PNNL

Abstract

At high pressure and temperature, it is possible to transform the high density thermodynamic form of a well known organic host (p-tert-butylcalix[4]arene) to the low density kinetic form and vice versa. This transformation involves converting a material that is effectively inactive with respect to gas sorption, into the form that has large lattice voids and that is sorptive under normal experimental conditions, despite the high density form being devoid of channels or porosity. Remarkably, particular gas molecules appear to diffuse through the solid into small lattice voids, and effect the transformation to the low density kinetic form, which involves significant expansion of the crystalline organic lattice.