Vibrational dynamics of the hydrogen bond in H(2)S-HF: Fourier-transform-infrared spectra and ab initio theory.
The rotationally resolved infrared spectrum of the hydrogen bonded complex H(2)S-HF and of its isotopomer D(2)S-DF in the HF/DF stretching range have been observed in a supersonic jet Fourier-transform infrared (FTIR) experiment and indicate a predissociation lifetime of 130 ps for H(2)S-HF. Complementary spectra taken at a temperature of 190 K in a cell without resolved rotational structure indicate the presence of strong anharmonic couplings between low frequency intermolecular modes and the HF donor stretch mode previously observed in other complexes with heavier acceptor molecules without rotational fine structure. The anharmonic analysis of the hot band progressions and of the rotational data confirm the coupling mechanism. The coupling constants and the absolute frequency of the hydrogen bonded stretch mode are in excellent agreement with theoretical predictions based on adiabatic variational calculations on potential surfaces computed at MP2 and CCSD(T) level. Complementary calculations with a perturbational approach further confirm the coupling model.
Asselin
Pierre
P
Université Pierre et Marie Curie-Paris 6, CNRS, Laboratoire Dynamique, Interactions et Réactivité, UMR 7075, Case 49, Place Jussieu, 75252 Cedex Paris, France.
Soulard
Pascale
P
Madebène
Bruno
B
Esmail Alikhani
M
M
Lewerenz
Marius
M
D003198:Computer Simulation; D006858:Hydrofluoric Acid / Q000737:chemistry*; D006860:Hydrogen Bonding; D006862:Hydrogen Sulfide / Q000737:chemistry*; D011789:Quantum Theory; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D014732:Vibration
D006858:Hydrofluoric Acid; D006862:Hydrogen Sulfide