PULSE RADIOLYSIS OF BENZENE CYCLOHEXANE MIXTURES

The radiolysis of benzene and mixtures of benzene and cyclohexane have been studied by the nanosecond pulse-radiolysis technique. In pure benzene, two short-lived transitory species are observed with absorption maxima at 320 mμ and t1/2 = 112 nsec and 515 mμ and t1/2 = 18.5 nsec. The effect of temperature and dilution in C6H12 shows that the 515-mμ peak is associated with the excimer of benzene. The effect of added solutes and of benzene dilution in C6H12 suggest that the 320-mμ absorption is associated with a free radical which is formed by the reaction of a benzene triplet with benzene. The effect of benzene concentration on the excited singlet and triplet yields and on the reaction of the ionic species is also studied. It is shown that the geminateion recombination time is shorter in benzene than in C6H12, and that ion recombination is a major source of energy transfer in the radiolysis of benzene/C6H12 mixtures.