Effect of cavity size on the adsorption of small molecules on two isoreticular cobalt-based MOF: An ONIOM approach

Publication date: 15 May 2019Source: Computational and Theoretical Chemistry, Volume 1156Author(s): Jacqueline Calderón, Rafael Añez, Paola AlejosAbstractThe interaction of CO2, CO, H2O, N2, N2O and O2 with the isoreticular metal-organic frameworks [Co(bdc)(pz)]n and [Co(bdc)(bpy)]n was studied. The ONIOM (M06/6-31G(d)HF/6-31G(d)) was applied to determine the structural and thermodynamic changes produced by the interaction among these small molecules and the framework structures. All the calculated adsorption energies are in the range of van der Waals non-covalent interactions, both influenced by dipole-quadrupole and quadruple-quadrupole electrostatic forces as well as confinement effect due to the different cavity sizes. The ΔHads values obtained for the adsorption of CO2, CO and N2O suggest that [Co(bdc)(pz)]n and [Co(bdc)(bpy)]n framework structures are potential materials for the capture of these gases at standard conditions, which [Co(bdc)(bpy)]n exhibits greater adsorptive selectivity of post-combustion CO2, with a CO2/N2 energy ratio around 150% higher than [Co(bdc)(pz)]n.Graphical abstract

Source: Computational and Theoretical Chemistry - April 3, 2019 Category: Chemistry Source Type: research