Experimental Determination of the Interaction Potential between a Helium Atom and the Interior Surface of a C60 Fullerene Molecule

TL;DR

This study uses terahertz spectroscopy and neutron scattering to experimentally determine the interaction potential between helium atoms and C60 fullerenes, providing insights into non-bonded atomic interactions within molecular cages.

Contribution

It presents the first experimental determination of the helium-C60 interaction potential, comparing it with quantum chemistry and empirical models.

Findings

Experimental potential matches quantum chemistry estimates

Provides detailed potential energy function for helium-fullerene interactions

Enhances understanding of non-bonded atomic forces in confined systems

Abstract

The interactions between atoms and molecules may be described by a potential energy function of the nuclear coordinates. Non-bonded interactions are dominated by repulsive forces at short range and attractive dispersion forces at long range. Experimental data on the detailed interaction potentials for non-bonded interatomic and intermolecular forces is scarce. Here we use terahertz spectroscopy and inelastic neutron scattering to determine the potential energy function for the non-bonded interaction between single He atoms and encapsulating C60 fullerene cages, in the helium endofullerenes 3He and 4He, synthesised by molecular surgery techniques. The experimentally derived potential is compared to estimates from quantum chemistry calculations, and from sums of empirical two-body potentials.