Supramolecular organization in lead(II) halides of 4,4′-dimethoxy-2,2′-bipyridine ligand

Two adducts of the N,N′-bidentate aromatic base 4,4′-dimethoxy-2,2′-bipyridine (4,4′-dmo-2,2′-bpy) of lead(II) salts, [Pb1.5(4,4′-dmo-2,2′-bpy)Br3]n (1) and [Pb(4,4′-dmo-2,2′-bpy)I2]n (2), have been synthesized and characterized by elemental analysis, IR, 1H-NMR spectroscopy and studied by thermal analysis as well as X-ray crystallography. The single-crystal X-ray data show two different kinds of Pb2+ ions in 1 with coordination numbers of four, Pb1 = PbN2Br2 and six, Pb2 = PbBr6, with hemidirected and holodirected coordination spheres, respectively. The coordination numbers of the Pb2+ ion in 2 is five, Pb1 = PbN2I3 with hemidirected coordination sphere. The supramolecular features in these 1D coordination polymers are negotiated through the weak but directional C–H⋯Br and C–H⋯I interactions and aromatic π–π stacking interactions as well as lone pair activity.