Investigation of Fluorine Atom Effect on Benzothiadiazole Acceptor Unit in Donor Acceptor Donor Systems

Synthesis of two new pi-conjugated monomers containing fluorine substituted benzothiadiazoles as acceptor units and 3,4-ethylenedioxythiophene (EDOT) as donor unit was accomplished by facilitating Stille cross-coupling reactions (4,7-bis(2,3-dihydrothieno[3,4-b][1,4] dioxin-5-yl)-5-fluorobenzo[c][1,2,5] thiadiazole (E2BTD-F) and 4,7-bis(2,3-dihydrothieno [3,4-b][1,4] dioxin-5-yl)-5,6-difluorobenzo[c][1,2,5] thiadiazole (E2BTD-2F)). NMR and HRMS spectra of newly synthesized compounds are in agreement with the structures. To compare fluorine substitution effects, non-fluorinated analogue (4,7-bis(2,3-dihydrothieno[3,4-b][1,4] dioxin-5-yl) benzo[c][1,2,5] thiadiazole (E2BTD)) was also synthesized. Besides a blue shift in their absorption spectra, an anodic shift was also noted in the oxidation potentials of both monomers with fluorine atom substitution on the acceptor unit. This was further confirmed by DFT calculations such that upon fluorine substitution EDOT donor units deviate from planarity. Electropolymerization of the monomers were achieved successfully via potentiodynamic polymerization method. A similar trend in optoelectronic properties was also observed for the polymer films as for the monomers. (C) 2019 The Electrochemical Society.


Synthesis of New Thienylene Pyrrole Monomers and Their Electropolymerizations
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In this study, four new 2,5-dithienylpyrroles (SNS) 1-(3-fluoro-phenyl)-2,5-di(thiophen-2-yl)-1H-pyrrole (m-FPTP), 1-(3-chlorophenyl)-2,5-di(thiophen-2-yl)-1H-pyrrole (m-ClPTP), 1-(3-bromo-phenyl)-2,5-di(thiophen-2-yl)-1H-pyrrole (m-BrPTP) and 1-(4-bromo-phenyl)-2,5-di(thiophen-2-yl)-1H-pyrrole (p-BrPTP) containing meta and para substituted benzene ring at the nitrogen atom were synthesized via Paal-Knorr condensation of 1,4-di(2-thienyl)-1,4-butanedione with corresponding halo-substituted anilines. The mon...
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Herein, we report the synthesis of two donor-acceptor-donor polymers (P1 and P2) based on thiophene (M1) and thieno [3,2-b]thiophene (M2) as the donor and 2,5-bis(dodecyloxy)benzene as the acceptor unit. The effects of different donor units on the polymers' electrochemical and optical properties were examined by cyclic voltammetry and spectroelectrochemical analysis. Introducing thieno[3,2-b]thiophene unit as the donor unit enhances pi-stacking and consequently lowering the bandgap of the resulting polymer....
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Syntheses and Characterization of Benzotriazole, Thienopyrroledione, and Benzodithiophene Containing Conjugated Random Terpolymers for Organic Solar Cells
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Citation Formats
D. Çakal, A. Akdağ, and A. M. Önal, “Investigation of Fluorine Atom Effect on Benzothiadiazole Acceptor Unit in Donor Acceptor Donor Systems,” JOURNAL OF THE ELECTROCHEMICAL SOCIETY, pp. 0–0, 2019, Accessed: 00, 2020. [Online]. Available: