Síntese, caracterização e estudo termoanalítico dos tereftalatos de térbio (III), disprósio (III), hólmio(III), érbio (III), túlio (III), ítérbio (III), lutécio (III) e ítrio(III)

Abstract

In this work the synthesis of the heavy lanthanides and yttrium were carried out, using the direct addition of the sodium terephthalate in the respectives metallic chloride solutions. The synthesized compounds were characterized by simultaneous Thermogravimetry and differential scanning calorimetry analysis (TG-DSC), differential scanning calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), thermogravimetric analyses coupled to Fourier Transform Infrared spectroscopy (TG-FTIR), EDTA complexometry and X ray powder Diffractometry. From the data, it was possible to obtain the general formula of each compound (Ln2(TFta)3.nH2O, where Ln = Tb(III), Dy(III), Ho(III), Er(III), Tm(III), Yb(III), Lu(III) and Y(III), TFta = terephthalate, and n = 4,5 (Tb, Dy and Ho), 4,0 (Er, Tm and Y), 5,0 (Yb) and 6,5 (Lu)), as well as unreported information about the thermal properties, in air atmosphere, thermal stability; molar dehydration enthalpy; main evolved gases from thermal decomposition (H2O, CO2 and CO), the coordination mode between metal and ligand and performing the comparison of the results of X -ray diffraction of the compounds synthesized by the powder method using and the single crystal obtained by hydrothermal synthesis reported in the literature.