Thermal and spectroscopic studies on solid ibuprofen complexes of lighter trivalent lanthanides

• Lighter trivalent lanthanide complexes of ibuprofen have been synthesized.
• The TG-FTIR allowed the identification of propane as the gas evolved during the thermal decomposition of the neodymium compound.
• The thermal analysis provided information about the composition, dehydration, thermal behavior and thermal decomposition of the samples.
• The theoretical and experimental spectroscopic studies suggest that the carboxylate group of ibuprofen is coordinated to the metals by a bidentate bond.

Solid-state compounds of general formula Ln(L)3, in which L is ibuprofen and Ln stands for trivalent La, Ce, Pr, Nd, Sm and Eu, have been synthesized. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), X-ray powder diffractometry (DRX), complexometry, Fourier-transformed infrared spectroscopy (FTIR) and thermogravimetry coupled to Fourier-transformed infrared spectroscopy (TG-FTIR) were used to characterize these compounds. The results provided information concerning the chemical composition, dehydration, coordination modes of the ligands, crystallinity of the samples, thermal behavior and thermal decomposition of the compounds. The theoretical and experimental spectroscopic studies suggest that ibuprofen coordinates through the carboxylate group as a chelating ligand.