A novel (4,6)-connected double-layered Ba(II) coordination polymer based on the flexible tricarboxylate ligand 2,2',2''-[1,3,5-triazine-2,4,6-triyltris(sulfanediyl)]triacetic acid.

In the title compound, poly[[triaqua{μ(4)-2-[4,6-bis(carboxymethylsulfanyl)-1,3,5-triazin-2-ylsulfanyl]acetato}{μ(2)-2-[4,6-bis(carboxymethylsulfanyl)-1,3,5-triazin-2-ylsulfanyl]acetato}barium(II)] monohydrate], {[Ba(C(9)H(8)N(3)O(6)S(3))(2)(H(2)O)(3)]·H(2)O}(n), each Ba(II) atom is nine-coordinated by six O atoms from carboxylate groups of four different 2-[4,6-bis(carboxymethylsulfanyl)-1,3,5-triazin-2-ylsulfanyl]acetate ligands and three O atoms from water molecules. The triazine ligand is partially deprotonated, as verified by intermolecular hydrogen-bonding parameters, and adopts μ(2)-η(1):η(1) and μ(4)-η(1):η(1):η(2) coordination modes to connect the Ba(II) centres, forming a novel double-layered structure. Topological analysis indicates that the whole structure is a novel (4,6)-connected net, considering the ligands and Ba(II) centres as four- and six-connected nodes, respectively.