Electron attachment as a probe of photoionization processes in liquid media

The effects of electron attaching additives on the photoionization threshold of pyrene in seven liquid media comprising a dielectric hydrocarbon liquid and an electron attaching additive, A, were studied. The photoionization threshold, I/sub L/, was found to be independent of the dielectric hydrocarbon liquid and the concentration of each A used. On the basis of these data it was concluded that in the presence of an efficient A at high concentrations, the photoejected electron is captured by A at times shorter than those required for electron solvation (or any possible trapping by the solvent) and that the photoionization process for a solute molecule in these dielectric liquids is probably completed at times less than or equal to 10-14 and greater than or equal to 10-16 s and its energetics are rather independent of the bulk properties of these liquids