Effect of gamma radiation on thermal decomposition, X-ray diffraction and electronic spectra of nickel (II) complexes of diethylene triamine, pyridine and 2-amino pyridine

Thermal behaviour, X-ray diffraction and electronic spectra of nickel (II) complexes of diethylene triamine, pyridine and 2-amino pyridine were studied before and after gamma irradiation. Irradiation enhanced thermal decomposition of the complexes, lowering activation energy, frequency factor and entropy of activation. From X-ray diffraction studies, unirradiated and irradiated complexes are found to be orthorhombic. Irradiation changed the lattice parameters. The parameters Dq, B′ and β were calculated from the UV–visible spectra of the complexes. Irradiation decreased LFSE (10 Dq) and increased Racah parameter B′ and the covalency factor β of the complexes except in nickel (II) complex of diethylenetriamine where the effect of irradiation is insignificant.