Structure and vibrational dynamics of hydrogen bond in hydrogenbissulfate anion in the gas phase and in the solid state: A computational study

Nature of a short hydrogen bond in hydrogenbissulfate ion was studied by quantum-chemical methods. Isolated triple charged anion is predicted to be unstable on the Hartree-Fock and Density Functional Theory levels using Pople basis sets with the exception of some small-size basis sets. For stable structures the predicted metric parameters are in poor agreement with the experiment and vary significantly with the basis set, indicating insufficient level of theory. The same is true for the calculated frequencies, in particular for the OH stretching fundamental that seems to be too high. Inclusion of the crystal field effects by imposing the periodicity in conjunction with the plane wave basis sets improves agreement with the neutron diffraction data considerably. Exception is the OH distance that was predicted to be too short. By quantization of the OH coordinate an almost perfect agreement with the experimental OH was found. Besides, quantization of the OH coordinate shifts the calculated vibrational frequency toward the experimental center of the broad OH stretching infrared absorption. Perspectives for application and extensions of presented methodology for vibrational spectroscopy and (bio)catalysis are given.