Hydrogen Isotope Fractionation between HC12" Ion and HCl

Hydrogen isotope fractionation between hydrogen dichloride ion in the condensed phase and gaseous hydrogen chloride has been studied both theoretically and experimentally. Quite good agreement between the experimental tritium fractionation factor and that theoretically calculated for two sets of vibrational data was found. Theoretical calculations of the fractionation factors of both deuterium and tritium over the large temperature range of 100—2000 K revealed some anomalies (minima and crossover points) in their temperature dependences. The relative tritiumdeuterium isotope effect has also been discussed within the framework of the presently accepted statistical-thermodynamic theory in the harmonic approximation and recent works by Stern et al.