Electrochemical Analysis in Charge-Transfer Science: Things Are Not Always What They Seem

Abstract

Charge transfer (CT) and charge transport (CTr) are essential for supporting life on Earth and for making our modern ways of living possible [Phys. Chem. Chem. Phys. 2020, 22, 21583-21629]. Electrochemical analysis, while relying on heterogeneous electron transfer (ET), is of key importance for characterizing CT systems and process [Curr. Opin. Electrochem. 2022, 31, 100862]. The huge difference between the timescales of electrochemical measurements and the picosecond CT reactions of interests places inherent demands for reliable interpretations of voltammetry analyses [J. Electrochem. Soc. 2019, 166, H3175-H3187]. Concurrently, the ubiquity of electric dipole warrants deep understanding of how they affect CT thermodynamics and kinetics [J. Am. Chem. Soc. 2014, 136, 12966-12973]. The localized dipole-generated fields affect the electrochemical potentials of donors and acceptors and, thus, the Franck-Condon contribution to the CT kinetics [Angew. Chem. Intnl. Ed. 2018, 57, 12365-12369]. In the context of our latest developments in electrochemical analysis, this presentation focuses on how molecular dipoles affect not only the potentials, but also the reorganization energy and the donor-acceptor coupling. Understanding the multifaceted nature of the effects of dipoles on charge transfer and charge transport drives the emergence of new paradigms for electronics, photonics and energy science and engineering.