Honeycomb Metal-Organic Framework with Lewis Acidic and Basic Bifunctional Sites: Selective Adsorption and CO Catalytic Fixation.

Carrying out the strategy of incorporating rod secondary building units and polar functional groups in metal-organic frameworks (MOFs) to accomplish the separation of CO and C hydrocarbons over CH as well as CO fixation, an oxalamide-functionalized ligand N, N'-bis(isophthalic acid)-oxalamide (HBDPO) has been designed. The solvothermal reaction of HBDPO with the oxophilic alkaline-earth Ba ion afforded a honeycomb Ba-MOF, {[Ba(BDPO)(HO)]·DMA} (1). Due to the existence of Lewis basic oxalamide groups and unsaturated Lewis acid metal sites in the tubular channels, the activated framework presents not only high CH, CH, and CO uptakes and selective capture from CH, but also efficient CO chemical fixation as a recyclable heterogeneous catalyst. Grand canonical Monte Carlo simulations were combined to explore the adsorption selectivities for CH-CH and CH-CH mixtures as well as the interaction mechanisms between the framework and epoxides.