Rahman, MSBharadwaj, VLautaha, AKHSSampson, PBrasch, NESeed, AJ2024-11-062024-11-062024-08-19Molecules, ISSN: 1420-3049 (Print); 1420-3049 (Online), MDPI AG, 29(16), 3918-. doi: 10.3390/molecules291639181420-30491420-3049http://hdl.handle.net/10292/18232Photoactive N-hydroxysulfonamides photocaged with the (6-bromo-7-hydroxycoumarin-4-yl)methyl chromophore have been successfully synthesized, and the mechanisms of photodecomposition investigated for two of the compounds. Upon irradiation up to 97% of a diagnostic marker for (H)NO release, sulfinate was observed for the trifluoromethanesulfonamide system. In the absence of a species that reacts rapidly with (H)NO, (H)NO instead reacts with the carbocation intermediate to ultimately generate (E)-BHC-oxime and (Z)-BHC-oxime. Alternatively, the carbocation intermediate reacts with solvent water to give a diol. Deprotonation of the N(H) proton is required for HNO generation via concerted C-O/N-S bond cleavage, whereas the protonation state of the O(H) does not affect the observed photoproducts. If the N(H) is protonated, C-O bond cleavage to generate the parent N-hydroxysulfonamide will occur, and/or O-N bond cleavage to generate a sulfonamide. The undesired competing O-N bond cleavage pathway increases when the volume percentage of water in acetonitrile/water solvent mixtures is increased.© 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).https://creativecommons.org/licenses/by/4.0/HNON-hydroxysulfonamidePiloty’s acidnitroxylphotocagephotochemistry3402 Inorganic Chemistry34 Chemical Sciences0304 Medicinal and Biomolecular Chemistry0305 Organic Chemistry0307 Theoretical and Computational ChemistryOrganic Chemistry3404 Medicinal and biomolecular chemistry3405 Organic chemistryJournal ArticleOpenAccess10.3390/molecules29163918