W. Ferenc, B. Bocian, M. Chudziak
Dec 1, 1999
Citations
0
Influential Citations
8
Citations
Journal
Journal of Thermal Analysis and Calorimetry
Abstract
The light lanthanide 2,3,4-trimethoxybenzoates were obtained by the addition of an equivalent quantity of 0.1 M ammonium 2,3,4-trimethoxybenzoate to a hot solution of the light lanthanide nitrate, followed by crystallization at 293 K. The contents of carbon and hydrogen were determined by elemental analysis, with V2O5 as oxidizing agent, and the lanthanide element contents were established by the oxalic acid method. The complexes are anhydrous compounds with a metal to ligand ratio of 1:3 and the general formula Ln(C10H11O5)3. They have the colour characteristic of Ln3+. Their IR spectra were run in the range 4000–400 cm−1 on an M-80 spectrophotometer by using KBr discs. In these complexes, the carboxylate group appears to be a bidentate chelating ligand. The X-ray powder patterns were taken on a DRON-2 diffractometer, using Ni-filtered CuKα radiation, within the range 2Θ=5–80°, by the Debye-Scherrer-Hull method. The diffractograms indicated that the complexes are crystalline compounds. Their thermal stabilities in air were studied (273–1173 K) through the use of TG, DTG and DTA techniques, with an OD-102 derivatograph.The 2,3,4-trimethoxybenzoates of La and Nd decompose in two steps, but those of Ce, Pr, Sm and Eu in only one stop. The anhydrous 2,3,4-trimethoxybenzoates of La and Nd decompose to oxides with the intermediate formation of oxycarbonates, while those of Ce, Pr, Sm and Eu decompose directly to the oxides. The solubilities of these complexes in water (293 K) are in the order of 10−3moldm−3.