Sulfonylcalix[4]arene-based metal-organic polyhedra with hierarchical porous structures for efficient Xe/Kr separation

Multiple space from the interior of metal-organic polyhedra(MOPs),the exterior among MOPs,and the inherent nature of big organic molecules makes MOPs as promising platform with hierarchical porous structures,especially when well-elucidated reticular chemistry principles were used.Herein we describe the preparation of a series of isoreticular octahedral MOPs featuring Zn4-p-tert-butylsulfonylcalix[4]arene clusters by the metal-directed assembly of three rigid organic ligands with different lengths.Intercage hydrogen-bonds and hydrophobic interactions between sulfonylcalix[4]arene groups direct the stacking of discrete MOPs into a novel permanent hierarchical porous material.More importantly,the optimal MOP 1-Zn exhibits high adsorption capacity of Xe and excellent Xe/Kr(20/80,v/v)separation performance,as demonstrated by adsorption isotherms,breakthrough experiments,and density functional theory calculations.Additionally,grand canonical Monte Carlo(GCMC)and dispersion-corrected density functional theory(DFT-D)theoretical calculations provide molecular-level insight over the adsorption/separation mechanism.