Highly planar cross-conjugated alternating polymers with multiple conformational locks: synthesis, characterization and their field-effect properties. Issue 39 (23rd September 2016)

• Record Type: Journal Article
• Authors: Zhang, Weifeng; Mao, Zupan; Zheng, Naihang; Zou, Jiabin; Wang, Liping; Wei, Congyuan; Huang, Jianyao; Gao, Dong; Yu, Gui
• Is Part Of: Journal of materials chemistry. Volume 4:Issue 39(2016)
• Page Start: 9266
• Page End: 9275
• Publication Date: 2016-09-23
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c6tc02891h
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Two highly planar cross-conjugated polymers with multiple conformational locks were designed and synthesized, and their charge transport properties were investigated. Abstract : It is meaningful to explore new design principles for organic semiconductors. Herein, we have developed two cross-conjugated alternating polymers based on 1, 2-di(thiophen-2-yl)ethane-1, 2-dione (DTO), namely PDTO-C1 and PDTO-C3, and investigated their charge transport properties by fabricating field-effect transistors devices. Single crystal X-ray crystallography shows that non-covalent S⋯O and C–H⋯O interactions exist inside the DTO units. These non-covalent interactions in combination with the C–H⋯O interactions of the thiophene-flanked dithienothiophene units, acting as conformational locks, are beneficial for acquiring the planar backbone conformation. PDTO-C1 and PDTO-C3 possess broad absorption spectra and HOMO and LUMO energy levels of ca. −5.50 and −3.6 eV, respectively. The highest mobility of 0.54 cm 2 V −1 s −1 was achieved in the PDTO-C3-based transistor devices, whereas PDTO-C1 affords a mobility of 0.22 cm 2 V −1 s −1 . Further thin film microstructure investigations indicate that both polymers can form highly-ordered lamellar packing with small π–π stacking distances down to 3.50 Å. These results demonstrate that the incorporation of cross-conjugation may be used as an additional design tactic for organic semiconductors to alter their optoelectronic properties.