| Abstrakt: |
The luminescence from 2,3-dimethylbutane (23DMB) containing a small amount of toluene (To) has been observed in the solid phase at 77 K during ?-irradiation or by ns pulse irradiation with X-rays. The emission spectrum from 23DMB–To (2 mol%) during ?-irradiation at 77 K consists of the fluorescence from the singletexcited toluene and the phosphorescence from the triplet-excited toluene. Both the singlet- and triplet-excited toluenes are formed by the energy transfer from the irradiated 23DMB to toluene. When nitrous oxide or propylene is added to the 23DMB–To mixture, the emission spectrum is changed and becomes very similar to that from the 23DMB–To mixture during illumination with UV lights at 77 K. The spectrum, which disappears upon the addition of nitrous oxide or propylene, consists mainly of phosphorescence. It is concluded that the triplet-excited toluene may be formed by the migration of a hole and an electron. The effects of electron scavengers, such as nitrous oxide and carbon dioxide, or hole scavengers, such as propylene or tetramethylethylene, on the fluorescence have been studied by nsec-pulse irradiation. Since the fluorescence is not appreciably affected by the addition of these scavengers, the singlet-excited toluene may be formed by the excitation transfer. |
