FT-microwave spectrum, large-amplitude motions, and ab initio calculations for N{sub 2}O{sub 5}
- National Inst. of Standards and Technology, Gaithersburg, MD (United States); and others
The Fourier-transform microwave spectrum of the highly reactive atmospheric reservoir species N{sub 2}O{sub 5}, recently studied in the mm-wave and extensively studied in the infrared, has been investigated. Two b-type asymmetric-rotor-like spectra are observed, which fit poorly to a rigid-rotor Hamiltonian. Guided by ab initio and dynamical calculations which show a planar configuration is energetically unfavorable, these spectra are assigned to two of the tunneling states of the molecule arising from a geared internal rotation of the two NO{sub 2} groups about their respective C{sub 2} axes. Only 4 of the 10 rotational-tunneling species possible in the G{sub 16} molecular symmetry group for this non-rigid molecule may be observed. This is due to the presence of the 4 equivalent spin-zero oxygen nuclei, which gives zero statistical weights for all but the A{sub 1}{sup +},A{sub 1}{sup -}, A{sub 2}{sup +}, and A{sub 2}{sup -} rotational-tunneling states. Consistent with the tunneling picture, the nuclear quadrupole hyperfine patterns demonstrate that the two nitrogen nuclei occupy dynamically equivalent positions. The hyperfine analysis further establishes that the two observed tunneling states are of A{sub 1}{sup +} and A{sub 1}{sup -} symmetry. Further analysis is being attempted to determine the barrier to internal rotation.
- OSTI ID:
- 456900
- Report Number(s):
- CONF-9506113-; TRN: 96:005788-0060
- Resource Relation:
- Conference: 50. symposium on molecular spectroscopy, Columbus, OH (United States), 12-16 Jun 1995; Other Information: PBD: 1995; Related Information: Is Part Of Ohio State University 50th international symposium on molecular spectroscopy; PB: 371 p.
- Country of Publication:
- United States
- Language:
- English
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