Mechanochemical syntheses, crystal structures, and photo-luminescent properties of a new hydrazone and its nickel and cadmium complexes

A new hydrazone, ethyl Z-2-(pyridine-2yl-methylene)hydrazinecarboxylate (C₉H₁₁N₃O₂; Hpyec) and its metal complexes bis(ethyl Z-2-(pyridine-2yl-methylene)hydrazinecarboxylate)nickel(II) monohydrate, [Ni(pyec)₂]·H₂O (1) and bis(acetato)(ethyl Z-2-(pyridine-2yl-methylene)hydrazinecarboxylate)cadmium(II), [Cd(Hpyec)(CH₃COO)₂] (2), have been prepared by mechanochemical syntheses and characterized by elemental analysis, UV–vis, IR and NMR spectroscopies, TG-DTA, and solid state emission techniques. The X-ray single crystal structures of both complexes were determined. In 1, the Ni²⁺ ion is coordinated by two N,N,O-tridentate anionic ligands to generate a distorted cis-NiO₂N₄ octahedron. In 2, the cadmium ion is seven-coordinate by one neutral N,N,O-tridentate ligand and two chelating acetate ions to generate a very-distorted CdN₂O₅ pentagonal bipyramid with the Hpyec atoms occupying both axial and one equatorial site. Crystal data: 1, C₁₈H₂₂N₆NiO₅, M _r = 461.12, monoclinic, P2₁/c, a = 10.8759(3) Å, b = 11.7055(4) Å, c = 16.8424(5) Å, β = 108.583(1)°, V = 2032.38(11) ų, Z = 4, R(F) = 0.023, wR(F ²) = 0.065; 2, C₁₃H₁₇CdN₃O₆, M _r = 423.69, monoclinic, Cc, a = 13.0215(10) Å, b = 15.8104(11) Å, c = 7.99(6) Å, β = 96.692(2)°, V = 1621.7(2) ų, Z = 4, R(F) = 0.017, wR(F ²) = 0.038.