An initial 1, 2-hydrogen shift versus a 1, 3-deuterium shift in emerging FCD2CH2CH2+ ions lead to differing patterns of deuteration in the neutral products that are recovered following reaction with a Brønsted base. Transient dideuterated fluoropropyl ions have been produced in [C3H4D2F+ PhO] ion-neutral complexes by 70 eV electron impact on FCD2CH2CH2OPh and the resulting fluoropropenes collected in a specially designed electron bombardment ...