VIBRATIONAL SPECTROSCOPIC AND THERMAL INVESTIGATIONS OF THE CYANO-BRIDGED POLYMERIC COMPLEXES WITH 3-AMINOMETHYLPYRIDINE

Abstract

New cyano-bridged polymeric complexes formulated as [Co(H2O)(ampy)Ni(CN)4]∙H2O and [Ni(ampy)2Ni(CN)4]∙H2O (ampy = 3-aminomethylpyridine: abbreviated henceforth as Co-Ni-ampy and Ni-Ni-ampy) have been obtained in powder form and characterized by vibrational (infrared and Raman) spectroscopy, thermal and elemental analyses. In previous study, structure of complex [Cd(NH3)(ampy)Ni(CN)4]n (Cd-Ni-ampy) was determined by single crystal X-ray diffraction methods. In this complex, the coordination environment of the Cd(II) ions are distorted octahedral geometry, whereas around the Ni(II) center is pyramidal. The spectral features suggest that Cd-Ni-ampy with Co-Ni-ampy are similar to each other and the ampy ligand is coordinated to metal ions as bidentate ligand. In addition, complex Ni-Ni-ampy is similar in structure to the Hofmann type complexes and its structure consists of polymeric layers of │Ni–Ni(CN)4│∞ with the ampy ligand bounded to the nickel(II) atom. Thermal stabilities and decomposition products of the complexes were investigated using TG, DTG and DTA curves in the temperature range of 30 – 700 °C in the static air atmosphere.