Two minimum energy structures of the HF2- -ethanol complex are examined. Both have a strong (FH)-H-...-O and weak (FH)-H-...-C hydrogen bond. For the lower energy structure the (FH)-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 (FH)-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. (C) 2003 Elsevier B.V. All rights reserved.