ENDOR study of an irradiated crystal of L-alanine: Structure and the environment of the unstable CH3ĊHCO2− radical

Abstract
The unstable CH3ĊHCO2 radical and its environment in an x‐ray irradiated crystal of L‐alanine were investigated at 77 K with the use of ENDOR technique. It was found that upon radical formation, the atoms of the radical shifted substantially from their original positions in the undamaged crystal. Unusually strong positive ENDOR signals were detected from the methyl protons of the radical: some signals were found to be stronger than the ESR signal.