Two new MOFs based on 5-((4-carboxypyridin-2-yl)oxy) isophthalic acid displaying the unique selective CO2 gas adsorption and Magnetic properties†

Two new water–stable magnetic framework, [Cu1.5(L)(H2O)]·2H2O (1), and [Co4(L)2(CH3CN)(OH)2(H2O)4]·3H2O (2) (H3L = 5-((4-carboxypyridin-2-yl)oxy) isophthalic acid), has been synthesized by solvothermal in similar reaction systems and characterized by infrared spectroscopy, powder X-ray diffraction, thermogravimetry measurements. As influenced by different metal ions, 1 shows a trinodal (4,4,4)-connected three-dimensional framework that possesses a one-dimensional pore channel based on [Cu2(COO)4] paddle-wheel secondary building units (SBUs). 2 is a two-dimensional layered network based on tetranuclear [Co4(COO)6(μ3-OH)2] SBUs and with a (3,6)-connected kgd topological structure. The gas adsorption explorations demonstrated that 1 exhibits commendable selectivity for CO2 over CH4. Meanwhile, both 1 and 2 show different degrees of antiferromagnetic exchange action.