Impact of Fluorine Substituents on π-Conjugated Polymer Main-Chain Conformations, Packing, and Electronic Couplings

Khanh Do; Qasim Saleem; Mahesh Kumar Ravva; Federico Cruciani; Zhipeng Kan; Jannic Wolf; Michael Ryan Hansen; Pierre M Beaujuge; Jean-Luc Brédas

doi:10.1002/adma.201601282

Impact of Fluorine Substituents on π-Conjugated Polymer Main-Chain Conformations, Packing, and Electronic Couplings

Adv Mater. 2016 Oct;28(37):8197-8205. doi: 10.1002/adma.201601282. Epub 2016 Jul 14.

Authors

Khanh Do^{1

2}, Qasim Saleem¹, Mahesh Kumar Ravva¹, Federico Cruciani¹, Zhipeng Kan¹, Jannic Wolf¹, Michael Ryan Hansen³, Pierre M Beaujuge⁴, Jean-Luc Brédas⁵

Affiliations

¹ Physical Science and Engineering Division, Solar & Photovoltaic Engineering Research Center (SPERC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
² School of Chemistry and Biochemistry & Center for Organic Photonics and Electronics (COPE), Georgia Institute of Technology, Atlanta, GA, 30332-0400, USA.
³ Institute of Physical Chemistry, Westfälische Wilhelms-Universität Münster, Corrensstr. 28/30, D-48149, Münster, Germany. mhansen@uni-muenster.de.
⁴ Physical Science and Engineering Division, Solar & Photovoltaic Engineering Research Center (SPERC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia. pierre.beaujuge@kaust.edu.sa.
⁵ Physical Science and Engineering Division, Solar & Photovoltaic Engineering Research Center (SPERC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia. jean-luc.bredas@kaust.edu.sa.

PMID: 27411743
DOI: 10.1002/adma.201601282

Abstract

Taking the π-conjugated polymers PBDT[2X]T (X = H, F) as model systems, the effects of fluorine substitution on main-chain conformations, packing, and electronic couplings are examined. This combination of molecular dynamics simulations and solid-state NMR shows that a higher propensity for backbone planarity in PBDT[2F]T leads to more pronounced, yet staggered, chain stacking, which generally leads to higher electronic couplings and binding energy between neighboring chains.

Keywords: molecular dynamics; organic electronics; solid-state nuclear magnetic resonance; thin-film morphology; π-conjugated polymers.