Chain length effects in the competition between intramolecular hydrogen migrations in the molecular ions of hydrogen migration in the molecular ions of α‐benzylamino‐ω‐benzyloxyalkanes as studied by deuterium labelling

The unimolecular decompositions upon electron impact of the bifunctional compounds OCH2-NH(CH2)n-OCH2O(n=2 to 7)have been studied by deuterium labelling. The molecular ions lose a benzyl radical and/or a benzaldehyde molecule, depending on the length of the aliphatic chain. Both reactions appear to be the result of the transfer of a hydrogen atom to the charge localized amino function in a cyclic transition state. The ring size of this transition state turns out to play a far more important role than the difference in reactivity of the migrating hydrogen atoms.