Terahertz Vibrational Motions Mediate Gas Uptake in Organic Clathrates

Clathrates,
supramolecular materials that contain guest molecules
trapped within a framework of a host lattice, are important in many
areas of science and technology. However, despite much research, fundamental
questions concerning the mechanism and kinetics associated with the
enclathration process remain unanswered. Here, through a combination
of terahertz spectroscopy, density functional theory, and molecular
dynamics simulations, we demonstrate that the gas-capture process
is mediated by a single terahertz vibrational mode and then use this
mode to track the uptake of gas. This result provides a critical molecular-level
understanding of this key kinetic process in clathrate science.