Abstract
Two conformers of ClCOOH were produced upon irradiation at 355 nm of a gaseous flowing mixture of Cl 2 , HCOOH, and N 2 . A step-scan Fourier-transform infrared spectrometer coupled with a multipass absorption cell was utilized to monitor the transient spectra of ClCOOH. Absorption bands with origins at 1808.0 and 1328.5 cm -1 are attributed to the C=O stretching and COH bending modes of t -ClCOOH, respectively; those at 1883.0 and 1284.9 cm -1 are assigned as the C=O stretching and COH bending modes of c -ClCOOH, respectively. These observed vibrational wavenumbers agree with corresponding values for t -ClCOOH and c -ClCOOH predicted with B3LYP/aug-cc-pVTZ density-functional theory and the observed rotational contours agree satisfactorily with simulated bands based on predicted rotational parameters. The observed relative intensities indicate that t -ClCOOH is more stable than c -ClCOOH by ∼3 kJ mol -1 . A simple kinetic model is employed to account for the production and decay of ClCOOH. © 2009 American Institute of Physics.