Spin Exchange in Nitroxide Biradicals

摘要: The dependence of the electron spin‐exchange energy upon temperature and solvent has been studied for carbonate, oxalate, succinate diesters tetramethyl‐piperidinol‐oxyl. An analysis is given exchange effects on ESR line positions, intensities, widths. For carbonate diester constant at low temperatures. As raised this gradually decreases, passes through a minimum, then increases exponentially. Interpretation suggests that temperatures occurs an indirect process involving core sigma electrons, whereas high direct more important.