A Flexible Doubly Interpenetrated Metal-Organic Framework with Breathing Behavior and Tunable Gate Opening Effect by Introducing Co into ZnO Clusters.

A ZnO clusters based flexible doubly interpenetrated metal-organic framework [(ZnO)(DCPB)DMF]·2DMF·8HO (JLU-Liu33, HDCPB = 1,3-di(4-carboxyphenyl)benzene, DMF = N,N-dimethylformamide) with pcu topology has been solvothermally synthesized. Because of its flexible structure, JLU-Liu33 exhibits a breathing behavior upon N and CO adsorption at low temperature, and CH and CH adsorption at 273 and 298 K. Furthermore, by adopting the direct synthesis method, two isomorphic compounds-JLU-Liu33L and JLU-Liu33H-have been obtained by partial substituting Zn with different amounts of Co into the JLU-Liu33 framework. The gas adsorption study of Co-doped materials reveals that the gate opening effect of JLU-Liu33 can be modulated by introducing different contents of Co into ZnO clusters. Meanwhile, with the increasing amount of Co, the adsorption amount and isosteric enthalpy values for CO have been improved. It is worth mentioning that JLU-Liu33H exhibits commendable selectivity for CO over CH which may be a good candidate for industrial gas purification and air separation applications.