSeBTSe was studied by cyclic and differential pulse voltammetry. There is a good agreement between electrochemical (0.62-0.66 eV) and optical (0.63 eV) bandgaps of the polymer. Like the monomer, the ambipolar polymer has four redox states and electrochromic properties: gray beige at neutral state, smoky azurite at oxidized state, beige at first reduced state and dark beige at second reduced state. (C) 2017 Elsevier Ltd. All rights reserved.