High‐resolution infrared analysis of the ν₁₇ band of pyridine

Abstract

A method for analyzing asymmetric top rovibrational bands displaying both blended and resolved features is described. The two-phase computational procedure uses a modified version of the asymmetric rotor-band contour program FASTPLOT to generate a preliminary set of upperstate spectroscopic constants. The parameters are subsequently refined by employing the assigned line-fitting formalism of the ASYROT program using both resolved and blended features. The technique is detailed in a comprehensive analysis of the Y17 band of pyridine. Inclusion of quartic centrifugal distortion constants was found to satisfactorily model a high-resolution (0.004 cm-') spectrum of this band, yielding a standard deviation of 0.00137 cm-'. The variation in the rotational parameters with vibrational quantum number is examined in terms of possible weak rovibrational perturbations to the v17 state. An ab initio calculation of the v17/u27 Coriolis coupling constant indicates the observed results are consistent with the interaction of these two vibrational states.

High Resolution Rovibrational Spectroscopy of Chiral and Aromatic Compounds

“…There exists one rovibrational analysis of the partially resolved n 11 band of pyridine. [91] A new and complete analysis of this band including also an analysis of the n 4 and n 12 bands is given in ref. [92].…”

Comparison of theoretical and experimental studies of infrared and microwave spectral data for 5- and 6-membered ring heterocycles: The rotation constants, centrifugal distortion and vibration rotation constants

“…1, 7-10), where MW and/or FT-IR high-resolution vibrational data are available [40][41][42][43][44][45][46][47][48]. We note that a study of the anharmonic frequencies of the azines has also been reported [40], but this did not include centrifugal distortion or vibration-rotation.…”

High‐Resolution Fourier Transform Infrared Spectroscopy

“…There exists one rovibrational analysis of the partially resolved ν 11 band of pyridine (Thiel et al 1991). A new and complete analysis of this band also including an analysis of the ν 4 and ν 12 bands is given by Albert et al (2005).…”