COMPLECȘI Ln(III)-Bi(III) ÎN BAZA IONILOR TRIETILENTETRAAMINHEXAACETAT  PRECURSORI MOLECULARI PENTRU OXIZII MICȘTI BiLnO3

Nelea POPA, Ion BULIMESTRU, Aurelian GULEA Universitatea de Stat din Moldova

Аннотация

Ln(III)-Bi(III) COMPLEXES BASED ON TRIETHYLENETETRAAMINEHEXAACETATE IONS AS MOLECULAR PRECURSORS FOR BiLnO3 MIXED OXIDES

The paper focuses on the synthesis and study of a series of heterometallic coordination compounds of lanthanides(III) and bismuth(III) with the general formula LnBi(ttha)·nH2O (ttha6- = triethylenetetraaminehexaacetate) as molecular pre-cursors for getting BiLnO3 mixed-oxides. Based on the IR spectra, the presence of two series of analogous complexes was established (Ln(III) = La, Pr, Nd, Gd, Dy, where n=7 and Ln(III) = Ho, Er, where n=10). Thermogravimetric analysis performed in oxygen flow results in the formation of the expected BiLnO3 oxides at already 600oC, while in nitrogen flow this process is not completed even at 900oC. Powder X-ray diffraction patterns of residues obtained upon thermal decom-position of the precursors confirmed that the heating rate and the nature of Ln(III) ions do not affect the composition of the final product, in all cases these are the expected pure BiLnO3 heterometallic oxides.

Keywords: coordination compounds, molecular precursors, Lanthanide(III), Bismuth(III), triethylenetetraaminehexaacetate, heating rate, mixed-oxide.