Synthesis, spectroscopy, electrochemistry and thermal study of uranyl N3O2 Schiff base complexes

Abstract

The new [UO2L(CH3OH)] [where L = bis(salicylaldehyde)2,6-diiminopyridine (L1), bis(5-methoxysalicylaldehyde)2,6-diiminopyridine (L2), bis(5-bromosalicylaldehyde)2,6-diiminopyridine (L3), bis(5-nitrosalicylaldehyde)2,6-diiminopyridine (L4)] complexes were synthesized and characterized by IR, UV–vis and elemental analysis. Methanol solvent is coordinated to uranyl complexes. The electrochemical properties of the uranyl complexes were investigated by cyclic voltammetry in DMF solvent. Thermogravimetry and differential thermoanalysis of the uranyl complexes were carried out in the range of 20–700 °C. The UO2L4 complex was decomposed in two and the others were decomposed in three stages. Up to 85 °C, the coordinated solvent was released then the Schiff base ligands were decomposed in one or two steps. Decomposition of synthesized complexes is related to the Schiff base characteristics. The thermal decomposition reaction is first order for the studied complexes.