DFT and FMO calculations for analysis of the stability of MOF

Abstract

Recently, metal organic framework (MOF) has attracted much attention as new porous adsorbent materials. Thousands of MOF structures can be fully crystalized from the various combinations of organic and inorganic subunits. In the present study, we investigated the stable structures and their electronic properties of the model systems of MOF, using the first principles molecular simulations based on density functional theory (DFT). We employed the model structure of the smallest unit for MIL-101(Al) and MIL-101-NH_2 (Al) MOFs. In addition, the interactions between Al ions and the subunits of MOF were investigated, using ab initio fragment MO (FMO) calculations. We investigated the interaction energies between Al and BDC/BDC- NH_2 by use of FMO method. The interaction energy between Al and BDC- NH_2 is significantly larger than that between Al and BDC. Therefore, it is elucidated that the NH_2 introduction to BDC enhances the interactions between Al and BDCs, resulting in the more stable framework for MIL-101- NH_2 (Al). We furthermore proposed new BDC derivatives and investigated the stability of the MOF systems including them. The results will be presented at the conference.