SPIN CATALYSIS - 3-SPIN MODEL

Recently it has been shown that in a radical triad one of the radical partners affects the chemical reactivity of the other pair, catalyzing the spin transformation of this pair. The phenomenon is shown to be c aused by the exchange interaction between the radical triad partners w hich stimulates doublet-doublet spin evolution and produces the oscill ating triplet-singlet spin conversion of the selected radical pair in the radical triad under the influence of the odd radical spin. The the ory of the phenomenon is developed and the equations for the rate of s pin evolution in a three-spin system are derived. A new type of quantu m beats is predicted.