SPECTROSCOPIC STUDIES OF TRIPLET EXCITONS IN SOME AROMATIC ORGANIC CRYSTALS

Author Institution: Department of Chemistry, University of PennsylvaniaFactor group splittings of several organic crystals in their triplet states have been studied in magnetic fields and polarized light at $4.2^{\circ}K$. The electronic Zeeman effect studies on oriented crystals of anthracene, naphthalene, and perylene leads to a description of the proper handling of the spin functions in organic crystals displaying intermolecular interactions in their triplet state. In addition, the mechanism leading to factor group splitting in the triplet state is examined and compared with the theoretical progress in attempting to calculate these splittings in terms of electronic exchange interactions