A Direct S0→Tn Transition in the Photoreaction of Heavy‐Atom‐Containing Molecules. Issue 17 (9th March 2020)

• Record Type: Journal Article
• Authors: Nakajima, Masaya; Nagasawa, Sho; Matsumoto, Koki; Kuribara, Takahito; Muranaka, Atsuya; Uchiyama, Masanobu; Nemoto, Tetsuhiro
• Is Part Of: Angewandte Chemie international edition. Volume 59:Issue 17(2020)
• Page Start: 6847
• Page End: 6852
• Publication Date: 2020-03-09
• Subjects: heavy-atom-containing molecules -- hypervalent iodine -- photoreactions -- S0→Tn transitions; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201915181
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: According to the Grotthuss–Draper law, light must be absorbed by a substrate to initiate a photoreaction. There have been several reports, however, on the promotion of photoreactions using hypervalent iodine during irradiation with light from a non‐absorbing region. This contradiction gave rise to a mystery regarding photoreactions involving hypervalent iodine. We demonstrated that the photoactivation of hypervalent iodine with light from the apparently non‐absorbing region proceeds via a direct S0 →T n transition, which has been considered a forbidden process. Spectroscopic, computational, and synthetic experimental results support this conclusion. Moreover, the photoactivation mode could be extended to monovalent iodine and bromine, as well as bismuth(III)‐containing molecules, providing new possibilities for studying photoreactions that involve heavy‐atom‐containing molecules. Abstract : Forget about forbiddance : Spectroscopic experiments reveal that photoreactions of heavy‐atom‐containing molecules with light in an apparently non‐absorbing region proceed via a forbidden direct S0 →T n transition. This phenomenon occurs in the photoreaction of aryl iodides (oxidation states I, III, and V), aryl bromides, and bismuth(III)‐containing molecules.