Preparation, characterization and thermal investigation of polymeric and monomeric binuclear complexes of dianils derived from 6-formylkhellin with cobalt(II), nickel(II) and copper(II)

Polymeric and monomeric binuclear complexes of Schiff bases derived from 6-formylkhellin and aromatic diamines with cobalt(II), nickel(II) and copper(II) were prepared and characterized by different analytical and spectral methods. The study showed that the investigated ligands give binuclear complexes with monomeric or polymeric nature. The complexes obtained are characterized by a lower magnetic moment value. The thermal behavior of the complexes was investigated by means of DTA, TGA and IR spectra. The thermal study indicates that the investigated ligands display a reducing effect during their thermal decomposition. The final products obtained are oxygen deficient metal(II) oxides, metal(I) oxide, metal(I) acetate or metal. The thermodynamic activation parameters of the thermal decomposition process of desolvated cobalt(II) complexes (7, 8) were calculated from TGA curve, and correlated to their room temperature structure.