The substitution of sterically bulky groups at precise locations along the periphery of fused-ring aromatic systems is demonstrated to increase electrochemical oxidation potentials by preventing relaxation events in the oxidized state. Phenothiazines, which undergo significant geometric relaxation upon oxidation, are used as fused-ring models to showcase that electron-donating methyl groups, which would generally be expected to lower oxidation potential, can lead to increased oxidation potentials when used as the steric drivers. Reduction events remain inaccessible through this molecular design route, a critical characteristic for electrochemical systems where high oxidation potentials are required and in which reductive decomposition must be prevented, as in high-voltage lithium-ion batteries. This study reveals a new avenue to alter the redox characteristics of fused-ring systems that find wide use as electroactive elements across a number of developing technologies.
|Number of pages||5|
|State||Published - Aug 18 2017|
Bibliographical noteFunding Information:
This work was funded by the National Science Foundation's Division of Chemistry (Award 1300653) and EPSCoR Program (Award 1355438). CFE thanks the Division of Organic Chemistry of the American Chemical Society for a Summer Undergraduate Research Fellowship. SAO and CR thank the University of Kentucky for start-up funding.
© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
- electronic structure
- redox chemistry
- strained molecules
- substituent effects
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry