Poly[bis-(μ(7)-3-sulfonato-l-alaninato)sodiumzinc].

The hydro-thermal reaction of Zn(CH(3)COO)(2), NaOH and l-cysteic acid produced the title compound, [Na(2)Zn(C(3)H(5)NO(5)S)(2)](n). The Zn(II) cation is situated on an inversion centre and is in a distorted octa-hedral environment, being chelated by two deprotoned l-cysteic acid ligands through two amino N atoms and two carb-oxy-lic O atoms, with the two axial positions occupied by two carb-oxy-lic O atoms from two other l-cysteic acid ligands. Each l-cysteic acid ligand bridges five Na(I) ions via its sulfonate group and two Zn(II) ions via its carboxyl group, forming a three-dimensional framework. Weak N-H⋯O hydrogen bonding is observed in the crystal structure.