Thermal and spectroscopic study of the 3,4-(methylenedioxy)cinnamate compounds of transition metals in the solid state

• Analysis of the compounds in solid state by TG-DTA/FT-IR.
• Thermal decomposition dependent on the nature of the transition metal ion.
• Infrared theoretical calculation employing Gauss View 5.0.2 W.
• Molecular structures for 3,4-(methylenedioxy)cinnamate compounds.

In this study, the trans-3,4-(methylenedioxy)cinnamic acid was used as precursor for the synthesis of transition metal compounds, which were characterized by coupled TG-DTA/FT-IR system, elemental analysis, FT-IR spectroscopic study and titrimetric analysis with EDTA. The characterization by these techniques allowed to determine the hydration water content, number of ligand coordinated to the metal, thermal behavior and thermal stability, as well as monitor the main gaseous products released in each decomposition step. The elemental and titrimetric analyses were performed in order to support TG-DTA data. A theoretical FT-IR calculation was made using the Gauss View 5.0.2 W program and the vibration frequencies obtained were compared with the experimental ones showing as a result a difference of around 30 cm−1 between them. In these spectra were analyzed the main vibration modes as COO− (carboxylate group), CC (aromatic ring, alkene), CO and CH2 (methylenedioxy group) and CH (alkenes, aromatic).

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