Search for low activation energy abstraction of H from C–H bonds by D atoms in hydrocarbons at 77 K

Abstract

Experiments have been done to determine whether thermal D atoms produced at 77 K in 3-methylpentane-d14 containing ∼1% C–H bonds as an isotopic impurity are able to abstract H by a low activation energy process, as CH3 radicals are known to do. The D atoms have been produced by 254 nm photolysis of DI. The trends in HD/D2 ratio with changing ratio of C–H bonds to [DI] are consistent with the conclusion that the D+C6H13H→ HD+C6H13 abstraction occurs at 77 K with low activation energy requiring either a tunneling mechanism or unusual molecular distortion in the glass.