Synthesis, Characterization and Thermal Behaviour of Solid-State Compounds of Heavy Trivalent Lanthanide and Yttrium Mandelates

Abstract

Characterization, thermal stability and thermal decomposition of heavy trivalent lanthanide mandelates Ln(C 6 H 5 CH(OH)CO 2 ) 3 ·2H 2 O (Ln = Tb to Lu and Y) were investigated employing simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC), experimental and theoretical infrared spectroscopy, X-ray diffractometry, complexometry and TG-DSC coupled to FTIR. The dehydration of the compounds occurs in a single step and the thermal decomposition of the anhydrous ones occurs in two, three, four or five consecutive steps, with formation of the respective oxides Tb 4 O 7 and Ln 2 O 3 (Ln = Dy to Lu and Y) as final residues. The results also provided information concerning the composition, thermal behavior and gaseous products evolved during the thermal decomposition of these compounds. The theoretical and experimental spectroscopic data suggest the possible modes of coordination of the ligand with the heavy lanthanides.

Copper‐Based MOF Crystals for Low‐k Dielectric Applications

“…The difference between the 𝜐 assym (1632) and 𝜐 symm (1453) stretching of COO − is 179 cm −1 and is found to be lower than the alkali metal coordination compound of Mandelic acid and hence can be assured that metal ion is coordinated to carboxylate group in the bidentate form. [17,18] All carboxylic groups have likely been deprotonated since the peaks for (C=O) in the carboxylic group at 1720 cm −1 and those for (COOH) at 860 cm −1 are absent from the spectrum. Vibrations at 1190 and 942 cm −1 , are due to CH bending and wagging modes of the phenyl ring respectively.…”