Syntheses, crystal structures and spectroscopic properties of cyano-bridged two-dimensional coordination polymers with 3-methylpyridazine

Six new two-dimensional heteropolynuclear complexes, [M(3-mpdz)2M′(μ-CN)4]n (M = Zn(II) or Cd(II); M′ = Ni(II), Pd(II) or Pt(II); 3-mpdz = 3-methylpyridazine) were synthesized and characterized by FT-IR, Raman spectroscopy, single crystal X-ray diffraction, thermal and elemental analyses techniques. The crystallographic analyses reveal that these complexes crystallize in the monoclinic system, space group C2/m. The M′(II) ion is coordinated by four cyanide-carbon atoms in a square planar geometry and the M(II) ion exhibits a distorted octahedral coordination with two 3-mpdz ligands and four bridging cyano groups. In all the complexes, adjacent 2D layers are further extended into 3D supramolecular network through C–H⋯π interactions. Thermal stabilities and decomposition products of the complexes were investigated in the temperature range of 30–700 °C in air atmosphere.