Dimensionally controlled hydrogen-bonded nanostructures: synthesis, structure, thermal and magnetic behaviour of the tris-(chelated)nickel(II) complex [Ni(bipy)3]Cl2·5.5H2O (bipy=2,2′-bipyridyl)

Single crystals of the compound of formula [Ni(bipy)3]Cl2·5.5H2O (bipy=2,2′-bipyridine) have been prepared and structurally characterised by X-ray diffraction. The structure analysis reveals that the complex has an approximate D3 symmetry. The coordination sphere consists of six nitrogen atoms of the three-bipyridine ligands in an octahedral arrangement about the nickel. One of the chlorine ions is surrounded by twelve CH⋯Cl hydrogen bonds. Three kinds of layers are found in the crystal structure: (i) the Λ-[Ni(bipy)3]2+ cation; (ii) the water/chloride positions (O(1w)/Cl(21) to O(7w)/Cl(27)); (iii) the Δ-[Ni(bipy)3]2+ cation and a chloride ion (Cl(1)). The layers are stacked in the order (i), (ii), (iii) and (ii) almost parallel to the ab-plane. A thermogravimetric analysis shows that the water and chloride molecules were removed at 231 °C leading to the compound [Ni(C25H19N5)](s) according to elemental analysis and IR data. The plot of 1/χM versus T in the range 2.0–300 K obeys the Curie law.