[1,2,5]thiadiazolo[3,4‐g]quinoxaline acceptor‐based donor–acceptor–donor‐type polymers: Effect of strength and size of donors on the band gap |
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| Authors: | Gurcan Gokce Baris Karabay Atilla Cihaner Merve Icli Ozkut |
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| Affiliation: | 1. Department of Chemical Engineering, YuzuncuYil University, Faculty of Engineering and Architecture, Van, Turkey;2. Department of Chemical Engineering and Applied Chemistry, Atilim Optoelectronic Materials and Solar Energy Laboratory (ATOMSEL), Atilim University, Ankara, Turkey |
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| Abstract: | Electrochromic polymers based on 1,2,5]thiadiazolo3,4‐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]thiadiazolo3,4‐g]quinoxaline) ( P1 ), poly(4‐(2,3‐dihydrothieno3,4‐b]1,4]dioxin‐5‐yl)‐9‐(2,3‐dihydrothieno3,4‐b]1,4]dioxin‐7‐yl)‐6,7‐diphenyl‐1,2,5]thiadiazolo3,4‐g]quinoxaline) ( P2 ), and poly(4‐(3,3‐didecyl‐3,4‐dihydro‐2H‐thieno3,4‐b]1,4]dioxepin‐6‐yl)‐9‐(3,3‐didecyl‐3,4‐dihydro‐2H‐thieno3,4‐b]1,4]dioxepin‐8‐yl)‐6,7‐diphenyl‐1,2,5]thiadiazolo3,4‐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. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3483–3493 |
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| Keywords: | band gap engineering 3 4‐ethylenedioxythiophene low band gap polymer 3 4‐proylenedioxythiophene redox polymers soluble polymer steric hindrance stimuli‐sensitive polymers thiadiazoloquinoxaline thin films thiophene |
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