First results from the CLS far-infrared beamline: the $\nu_{12}$ and $\nu_{17}$ bands of acrolein, CH$_{2}$CHCHO

Synchrotron radiation from the new Canadian Light Source facility has been used to obtain a high resolution (0.0012 cm$^{-1})$ absorption spectrum of acrolein vapor in the 550-660 cm$^{-1}$ region. Almost 2000 transitions have been included in a detailed analysis of the $\nu_{12} $ ($\sim $564 cm$^{-1})$ and $\nu_{17} $ ($\sim $593 cm$^{-1})$ fundamental bands, yielding precise values for the band origins, rotational and centrifugal distortion parameters. The analysis included the a- and b-type Coriolis interactions connecting $\nu_{12} $ and $\nu_{17} $, as well as an a-type Coriolis interaction between $\nu_{17} $ and a ``dark'' perturbing state, identified as 4$\nu_{18} $. We believe that this is the first high-resolution infrared study of acrolein.