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Title: Helical Poly(5-alkyl-2,3-thiophene)s: Controlled Synthesis and Structure Characterization

Abstract

Whereas Poly(3-alkyl-2,5-thiophene)s (P3AT), with many potential applications, have been extensively investigated, their ortho-connected isomers, poly(5-alkyl-2,3-thiophene)s (P5AT), have never been reported because of the difficulty in their syntheses. We herein present the first synthesis of regioregular P5AT via controlled Suzuki cross-coupling polymerization with PEPPSI-IPr as catalyst, affording the polymers with tunable molecular weight, narrow polydispersity (PDI) and well-defined functional end groups at the gram scale. The helical geometry of P5AT was studied by a combination of NMR, small angle x-ray scattering (SAXS) and scanning tunneling microscopy (STM). Particularly, the single polymer chain of poly(5- 2 butyl-2,3-thiophene) (P5BT) on highly oriented pyrolytic graphite (HOPG) substrates with either M or P helical conformation was directly observed by STM. The comparison of UV-vis absorption between poly(5-hexyl-2,3-thiophene) (P5HT) (λ = 345 nm) and poly(3-hexyl-2,5- thiophene) (P3HT) (λ = 450 nm) indicated that the degree of conjugation of the backbone in P5HT is less than in P3HT, which may be a consequence of the helical geometry of the former compared to the more planar geometry of the latter. Moreover, we found that P5HT can emit green fluorescence under UV (λ = 360 nm) irradiation

Authors:
; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1265664
Grant/Contract Number:
AC05-00OR22725
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Macromolecules
Additional Journal Information:
Journal Volume: 49; Journal Issue: 13; Journal ID: ISSN 0024-9297
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Zhang, Hong-Hai, Ma, Chuanxu, Bonnesen, Peter V., Zhu, Jiahua, Sumpter, Bobby G., Carrillo, Jan-Michael Y., Yin, Panchao, Wang, Yangyang, Li, An-Ping, and Hong, Kunlun. Helical Poly(5-alkyl-2,3-thiophene)s: Controlled Synthesis and Structure Characterization. United States: N. p., 2016. Web. doi:10.1021/acs.macromol.6b01233.
Zhang, Hong-Hai, Ma, Chuanxu, Bonnesen, Peter V., Zhu, Jiahua, Sumpter, Bobby G., Carrillo, Jan-Michael Y., Yin, Panchao, Wang, Yangyang, Li, An-Ping, & Hong, Kunlun. Helical Poly(5-alkyl-2,3-thiophene)s: Controlled Synthesis and Structure Characterization. United States. doi:10.1021/acs.macromol.6b01233.
Zhang, Hong-Hai, Ma, Chuanxu, Bonnesen, Peter V., Zhu, Jiahua, Sumpter, Bobby G., Carrillo, Jan-Michael Y., Yin, Panchao, Wang, Yangyang, Li, An-Ping, and Hong, Kunlun. Tue . "Helical Poly(5-alkyl-2,3-thiophene)s: Controlled Synthesis and Structure Characterization". United States. doi:10.1021/acs.macromol.6b01233. https://www.osti.gov/servlets/purl/1265664.
@article{osti_1265664,
title = {Helical Poly(5-alkyl-2,3-thiophene)s: Controlled Synthesis and Structure Characterization},
author = {Zhang, Hong-Hai and Ma, Chuanxu and Bonnesen, Peter V. and Zhu, Jiahua and Sumpter, Bobby G. and Carrillo, Jan-Michael Y. and Yin, Panchao and Wang, Yangyang and Li, An-Ping and Hong, Kunlun},
abstractNote = {Whereas Poly(3-alkyl-2,5-thiophene)s (P3AT), with many potential applications, have been extensively investigated, their ortho-connected isomers, poly(5-alkyl-2,3-thiophene)s (P5AT), have never been reported because of the difficulty in their syntheses. We herein present the first synthesis of regioregular P5AT via controlled Suzuki cross-coupling polymerization with PEPPSI-IPr as catalyst, affording the polymers with tunable molecular weight, narrow polydispersity (PDI) and well-defined functional end groups at the gram scale. The helical geometry of P5AT was studied by a combination of NMR, small angle x-ray scattering (SAXS) and scanning tunneling microscopy (STM). Particularly, the single polymer chain of poly(5- 2 butyl-2,3-thiophene) (P5BT) on highly oriented pyrolytic graphite (HOPG) substrates with either M or P helical conformation was directly observed by STM. The comparison of UV-vis absorption between poly(5-hexyl-2,3-thiophene) (P5HT) (λ = 345 nm) and poly(3-hexyl-2,5- thiophene) (P3HT) (λ = 450 nm) indicated that the degree of conjugation of the backbone in P5HT is less than in P3HT, which may be a consequence of the helical geometry of the former compared to the more planar geometry of the latter. Moreover, we found that P5HT can emit green fluorescence under UV (λ = 360 nm) irradiation},
doi = {10.1021/acs.macromol.6b01233},
journal = {Macromolecules},
number = 13,
volume = 49,
place = {United States},
year = {Tue Jul 12 00:00:00 EDT 2016},
month = {Tue Jul 12 00:00:00 EDT 2016}
}

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