A New Two-Dimensional Lead(II) Coordination Polymer Containing Left- and Right-Handed Helical Chains Constructed from 1H-Benzimidazole-2-carboxylic Acid

A new two-dimensional lead(II) coordination polymer, [Pb(C10H5N3O4)](n), was prepared by reacting lead nitrate with 1H-benzimidazole-2-carboxylic acid (H(2)BI2C) under solvothermal conditions. The asymmetric unit of the compound contains one crystallographically independent Pb-II cation and one unique BI2C(2-) dianion. The Pb-II ion is five-coordinated by three carboxylate O atoms and two imidazole N atoms from three different BI2C(2-) dianions, displaying an interesting hemidirected coordination. It is worth noting that the BI2C(2-) group acts as a mu (3)-bridging ligand to link the Pb-II ions into a two-dimensional layer, which is composed of left- and right-handed helical chains. This two-dimensional layer can be simplified as a 3-connected fes topology with the Schlafli symbol of (4 center dot 8(2)). In addition, the title compound shows an intense emission at 549 nm when excited at 353 nm, and it displays a high thermal stability up to 410 degrees C.