Síntese e caracterização de quelatos de cádmio e cobre com 8-hidroxiquinolina

Abstract

This work brings the results of obtainment, description and analysis of the thermal behavior of chelates of cadmium (Cd) and copper (Cu) with 8-hydroxyquinoline (8-HQ). For the formation of the chelates, aqueous solutions of the nitrates of Cd and Cu and 8-HQ dissolved in acetone were used, raising the pH with the addition of the ammonium hydroxide. With the Fourier transform infrared (FTIR) vibration spectroscopy technique, it can confirm the chelation of the metals with the formation of CN, CO, Metal-O, Metal-N, X-ray diffractometry (DRX), confirming the presence of the studied metals. The hermogravimetry and differential thermal analysis were carried out under heating rates of 5, 10 and 20°C/min and atmospheres of synthetic air and nitrogen. Under an atmosphere of synthetic air, it was observed that the final decomposition temperatures and the complete decomposition of the organic matter were obtained. In the nitrogen dynamic atmosphere it was observed for the cadmium and copper compounds that decomposition is not complete under the conditions of analysis. From the TGA curves it was determined that the copper chelate is anhydrous and that of cadmium is dihydrate, and with the DTA curves it was observed endothermic peaks, attributed to dehydration and fusion, and exothermic peaks, under an atmosphere of synthetic air, for the oxidative decomposition of complexes of anhydrous. Thus, it is concluded that the analysis conditions interfere in the thermal decomposition behavior of the chelates.