Adsorption of RDX and TATP on IRMOF-1: an ab initio study

Abstract

The adsorption of 1,3,5-trinitro-s-triazine (RDX) and triacetone triperoxide (TATP) on representative fragments of metal organic framework (IRMOF-1) was studied at the B3LYP/6-31G(d) level of theory. For examined adsorbates several possible adsorption positions toward the IRMOF-1 fragments were found. The adsorption strength of the adsorbate on IRMOF-1 is largely affected by the geometry of the active site of IRMOF-1 which controls the orientation of the target molecule with respect to the IRMOF-1 fragment. The calculations show that the adsorption on these fragments occurs due to the formation of hydrogen bonds between the molecular C-H groups and the oxygen atoms of IRMOF-1. The RDX and TATP molecules are the most strongly adsorbed on the linker fragment of IRMOF-1. This type of adsorption results in the polarization of RDX and TATP on the IRMOF-1 fragments. The interaction energy of two most stable RDX-, and TATP-IRMOF-1 adsorption systems are -9.8 and -12.8 kcal/mol, respectively. It can be concluded that the 1,4-benzenedicarboxylate site of IRMOF-1 shows the stronger molecular adsorption of RDX and TATP than the site containing [Zn 4 O(CO 2 ) 6 ] and also it is characterized by higher reactivity than the other considered sites. The binding of studied explosive molecules to IRMOF-1 consists of interplay between attractive interactions between the target molecule and MOF as well as the shielding by the IRMOF-1 fragment induced by the molecular adsorption. The relative importance of these effects depends on the chemical nature, the size, and the shape of the molecule and MOF. Small-size molecules require smaller space for the adsorption and also they are less shielded by the sizeable adsorbent. So they interact better when adsorbed on larger IRMOF-1 fragment. On the other side, larger molecules show higher adsorption strength with small fragments of IRMOF-1.

Interpreting the CO2 Adsorption on Functionalized Organic Group of IRMOF-1: A B3LYP Density Functional Theory based Study

“…Due to the inherent ability of the organic ligand to interaction with CO2 and the ability to receive functional groups, the reinforcement of H2BDC linker is reasonable and simple approach for increase the CO2-framework interaction. As reported in the previous studies, calculation of the chemical properties of IRMOF-1 using a representative fragment is in good agreement with the experimental results [42][43][44]. In order to practical modelling of the IRMOF-1 structure via a DFT calculation, H2BDC linker was separated from the large size of IRMOF-1 cell to reduce the calculation time and applied the modification by functionalizing various groups.…”

Molecular simulations of adsorption of RDX and TATP on IRMOF-1(Be)

“…This implies much higher binding affinity of the IRMOF-1(Be) linkers for RDX than the connector shows. The same conclusion was made for RDX interacting with IRMOF-1(Zn) [36,44] with similar intermolecular binding between RDX and the IRMOF-1(Zn) models (multiple C-H…O H-bridges).…”

“…Preliminary investigations (performed only as a first approximation) focused on the interactions of RDX and TATP with small IRMOF-1(Zn) fragments [44]. It was shown that the selected explosive molecules interact more strongly with the linker of IRMOF-1(Zn) than with the connector.…”

Coordination Polymer Frameworks for Next Generation Optoelectronic Devices

“…Among the series of IRMOFs (IRMOF 1-16) introduced by Yaghi and coworkers [58][59][60], several IRMOFs have shown effective selective preconcentration properties, including IRMOF-10 [61][62][63][64].…”