Novel electroluminescent cationic polyelectrolyte based on poly[(fluorene‐2,7‐diylvinylene)‐alt‐(1,4‐phenylenevinylene)] and its precursor |
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Authors: | John A. Mikroyannidis Vasilis P. Barberis Věra Cimrová |
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Affiliation: | 1. Chemical Technology Laboratory, Department of Chemistry, University of Patras, GR‐26500 Patras, Greece;2. John A. Mikroyannidis, Chemical Technology Laboratory, Department of Chemistry, University of Patras, GR‐26500 Patras, Greece;3. Věra Cimrová, Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, 162 06 Prague 6, Czech Republic;4. Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2,162 06 Prague 6, Czech Republic |
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Abstract: | A novel conjugated poly[(fluorene‐2,7‐vinylene)‐alt‐(1,4‐phenylenevinylene)] derivative 2 with quaternizable tertiary amino groups was synthesized by Heck coupling of a substituted 2,7‐dibromofluorene and 1,4‐dialkoxy‐2,5‐divinylbenzene. The corresponding quaternary ammonium cationic polyelectrolyte 3 was obtained by the treatment of 2 with bromoethane. Both polymers were soluble in common organic solvents, like tetrahydrofuran, chloroform, and dichloromethane. Polymer 3 showed a limited solubility in alcohols and was insoluble in water. Photophysical and electrochemical properties of the resulting polymers were fully investigated. An intensive green photoluminescence (PL) with maxima at 550 and 545 nm was observed from thin films of 2 and 3 polymers, respectively, red‐shifted compared with the PL emission spectra measured in the solution. The electrochemical band gaps were 2.38–2.45 eV. Single‐layer and double‐layer (with poly[3,4‐(ethylenedioxy)thiophene]/poly (styrenesulfonate) (PEDOT:PSS)) light‐emitting devices (LEDs) with ITO and Al electrodes were prepared and studied. They emitted a green light and their electroluminescence (EL) spectra were similar to those of PL thin films. The external EL efficiency was determined to be 0.43 and 0.32% for ITO/PEDOT:PSS/ 2 /Al and ITO/PEDOT:PSS/ 3 /Al LEDs, respectively. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1016–1027, 2007 |
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Keywords: | conjugated polymers electrochemical properties electroluminescence Heck polymerization light‐emitting diodes light‐emitting polymer photophysics polyelectrolyte poly[(fluorene‐2,7‐vinylene)‐alt‐(1,4‐phenylenevinylene)] derivative synthesis |
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