[Cd{C2(COO)2}(H2O)3]·H2O,the first cadmium salt of acetylenedicarboxylic acid

In catena‐poly­tri­aqua­cadmium(II)]‐μ‐acetyl­enedi­carboxyl­ato‐κ⁴O,O′:O′′,O′′′] hydrate], {Cd(C₄O₄)(H₂O)₃]·­H₂O}_n, the Cd^II atom is coordinated by two bidentate carboxyl­ate groups and three water mol­ecules, thus forming a sevenfold coordination polyhedron with all atoms located on general sites. These polyhedra are connected by the bifunctional acetyl­enedi­carboxyl­ate ligands, forming zigzag chains running parallel to 120]. Hydro­gen bonds, which involve the non‐coordinated water mol­ecule, connect these chains to form a three‐dimensional framework.