Interactions between the chloride anion and aromatic molecules: Infrared spectra of the Cl-C6H5CH3, Cl-C 6H5NH2 and Cl-C6H5OH complexes

Abstract

The Cl--C6H5CH3-Ar, Cl --C6H5N3Ar, and Cl --C6H5OH.Ar anion complexes are investigated using infrared photodissociation spectroscopy and ab initio calculations at the MP2/aug-cc-pVDZ level. The results indicate that for Cl--C 6H5NH2 and CI5-C6H 5OH, the Cl- anion is attached to the substituent group by a single near-linear hydrogen bond. For Cl--C6H 5CH3, the Cl5 is attached to an orifco-hydrogen atom on the aromatic ring and to a hydrogen atom on the methyl group by a weaker hydrogen bond. The principal spectroscopic consequence of the hydrogen-bonding interaction in the three complexes is a red-shift and intensity increase for the CH, NH, and OH stretching modes. Complexities in the infrar..