EFFECTS OF HIGH PRESSURES ON THE PHOSPHORESCENCE OF AROMATIC HYDROCARBONS.
CALIFORNIA UNIV SANTA BARBARA DEPT OF CHEMISTRY
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The phosphorescence spectra, intensities and lifetimes were measured for ten aromatic hydrocarbons, dispersed in polymethylmethacrylate, in the 0-32 kbar pressure range at 298K. It was observed that the red shift is small 200-450cm at 32 kbar and comparable to the red shift observed in fluorescence. The measured phosphorescence lifetime decreases montonically with increasing pressures over the 0-32 kbar range for nine of the ten aromatics. From dynamic intensity measurements at 0, 10, and 20 kbar pressure it is concluded that the natural lifetime decreases by about 30 at 20 kbar. Also, the radiationless rate constant must increase by roughly the same amount. It is concluded that pressure enhances spin-orbit interaction and the vibrational overlap factors. Author
- Organic Chemistry
- Atomic and Molecular Physics and Spectroscopy