van der Waals complexes between COCl2, COFCl, COF2, and chlorine molecule: An infrared matrix isolation and ab initio study.

Due to their importance in stratosphere, spectroscopic studies of halogenated carbonyls (COF2, COFCl, COCl2) and their complexes with Cl2 are reviewed, including previously unpublished data. In particular, quantitative analysis of νCO Fermi resonance has been made for free and complexed halogenated carbonyls. Ab initio calculations have been undertaken on all these structures. The structure, complexation energy and vibrational analysis at the harmonic approximations have been calculated at the self-consistent field and Mo\ller–Plesset 2 levels. The calculated frequency shifts are in overall agreement with the experimental data. This result was not obvious owing to the weakness of the complexes. © 1995 American Institute of Physics. [ABSTRACT FROM AUTHOR]