Tunneling-rotation spectrum of the hydrogen fluoride dimer

• Published in: Journal of molecular spectroscopy 1990-06, Vol.141 (2), p.204-222
• Main Authors: Belov, S.P., Karyakin, E.N., Kozin, I.N., Krupnov, A.F., Polyansky, O.L., Tretyakov, M.Yu, Zobov, N.F., Suenram, R.D., Lafferty, W.J.
• Format: Article
• Language: English
• Subjects: Atomic and molecular physics; Exact sciences and technology; Molecular properties and interactions with photons; Physics; Properties of molecules and molecular ions; Rotation, vibration and vibration-rotation constants
• ISSN: 0022-2852; 1096-083X
• DOI: 10.1016/0022-2852(90)90158-M

The tunneling-rotation spectrum of the ground state of the hydrogen fluoride dimer, HF⋯HF, has been extended to the submillimeter wavelength region with the RAD-3 submillimeter spectrometer at Gorky in the frequency range 180–380 GHz at 210 K and pressures from 0.5 to 1.5 Torr. The spectrum has been reinvestigated at lower frequencies with a conventional Stark spectrometer at pressures between 0.1 to 0.2 Torr at the National Institute of Standards and Technology. Lines of the a-type K = 3 subband have been observed for the first time. The tunneling frequency for the K = 3 state is 114 306.35(53) MHz. The rotational constants of this subband are somewhat anomalous as compared with those for the lower K sublevels. For example, the B rotational constant for the B u state is larger than that for the A g state, while for all the lower K sublevels the opposite is true. Higher- J R- and P-branch lines of the K = 0 through K = 2 subbands have been identified and improved rotational constants for these states have been obtained. An atlas of all a- and b-type far infrared and microwave ground state tunneling-rotation transitions for K up to 3 giving frequency, uncertainty, and relative intensity has been prepared.