Six new two-dimensional heteropolynuclear complexes, [ M( 3- mpdz)(2)M(mu l- CN)(4)](n) ( M = Zn( II) or Cd( II); M0 = 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 M0( 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 tau interactions. Thermal stabilities and decomposition products of the complexes were investigated in the temperature range of 30- 700 circle C in air atmosphere.(C) 2014 Elsevier B. V. All rights reserved.