A DFT Study on the C−H Bond Dissociation Enthalpies of Haloalkanes: Correlation between the Bond Dissociation Enthalpies and Activation Energies for Hydrogen Abstraction

Abstract

The C−H bond dissociation enthalpies of halomethanes were computed from the results of density functional theory (DFT) calculations at the B3LYP level with various basis sets, such as 6-311G(d,p) and 6-311++G(3df,2p). Reasonably accurate C−H bond dissociation enthalpies were obtained even at the B3LYP/6-311G(d,p) level when ROB3LYP method was used for radicals. Applying the same procedure, the C−H bond dissociation enthalpies for a series of haloethanes were also calculated. Good correlation has been observed between the activation energies for the hydrogen abstraction from haloalkanes by OH radical and the corresponding C−H bond dissociation enthalpy values.