Guest-Induced Gate Opening and Breathing Phenomena in Soft Porous Crystals: Building Thermodynamically Consistent Isotherms

Metal organic-frameworks (MOFs) have emerged as a novel and fascinating family of porous materials offering promising perspectives for designing tailor-made adsorbents and catalysts. Particularly, great attention has been paid to flexible nanoporous MOFs (or Soft Porous Crystals) displaying structural phase transitions promoted by external stimuli. This is the case of guest-induced structural transitions upon adsorption being at the origin of the striking gate opening and breathing phenomena. We present here a short overview of the formulation of thermodynamic isotherms for describing S-shaped adsorption/desorption curves typical of such phenomena, as well as recent thermodynamic methods for estimating phase transition energies. These methods might be valuable for the rational design of gate opening/breathing MOFs.