Electron paramagnetic resonance spectra of the tert-butylperoxy and tert-butoxy adducts to phenyl tert-butyl nitrone and 2-methyl-2-nitrosopropane. Oxygen-17 hyperfine coupling constants

Abstract

tert-Butylperoxy radicals enriched with oxygen-17 react with phenyl tert-butyl nitrone to give α-tert-butylperoxybenzyl tert-butyl nitroxide with aN = 13.42 G, aH = 0.95 G, aoβ = 2.9 G, g = 2.0064. The O-hfsc decreases with an increase in temperature while the H-hfsc increases with an increase in temperature. This radical is not stable above about 273 K and is replaced by α-tert-butoxybenzyl tert-butyl nitroxide, aN = 13.62 G, aH = 1.72 G, aoβ = 5.05 G, g = 2.0064.Alkylperoxy radicals are also trapped by 2-methyl-2-nitrosopropane to give alkylperoxy tert-butyl nitroxide aN = 28.7 G, aoROO = 4.6 G, g = 2.0056 while the epr parameters for alkoxy tert-butyl nitroxide are aN = 27.25 G, aoRO = 1.03 G, g = 2.0057.