Structural-Deformation-Energy-Modulation Strategy in a Soft Porous Coordination Polymer with an Interpenetrated Framework

Angew Chem Int Ed Engl. 2020 Sep 1;59(36):15517-15521. doi: 10.1002/anie.202003186. Epub 2020 May 4.

Abstract

To achieve unique molecular-recognition patterns, a rational control of the flexibility of porous coordination polymers (PCPs) is highly sought, but it remains elusive. From a thermodynamic perspective, the competitive relationship between the structural deformation energy (Edef ) of soft PCPs and the guest interaction is key for selective a guest-triggered structural-transformation behavior. Therefore, it is vital to investigate and control Edef to regulate this competition for flexibility control. Driven by these theoretical insights, we demonstrate an Edef -modulation strategy via encoding inter-framework hydrogen bonds into a soft PCP with an interpenetrated structure. As a proof of this concept, the enhanced Edef of PCP enables a selective gate-opening behavior toward CHCl3 over CH2 Cl2 by changing the adsorption-energy landscape of the compounds. This study provides a new direction for the design of functional soft porous materials.

Keywords: energy landscape; flexibility; molecular recognition; porous coordination polymer; structural-deformation energy.