Reaction of n-Heptyl Radicals with Tetramethylethylene

These experiments were designed to investigate the effects of the temperature and the amount of molecular reactant laid down on the extent of reaction (conversion) which occurred. The concentration of n-heptyl radicals was kept constant throughout the complete series of 

R = Complete reaction (E 5 kcal mole i). S = Slight reaction (E si 5 kcal mole i). 

If only the thermal energy of the bombarding olefin molecules was available to overcome the activation energy barrier for reaction then there should be a marked dependence of the conversion on the jet temperature. The results (Fig. 15) show clearly that this is not so and in fact the points for different temperatures all fall on the same curve. Therefore the thermal energy of the alighting molecules is unimportant. Either the reactions must occur at 77°K after the molecules have lost their thermal energy, or if they do occur immediately after bombardment 

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