Intermolecular Interaction Energies in Hydroquinone Clathrates at High Pressure

Abstract

The energy landscape and its evolution with pressure have been studied for two hydroquinone clathrates in combination with the apohost β-hydroquinone structure. Pressure is used as a means for probing interatomic, or intermolecular, potentials. The forces in organic clathrates are generally dominated by strong intermolecular interactions in a host framework, with smaller contributions from subtle interactions between the guest molecules and the surrounding framework. Pairwise intermolecular interactions energies have been quantified for the hydroquinone–methanol and hydroquinone–acetonitrile clathrate up to pressures of 8.6(2) and 14.1(4) GPa, respectively. In both cases, reversible pressure induced phase transitions are observed, where the host framework tilts to form skewed cavity channels and break the 3-fold rotation symmetry. The compression of the hydroquinone–acetonitrile structure is found to be isotropic, whereas it is anisotropic for the hydroquinone–methanol compound, emphasizing the implicatio...