Vibrational dynamics of the bifluoride ion. I. Construction of a model potential surface

Construction of an extended model potential surface for the bifluoride ion [FHF−] is described, based on ab initio calculations for the free ion at the CID (configuration interaction, double replacement) level with a Huzinaga–Dunning double‐zeta basis set. 710 data points were generated, for displacements in the three noncyclic vibrational coordinates exploring the potential surface to a height at least 30 000 cm−1 above its minimum, and giving a realistic account of the dissociation into HF+F−. Analogous calculations were made for HF and F− using the same basis. The predicted hydrogen bond energy (De) is 48.13 kcal/mol, with equilibrium F–F separation Re =4.2905 a.u., in good agreement with other recent calculations. A model potential has been constructed, based on a superposition of Morse potentials associated with each H–F distance plus a fairly structureless correction function expressible as a 36‐term least‐squares polynomial in the prolate spheroidal coordinates used to describe vibrational displace...

[1]  W. Thorson,et al.  Vibrational dynamics of the bifluoride ion. II. Adiabatic separation and proton dynamics , 1990 .

[2]  K. Kawaguchi,et al.  Infrared diode laser study of the hydrogen bifluoride anion: FHF− and FDF− , 1986 .

[3]  H. Schaefer,et al.  Extensive theoretical studies of the hydrogen‐bonded complexes (H2O)2, (H2O)2H+, (HF)2, (HF)2H+, F2H−, and (NH3)2 , 1986 .

[4]  W. D. Allen,et al.  The infrared spectrum of the hydrogen bifluoride anion: unprecedented variation with level of theory , 1986 .

[5]  M. Heni,et al.  The stability of the bifluoride ion (HF−2) in the gas phase , 1985 .

[6]  S. Peyerimhoff,et al.  Ab initio SCF and CI calculations of the hydrogen bonding energy of hydrogen bifluoride and bichloride ions , 1985 .

[7]  T. Mcmahon,et al.  Strong hydrogen bonding in gas-phase anions. An ion cyclotron resonance determination of fluoride binding energetics to Broensted acids from gas-phase fluoride exchange equilibrium measurements , 1983 .

[8]  L. L. Lohr,et al.  Ab initio study of protonic motion in the bifluoride ion HF2 , 1981 .

[9]  W. Thorson,et al.  Vibrational dynamics of hydrogen bonds. I. FHF− system , 1979 .

[10]  T. H. Dunning.  Gaussian Basis Functions for Use in Molecular Calculations. III. Contraction of (10s6p) Atomic Basis Sets for the First‐Row Atoms , 1970 .

[11]  D. Mcdaniel,et al.  Strong Hydrogen Bonds. II. The Hydrogen Difluoride Ion , 1964 .

[12]  T. C. Waddington.  The lattice energies of potassium, rubidium and caesium bifluorides and the strength of the bonds in the bifluoride, HF–2, ion , 1958 .

[13]  H. W. Thompson,et al.  Infra-red spectra and the solid state. III. Potassium bifluoride , 1951, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.