Characterization of alkoxy free radicals

Abstract

Alkoxy radicals have been produced by x irradiation in a variety of compounds containing hydroxy groups. The relationship between the g tensor and its correlated hyperfine coupling tensors are explored as an additional means for characterizing alkoxy radicals. A simple model of the spin density distribution in an alkoxy radical is able to account for the main features of the anisotropic coupling. The model places 0.75 spin density in a p orbital of the oxygen atom and a small positive density along the C-H bond axis.

Radiation Products at 77 K in Trehalose Single Crystals: EMR and DFT Analysis

“…EPR angular variations reveal both centers with small and relatively large g anisotropy, indicating the presence of both alkyl and alkoxy radicals, respectively. 42,43 Because of the differences in relaxation times and hence powersaturation behavior, the alkoxy radicals are better visible at high microwave power (10 mW), whereas the alkyl radicals are preferably measured at low microwave power (0.01 mW). 4.2.1.…”

Combined Electron Magnetic Resonance and Density Functional Theory Study of 10 K X-Irradiated β-d-Fructose Single Crystals

“…The weak resonance lines on each side of the central region (Figure a) also exhibit very small g anisotropy which leads to the conclusion that they are not related to alkoxy radicals. Indeed, paramagnetic absorption of alkoxy radicals is characterized by considerable g shifts arising from spin−orbit coupling of the unpaired electron localized primarily on the oxygen atom. , …”

“…Indeed, paramagnetic absorption of alkoxy radicals is characterized by considerable g shifts arising from spin-orbit coupling of the unpaired electron localized primarily on the oxygen atom. 34,35 The EPR angular variation did not allow an accurate interpretation of the spectra, and unfortunately ENDOR measurements for the weak flanking lines were not successful probably due to the low intensity of the EPR signals. Therefore, the results presented below are limited to the resonances of the central part of the spectrum.…”