Obtenção e decomposição térmica dos quelatos de Co, Mn e Ni com 8-hidroxiquinolina

Abstract

In this work we studied the acquisition of complex manganese, cobalt and nickel with 8-hydroxyquinoline and the thermal decomposition behavior of these complexes. The complexes were obtained using acetic acid and precipitated with increasing pH with ammonium hydroxide solution. The thermal behavior was performed by thermogravimetry and differential thermal analysis under heating rates of 5, 10 and 20 ° C / min and an atmosphere of synthetic air and nitrogen. Under an atmosphere of synthetic air was observed that it is possible to obtain oxides of different stoichiometry and a displacement of the final temperatures of decomposition. In a dynamic atmosphere of nitrogen was observed for compounds of nickel and cobalt that the decomposition is not complete under the conditions of analysis, with the formation of carbonaceous material. For the TG curves it was determined that all complexes are dihydrated. For the DTA curves observed endothermic peaks attributed to dehydration and exothermic peaks, under an atmosphere of synthetic air for the oxidative decomposition of anhydrous complexes. Thus, we conclude that the analysis conditions interfere with the behavior of thermal decomposition of the chelates.