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Updated: Jul 10, 2026

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
Radical trapping properties of 3-aryl-2H-benzo[1,4]oxazin-4-oxides
Paola Astolfi1, Milvia Marini, Pierluigi Stipa
1Dipartimento di Scienze e Tecnologie Chimiche, Università Politecnica delle Marche, via Brecce Bianche, I-60131, Ancona, Italy.
Abstract:
A series of 3-aryl-2H-benzo[1,4]oxazin-4-oxides was prepared, and their ability to trap free radicals was investigated by EPR spectroscopy. In organic solvents, these compounds were able to efficiently scavenge all carbon- and oxygen-centered radicals tested, giving very persistent aminoxyls, except with superoxide anion whose spin adducts were unstable. The main feature of these nitrones as spin traps lies in the possibility to recognize the initial radical trapped. In fact, besides a g-factor and aminoxyl nitrogen EPR coupling constant dependence on the species trapped, the EPR spectra also show different patterns due to hyperfine splittings characteristic of the radical scavenged. This last important feature was investigated by means of density functional theory calculations.
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