A Direct S0→Tn Transition in the Photoreaction of Heavy‐Atom‐Containing Molecules. (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. Volume 132:Number 17(2020)
• Page Start: 6914
• Page End: 6919
• Publication Date: 2020-03-09
• Subjects: Hypervalentes Iod -- Moleküle mit Schweratomen -- Photoreaktionen -- S0→Tn-Übergänge; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201915181
• Languages: English
• ISSNs: 0044-8249

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 : Verbote nicht so streng gesehen : Spektroskopie‐Experimente zeigen, dass Photoreaktionen von Molekülen, die Schweratome enthalten, mit Licht in einer anscheinend nicht‐absorbierenden Region über einen verbotenen, direkten S0 →T n ‐Übergang verlaufen. Das Phänomen tritt in der Photoreaktion von Aryliodiden (Oxidationsstufen I, III und V), Arylbromiden und Bismut(III) enthaltenden Molekülen auf.