ENVIRONMENTAL EFFECTS ON PHOSPHORESCENCE .6. MATRIX SITE EFFECTS FOR TRIPHENYLENE

The phosphorescence lifetime and spectra of triphenylene are studied in different matrices at 77°K and as a function of increasing pressure (0-30 kbar). The magnitude of the pressure shift of the spectra and the pressure coefficient of the lifetime depend upon the size of the molecules comprising the solvent cage. This difference in pressure response is attributed to the preponderance of repulsive interactions between highly symmetric triphenylene and smaller solvent molecules under pressure.