Enhanced Aerogen-π Interaction by a Cation-π Force.

The interaction between a noble gas atom and an aromatic π-electron system, which mainly originates from the London dispersion force, is very weak and has not attracted enough attention yet. Herein, we reported a type of notably enhanced aerogen-π interaction between cation-π systems and noble gas atoms. The binding strength of a divalent cation-π system with a xenon atom is comparable to a moderate hydrogen bond (up to ca. 7 kcal mol(-1)), whereas krypton and argon atoms produce slightly weaker interactions. Energy-decomposition analysis reveals that the induction interaction is responsible for the stabilization of divalent cation-π⋅Xe species besides the dispersion interaction. Our results might be helpful to increase the understanding of some unsolved mysteries of aerogens.