Triplet 4‐Nitrenemethyl‐Pyridine‐N‐Oxide: A Model Alkyl Nitrene Isolated in Cryogenic Matrices. - Nunes, Cláudio M.; Jesus, A. J. Lopes; Caneca, Tatiana; Aragay, Gemma; Ballester, Pablo; Fausto, Rui (Journal of Physical Organic Chemistry, 2026)