Density functional theory (DFT) studies have been performed in the title complexes to determine the effect of electron-withdrawing halogens around the C=C bond on the metal-olefin bond dissociation energy. Calculations indicate that the nickel-olefin bond dissociation energy would be nearly independent of the number of electron-withdrawing elements around the double bond. The results are explained in terms of electronic, steric, and reorganizational effects that derive from the olefin-metal interaction and are compared to computational and experimental results for related complexes, which show similar metal-olefin bond strength behavior. It has been found that reorganizational effects in both the olefin and Ni(PH3)(2)(CO) play a determining role in the overall bond dissociation energy trend.