Hydrothermal synthesis of two new lead-containing coordination polymers: 2∞[PbCl2(4,4′-bipy)] and 2∞[Pb2(NO3)4(H2O)2(4,4′-bipy)2](4,4′-bipy)2

Hydrothermal reaction of Pb(II)X2 (X = Cl−, NO3−) and 4,4′-bipyridine in a molar ratio of 1:1 resulted in the formation of two new Pb(II) coordination polymers, 2∞[PbCl2(4,4′-bipy)], (1), and 2∞[Pb2(NO3)4(H2O)2(4,4′-bipy)2](4,4′-bipy)2, (2). Compound 1 crystallizes in the triclinic crystal system (P1¯), and the stereochemically active lone pair generates a distorted structure different from the similar bromide analogue reported previously, where the Pb2+ lone pair is apparently not “active”. Compound 2 crystallizes in the monoclinic crystal system (P21/c), with an unusual layered structure consisting of flat slabs of {Pb(NO3)4/2Pb(H2O)2(NO3)2} bilayers linked into a 3D network via hydrogen bonds involving undulating layers of two independent uncoordinated 4,4′-bipyridine molecules.