Using high-resolution Fourier transform spectra of propane recorded in the 13.4 μm (resolution of 0.002 cm-1) and in the 27.4 μm (resolution 0.0011 cm-1) spectral regions, it was possible to perform a thorough assignment of both the ν26 band at 745 cm-1 and the 2 ν9¬ - ν9 band at about 370 cm-1. This simultaneous assignment was necessary since the 261 and 92 rotational levels interact strongly through an A-type Coriolis interaction. The experimental upper-state rotational levels were fit using a Hamiltonian matrix which takes in account explicitly this strong A-type Coriolis interaction. With this model the experimental energy levels were fit to within their experimental uncertainties and accurate band centers, rotational, centrifugal distortion and coupling constants were determined. The following band centers were derived: νo(ν26) = 748.530882 (80 ) cm-1 and νo(2 ν9) = 740.29213 (10 ) cm-1.
Citation: Molecular Physics
Pub Type: Journals
Propane, High-Resolution Infrared Spectroscopy, Coriolis Resonances, Spectroscopic Constants