Long-range chain orientation in 1-D co-ordination polymers as a function of anions and intermolecular aromatic interactions

The influence of anions and intermolecular aromatic interactions on the orientation of one dimensional silver(I) co-ordination polymers has been studied. Reaction of AgX with 2,7-diazapyrene (diaz) (X=BF4- or NO3-), 1,4-bis(4-pyridyl)butadiyne (pybut) (X=BF4-, NO3-, PF6- or MeCO2-), 4,4'-bipy (X=BF4-) or 1,4-bis(4-pyridylethynyl)phenylene (pyphe) (X=PF6-) afforded products of general formula {[Ag(ligand)]X}(infinity). All of the products have been structurally characterised by single crystal X-ray diffraction confirming that they exist as one-dimensional linear chain co-ordination polymers. The arrangement of the chains with respect to each other in the solid state is discussed and evaluated in terms of the relative co-ordinating ability of the anion used and the tendency of the N-donor ligand to adopt intermolecular aromatic interactions. For the complexes of diaz the overriding force in controlling chain orientation was shown to be pi-pi interactions between diaz ligands on adjacent chains. In the case of the pybut complexes the most dominant forces were shown to be metal-anion interactions with aromatic pi-pi interactions and Ag . . . Ag interactions playing a less influential role. In the case of {[Ag(pyphe)]PF6}(infinity) Ag . . . aromatic interactions are important in the overall arrangement of adjacent chains.