Open‐Shell Donor–Acceptor Conjugated Polymers with High Electrical Conductivity

Authors

Lifeng Huang, University of Southern Mississippi
Naresh Eedugurala, University of Southern MississippiFollow
Anthony Benasco, University of Southern MississippiFollow
Song Zhang, University of Southern MississippiFollow
Kevin S. Mayer, University of Southern MississippiFollow
Daniel J. Adams, University of Southern MississippiFollow
Benjamin Fowler, University of Alabama
Molly M. Lockart, University of AlabamaFollow
Mohammad Saghayezhian, Louisiana State University
Hamas Tahir, University of Southern Mississippi
Eric R. King, University of Southern MississippiFollow
Sarah Morgan, University of Southern MississippiFollow
Michael K. Bowman, University of AlabamaFollow
Xiaodan Gu, University of Southern MississippiFollow
Jason Azoulay, University of Southern MississippiFollow

Document Type

Article

Publication Date

5-4-2020

School

Polymer Science and Engineering

Abstract

Conductive polymers largely derive their electronic functionality from chemical doping, processes by which redox and charge‐transfer reactions form mobile carriers. While decades of research have demonstrated fundamentally new technologies that merge the unique functionality of these materials with the chemical versatility of macromolecules, doping and the resultant material properties are not ideal for many applications. Here, it is demonstrated that open‐shell conjugated polymers comprised of alternating cyclopentadithiophene and thiadiazoloquinoxaline units can achieve high electrical conductivities in their native “undoped” form. Spectroscopic, electrochemical, electron paramagnetic resonance, and magnetic susceptibility measurements demonstrate that this donor–acceptor architecture promotes very narrow bandgaps, strong electronic correlations, high‐spin ground states, and long‐range π‐delocalization. A comparative study of structural variants and processing methodologies demonstrates that the conductivity can be tuned up to 8.18 S cm⁻¹. This exceeds other neutral narrow bandgap conjugated polymers, many doped polymers, radical conductors, and is comparable to commercial grades of poly(styrene‐sulfonate)‐doped poly(3,4‐ethylenedioxythiophene). X‐ray and morphological studies trace the high conductivity to rigid backbone conformations emanating from strong π‐interactions and long‐range ordered structures formed through self‐organization that lead to a network of delocalized open‐shell sites in electronic communication. The results offer a new platform for the transport of charge in molecular systems.

Publication Title

Advanced Functional Materials

Recommended Citation

Huang, L., Eedugurala, N., Benasco, A., Zhang, S., Mayer, K. S., Adams, D. J., Fowler, B., Lockart, M. M., Saghayezhian, M., Tahir, H., King, E. R., Morgan, S., Bowman, M. K., Gu, X., Azoulay, J. (2020). Open‐Shell Donor–Acceptor Conjugated Polymers with High Electrical Conductivity. Advanced Functional Materials.
Available at: https://aquila.usm.edu/fac_pubs/17371