Coriolis analysis of several high-resolution infrared bands of bicyclo[111]pentane-d0 and -d1

Journal Article · Fri Jun 01 00:00:00 EDT 2012 · Journal of Molecular Spectroscopy

DOI:https://doi.org/10.1016/j.jms.2012.06.008· OSTI ID:1052515

Perry, A.; Martin, M. A.; Nibler, J. W.; Maki, A.; Weber, A.; Blake, T. A.

High resolution infrared absorption spectra have been analyzed for two bicyclo[1.1.1]pentane isotopologues, C5H8 (-d0) and C5H7D (-d1), where in the latter the D-atom replaces a hydrogen on the C3 symmetry axis such that the molecular symmetry is reduced from D3h to C3v. Two (a2") parallel bands, ν17 and ν18, of bicyclopentane-d0 were studied and the former was found to be profoundly affected by Coriolis coupling with the nearby (e') perpendicular band, ν11. Weaker coupling was observed between the ν18 band and the nearby ν13(e') band, for which fewer transitions could be assigned. For bicyclopentane-d1, the ν5 parallel band was also studied along with the nearby ν15(e') band to which it is coupled through a similar type of Coriolis resonance. For both isotopologues, quantum calculations (B3LYP/cc-pVTZ) done at the anharmonic level were very helpful in unraveling the complexities caused by the Coriolis interactions, provided that care is taken in identifying the effect of any Coriolis resonances in the theoretical values of aB and q rovibrational parameters. The ground state B0 constants were found to be 0.2399412(2) and 0.2267506(11) cm-1 for the -d0 and -d1 isotopologues. The difference yields an Rs substitution value of 2.0309(2) Å for the position of the axial H atom relative to the -d0 center of mass, a result in good accord with a corresponding Ra value of 2.044(6) Å from electron diffraction data. For both isotopologues, the theoretical results from the quantum calculations are in good agreement with all corresponding values determined from the spectra.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1052515
• Report Number(s): PNNL-SA-87628; 32692; KP1704020
• Journal Information: Journal of Molecular Spectroscopy, Vol. 276-277, Issue C; ISSN 0022-2852
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
Environmental Molecular Sciences Laboratory