Studies of various mechanisms of nuclear polarisation due to a resonant high-frequency field in radical reactions

Two different mechanisms of creation of nuclear polarisation in radical reaction products are studied by means of the high-frequency field influence on intermediate radical pairs (stimulated nuclear polarisation, SNP) and on intermediate short-lived radicals (dynamic nuclear polarisation, DNP). Criteria are formulated for distinguishing the contributions of DNP and SNP effects, and experimental demonstration of this possibility is presented for photoinduced reactions of quinones