Effective gas adsorption and magnetic properties in a N-oxide-functionalized 3D pillared microporous Mn(Ⅱ) metal-organic framework

N -Oxide-functional isonicotinic acid N -Oxide (HINO) ligand has been selected to construct functional metal–organic frameworks (MOFs). And based on HINO ligand and Mn(Ⅱ) center, a novel N -Oxide-functional three-dimensional (3D) pillared microporous Mn(Ⅱ)-MOF, [Mn(INO) 2 ·CH 3 OH] n ( 1 ), has been constructed. MOF 1 has been characterized by single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), thermogravimetric analyses (TGA), elemental analyses (EA) and infrared spectroscopy (IR). Structural analysis reveal that in MOF 1 , the N -Oxide group and carboxylic group of INO ligand connect Mn(Ⅱ) centers to form a one-dimensional (1D) Mn-O chain, and then the 1D chains are supported by INO ligands with two types of coordination modes to generate its 3D pillared microporous framework. Given the 1D Mn-O chains in MOF 1 , magnetic susceptibility measurements have been conducted, which show antiferromagnetic exchange interactions between Mn(Ⅱ) centers in the Mn-O chain. Given the porosity of MOF 1 and the N -Oxide sites and vacant carboxylic O sites on its pore surfaces, gas adsorption experiments of MOF 1 have been investigated by N 2 , CH 4 and CO 2 gases. MOF 1 displays good adsorption capacity, affinity and selectivity of CO 2 over CH 4 and N 2 , indicating its potential application in postcombustion CO 2 capture and gas separation.