Yields of excited singlet state in the radiolysis of alkane containing toluene in the solid phase at 77K

When alkane containing a small amount of toluene is γ-irradiated in the solid phase at 77K, excited toluene is formed by energy transfer from irradiated alkane to toluene. Fluorescence from excited singlet toluene has been measured during γ-irradiation and after nanosecond pulse irradiation. Yields of the excited singlet toluene (S) have been determined for the first time in the solid phase at 77K and the following G-values were measured: G(S)=0.8 to 0.9, 0.7, and 0.7 in the radiolysis of cyclohexane, 2,3-dimethylbutane and 3-methylpentane containing toluene (0.2mol dm-3), respectively. The rate constants for energy migration, obtained experimentally from the kinetics, are of the same order of magnitude as those calculated by the theory of exciton migration. (author)