A bicapped trigonal-prismatic lead complex: catena-poly[[[aquabis(1,10-phenanthroline-kappa2N,N')lead(II)]-mu-squarato-kappaO1:kappa2O2,O3] dihydrate].

The asymmetric unit of the title compound, {[Pb(C4O4)(C12H8N2)2(H2O)].2H2O}n, contains one squarate dianion, two phenanthroline (phen) ligands and one aqua ligand all coordinated to Pb, and two solvent water molecules. The eight-coordinate Pb metal ion displays a distorted bicapped trigonal-prismatic coordination environment, defined by three squarate O atoms, four N atoms from two chelating phen ligands and one O atom from the coordinated water molecule. The crystal structure contains chains of squarate-1,2,3-bridged PbII ions running in the [010] direction. These polymeric chains are linked to one another via offset face-to-face pi-pi interactions between the phen ligands, which lead to a two-dimensional network extending along the (001) plane. The crystal structure is also stabilized by O-H...O intermolecular hydrogen-bond interactions, forming a three-dimensional network.