Two-Level Fluorescence of Ovalene

Abstract
Ovalene fluorescence has been studied as a function of pressure (0–30 kbar) in condensed media at room and liquid nitrogen temperatures. The red shift of the α and p bands are 8 and 22 cm−1/kbar, respectively, in polymethylmethacrylate. The fluorescence kinetics are consistent with two‐level emission; the greater pressure dependence of the lifetimes compared to the relative intensities being attributed to differential level shifts and its influence on the thermal population of the adjacent singlet level.