Radical recombination efficiency hypothesis

FIGURE 7. The proposed effect of stress in the several stages of the decreased radical recombination efficiency hypothesis. 

HL Stress-Induced Changes in krecombmatumi the Decreased Radical Recombination Efficiency Hypothesis... 

The fact that the quantum yields determined in the condensed phase are lower than those obtained in the vapour phase may be due to (i) efficient deactivation of the excited acetone molecules, or ( ) recombination of the CH3CO and CH3 radicals in the solvent cage . A decision between these alternatives might be made by studying the solvent effect. Namely, the lowest quantum yields are expected to occur in the photolysis of liquid acetone or in the photolysis in aqueous solution if efficient deactivation or if the cage effect, respectively, were responsible for the low quantum yields in condensed phase. On the basis of the results presented in Table 18, as well as on those of Pieck and Steacie made with mixtures of liquid acetone and acetone-rfg, the quenching hypothesis seems to be more likely. However, probably both effects play some role. 

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