A CROSS-CORRELATION MECHANISM FOR THE FORMATION OF SPIN POLARIZATION

Photolysis of acetone in the presence of various hydrogen donors and o f 3-hydroxy-3-methyl-2-butanone involves the formation of propan-2-oly l radicals which show both electron and nuclear spin polarization. The electron polarization of the radicals leads to additional nuclear pol arization of the reaction products. Transfer of electron to nuclear po larization can occur by cross-relaxation and cross-correlation. The la tter is described in detail. Experimentally, the mechanisms lead to fo rmation of net nuclear polarization for symmetrical radical pairs as w ell as an unusual kinetic behavior of multiplet effects.