Photochemical Rearrangements of Pyridine N-Oxides: Pathways to Oxaziridine Derivatives
The photochemical behavior of substituted pyridine N-Oxides is characterized by complex rearrangements culminating in the formation of valuable photoproducts. The CAS(10,8)/cc-pVDZ approach with NEVPT2 corrections is applied to investigate geometric distortions associated with the S1 excited state, conical intersections, and the ultimate transformation of pyridine N-Oxides into oxaziridine-like derivative formations. Our results reveal that the deactivation of the S1 excited state is driven by an out-of-plane rotation of the N-O oxygen atom, resulting in the formation of a lone pair over the nitrogen atom. Along this excited-state reaction pathway, the N-O bond undergoes significant weakening, while a C=C double bond emerges mainly in the excited state. The deactivation at the minimum-energy conical intersection leading to the ground state reveals the formation of an oxaziridine-like intermediate, which subsequently converts into a 1,2-oxazepine derivative.
Authors
- Leandro Ayarde‐Henríquez (ORCID: https://orcid.org/0000-0001-5963-6028)
- Adolfo E. Ensuncho (ORCID: https://orcid.org/0000-0003-0384-8667)
- Jorge Soto‐Delgado (ORCID: https://orcid.org/0000-0002-2983-1727)
- Efraín Polo-Cuadrado (ORCID: https://orcid.org/0000-0003-2280-9321)
- Mitchell Bacho (ORCID: https://orcid.org/0000-0002-1754-6793)
- Cristian Guerra (ORCID: https://orcid.org/0000-0002-9664-2504)
- Yeray A. Rodríguez‐Núñez (ORCID: https://orcid.org/0000-0003-4935-876X)
- Cristopher A. Fica-Cornejo (ORCID: https://orcid.org/0009-0001-1250-0841)
- Manuel E. Taborda-Martínez
- Victor B. Fuentes-Guerrero
- Eduardo I. Torres-Olguín (ORCID: https://orcid.org/0009-0006-7023-5181)
- Daniela Rodríguez-García (ORCID: https://orcid.org/0009-0004-2829-7480)
Institutions
- University of Concepción (CL)
- Trinity College Dublin (IE)
- University of Magdalena (CO)
- San Sebastián University (CL)
- Viña del Mar University (CL)
- University of Córdoba (CO)
- Advanced Materials and BioEngineering Research (IE)
- University of Chile (CL)
Publication Details
- Journal
- Molecules
- Published
- 2025-12-14
- DOI
- https://doi.org/10.3390/molecules30244776
- Citations
- 1
- Primary Topic
- Radical Photochemical Reactions
- Type
- article
- Field-Weighted Citation Impact
- 0.94
Funders
- Irish Centre for High-End Computing