eprintid: 10187533 rev_number: 7 eprint_status: archive userid: 699 dir: disk0/10/18/75/33 datestamp: 2024-02-22 11:46:56 lastmod: 2024-02-22 11:46:56 status_changed: 2024-02-22 11:46:56 type: article metadata_visibility: show sword_depositor: 699 creators_name: Giussani, Angelo creators_name: Worth, Graham A title: A First Proposal on the Nitrobenzene Photorelease Mechanism of NO2 and Its Relation to NO Formation through a Roaming Mechanism ispublished: inpress divisions: UCL divisions: B04 divisions: C06 divisions: F56 note: © 2024 The Authors. Published by American Chemical Society. This publication is licensed under CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/). abstract: Despite the fact that NO2 is considered to be the main photoproduct of nitrobenzene photochemistry, no mechanism has ever been proposed to rationalize its formation. NO photorelease is instead a more studied process, probably due to its application in the drug delivery sector and the study of roaming mechanisms. In this contribution, a photoinduced mechanism accounting for the formation of NO2 in nitrobenzene is theorized based on CASPT2, CASSCF, and DFT electronic structure calculations and CASSCF classical dynamics. A triplet nπ* state is shown to evolve toward C-NO2 dissociation, being, in fact, the only low-lying excited state favoring such a deformation. Along the triplet dissociation path, the possibility to decay to the singlet ground state results in the frustration of the dissociation and in the recombination of the fragments, either back to the nitro or the nitrite isomer. The thermal decomposition of the latter to NO constitutes globally a roaming mechanism of NO formation. date: 2024-02-19 date_type: published official_url: https://doi.org/10.1021/acs.jpclett.3c03457 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 2248524 doi: 10.1021/acs.jpclett.3c03457 medium: Print-Electronic lyricists_name: Worth, Graham lyricists_id: GWORT12 actors_name: Flynn, Bernadette actors_id: BFFLY94 actors_role: owner full_text_status: public publication: The Journal of Physical Chemistry Letters pagerange: 2216-2221 event_location: United States citation: Giussani, Angelo; Worth, Graham A; (2024) A First Proposal on the Nitrobenzene Photorelease Mechanism of NO2 and Its Relation to NO Formation through a Roaming Mechanism. The Journal of Physical Chemistry Letters pp. 2216-2221. 10.1021/acs.jpclett.3c03457 <https://doi.org/10.1021/acs.jpclett.3c03457>. (In press). Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10187533/1/giussani-worth-2024-a-first-proposal-on-the-nitrobenzene-photorelease-mechanism-of-no2-and-its-relation-to-no-formation.pdf