Solvothermal synthesis of two novel Co(II)-based coordination polymers for the efficient UV-light-driven degradation of methyl violet and magnetic properties

Abstract

Two novel Co(II) coordination polymers (CPs), formulated as {[Co2(L)(H2O)6]·H2O}n (1) and {[Co(bidpe)2(H2O)2]·H2L·3.5H2O}n (2) (H4L = 3,5-bis(3,4-dicarboxylphenoxy)pyridine, bidpe = 4,4′-bis(lmidazolyl)diphenyl ether), have been solvothermally synthesized and characterized by various techniques. Complex 1 exhibited a 2D→3D supramolecular framework through H-bonds with a point symbol of (12)(4·125)(4) topology. However, with the introduction of additional bibpe ligand, the H4L ligand did not coordinate with Co(II) ions in the synthesis of 2. Complex 2 possessed a 1D [Co(bidpe)2]n loop line, which was further linked by H-bonds to form a 3D supramolecular architecture. In particular, both the CPs exhibited efficient photocatalytic activities towards the degradation of methyl violet (MV) under low-energy irradiation of a 125 W Hg lamp, which could be attributed to their high efficiencies in generating ·OH radicals. Moreover, the variable-temperature magnetic analyses indicated that 1 and 2 exhibit antiferromagnetic behavior between the adjacent Co(II) ions.