Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5210141 | Reactive and Functional Polymers | 2012 | 8 Pages |
Abstract
A series of new fluorene derivatives bearing pendant quinoxaline moieties with different donor groups, namely 5â²H-spiro[fluorene-9,4â²-pyrrolo[1,2-a]quinoxaline] (FQ), 2,7-di(thiophen-2-yl)-5â²H-spiro[fluorene-9,4â²-pyrrolo[1,2-a]quinoxaline] (TQT), 2,7-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-5â²H-spiro[fluorene-9,4â²-pyrrolo[1,2-a]quinoxaline] (EQE) and 2,7-bis(3,3-dihexyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-6-yl)-5â²H-spiro[fluorene-9,4â²-pyrrolo[1,2-a]quinoxaline] (PQP) were synthesized. The monomers were electropolymerized via potentiodynamic methods in order to understand the effects of donor units on the electrochemical and optoelectronic properties of the resulting polymers. It was found that polymer films exhibit reversible redox behavior accompanied with a reversible electrochromic behavior (Epox = 0.95Â V for poly(2,7-di(thiophen-2-yl)-5â²H-spiro[fluorene-9,4'-pyrrolo[1,2-a]quinoxaline]) (PTQT), Epox = 0.90Â V for poly(2,7-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-5â²H-spiro[fluorene-9,4â²-pyrrolo[1,2-a]quinoxaline]) (PEQE) and Epox = 0.67Â V for poly(2,7-bis(3,3-dihexyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-6-yl)-5â²H-spiro[fluorene-9,4â²-pyrrolo[1,2 a]quinoxaline]) (PPQP)). The band gap values (Eg) of the polymers were found to be 2.47, 1.93 and 1.66Â eV for PTQT, PEQE and PPQP, respectively. Furthermore, the ion sensitivity of PQP and its polymer PPQP was also investigated by monitoring the change in the fluorescence intensity. Among various common ions, both PQP and PPQP were found to be selective towards Fe2+ ions by quenching the fluorescence efficiency with a Stern-Volmer constant (Ksv) of (5.9Â ÃÂ 103 Mâ1) and (2.7Â ÃÂ 104 Mâ1) for monomer and polymer solutions, respectively.
Related Topics
Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
Arif Kivrak, Buket Bezgin Carbas, Metin Zora, Ahmet M. Ãnal,