catena-Poly[[bis[aqua(1,10-phenanthroline)lead(II)]-di-mu3-5-carboxy-3-sulfonatobenzoato] dihydrate].

In the centrosymmetric title polymer, catena-poly[[bis[aqua(1,10-phenanthroline-kappa2N,N')lead(II)]-di-mu3-5-carboxy-3-sulfonatobenzoato-1:2:1'kappa4O3:O1,O1':O1;2':1:2kappa4O1:O1,O1':O3] dihydrate], {[Pb(C8H4O7S)(C12H8N2)(H2O)].H2O}n, each seven-coordinate lead(II) ion is bound by five O atoms from one water molecule and three 5-sulfoisophthalate (sip) anions, and by two N atoms from a 1,10-phenanthroline (phen) ligand. The sip sulfonate group is monodentate. One O atom of the sip carboxylate group is chelated to one Pb2+ cation, with the other also bridging an adjacent Pb2+ cation. The carboxyl group is uncoordinated. This unusual coordination results in a chain structure along the b axis, which is linked by strong intermolecular hydrogen bonds into a three-dimensional network.