Host/guest deuteration effects on mixed crystals

The phosporescence characteristics of twelve guest/host mized crystal systems were investigated. A large thermally-activated intermolecular effect of host deuteration on the phosphorescence of the guest was noted. All observed effects can be rationalized using a kinetic model which implies thermal activation of triplet guest to triplet host, entrapment of energy at defects in the host exciton band, and the effects of deuteration on the thermal band gaps. (Auth.)