Ligand Configuration-Directed Pillared Kagome-Layer MOFs: Synthesis, Structure, and Adsorption of Propane/Propylene Properties

Based on the predesigned single ligands with different configurations, two pillared Kagome-layer metal–organic frameworks (MOFs), Cu(dcpy) and Cu2(pdda)2(H2O), have been successfully fabricated by the ligand-to-axial approach. The two MOFs present binodal (3,6)- and (3,5)-connected nets based on Cu2 paddlewheel nodes, respectively. The different ligand configurations lead to distinct architectures, in which the structure of Cu(dcpy) can be described by an A-A-A parallel fashion between the staggered Kagome layers, while the layers stack in an A-B-A-B eclipsing fashion for the structure of Cu2(pdda)2(H2O). Such structural differences demonstrate that the reduced connectivity of Cu2 units caused by the coordination orientation of ligands can be achieved through the change from a framework with no functionality to a functionalized framework. Both MOFs possess high porosity characterized by N2 adsorption and exhibit preferential binding of C3H8 than C3H6 in low-pressure regions.