First Singlethyphen;Singlet Electronic Transition in the Phenanthrene Molecule and the Band Structure of the Phenanthrene Crystal

摘要

The absorption and emission spectra of single crystals of phenanthrene have been studied at 20deg;K. The data show that the transition moment in the molecule is shorthyphen;axis polarized, and that the factor group splitting in the crystal is 47 cmmdash;1. The emission originates in a region of very weak absorption at a frequency below the main absorption in analogy to several other molecular crystals whose spectra have been studied. It is suggested that the emitting level corresponds to a distorted lattice site.