Resolution Enhancement of ESR Spectra from Irradiated Single Crystals of Glycine

The electron spin resonance spectrum of ⁺H₃NĊHCOO⁻ in single crystals of glycine $\gamma$ irradiated at room temperature has been re‐examined at X band and evaluated by resolution‐enhancement technique. The resolution enhancement is obtained by reducing the linewidth by a factor of maximum 0.55 at the expense of the signal‐to‐noise ratio. The calculations, which require a high‐speed digital computer, consist of three steps: (1) transformation of the experimental spectrum to a complex Fourier plane, (2) multiplication of this Fourier spectrum with a suitable linewidth‐reduction function, and (3) inverse transformation back to the real plane. From the obtained constants, the hyperfine coupling tensors have been calculated, including contributions from second‐order effects ${\mathrm{(\Delta M}}_I\text{\hspace{0.17em}=\hspace{0.17em}±\hspace{0.17em}1)}$ . One of the principal values of one of the tensors was appreciably affected by these second‐order effects. The results fully confirm the structure of the radical.