The combination of CF3CHF and CH3 or CD3 radicals was used to prepare vibrationally excited CF3CHFCH3 or CF3CHFCD3 Molecules with 97 kcal mol(-1) of internal energy. The experimental unimolecular rate constants were 3.7 x 10(6) s(-1) for 2,3-FH elimination from CF3CHFCH3 and 1.3 x 10(6) s(-1) for 2,3-DF elimination from CF3CHFCD3. Unimolecular rate constants for 1,2-FH elimination reaction were approximately 230 and 98 times smaller for CF3CHFCH3 and CF3CHFCD3, respectively, than the corresponding rate constants for 2,3-FH elimination. Density functional theory (DF-F) was used to calculate the structures and vibrational frequencies of the molecules and transition states; this information was subsequently employed for calculations of RRKM rate constants. Comparison of the experimental and calculated rate constants gave a threshold energy of 73 +/- 2 kcal mol(-1) for the 1,2-FH elimination process and 60.5 +/- 1.5 kcal mol(-1) for the 2,3-FH elimination reaction from CF3CHFCH3. The calculated kinetic-isotope effects agree with the experimental results. The experimentally derived threshold energies for 1,2-FH and 2,3-FH elimination reactions from several fluoropropanes and fluorochloropropanes are summarized and compared to those from DFT calculations.