Dual-Functionalized Metal–Organic Frameworks Constructed from Hexatopic Ligand for Selective CO2 Adsorption

A ligand design approach, which requires rational design of ligand based on the knowledge of specific target, was applied for the synthesis of two interesting and robust MOFs 1 and 2 containing unusual several types of copper­(II) secondary building units (SBUs). Thanks to unsaturated metal centers (UMCs) and azo group, microporous material 1 exhibited not only high CO2 uptake but also an impressive selective adsorption of CO2 over CH4 and N2. Moreover, a high H2 uptake of 1 was also observed.