Rotational spectra of the Kr-H2O van der Waals complex

Abstract

Rotational spectra of the Kr-H2O van der Waals complex were measured in the frequency range 4–19 GHz using a pulsed jet cavity Fourier transform microwave spectrometer. The isotopomers studied include those of H2O, HDO, D2O, H2 17O and H2 18O with the six most abundant isotopes of Kr. A tunnelling splitting due to a large amplitude internal motion of the H2O subunit that exchanges bonded and non-bonded hydrogen atoms was observed. Nuclear quadrupole hyperfine structure was resolved and measured for the complexes containing 83Kr, D, and l7O, and the corresponding nuclear quadrupole coupling constants were determined. These were used to estimate structural parameters and to derive information about the intermolecular dynamics. The results, and in some instances the spectroscopic constants themselves, were compared with experimental and theoretical data previously reported for Ar-H2O.