Local spin density theory of free radicals: Nitroxides

Abstract

Local spin density theory is applied to the nitroxides H2NO, (CH3)2NO, (CH3)2NO⋅⋅⋅HOCH3. Spin density is localized on the NO group. In dimethylnitroxide the spin density is partitioned one to one between N and O. Substitution of the hydrogen atoms in dihydrogen nitroxide by methyl groups as well as addition of a hydrogen bridge result in an enhancement of the spin density on nitrogen. The hydrogen bridged compound models the spin density distribution in tanol (2,2,6,6-tetrametyl-4-piperidinol-1-oxyl) which has been investigated by polarized neutron diffraction.