Novel 3-D Framework Nickel(II) Complex with Azide, Nicotinic Acid, and Nicotinate(1−) as Coligands:  Hydrothermal Synthesis, Structure, and Magnetic Properties

The hydrothermal reaction of Ni(NO₃)₂, NaN₃, and nicotinic acid (Hnic) yielded a 3-D supramolecular framework complex, [Ni_1.5(N₃)(nic)₂(Hnic)]_n (1) with unusual magnetic properties. In 1, Hnic and nic^-1 coexist and show different coordination modes (μ₂-Hnic-N,O, μ₂-nic-N,O, and μ₃-nic-N,O,O bridging Ni^II ions), and azide groups adopt μ-1,1 (EO) bridging mode linking Ni^II ions with an unusual Ni−N−Ni angle.