Significant gas uptake enhancement by post-exchange of zinc(II) with copper(II) within a metal–organic framework

Coordination of a tetratopic nitrogen-rich linker with Zn2+ under solvothermal conditions afforded a Zn-based metal organic framework (MOF), where the Zn(II) ions could be exchanged by Cu(II) ions in a single-crystal-to-single-crystal fashion leading to a new Cu-based MOF. Such transformation induces a significant enhancement in gas sorption along with a high selectivity towards CO2 over N2 and CH4.