Department of Chemistry
Synthesis and properties of benzo[c]-, pyrrolo[3,4-c]-, and thieno[3,4-c]-pyrrole-4,6-dione copolymers
© The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2015.New π-conjugated alternating donor-acceptor polymers, BPD-DTT and PPD-DTT, based respectively on benzo[c]pyrrole-4,6-dione (BPD) and pyrrolo[3,4-c]pyrrole-4,6-dione (PPD) acceptor structures with the 2,5-dithienylthieno[3,2-b]thiophene (DTT) donor structure were synthesized via Stille cross-coupling polymerization to study their physical and optoelectronic properties. For comparison, an analogous polymer, TPD-DTT, derived from thieno[3,4-c]pyrrole-4,6-dione (TPD) was also prepared by the same approach. These polymers displayed reasonably good solubility in common organic solvents (e.g., THF, toluene, etc.), and were thermally stable to about 350 °C in nitrogen or air. Both BPD-DTT and PPD-DTT showed blue shifts in their UV-vis absorptions and photoluminescence compared with those of TPD-DTT, suggesting that both possess lower degrees of π-delocalization than TPD-DTT, and thus shorter effective π-conjugation lengths and higher air stability as evidenced from their lower HOMO energy levels. Optical band gaps of 1.61 eV, 1.82 eV, and 1.73 eV and HOMO levels of -5.06 eV, -5.32 eV, and -5.20 eV were estimated for TPD-DTT, BPD-DTT and PPD-DTT respectively from spectral and electrochemical measurements. Electrical characterization showed that all three polymers behaved predominantly as p-type semiconductors in organic field-effect transistor and bulk-heterojunction organic solar cell devices.
Source Publication Title
New Journal of Chemistry
Royal Society of Chemistry
Lu, Yong, Yanlian Lei, Bo Wu, Xiaofeng Xu, Furong Zhu, Xiao Hu, Beng S. Ong, and Siu Choon Ng. "Synthesis and properties of benzo[c]-, pyrrolo[3,4-c]-, and thieno[3,4-c]-pyrrole-4,6-dione copolymers." New Journal of Chemistry 39.4 (2015): 2642-2650.