Synthesis and crystal structure of a two-dimensional CoII coordination polymer: poly[(μ3-3-carboxybenzoato)[μ2-5-(pyridin-4-yl)-1H,2′H-3,3′-bi[1,2,4-triazole]]cobalt(II)]

In the title compound, [Co(C8H5O4)(C9H6N7)]n, the divalent CoII atom is six-coordinated to three N atoms from two symmetrical 5-(pyridin-4-yl)-1H,2′H-3,3′-bi[1,2,4-triazole] (H2pyttz) ligands and three O atoms from three symmetrical 3-carboxybenzoate (Hbdic) ligands, leading to a distorted {CoN3O3} octahedral coordination environment. Two CoII cations are linked by four bridging carboxylate groups to generate a dinuclear [Co2(CO2)4] unit. The dinuclear units are further connected into a chain along [010] via the Hbdic ligands. The other infinite chain, along [100], is formed through the H2pyttz ligands. Finally, the two kinds of chains are cross-linked, by sharing the CoII cations, into a two-dimensional network. In the crystal, adjacent layers are further linked by O—H...N hydrogen bonds into a three-dimensional framework