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Abstract N‐phenyl dibenzothiophene sulfoximine has been demonstrated to produce phenyl nitrene and dibenzothiopheneS‐oxide upon irradiation with UV‐A light, and dibenzothiopheneS‐oxide upon further irradiation releases triplet atomic oxygen. Thus,N‐phenyl dibenzothiophene sulfoximine exhibits a rare dual‐release capability in its photochemistry. In this work,N‐substituted dibenzothiophene sulfoximine derivatives are irradiated with UV‐A light to compare their photochemistry and quantum yield of dibenzothiopheneS‐oxide production with that ofN‐phenyl dibenzothiophene sulfoximine. BothN‐aryl andN‐alkyl derivatives of dibenzothiophene sulfoximine are examined to observe their effects on the quantum yield of the photolysis reaction. Adding electron withdrawingN‐aryl substituents is shown to increase the quantum yield of dibenzothiopheneS‐oxide production, while adding electron donatingN‐aryl substituents is shown to decrease the quantum yield. The quantum yield was slightly lowered or not increased by mostN‐alkyl substituents. Furthermore, the quantum yield was not augmented by branching and steric hindrance effects associated with theN‐alkyl substituents. These results suggest that electronic modulation of the sulfoximine bonds affects the observed photolysis reaction.
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Two‐step Two‐intermediate Photorelease Bolm‐McCulla Reaction: Dual Release of Nitrene and Atomic Oxygen Reactive Intermediates
Abstract This article is a highlight of the paper by Isor et al. in this issue ofPhotochemistry and Photobiology. It describes the photolysis of a dibenzothiophene sulfoximine (bearingN‐phenyl imino andS‐oxide groups) to produce two reactive intermediates in tandem. The sulfoximine undergoes a S–N and S–O photocleavage to release phenyl nitrene and atomic oxygen [O(3P)]. The phenyl nitrene dimerizes to azobenzene or is trapped by diethylamine to reach an azepine. From there, atomic oxygen arises in a secondary photolysis of dibenzothiophene sulfoxide. A computational analysis also reveals that the S–N bond is labile for initial nitrene release, with the secondary release of atomic oxygen by S–O cleavage. Whether future sulfoximine scaffolds can produce the reverse order release of O(3P) then nitrene, or release both simultaneously, is yet to be established. Nonetheless, molecules with dual‐intermediate release, such as coupled photoaffinity labeling and cellular oxidation, are worth pursuing.
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- Award ID(s):
- 1856765
- PAR ID:
- 10445898
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Photochemistry and Photobiology
- Volume:
- 97
- Issue:
- 6
- ISSN:
- 0031-8655
- Page Range / eLocation ID:
- p. 1453-1455
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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