Dynamic porous metal-organic frameworks: synthesis, structure and sorption property

Three new porous metal-organic frameworks {[Co(L)(PIN)]center dot dioxane center dot H2O}(n) (1), {[Co(L)(DPE)]center dot 0.5DPE}(n) (2) and {[Co(L)(BPE)]center dot 4H(2)O}(n) (3) with the same 2-fold interpenetrating hms topology based on 5-(pyridin-4-yl)isophthalate (L2-) and different pillar ligands of N-(4-pyridyl) isonicotinamide (PIN), 1,2-di(4-pyridyl) ethylene (DPE) and 1,2-bis(4-pyridyl) ethane (BPE) have been prepared and characterized by IR, thermogravimetric analysis, single crystal and powder X-ray diffractions. Interestingly, 1 possesses a flexible framework upon desolvation and H2O/MeOH/EtOH vapor adsorption, and the desolvated sample exhibits a stepwise uptake of CO2 (195 K), H2O (298 K) and MeOH (298 K). More importantly, the desolvated 1 shows high enthalpy of CO2 adsorption and high selectivity for CO2 over N-2 as well as H2O/MeOH over EtOH at 298 K.