Phosphorescence of biacetyl sensitized by benzene in gas phase pulse radiolysis

The phophorescence of biacetyl induced by an energy transfer to biacetyl from triplet benzene produced in the pulse radiolysis of benzene-biacetyl mixtures has been studied. The time required to reach the maximum intensity of phosphorescence, t_max, after the electron pulse, varies as a function of biacetyl pressure at constant benzene pressure (40 torr), which gives the lifetime of triplet benzene τ = (6.7 ± 3.2) × 10⁻⁶ s and the rate constant of the energy transfer k_{C6H6^*(T1) + biacetyl} = (1.6 ± 0.7) × 10⁻¹⁰ cm³ molecule⁻¹ s⁻¹.