Synthesis, characterization and thermal behaviour on solid pyruvates of light trivalent lanthanides

A B Siqueira,G Bannach,M Ionashiro,E C Rodrigues,C T De Carvalho,E Y Ionashiro

doi:10.1590/s0100-46702007000400007

Abstract

Solid State Ln-L compounds, where Ln stands for light trivalent lanthanides (La - Gd) and L is pyruvate, have been synthesized. Thermogravimetry and derivative thermogravimetry (TG/DTG), differential scanning calorimetry (DSC), X-Ray powder diffractometry, infrared spectroscopy, elemental analysis, and complexometry were used to characterize and to study the thermal behaviour of these compounds. The results led to information about the composition, dehydration, ligand denticity, thermal behaviour and thermal decomposition of the isolated compounds.

Highlights

Experimental detailsSeveral investigations on pyruvic acid (HPy), as well as compounds derivatives of HPy, have been carried out in biological science reseaches
In aqueous solutions the formation of some metal ions complexes with pyruvic acid in the ratio of metal: ligand 1:1 and 1:2 have been established by the spectroscopic method [13]; the stability constants and thermodynamic functions of complexes formation of lanthanides with pyruvic acid: ∆G, ∆H, ∆S, have been determined [4]
The amorphous state is undoubtedly due to the decreasing solubility with increasing temperature, where the precipitation of these compounds occurs fastly near to ebullition temperature

Summary

Introduction

Experimental detailsSeveral investigations on pyruvic acid (HPy), as well as compounds derivatives of HPy, have been carried out in biological science reseaches. The aim of this work has been to obtain light trivalent lanthanide pyruvates in solid state and to investigate by means of complexometry, elemental analysis, X-Ray powder diffractometry, infrared spectroscopy, thermogravimetry (TG) and differential scanning calorimetry (DSC). The solid-state compounds were prepared by adding equivalent quantities of hot solution of sodium pyruvate to hot solution of the respective

Results

Conclusion