Molecular-level characterization of the breathing behavior of the jungle-gym-type DMOF-1 metal-organic framework.

Fundamental insights into the molecular mechanisms that determine the breathing behavior of the jungle-gym-type DMOF-1 metal-organic framework upon adsorption of benzene and isopropyl alcohol are gained from computer simulations. In all cases, good agreement is obtained between the calculated and experimental structural parameters. In the case of benzene adsorption, DMOF-1 is predicted to exist in a narrow pore configuration at high loadings and/or low temperature. A structural transition into a large pore configuration is then observed as the temperature increases and/or the loading decreases, which is directly related to the spatial distribution and molecular interactions of the benzene molecules within the pores. The isopropyl alcohol adsorption simulations indicate that DMOF-1 undergoes two distinct structural transitions (from large pore to narrow pore and then back to large pore) as the number of adsorbed molecules increases, which is explained in terms of the formation of hydrogen bonds between the isopropyl molecules and the framework.