Paramagnetic resonance study of photolyzed crystals of dimethylnitramine

Abstract

The uv-irradiation of single crystals of dimethylnitramine, (CH3)2–N–NO2, produces an EPR spectrum arising from an unpaired electron with hyperfine coupling to six hydrogen and one nitrogen nuclei. The parameters of the axial spin Hamiltonian are g∥=2.0017, g⊥=2.0091, A∥(N) =33.0 G, A⊥(N) =6.5 G, and Aiso(H) =14.0 G. The spectrum is assigned to a (CH3)2–N radical. INDO molecular orbital calculations of hyperfine splittings in the (CH3)2–N radical support the assignment when allowance is made for the strong dependence of the hydrogen isotropic hyperfine splitting on the C–N bond length.