Low-temperature NMR investigation of iminoxyl radicals

By analysis of proton magnetic resonance spectra recorded at 4.2 and 3 K, the isotropic and anisotropic constants for the coupling of the unpaired electron with all the protons were determined for two investigated radicals. On the basis of these results, conclusions were reached on the spin density distribution and on the participation of the unpaired electron in hydrogen bond formation.We express our sincere gratitude to I. F. Shchegolev for useful discussions.