Rotationally-resolved infrared absorption spectra of the two lowest-energy fundamental bands for each of the three infrared active symmetry species of 2,5-norbornadiene (C2v point group symmetry; asymmetry parameter ? = -0.2203), ?11 (a1), ?12(a1), ?28(b1), ?29(b1), ?38(b2), and ?39(b2), have been measured, assigned and fit to a semi-rigid rotor Hamiltonian to produce a set of spectroscopic constants for each band. The fit band centers are ?11 (a1), c-type transitions, 728.852357(3) cm-1; ?12 (a1), c-type transitions, 417.31604(1) cm-1; ?28 (b1), a-type transitions, 656.719741(3) cm-1; ?29 (b1), a-type transitions, 500.31425(1) cm-1; ?38 (b2), b-type transitions, 800.82243(2) cm-1; and ?39 (b2), b-type transitions, 539.23110(6) cm-1. Using ground state combination differences from the ?11 and ?28 bands and previously published microwave data, an improved set of ground state spectroscopic constants were fit for the parent isotopologue of the molecule.
This research was conducted at the Pacific Northwest National Laboratory (PNNL), which is operated by Battelle Memorial Institute for the Department of Energy (DOE) under Contract No. DE-AC05-76RL01830.
Revised: October 13, 2020 |
Published: September 30, 2020
Citation
Sams R.L., and T.A. Blake. 2020.Ro-vibrational Spectroscopy of 2,5-Norbornadiene between 400 and 850 cm-1.Journal of Molecular Spectroscopy 373.PNNL-SA-153806.doi:10.1016/j.jms.2020.111354