Using a simple π-conjugated trimer, EDOT-phenylene-EDOT (EDOT = 3,4-ethylenedioxythiophene), we evaluate the effect that fluorine substituents have upon changes in conformation, conjugation, and oxidation potentials in π-conjugated structures. These variations are assessed as a function of the fluorine atom's propensity to feature in hydrogen and/or halogen bonding with other heteroatoms. The molecular motif was chosen because the EDOT unit presents the possibility of competing O···X or S···X noncovalent contacts (where X = H or F). Such nonbonding interactions are acknowledged to be highly influential in dictating molecular and polymer morphology and inducing changes in certain physical properties. We studied four compounds, beginning with an unsubstituted bridging phenylene ring and then adding one, two, or four fluorine units to the parent molecule. Our studies involve single-crystal X-ray diffraction studies, cyclic voltammetry, absorption spectroscopy, and density functional theory calculations to identify the dominant noncovalent interactions and elucidate their effects on the molecules described. Experimental studies have also been carried out on the corresponding electrochemically synthesized polymers to confirm that these noncovalent interactions and their effects persist in polymers. Our findings show that hydrogen bonding and halogen bonding feature in these molecules and their corresponding polymers.
|Number of pages||10|
|Journal||Chemistry of Materials|
|State||Published - Sep 10 2019|
Bibliographical noteFunding Information:
T.K., R.P., R.N., and P.J.S. thank the European Commission (Marie Curie Action of FP7, Grant PIRSES-GA-2013-612670) for financial support. The work at the University of Kentucky was supported by the National Science Foundation Designing Materials to Revolutionize and Engineer our Future (NSF DMREF) program under Award DMR-1627428. Supercomputing resources on the Lipscomb High Performance Computing Cluster were provided by the University of Kentucky Information Technology Department and Center for Computational Sciences (CCS).
© 2019 American Chemical Society.
ASJC Scopus subject areas
- Chemistry (all)
- Chemical Engineering (all)
- Materials Chemistry