A binuclear zinc polymer with paddlewheel building units and intersecting helical chains based on a flexible 4-[(carboxymethyl)sulfanyl]benzoic acid ligand.

The asymmetric unit of the title compound, poly[{μ(4)-4-[(carboxylatomethyl)sulfanyl]benzoato}(N,N-dimethylformamide)zinc], [Zn(C(9)H(6)O(4)S)(C(3)H(7)NO)](n), consists of one crystallographically independent Zn(II) cation, one 4-[(carboxylatomethyl)sulfanyl]benzoate (L(2-)) ligand and one coordinated dimethylformamide (DMF) molecule. The zinc ion is coordinated by five O atoms from four separate L(2-) ligands and one DMF molecule, and the ZnO(5) unit displays a distorted square-based-pyramidal geometry. Two ZnO(5) units form a binuclear zinc-tetracarboxylate paddlewheel cluster, and these are bridged by L(2-) ligands to generate an intersecting helical chain (Zn(2+) ions as nodes), which is composed of right-handed (P) and left-handed (M) helices. Weak C-H···O hydrogen bonds extend the one-dimensional coordinated chain into a weakly bound three-dimensional supramolecular architecture.