Fluorescence Spectra in Frozen Heptane at High Pressures

Abstract
The fluorescence spectra of coronene and 1,12-benzoperylene have been studied in frozen heptane as a function of pressure (0–30 kbar). The fluorescence red shifts at 77°K are 5 cm−1/kbar and 8.3 cm−1/kbar, respectively. High pressures broaden vibronic bands and increase background intensity. The 0, 0 band becomes more pronounced under pressure. The intensity pattern of the 1,12-benzoperylene fluorescence is altered considerably by compression of the heptane matrix. Permanent changes in the spectra after pressure treatment are very slight compared to the reversible effects of high pressures on the spectral characteristics of these two aromatic hydrocarbons.