Applications of pillararene NACs in adsorption and separation

This review describes a novel kind of materials for adsorption and separation, nonporous adaptive crystals (NACs), which are firstly mentioned and defined by us. Compared with traditional porous materials, NACs of pillararenes can be synthesized easily, have good chemical, humid and thermal stabilities, are soluble in many common organic solvents, and can be reused many times. Here, we focus on the discussion of pillararene-based NACs for adsorption and separation and the crystal structure transformations from the initial nonporous crystalline state to new guest-loaded structures during the adsorption and separation processes. Single-crystal X-ray diffraction, powder X-ray diffraction, gas chromatography and solution NMR are the main techniques to investigate the adsorption and separation processes and the structural transformations. It is expected that this kind of materials will show practical applications in the chemical industry.