Molecular Simulation of a Zn–Triazamacrocyle Metal–Organic Frameworks Family with Extraframework Anions

Abstract

We report an investigation by means of adsorption experiments and molecular simulation of the behavior of a recently synthesized cationic metal-organic framework. We used a combination of quantum chemistry calculations and classical, forcefield-based Grand Canonical Monte Carlo simulations to shed light into the localization of extra-framework halogenide anions in the material. We also studied the adsorption of small gas molecules into the pores of the material using molecular simulation, and investigated the coadsorption of binary gas mixtures.

Revealing the effect of structure curations on the simulated CO2 separation performances of MOFs

“…Studies showed that identification of the location or distribution of CBIs inside frameworks is necessary to better understand the gas adsorption properties of MOFs. 57,58 However, changing the configuration and position of the CBIs within the framework is computationally demanding due to the requirement of fully flexible modeling of ions. Therefore, we selected two representative MOFs, VEHRIL and UXUPEJ, to examine the impact of flexible modeling of CBIs on the simulated CO 2 adsorption results of the MOFs.…”

CO2/CH4 Separation in Ion-Exchanged Zeolite-like Metal Organic Frameworks with Sodalite Topology (sod-ZMOFs)

“…Molecular simulation techniques have been widely used to predict and evaluate gas separation performances of various MOFs. − Whereas some of these studies focused on only adsorption selectivities, ,,− others considered both adsorption and diffusion selectivities. ,,,, However, the only studies on ZMOFs, to the best of our knowledge, were focused on binary mixtures of CO 2 and CH 4 , − CO 2 and H 2 , and CO 2 and N 2 in rho- ZMOFs.…”

Computational characterization and prediction of metal–organic framework properties

“…[123,124,125,109] These are methodologically similar to simulations of adsorption in neutral MOFs, except for the very large strength of the Coulombic ion-guest interactions. While simulations of adsorption are treated in detail in Section 4, we give in Figure 10 a rather typical example of results from molecular simulation in ionic MOFs, here in the case of the anionic rho-ZMOF with extra-framework Na + cations.…”

“…These simulations can also borrow methodologies from the very extensive scientific literature available on the topic of extra-framework cation localization in zeolites, [116,117,118] including the use of simulated annealing [119] or parallel tempering methods [120,121] Once the localization of extra-framework ions has been determined, it can then be used as input or basis for the study of adsorption properties of the ionic MOF. [123,124,125,109] These are methodologically similar to simulations of adsorption in neutral MOFs, except for the very large strength of the Coulombic ion-guest interactions. While simulations of adsorption are treated in detail in Section 4, we give in Figure 10 a rather typical example of results from molecular simulation in ionic MOFs, here in the case of the anionic rho-ZMOF with extra-framework Na + cations.…”

“…Due to the electric fields generated inside their nanopores by the presence of extraframeworks ions, ionic MOFs show strong interactions with guest molecules, and specific interactions with polar guests in particular. This effect can in turn be leveraged for applications in gas adsorption and storage, [107,108] separation, [109] molecular recognition, [110] drug delivery, [111] ion exchange [112] and catalysis. [113,114,115] Since the extra-framework ions in…”