EFFECT OF KINETIC ENERGY ON IONIC REACTIONS IN PROPYLENE AND CYCLOPROPANE

The reactions of the C3H6+ molecule-ion in the propylene and cyclopropane systems have been studied as a function of ion exit energy in a single-stage mass spectrometer. The yields of the products C3H7+, C4H7+, C4H8+, and C5H9+ decrease markedly with increasing ion energy with a number of low mass products, C3H5+, C3H4+, C3H3+ and, in low yield, C2 ions, being formed at high ion energies. The yield curves for each of these latter products show definite energy thresholds characteristic of endothermic reactions and comparison of these thresholds with calculated reaction heats provides some information on the reactions occurring.