Flexible Microporous Framework Based on Pb₄ Clusters for Highly Selective Storage and Separation of Energy Gases

In this work, a microporous Pb­(II)-based framework (FJI-H22) has been synthesized upon solvothermal reaction, which is constructed from two kinds of rarely seen tetranuclear Pb­(II) clusters. FJI-H22 has two kinds of one-dimensional microporous channels (ca. 12.80 Å × 15.08 and 6.05 Å × 11.83 Å) along the crystallographic b axis. Interestingly, when immersed in methanol FJI-H22 can undergo reverse single-crystal-to-single-crystal transformations to form FJI-H22-MeOH. In particular, high stability (stable up to 300 °C in atmosphere), large Brunauer–Emmett–Teller (BET) surface area (483 m2·g–1), and the nature of microporosity enable desolvated FJI-H22 to be a good candidate for purification of natural gas. As anticipated, desolvated FJI-H22 can selectively adsorb C2/C3 hydrocarbons over CH4 at 298 K and 1 bar. Furthermore, ideal adsorbed solution theory calculations reveal that FJI-H22 shows highly selective separation of higher hydrocarbons over CH4 under ambient conditions