Complexes of the noble-gas atoms with unsaturated ions: A theoretical investigation on the exemplary (H2C = NH2 +)Ar

The (H2C = NH2 +)Ar isomeric complexes recently observed by Duncan and coworkers using gas phase infrared spectroscopy [Chem. Phys. Lett. 726 (2019) 53-56] were theoretically investigated by different techniques of bonding analysis. The higher stability of the NH-coordinated complex with respect to the C-coordinated one arises from a major contribution of the inductive binding component, the electrostatic and dispersion contributions being, instead, comparable in the two isomers. A similar situation expectedly occurs in other complexes of the noble-gas atoms with unsaturated and aromatic ions, observed to feature the competitive occurrence of a more stable H-bonded isomer and a less stable ?-stacked one.