Anionic and neutral metal-4,4'-bipyridine networks. Synthesis, structures and thermal properties of one- and three-dimensional coordination polymers constructed by metal salts and 4,4'-bipyridine
Abstract
Two compounds, [Zn3(4,4'-bipy)3(H2O)6(SO4)4]((4,4'-H2bipy)(10H2O (1) and [Cu(4,4'-bipy)(H2O)3(SO4)](2H2O (2) (4,4'-bipy = 4,4'-bipyridine), were obtained from the reactions of different metal salts and 4,4'-bipy under weak acidic conditions. 1 is the first anionic 3D coordination network constructed by 4,4'-bipy in which each structural unit consists of three Zn(II) atoms with the formula [Zn3(4,4'-bipy)3(H2O)6(SO4)4]2?. Two Zn(II) atoms are linked by 4,4'-bipy units to form linear [4,4'-bipy-Zn(1)-4,4'-bipy-Zn(2)]( chains, the third Zn(II) atom is also connected by 4,4'-bipy unit and form another type of linear [Zn(3)-4,4'-bipy]( chains; both types of chains are interlinked covalently by µ2-sulfate bridges, resulting in a 3D coordination network of novel topology. The large cationic [4,4'-H2bipy]2+ molecules as well as lattice water molecules occupy the channels. 2 comprises 1D linear coordination chains. The adjacent chains are each arranged in a cross-like fashion at the midpoints of the 4,4'-bipy ligands, resulting in a 3D supramolecular arrays