Abstract
An analysis of the electron spin resonance spectrum of γ‐irradiated crystals of N(CH3)4Cl shows that the paramagnetic species stable at room temperature is (CH3)3N+. The isotropic coupling constants are found to be 18.0 G for the nitrogen and 26.7 G for the methyl protons. All methyl protons are found to be equivalent. The radical is probably planar and is found to execute restricted rotation at room temperature.