CNRS-ENS-UPMC, Département de Chimie, École Normale Supérieure, 24 rue Lhomond, 75005 Paris, France.
J Chem Phys. 2013 May 7;138(17):174706. doi: 10.1063/1.4802888.
Soft porous crystals are flexible metal-organic frameworks that respond to physical stimuli (temperature, pressure, and gas adsorption) by large changes in their structure and unit cell volume. We propose here a thermodynamic treatment, based on the osmotic ensemble, of the interplay between guest adsorption and host deformation, where the bare host material can undergo elastic deformation, as well as structural transitions between metastable phases in the case of a multistable material. We show that in addition to structural transitions between metastable phases of bistable or multistable host frameworks, a new guest-stabilized host phase can be created when the size of the adsorbate is larger than the empty material's pore size. We then confront the findings of our approach with experimental data for systems exhibiting phenomena such as gate opening and breathing.
软质多孔晶体是柔性的金属有机骨架，通过结构和单元体积的大幅变化来响应物理刺激（温度、压力和气体吸附）。在这里，我们提出了一种基于渗透压集合的热力学处理方法，研究了客体吸附和主体变形之间的相互作用，其中裸主体材料可以发生弹性变形，并且在多稳态材料的情况下，可以在亚稳相之间发生结构转变。我们表明，除了双稳态或多稳态主体框架的亚稳相之间的结构转变之外，当吸附物的尺寸大于空材料的孔径时，也可以创建一个新的被吸附物稳定的主体相。然后，我们将我们的方法的结果与表现出如门控开启和呼吸等现象的系统的实验数据进行了对比。
