Discovery and characterization of an acridine radical photoreductant

Ian A. MacKenzie, Leifeng Wang, Nicholas P. R. Onuska, Olivia F. Williams, Khadiza Begam, Andrew M. Moran, Barry D. Dunietz and David A. Nicewicz ()
Additional contact information
Ian A. MacKenzie: University of North Carolina at Chapel Hill
Leifeng Wang: University of North Carolina at Chapel Hill
Nicholas P. R. Onuska: University of North Carolina at Chapel Hill
Olivia F. Williams: University of North Carolina at Chapel Hill
Khadiza Begam: Kent State University
Andrew M. Moran: University of North Carolina at Chapel Hill
Barry D. Dunietz: Kent State University
David A. Nicewicz: University of North Carolina at Chapel Hill

Nature, 2020, vol. 580, issue 7801, 76-80

Abstract: Abstract Photoinduced electron transfer (PET) is a phenomenon whereby the absorption of light by a chemical species provides an energetic driving force for an electron-transfer reaction1–4. This mechanism is relevant in many areas of chemistry, including the study of natural and artificial photosynthesis, photovoltaics and photosensitive materials. In recent years, research in the area of photoredox catalysis has enabled the use of PET for the catalytic generation of both neutral and charged organic free-radical species. These technologies have enabled previously inaccessible chemical transformations and have been widely used in both academic and industrial settings. Such reactions are often catalysed by visible-light-absorbing organic molecules or transition-metal complexes of ruthenium, iridium, chromium or copper5,6. Although various closed-shell organic molecules have been shown to behave as competent electron-transfer catalysts in photoredox reactions, there are only limited reports of PET reactions involving neutral organic radicals as excited-state donors or acceptors. This is unsurprising because the lifetimes of doublet excited states of neutral organic radicals are typically several orders of magnitude shorter than the singlet lifetimes of known transition-metal photoredox catalysts7–11. Here we document the discovery, characterization and reactivity of a neutral acridine radical with a maximum excited-state oxidation potential of −3.36 volts versus a saturated calomel electrode, which is similarly reducing to elemental lithium, making this radical one of the most potent chemical reductants reported12. Spectroscopic, computational and chemical studies indicate that the formation of a twisted intramolecular charge-transfer species enables the population of higher-energy doublet excited states, leading to the observed potent photoreducing behaviour. We demonstrate that this catalytically generated PET catalyst facilitates several chemical reactions that typically require alkali metal reductants and can be used in other organic transformations that require dissolving metal reductants.

Date: 2020
References: Add references at CitEc
Citations: View citations in EconPapers (5)

Downloads: (external link)
https://www.nature.com/articles/s41586-020-2131-1 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:580:y:2020:i:7801:d:10.1038_s41586-020-2131-1

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/s41586-020-2131-1

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().