Solvent Effect on the Vibrational Structures of the Fluorescence and Absorption Spectra of Pyrene

Abstract The anomalously large Ham effect observed in pyrene has been studied in various solvents at room temperature by measuring the fluorescence and absorption spectra. As in the case of benzene, the Ham bands of pyrene were assigned to the 0–0 and ag-vibration bands. This was confirmed by fluorescence polarization measurement. The correlation of the intensities of the fluorescence and absorption bands to solvent polarities is discussed.