ABINITIO STUDY OF THE WEAKLY BONDED CO-CL2 COMPLEX

Ab initio structure and vibrational frequency calculations have been performed on the weakly bonded CO-Cl2 complex at the SCF and MP2 levels of approximation. Minima were found for the two linear structures, specifically CO-Cl2 and OC-Cl2, with the latter being slightly more stable than the former. In addition, minima were found for two nonlinear structures, one T-shaped and the other essentially parallel. In the T-shaped structure, the oxygen is very weakly bonded to the chlorines (C2v symmetry). The parallel isomer is slightly lower in energy than the T-shaped structure; however, both of the nonlinear isomers are less stable then either of the linear isomers. The calculated properties of the OC-Cl2 isomer are in excellent agreement with experimental results reported earlier, lending further support to the conclusion that the structure of the experimentally observed isomer is OC-Cl2 rather than CO-Cl2.