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The rapid development of light-activated organic photoredox catalysts has led to the proliferation of powerful synthetic chemical strategies with industrial and pharmaceutical applications. Despite the advancement in synthetic approaches, a detailed understanding of the mechanisms governing these reactions has lagged. Time-resolved optical spectroscopy provides a method to track organic photoredox catalysis processes and reveal the energy pathways that drive reaction mechanisms. These measurements are sensitive to key processes in organic photoredox catalysis such as charge or energy transfer, lifetimes of singlet or triplet states, and solvation dynamics. The sensitivity and specificity of ultrafast spectroscopic measurements can provide a new perspective on the mechanisms of these reactions, including electron-transfer events, the role of solvent, and the short lifetimes of radical intermediates.
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Kinetic Control over Disproportionation Stabilizes Wurster’s Blue Catholyte for Nonaqueous Redox Flow Batteries
Redoxmers are organic molecules that serve as charge carriers in redox flow batteries. While these materials are affordable and easy to source, insufficient stability of their charged states (radical ions) remains a challenge. A common reaction of these species is their disproportionation. This reversible reaction yields unstable multiply charged states, shifting the overall charge transfer equilibrium toward the decomposition products. Here we show how kinetic controls can be engineered into a redoxmer molecule to suppress these unwanted charge transfer reactions. This approach is used to transform Wurster’s blue, which is historically the first example of a stable radical ion in organic chemistry, into an exceptionally durable redoxmer molecule that persists over thousands of electrochemical cycles.
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- PAR ID:
- 10611019
- Editor(s):
- Kamat, Prashant V
- Publisher / Repository:
- American Chemical Society
- Date Published:
- Journal Name:
- ACS Energy Letters
- Volume:
- 9
- Issue:
- 12
- ISSN:
- 2380-8195
- Page Range / eLocation ID:
- 5737 to 5743
- Subject(s) / Keyword(s):
- Cations Electrolytes Molecules Redox reactions Stability
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript
- Journal Article:
- https://doi.org/10.1021/acsenergylett.4c02449
