Methyl Dynamics Studied by ENDOR Spectroscopy: A New Method

We present a new method to study classical methyl group rotation in radicals by exploiting the ENDOR line intensities and their temperature variation. The proposed method works for low barrier as well as high barrier systems. The method lies on the fact that the methyl rotation modulates the proton contact coupling constant. This gives rise to a specific relaxation path which affects in a dramatic way the EPR desaturation determining the ENDOR line intensity.

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