A Dynamic Chemical Clip in Supramolecular Framework for Sorting Alkylaromatic Isomers using Thermodynamic and Kinetic Preferences

Angew Chem Int Ed Engl. 2021 Sep 1;60(36):19921-19927. doi: 10.1002/anie.202106784. Epub 2021 Jul 26.

Abstract

Adsorptive chemical separation is at the forefront of future technologies, for use in chemical and petrochemical industries. In this process, a porous adsorbent selectively allows a single component from a mixture of three or more chemical components to be adsorbed or permeate. To separate the unsorted chemicals, a different adsorbent is needed. A unique adsorbent which can recognize and separate each of the chemicals from a mixture of three or more components is the necessity for the next generation porous materials. In this regard, we demonstrate a "dynamic chemical clip" in a supramolecular framework capable of thermodynamic and kinetics-based chemical separation. The dynamic space, featuring a strong preference for aromatic guests through π-π and C-H⋅⋅⋅π interactions and adaptability, can recognize the individual chemical isomers from mixtures and separate those based on thermodynamic and kinetic factors. The liquid-phase selectivity and separation of the aromatic isomers are possible by the adaptability of the "chemical clip" and here we elucidate the prime factors in a combinatorial approach involving crystallographic evidence and detailed computational studies.

Keywords: BTEX selectivity; coordination polymers; dynamic space; liquid-phase separation; supramolecular frameworks.