Hydrothermal synthesis of two new lead-containing coordination polymers:: 2∞[Pb2Cl2(4,4′-bipy)] and 2∞[Pb2(NO3)4(H2O)2(4,4′-bipy)2](4,4′-bipy)2

Hydrothermal reaction of Pb(II)X-2 (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)(infinity)[PbCl2(4,4'-bipy)], (1), and (2)(infinity)[Pb-2(NO3)(4)(H2O)(2)(4,4'-bipy)(2)](4,4'-bipy)(2), (2). Compound 1 crystallizes in the triclinic crystal system (P (1) over bar), 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 (P2(1)/c), with an unusual layered structure consisting of flat slabs of {Pb(NO3)(4/2)Pb(H2O)(2)(NO3)(2)} bilayers linked into a 3D network via hydrogen bonds involving undulating layers of two independent uncoordinated 4,4'-bipyridine molecules. (C) 2004 Elsevier Ltd. All rights reserved.