Synthèse, caractérisation et étude structurale par DRX de l'oxalate mixte de cuivre et de sodium Na2Cu(C2O4)2.2H2O et de l'acide oxalique

Abstract

The principal topic of this memory bases on the synthesis and the characterization of mixed oxalates. The phase Na2 Cu (C2O4)2.2H2O is synthesized and its ab initio crystalline structure solved from the data of the powder X-rays diffraction. The thermal analysis is carried out with ATG made it possible to completely describe the mechanisms of the thermal decomposition of this mixed oxalate. The simultaneous formation of many intermediate phases contributes to the complexity of the reactional mechanisms which depend on the heating rate. The final stages of the thermal decomposition of the studied precursor led to the formation of simple oxides CuO and Na2O3. The variety of oxalic acid 2[½(C2H2O4 )] C2H1O4 –( H3O+ ) 2 (H2O) of triclinic symmetry was synthesized according to an original procedure and was determined by the diffraction of x-rays on monocrystal. The use of the spectroscopy Infrared (IR) in this present work made it possible in a preliminary stage to confirm the existence of groupings oxalates and water molecules.