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'I'he radiolysis of dilute solutions of ethane-de, propane-&, and n-butane-dlo in liquid hydrocarbons at 195 'I< results in the production of D 1 and H D in amounts which are determined by the rclative ionization potentials of solvent and solute. Solvents of higher ionization potential cnhance the production of TI? and HT> from deuterated solutes of lower ionization potential. \Vhcn the ionization potentials arc in thc reverse order the yields are diminished. 'l'his solute-solvent interaction, which is ionic in nature, is a general phenomenon in the radiolysis of mixtures of saturated hydrocarbons in the liquid phase and is consiste~~t with charge transfer between solvent and solute.Thc radiolysis ol saturated hydrocarboils yields hydrogen as a major product. Tlie use of cleuterated hydrocarbons (cyclohexane-dl? and i~~etl~ylcycloliexane-did) as aids to the study of the mechanisin of hydrogen formation has been described by Dyne and Denhartog (1). 'They slio~ved that the yield of deuterium (HD + D2) iron1 dilute solutions (-5 electroil %) of a deuterated hydrocarbon in a liydrocarbon solvent uJas not governed solely by the concentration of the deuterated species. The solvent exerted a iliajor effect on tlie yields, e.g., .\\;it11 sz-pentane as solvent the yield of D2 u-as ten times and the yield of I-ID \\.as eight times greater than when n-decane n:as the solvent. I-Iardwicli (2) shelved that this effect of solvent could be correlated \\-it11 tlie relative ionization poteiitials of the cleuterated solute molecules and tlie solvent molcculcs. Talting the standard value as the !+Id of D? from a dilute solution of c~~clohesane-dl? in cyclohexane, enhanced yields of D 2 were observed for solvents with ionizatioil potentials greater than that of cyclolicxaiie, u.liile diminished yields were observed for solvents of lower ionization potential. This correlation -\]:it11 ionization potential ]\.as interpreted by I-Iard\viclc in terms of a charge transfer mecliai~ism. FIo\vever, tlie ionization potentials of the two deuterated hydrocarboils used by Dyne and Denhartog, methylcycloliexane-d~4 (9.85 f 0.03 eV) and cyclohexane-dl2 (0.88 0.02 eV) are esseiltially the same (3), while the range in ionization potentials of the hydrocarbon solvei~ts used is small (-0.5 eV). Tlie lower liydrocarbons, ethane, propane, aiid n-butane, have wide and clear-cut differences in ionization potentials, viz. ethane ll.G5 eV, propane 11.08 eV, and n-butane 10.63 eV (4). Using these hydrocarbons as solvents and their deuterated analogues as solutes, we have determined that this effect of solvent on tlie radiolysis of dilute solutions of hydrocarbon solute is a general plienon~enon in the radiolysis of saturated hydrocarbons in the liquid phase. I-Iomever, altliougli our results are qualitatively in agreement with I-Iardwiclc's theory, we did not obtain quantitative agreement with tlie simple theory.For the series of hydrocarbons chose11 the most convenient temperature for carrying out experiments in tlie liquid phase is that of a ...

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