Construction of a thiourea-based metal–organic framework with open Ag+ sites for the separation of propene/propane mixtures†
We reported a new method to construct porous thiourea-based metal–organic frameworks AGTU-3a with open Ag+ sites through the removal of anions in pores under mild conditions. By taking advantage of the deprotonation of thiourea-based ligands, the cationic frameworks can be transformed into neutral frameworks and anions in pores can be easily removed through treating with triethylamine under mild conditions. With the planar coordination geometry of open Ag+ sites and π-complexation of Ag+–olefin interactions, AGTU-3a shows good performance in the separation of propene/propane mixtures. As far as we know, our work would provide a new route to construct open Ag+ sites in MOFs and this is the first Ag+-based MOF with open Ag+ sites as nodes applied in the separation of olefin/paraffin mixtures.