Polycyclic Aromatic Hydrocarbon Solute Probes: Effect of Solvent Polarity on the Ovalene and Benzo[ghi]perylene Fluorescence Emission Fine Structures

Abstract

Fluorescence properties of benzo[ghi]perylene (BPe) and ovalene (Ov) dissolved in 25 solvents of varying polarity are reported. Measurements indicate that emission intensities depend on solvent polarity. The BPe and Ov solvent polarity scales are defined as the ratio of the fluorescence emission intensities of bands I and III of the vibronic spectra. Benzo[ghi]perylene and ovalene solute probes enable fluorescence measurements to be made in spectral regions less prone to solvent inner filtering and other artifacts which have hampered the use of pyrene (Py) as a polarity probe molecule.