We have used EPR spectroscopy to determine the rate of spin exchange between cation radicals held in rigid polymeric matrixes. Radicals of this type are thought to be the charge carriers during electrophotographic conduction. A variety of diamagnetic compounds were added to these samples to examine the idea of "superexchange" which was proposed in earlier work. Diamagnetic tertiary amines are proposed as conduits for spin exchange in the "superexchange" mechanism. :This work shows that this mechanism is incorrect. We also demonstrate how measurement of exchange energies can be used to find relative separations of radicals held in the polymeric matrixes.