Synthesis, characterization and thermal studies on solid compounds of 2-chlorobenzylidenepyruvate of heavier trivalent lanthanides and yttrium(III)

Abstract

Solid-state compounds of general formula LnL 3 ⋅nH 2 O, where Ln represents heavier lanthanides and yttrium and L is 2-chlorobenzylidenepyruvate, have been synthesized. Chemical analysis, simultaneous thermogravimetry-differential analysis (TG-DTA), differential scanning calorimetry (DSC), X-ray powder diffractometry, elemental analysis and infrared spectroscopy have been employed to characterize and to study the thermal behaviour of these compounds in dynamic air atmosphere.On heating these compounds decompose in four (Gd, Tb, Ho to Lu, Y) or five (Eu, Dy) steps. They lose the hydration water in the first step and the thermal decomposition of the anhydrous compounds up to 1200°C occurs with the formation of the respective oxide, Tb 4 O 7 and Ln 2 O 3 (Ln=Eu, Gd, Dy to Lu and Y) as final residue. The dehydration enthalpies found for these compounds (Eu, to Lu and Y) were: 65.77, 55.63, 86.89, 121.65, 99.80, 109.59, 131.02, 119.78, 205.46 and 83.11 kJ mol -1 , respectively.

Synthesis, thermal behavior, and spectroscopic study of the solid nalidixate of selected light trivalent lanthanides

“…The X-ray powder patterns ( Figure 1S-Supplementary Material) indicate that all the trivalent lanthanide compounds were obtained with low crystalline degree. This feature is undoubtedly due to the low solubility of the compounds and because the stirring and/or the adding velocity of the ligand solution to the respective metal chloride was not rigorously controlled, as already observed for other compounds [42,43].…”

Synthesis, characterization and thermal behaviour of solid 2-methoxycinnamylidenepyruvate of some bivalent metal ions in CO2 and N2 atmospheres

“…Sodium 2-methoxycinnamylidenepyruvate (Na-2-MeO-CP) and its corresponding acid were both synthesized following the same procedure as described in literature [12], with some modifications, which were as follows: an aqueous solution of sodium pyruvate (1.5g per 10 mL) was added dropwise with continuos stirring to a methanolic solution of 2-methoxycinnamaldehyde (2.0g per 50mL). Five millilitres of an aqueous sodium hydroxide solution -1…”

Synthesis, characterization and thermal behaviour of solid 2-methoxycinnamylidenepyruvate of some bivalent metal ions in CO2 and N2 atmospheres

“…The 2-methoxycinnamaldehyde, (CH O- 3 C H -(CH) -CHO) 96% pure predominantly trans, 6 4 2 was obtained from Aldrich and sodium pyruvate (H C-CO-COONa) 99% pure was obtained from 3 Sigma. Sodium 2-methoxycinnamylidenepyruvate (Na-2-MeO-CP) and its corresponding acid were both synthesized following the same procedure as described in literature [12], with some modifications, which were as follows: an aqueous solution of sodium pyruvate (1.5g per 10 mL) was added dropwise with continuos stirring to a methanolic solution of 2-methoxycinnamaldehyde (2.0g per 50mL). Five millilitres of an aqueous sodium hydroxide solution -1 1.25 mol.…”