Phenanthrene[2]arene: synthesis and application as nonporous adaptive crystals in the separation of benzene from cyclohexane

In this work, we design and synthesize a new macrocycle, phenanthrene[2]arene 1, with nanometer-sized cavities in high yield. The nonporous adaptive crystals of phenanthrene[2]arene exhibit excellent benzene (PhH) adsorption capacity, and one host molecule can at maximum adsorb five PhH molecules. Moreover, activated crystals of 1 are able to separate PhH from an equimolar mixture of PhH and cyclohexane (Cy) and the purity of the PhH can reach 98.4% under mild and user-friendly conditions. In addition, fast adsorption, high loading ratios, high purity, and easy recycling are achieved with the present system for the separation of PhH and Cy, which is promising for practical applications.