Radio Induced 12C/13C Magnetic Isotope Effect

Abstract
The separation of carbon isotopes 12 C and 13 C induced by magnetic electron–nuclear interaction in radical pairs is increased by selective microwave pumping at the frequency of EPR transitions in 13 C-containing radicals; the pumping accelerates the triplet–singlet conversion of 13 C radical pairs and therefore increases the nuclear spin selectivity of chemical reactions; this new effect has been called the radio induced magnetic isotope effect (RIMIE).