New copolymers with thieno[3,2-b]thiophene or dithieno[3,2-b:2',3'-d]thiophene units possessing electron-withdrawing 4-cyanophenyl groups: synthesis and photophysical, electrochemical, and electroluminescent properties

0475915 - ÚMCH 2018 RIV US eng J - Článek v odborném periodiku
Výprachtický, Drahomír - Demirtas, I. - Dzhabarov, Vagif - Pokorná, Veronika - Ertas, E. - Ozturk, T. - Cimrová, Věra
New copolymers with thieno[3,2-b]thiophene or dithieno[3,2-b:2',3'-d]thiophene units possessing electron-withdrawing 4-cyanophenyl groups: synthesis and photophysical, electrochemical, and electroluminescent properties.
Journal of Polymer Science. Part A - Polymer Chemistry. Roč. 55, č. 16 (2017), s. 2629-2638. ISSN 0887-624X. E-ISSN 1099-0518
Grant CEP: GA ČR(CZ) GA13-26542S
Institucionální podpora: RVO:61389013
Klíčová slova: conjugated polymers * electrochemistry * electroluminescence
Obor OECD: Condensed matter physics (including formerly solid state physics, supercond.)
Impakt faktor: 2.588, rok: 2017

New monomers containing 4-cyanophenyl (-PhCN) groups attached to a thieno[3,2-b]thiophene (TT) or dithieno[3,2-b:2´,3´-d]thiophene (DTT) structure were synthesized and characterized as 4-(2,5-dibromothieno[3,2-b]thiophen-3-yl)benzonitrile (Br-TT-PhCN) or 4,4´-(2,6-dibromodithieno[3,2-b:2´,3´-d]thiophene-3,5-diyl)dibenzonitrile (Br-DTT-PhCN). The Suzuki coupling of 9,9-dioctylfluorene-2,7-diboronic acid bis(1,3-propanediol)ester and the Br-TT-PhCN or Br-DTT-PhCN monomer was utilized for the syntheses of novel copolymers poly{9,9-dioctylfluorene-2,7-diyl-alt-3-(4´-cyanophenyl)thieno[3,2-b]thiophene-2,5-diyl} (PFTT-PhCN) and poly{9,9-dioctylfluorene-2,7-diyl-alt-3,5-bis(4´-cyanophenyl)dithieno[3,2-b:2´,3´-d]thiophene-2,6-diyl} (PFDTT-PhCN), respectively. The photophysical, electrochemical, and electroluminescent (EL) properties of these novel copolymers were studied. Their photoluminescence (PL) exhibited the same emission maximum for both copolymers in solution. Red-shifted PL emissions were observed in the thin films. The PL emission maximum of PFTT-PhCN was more significantly redshifted than that of PFDTT-PhCN, indicating more pronounced excimer or aggregate formation in PFTT-PhCN. The ionization potential (HOMO level) and electron affinity (LUMO level) values were 5.54 and 2.81 eV, respectively, for PFTT-PhCN and were 5.57 and 2.92 eV, respectively, for PFDTT-PhCN. Polymer light-emitting diodes (LEDs) with copolymer active layers were fabricated and studied. Anomalous behavior and memory effects were observed from the current-voltage characteristics of the LEDs for both copolymers.
Trvalý link: http://hdl.handle.net/11104/0272757