Selective separation of 2,5-dimethylfuran and 2,5-dimethyltetrahydrofuran using nonporous adaptive crystals of a hybrid[3]arene

Abstract

The separation of 2,5-dimethylfuran (DMeF) and 2,5-methyltetrahydrofuran (DMeTHF) mixtures plays a crucial role in the chemical industry. However, it remains a great challenge to separate them from a mixture due to their close boiling points and the formation of an azeotrope using traditional separating methods. Herein, we succeeded in separating DMeF from its 50 : 50 v/v DMeF/DMeTHF mixture using nonporous adaptive crystals (NACs) of a hybrid[3]arene (HB3). We found that HB3 crystals revealed a 98.6% selectivity to DMeF after adsorption in a 50 : 50 v/v DMeF/DMeTHF mixture. Single crystal X-ray diffraction (SCXRD) revealed that the specific selectivity is derived from forming an intermolecular packed host–guest complex between HB3 and DMeF. The cycling experiment demonstrated that the HB3 crystals could be reused over ten cycles without losing their performance.