A computational study of the pyrrole⋯CO and pyridine⋯CO complexes

Pyrrole⋯CO and pyridine⋯CO van der Waals clusters in various configurations have been studied at the MP2/cc-pVQZ level in order to resolve ambiguity in previous microwave spectroscopy studies. For pyrrole⋯CO the previously proposed configuration - with the CO fragment bound to the pyrrole ring - was found to be the most stable. For pyridine⋯CO the “preferred” planar structure proposed by Bettens and Bauder [R.P.A. Bettens, A. Bauder, J. Chem. Phys. 102 (1995) 1501] was found to be significantly more stable than their competing structure, but two other structure of similar configuration to the pyrrole⋯CO cluster were found to be more stable.