High-resolution synchrotron infrared spectroscopy of acrolein: The interacting 101 and 141181 states and other vibrational levels between 1020 and 1200 cm−1

Abstract

Vibrational states of trans-acrolein (propenal) between 1020 and 1200 cm−1 are analyzed using high-resolution infrared spectra obtained at the Canadian Light Source synchrotron radiation facility. The one fundamental in this range, ν10 (C-C stretch vibration) is found to be strongly mixed with a combination vibration ν14 + ν18 by a Fermi-type interaction. Five additional states are directly observed via hot, combination, and overtone bands: ν11 + ν18, ν16 + ν18, ν15 + ν18, 2ν12, and 2ν17. These seven vibrational states are analyzed in a large multi-state fit, along with nine more states which are not directly observed but which affect the observed states by means of many perturbations. Though this fit is cumbersome, incomplete, and not unique, it can account for 3668 out of 3835 assigned lines with an average error of less than 0.0004 cm−1.