Thermodynamic study of sorption processes of gaseous benzene and water on metal–organic framework [Zn4(dmf)(ur)2(ndc)4]

• Pressure of guests was measured in systems host (Zn4(dmf)(ur)2(ndc)4) – guests (benzene, water).
• The volatilities of guests and thermodynamic values of desorption processes were obtained.
• Gibbs energy change in the process of bonding of liquid guest by the framework was calculated.
• Several energy-different states of guests in [Zn4(dmf)(ur)2(ndc)4] were revealed.

The pressure of guests was measured by the static method with glass membrane-gauge manometers in the systems host (metal–organic framework [Zn4(dmf)(ur)2(ndc)4]) – guests (benzene, water) within the temperature range 316 K to 470 K. As a result of this study the thermal stability of investigated systems were established, the temperature dependences of pressure for evaporation processes and the composition of the gas phase were obtained, enthalpies and entropies of desorption were determined, Gibbs energy change in the process of bonding of liquid guest by the framework was calculated. On the base of this information the conclusions about the nature of the interactions between host and guest molecules were made. The adsorption properties of the polymer have been investigated by the isopiestic method.