Experimental and theoretical investigations of the gas adsorption sites in rht-metal–organic frameworks

Abstract

rht-metal–organic frameworks (MOFs) represent a highly popular class of MOFs in the world of porous crystalline materials. MOFs belonging to this family consist of M²⁺ ions coordinated to hexatopic organic linkers containing three coplanar isophthalate-based moieties. rht-MOFs are a promising platform of MOFs because they display open-metal sites through the [M₂(O₂CR)₄] clusters, high surface areas, and tunable pore sizes and chemical functionalities. They have been shown to exhibit high uptake for various energy-related gases, such as H₂ and CO₂. Detailed insights into the gas sorption mechanisms and binding sites in these MOFs can be made by way of experimental techniques, including neutron powder diffraction (NPD) and inelastic neutron scattering (INS), and theoretical methods, such as Monte Carlo (MC) simulations and electronic structure calculations. In this highlight, we review the important experimental and theoretical studies that have been performed to investigate the favorable gas sorption sites in these MOFs. A better understanding of the gas sorption mechanisms in rht-MOFs and related structures can allow for the rational design of new materials that are tailored for specific applications.