CH-{\pi} interaction-induced deep orbital deformation in a benzene-methane weak binding system

TL;DR

This study reveals that CH-π interactions in benzene-methane complexes cause significant orbital deformations, challenging previous assumptions that nonbonding interactions do not alter molecular orbitals.

Contribution

First systematic investigation of orbital distribution and deformation in benzene-methane complexes due to CH-π interactions using ab initio methods.

Findings

Strong deformation observed in HOMO-4 and LUMO+2 orbitals

CH-π interaction influences orbital distribution and composition

Orbital changes challenge previous beliefs about nonbonding interactions

Abstract

The nonbonding interaction between benzene and methane, called CH-{\pi} interaction, plays an important role in physical, chemical, and biological fields. CH-{\pi} interaction can decrease the system total energy and promote the formation of special geometric configurations. This work investigates systemically the orbital distribution and composition of the benzene-methane complex for the first time using ab initio calculation based on different methods and basis sets. Surprisingly, we find strong deformation in HOMO-4 and LUMO+2 induced by CH-{\pi} interaction, extending the general view that nonbonding interaction does not cause orbital change of molecules.