The HF2−–CH3CH2OH complex: a theoretical study

Two minimum energy structures of the HF2−–ethanol complex are examined. Both have a strong F⋯H–O and weak F⋯H–C hydrogen bond. For the lower energy structure the F⋯H–C bond involves an H atom of the CH3 group. The binding energy is 19.6 kcal/mol and the blue shift of the F–H–F asymmetric stretch is 746 cm−1. For the other structure, which is only 0.6 kcal/mol higher, the F⋯H–C bond involves an H atom of the CH2 group. This structure has an entropic advantage of +2.4 cal/mol/K and the Gibbs energies of the two structures are essentially identical at 298 K.