Synthesis, characterization and thermal behaviour of solid 2-methoxycinnamylidenepyruvate of light trivalent lanthanides

Abstract

Compostos Ln-2-MeO-CP no estado sólido, em que o símbolo Ln representa lantanídeos trivalentes (La, Ce, Pr, Nd, Sm, Eu, Gd) e 2-MeO-CP é 2-metoxicinamalpiruvato, foram sintetizados neste trabalho. As técnicas de termogravimetria e análise térmica diferencial simultâneas (TG-DTA), calorimetria exploratória diferencial (DSC), difratometria de raios X, espectroscopia de absorção no infravermelho (espectros experimental e teórico) e complexometria foram usadas para caracterizar e estudar o comportamento térmico destes compostos. Os resultados informam sobre a composição e a estabilidade dos complexos isolados.Solid state Ln-2-MeO-CP compounds, where Ln stands for light trivalent lanthanides (La, Ce, Pr, Nd, Sm, Eu, Gd) and 2-MeO-CP is 2-methoxycinnamylidenepyruvate, were synthesized in this work. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC), X-ray powder diffractometry, experimental and theoretical infrared spectroscopy and complexometry were used to characterize and to study the thermal behaviour of these compounds. The results led to information regarding the composition and stability of the isolated complexes.

Rare-earth metal compounds with a novel ligand 2-methoxycinnamylidenepyruvate: A thermal and spectroscopic approach

“…In this study, the organic ligand 2methoxycinnamylidenepyruvate (2-MeO-HCP), obtained from aldolic condensation of cinnamic acid and pyruvate, was used to synthesize the compounds in solid state with heavy trivalent lanthanides. The synthesis and characterization of 2-MeO-HCP and other compounds have been reported in previous studies [10][11][12] which aimed at fundamentally performing the synthesis and investigation of the compounds in solid state by the establishment of stoichiometry, thermal behavior and thermal decomposition, FT-IR spectroscopy and the classical analysis method of titration with EDTA. In this paper, the compounds of lanthanides 2-methoxycinnamylidenepyruvate were studied using the techniques mentioned, as well as employing complementary techniques like X-ray powder diffraction to provide qualitative information on the cristallinity of the compounds and mass spectrometry coupled to a thermogravimetric system (TG/MS) to support the gases analysis performed by TG/FT-IR on the gases evolved from the samples undergone thermal decomposition process.…”