Two new entangled coordination polymers constructed by flexible coligands: Synthesis, magnetism, and gas absorption

Two isostructural metal–organic polymers, namely {[M(bce)(bib)]·solv}n (M = Co(II) and solv = CH3OH·H2O for 1; M = Ni(II) and solv = 0.5CH3OH·0·25H2O for 2) (H2bce = 1,2-bis(4-carboxy-phenoxy)ethane and bib = 2,3-bis(4-pyridyl)butane), have been synthesized and characterized. The structures of the two compounds show 2D → 2D parallel interpenetrated frameworks with polyrotaxane and polycatenane character. The magnetic behaviors of 1 and 2 indicate antiferromagnetic interactions within paddle-wheel units. Furthermore, the compound 1 exhibits relative high N2 uptake adsorption capacity.