Contracting pore channels of a magnesium-based metal-organic framework by decorating methyl groups for effective Xe/Kr separation.

A new magnesium-based metal-organic framework with unprecedented short-chain secondary building units and ultra-micropore channels approaching the kinetic diameters of Xe is fabricated by decorating methyl groups on ligands. Due to the contracted pores, this MOF exhibits very high selectivity values for Xe/Kr, which ranks it among the top porous absorbents.