Methionine-Based Radicals: Time Scales and Species
Résumé
Abstract l -Methionine is an amino acid, which provides anti-oxidative properties. We report on radicals and radical cations being likely (short-lived) intermediates formed upon photo-oxidation reactions of methionine. In this context, we present photo-CIDNP experiments indicating that the character of the photooxidants is decisive for the observation of CIDNP effects based on methionine. Based on calculated hyperfine data and pK a values and on our experimental observations, we suggest that CIDNP polarizations are produced by an overlay of at least three geminal radical pairs, i.e., two α -thio carbon-centered radicals D · and G ·, aminyl radical N ·, and, possibly, 2c–3e radical cation SN . + as short-lived reaction intermediates.
Domaines
Chimie théorique et/ou physique
Origine : Fichiers produits par l'(les) auteur(s)