Electron attachment to toluene in n-hexane and 2,2-dimethylbutane at high pressure

The effect of dilute concentration of toluene on the electron mobility in two isometric hexanes was studied as a function of pressure from 1 bar to 3 kbar and at selected temperatures between 9 and 60 degrees C. The effect of toluene on the mobility is small at 1 bar but quite large at the higher pressures. The results are interpreted in terms of reversible electron attachment to a toluene species which is the monomer in n-hexane. For this reaction triangle Hr is - 12.0 kcal /mol in n-hexane at 2.5 kbar. In 2,2-dimethylbutane attachment to a dimeric species is indicated. The volume changes for these attachment reactions are large, between -80 and -100 cm3/mol. In hexane the volume changes are attributed in part to the electrostriction of the solvent by the toluene anion and in part to a positive molar volume of the electron. 19 refs., 8 figs., 3 tabs