A one-dimensional cadmium metal-organic chain based on a [Cd4(COO)4] secondary building unit and a flexible dicarboxylic acid ligand.

An infinite one-dimensional cadmium metal-organic chain, namely catena-poly[aquabis(μ3-2,2'-{[1,2-phenylenebis(methylene)]bis(sulfanediyl)}dibenzoato)dicadmium(II)], [Cd2(C22H16O4S2)2(H2O)]n, was synthesized by solvothermal reaction of Cd(NO3)2·4H2O and 2,2'-{[1,2-phenylenebis(methylene)]bis(sulfanediyl)}dibenzoic acid (H2L). The Cd(II) centres have six-coordinate CdS2O4 and CdSO5 geometries. Due to the flexible -CH2-S- arms, the L(2-) ligand adopts both syn and anti conformations. Four Cd(II) cations are linked by two syn L(2-) ligands to form a centrosymmetric planar tetranuclear Cd(II) core, which is further extended through bonding to the anti L(2-) ligands to form a one-dimensional metal-organic chain. Adjacent one-dimensional chains are connected by C-H···π interactions and nonclassical C-H···O hydrogen bonds to form the resultant three-dimensional supramolecular framework.