Electronic Spectra of Perylene Crystals

Abstract

The electronic absorption and emission spectra of α and β forms of perylene have been investigated. The lowtemperature spectra have been studied with the (001) plane, and adetailed vibrational analysis is presented. The reflection measurements with the (001) plane and the (110)or (1\bar10) plane are carried out, and the Kramers-Kronig transformation is carried out in order to obtain the absorption coefficient. The results present reasonable evidence for the existence of the intermolccular CT transition in the 27000 cm−1 region. The emission spectra at 4.2 K present several novel features of the mechanism of a monomer-like emission of the α-crystal.