Helices versus zigzag chains: one-dimensional coordination polymers of Ag(I) and bis(4-pyridyl)amine

Five one-dimensional coordination polymers were prepared by the reaction of a bent bridging ligand, bis(4-pyridyl)amine (bpa), with an extensive series of AgX salts (X = CF₃SO₃, PF₆, ClO₄, NO₃). The 1D polymer networks formed with AgCF₃SO₃ (1), AgPF₆ (2·MeCN), and AgClO₄ (3·2MeCN) all incorporated MeCN and were found to adopt a zigzag arrangement. The networks formed with AgClO₄ (4) and AgNO₃ (5) did not contain any solvent and adopted a single-stranded helical arrangement. Two-dimensional H-bonding networks were formed for 1 and 3·2MeCN, with network topologies 4.8² and (4, 4), respectively, whereas three-dimensional H-bonded networks of helices were formed for 4, showing an (8, 3)-a network topology, and 5, showing the topology of the α-polonium net. The three-dimensional networks both exhibited 4-fold interpenetration. The NO₃^- anion in 5 appeared to be acting as a template for the 3D structure.