Interaction of H2 with fragments of MOF-5 and its implications for the design and development of new MOFs: A computational study

The interaction energies (IEs) of H2 and various organic ligands have been computed using coupled-cluster method with singles, doubles, and noniterative triples (CCSD(T)) at the complete basis set (CBS) limit. The density fitting-density functional theory-symmetry adapted perturbation theory (DF-DFT-SAPT) approach has been used to probe the nature of interaction between H2 and organic linkers. It has been found that dispersive interaction predominantly stabilizes the intermolecular complex formation of H2 on a variety of organic linkers. Furthermore, H2 binding affinity of inorganic connectors is improved by partial isomorphic substitution of Zn by different metal ions such as Fe, Co, Ni and Cu. A new modified metal-organic framework (MOF-5 M) has been designed based upon the insight from the organic and inorganic fragments. The present study provides valuable information required for the design of novel MOFs with improved affinity for H2 adsorption.