A Photophysical Study of Sensitization‐Initiated Electron Transfer: Insights into the Mechanism of Photoredox Activity. Issue 24 (7th April 2020)

• Record Type: Journal Article
• Authors: Coles, Max S.; Quach, Gina; Beves, Jonathon E.; Moore, Evan G.
• Is Part Of: Angewandte Chemie international edition. Volume 59:Issue 24(2020)
• Page Start: 9522
• Page End: 9526
• Publication Date: 2020-04-07
• Subjects: absorption spectroscopy -- catalysis -- photoredox chemistry -- reaction mechanisms -- sensitization-initiated electron transfer; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201916359
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The development of photocatalytic reactions has provided many novel opportunities to expand the scope of synthetic organic chemistry. In parallel with progress towards uncovering new reactivity, there is consensus that efforts focused on providing detailed mechanistic insight in order to uncover underlying excited‐state reactions are essential to maximise formation of desired products. With this in mind, we have investigated the recently reported sensitization‐initiated electron transfer (SenI‐ET) reaction for the C−H arylation of activated aryl halides. Using a variety of techniques, and in particular nanosecond transient absorption spectroscopy, we are able to distinguish several characteristic signals from the excited‐state species involved in the reaction, and subsequent kinetic analysis under various conditions has facilitated a detailed insight into the likely reaction mechanism. Abstract : Sensitization‐initiated electron transfer (SenI‐ET) for photocatalysis has been investigated under various reaction conditions by nanosecond transient absorption (ns‐TA) spectroscopy. By characterising the kinetic behaviour of the different excited‐state species involved, detailed insight into the reaction mechanism has been obtained.