catena-Poly[[aqua(3-methylbenzoato-κ2O,O')lead(II)]-μ-3-methylbenzoato-κ4O:O,O′:O′]

The reaction of lead(II) acetate and 3-methylbenzoic acid (MBA) in aqueous solution yielded the title polymer, [Pb(C8H7O2)(2)(H2O)](n). The asymmetric unit contains two Pb II atoms, four MBA ligands and two water molecules. Each Pb II cation is heptacoordinated and chelated by four carboxylate O atoms from two MBA ligands. The Pb atoms are bridged through the carboxylate O atoms from another two MBA ligands, leading to a central Pb2O2 core. The Pb-O bond lengths are in the range 2.325 (3)-2.757 (4)angstrom. The intra-and interdimer Pb center dot center dot center dot Pb distances are 4.2942 (3) and 4.2283 (3) angstrom, respectively, indicating little direct metal-metal interaction. The coordinating water molecules and carboxylate O atoms are involved in extensive O-H center dot center dot center dot O hydrogen-bonding interactions. The complex has an extended ladder-like chain structure and the chains are assembled by hydrogen bonds and pi-pi interactions [centroid-centroid distance = 3.6246 (3) angstrom] into a three-dimensional supramolecular structure.