ISOTOPIC AND HOT RADICAL EFFECTS IN THE REACTION OF HYDROGEN ATOMS WITH ETHYLENE

Abstract

Reactions of D atoms with C₂H₄, H atoms with C₂D₄, and H atoms with C₂H₄, at room temperature are compared. Pronounced differences in the extent of isotopic exchange have been found. The observed isotopic and pressure effects provide evidence for the importance of "hot" ethyl radicals in these reactions and their responsibility for isotopic exchange. The atoms are generated by the mercury-photosensitized decomposition of hydrogen and deuterium and their concentration is sufficiently small so that "atomic cracking" does not occur.