Tuning the Channel Size and Structure Flexibility of Metal-Organic Frameworks for the Selective Adsorption of Noble Gases.

Two ultramicroporous metal-organic frameworks, Zn(ox)0.5(trz) and Zn(ox)0.5(atrz) (ox = oxalate, trz = triazolate, and atrz = 3-aminotriazolate), have been synthesized and tested for the adsorptive separation of Xe and Kr. We demonstrate that the Xe/Kr adsorption selectivity relates to the pore size as well as the structure flexibility of the adsorbents.