The paper concerns applications of the dynamic (DNP) and stimulated (S
NP) nuclear polarization method to the solution of various photochemic
al problems. The results of investigation of exchange interaction in r
adical pairs localized in micelles of different size have been summari
zed. The effect of weak field DNP in degenerate electron exchange reac
tions has been applied to measure the rate constants of electron excha
nge and to study CIDEP and mechanisms of photochemical reactions.