The F + CH3COCl and H + ICH2COCl reaction systems were studied by the infrared chemiluminescence method in a flow reactor. The primary reaction of F + CH3COCl gives a nascent HF(upsilon) distribution of P-1-P-3 = 21:52:27. A linear surprisal analysis gives P-0 = 3 and [f(v)(HF)]= 0.60, which is typical for H abstraction reactions by F atoms. The C-H bond. energy in acetyl chloride is estimated as less than or equal to 101.2 kcal mol(-1), from the highest HF(upsilon, J) level populated in the primary reaction. The H + ICH2COCl primary reaction leads to HI + CH2COCl. The secondary F + CH2COCl and H + CH2COCl reactions give chemically activated FCH2COCl*/CH3COCl* molecules. The 1,2-HCl elimination channel is the dominant unimolecular pathway for both reactions under our experimental conditions. The HCl(upsilon) distribution from CH(3)COC1* is P-1-P-4 = 39:32:20:9. Surprisal analysis was used to estimate the Po value as 36% and [f(v)(HCl)] = 0.12. The reaction time had to be increased from less than or equal to 0.2 ms to greater than or equal to 0.5 ms to record the HCl(upsilon) emission from F + CH2COCl, and the best distribution was P-1-P-4 = 68:24:5:3. The estimated [f(v)(HCl)] was only 0.06 which is a lower limit due to HCl(upsilon) relaxation. The CO(upsilon = 1 --> 0) emission could also be observed from this reaction with an intensity that was typically less than 10% of the HCl(upsilon) emission. Ab initio calculations for FCH2-COCl at MP2/6-31G* level give the threshold energy for HCl elimination as 61 kcal mol(-1), which is 12 kcal mol(-1) larger than that for CH3COCl at the same level. The threshold energies for the other reactions of FCH2COCl are 81.0 for CO elimination, 82.5 for C-C dissociation, and 78.4 for C-Cl dissociation. RRKM and ab initio calculations indicate that CO formation results from the FCH2COCl --> FCH2 + COCl dissociation step followed by COCl --> CO + Cl. For CH3COCl*, with 105 kcal mol(-1) energy, HCl elimination accounts for 98% of the total reaction and C-C dissociation accounts for the rest. The C-Cl dissociation channel is not important for either molecule at these energies.