Infrared spectra of matrix isolated ClCO and <i>a</i> <i>b</i> <i>i</i> <i>n</i> <i>i</i> <i>t</i> <i>i</i> <i>o</i> calculation

Abstract

Cl atoms and CO molecules were trapped in a solid Ar matrix at 16 K. The formation of ClCO was followed via its IR spectrum. The vibrational frequencies of 35Cl12C16O were observed at 1876.7, 570.1, and 334.6 cm−1. Experiments with different CO isotopomers were performed in order to confirm the assignment of the absorptions and to characterize the force field. The results extend and correct earlier data [M. E. Jacox and D. E. Milligan, J. Chem. Phys. 43, 866 (1965)]. With the help of quantum chemical calculations (UHF, MP2), the optimized ClCO bond angle was obtained to be 129.2°. The computed bond lengths were determined to be 1.159 Å for C–O and 1.807 Å for C–Cl. Based on force constant calculations, the C–Cl bond in ClCO was found to be extremely weak compared to that in Cl2CO.