High resolution NMR of free radicals: 13C magic angle spinning of two solid organic free radicals derived from 4,5-dihydro-1H-imidazol-3-oxide-1-oxyl and theoretical calculation of their NMR properties

Abstract

Dedicated to our friend Prof. Julio Alvarez-Builla on the occasion of his 65 th anniversary Abstract The 13 C CPMAS NMR spectra of two 4,4,5,5-tetramethyl-2-(1H-and 2H-pyrazol-3-yl)-2-imidazoline-1-oxyl-3-oxides have been recorded and their signals assigned, through unrestricted density functional theory (UDFT) calculations of their absolute shieldings, with satisfactory results.