ESR and ENDOR study of x‐irradiated single crystals of β‐alanine at room temperature

Three radicals have been identified in the room temperature ESR spectra of x‐irradiated single crystals of β‐alanine (N+H3CH2CH2CO−2). ENDOR spectra from one radical exhibit hyperfine coupling to 1 α‐proton (Axx=−33.12, Ayy=—20.68, Azz=−10.50 G) and 2 β‐protons [Aiso(Hβ1) =13.24 G, Aiso(Hβ2) =4.89 G]. From the anisotropic nature of the α‐proton coupling it has been determined that these splittings arise from a N+H3CH2ĊHCO−2 radical. It has been shown that this radical is the decay product of the unstable low temperature oxidation product. A second room temperature radical, N+H3CH2CH2Ċ=0, has been shown to be a decay product of the primary reduction product. A minor room temperature product has been tentatively identified as a ĊH2–CH2–R radical.