The electron paramagnetic resonance spectrum of the [·N(CH₃)₃]⁺ radical in γ-irradiated [NH(CH₃)₃]₂SnCl₆ crystals

A paramagnetic species identified as the [·N(CH₃)₃]⁺ radical was detected by electron paramagnetic resonance (EPR) in γ-irradiated [NH(CH₃)₃]₂SnCl₆ crystals. The EPR spectrum of this radical exhibits axial symmetry, with the symmetry axis pointing parallel to a 〈111〉 axis of the cubic host lattice. The g-factor and the proton hyperfine splitting are isotropic, but the nitrogen splitting is highly anisotropic. The observed nitrogen splitting is such that the unpaired electron of the radical can be regarded as centered on nitrogen and located in a 2pπ orbital. The three methyl groups of the radical can be regarded as to execute free or nearly free rotations, but the radical itself remains fixed in orientation in the crystal lattice.