Calculation of rearrangement and 1,2-HX elimination pathways of select
chloroflouropropanes and comparison of experimental and theoretical rate constants.
William C. Everett and George L. Heard
University of North Carolina at Asheville
HCFCs are first generation replacements for freon and an understanding of their reaction pathways
is extremely important for predicting atmospheric and environmental effects. We have optimized a
series of ground-state and transition-state geometries for specific HCFCs which can eliminate HCl
or HF to become more dangerous CFCs. B3PW91/6-311G(2d,p) is chosen as the theoretical
method, based on our previous success with similar molecules. Reaction rates are calculated using
vibrational frequencies and moments of inertia obtained from our calculations and RRKM theory.
Compounds under investigation are CF3CF2CH2Cl, CF3CFClCH2F, CF2ClCF2CH2Cl,
CF2ClCHFCF3, and CF3CHClCF3. 1,2-HF and 1,2-HCl eliminations are considered as well as a
1,2-FCl interchange first proposed by our group.