Heterocyclic radicals. Part III. An electron spin resonance investigation of some selenium-containing radicals
Abstract
The isotropic e.s.r. spectra of a number of selenium-containing aromatic radicals are reported. The variations of the line-widths of these spectra are described and discussed semi-quantitatively in terms of spin–orbit and spin–rotational relaxation mechanisms. Simple Hückel and McLachlan MO calculations are employed to account for the observed hyperfine splittings, including those from 77Se, and to assist with their assignment where necessary. Finally, a semi-empirical theory of g-values for aromatic radicals is used to account for the observed g-shifts.