Adsorptive Separation of Methylfuran and Dimethylfuran by a Robust Porous Organic Cage

Abstract

As vital raw materials in the chemical industry, 2-methylfuran (MeF) and 2,5-dimethylfuran (DMeF) are commonly produced as mixtures. The selective separation of MeF and DMeF is crucial yet challenging, with significant industrial and economic implications. This study presents an energy-efficient separation technique using a robust calix[4]­resorcinarene-based supramolecular porous organic cage (POC), CPOC-301, to effectively capture DMeF from an equimolar MeF/DMeF mixture within 2 h, yielding 95.3% purity. The exceptional separation efficiency stems from the superior structural stability of CPOC-301, maintaining its initial porous crystalline structure during separation. Calculations show that CPOC-301 forms more C–H···π hydrogen bonds with DMeF versus MeF, accounting for its DMeF selectivity. CPOC-301 can be easily regenerated via heat under a vacuum and reused for over five adsorption–desorption cycles without significant performance loss. This work introduces an approach to separate similar organic molecules effectively using POC materials.