Thermal behaviour of succinic acid, sodium succinate and its compounds with some bivalent transitions metal ions in dynamic N2 and CO2 atmospheres
Thermal stability and thermal decomposition of succinic acid, sodium succinate and its compounds with Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) were investigated employing simultaneous thermogravimetry and differential thermal analysis (TG-DTA) in nitrogen and carbon dioxide atmospheres and TG-FTIR in nitrogen atmosphere. On heating, in both atmospheres the succinic acid melt and evaporate, while for the sodium succinate the thermal decomposition occurs with the formation of sodium carbonate. For the transition metal succinates the final residue up to 1180 oC in N2 atmosphere was a mixture of metal and metal oxide in no simple stoichiometric relation, except for Zn compound, where the residue was a small quantity of carbonaceous residue. For the CO2 atmosphere the final residue up to 980 oC was: MnO, Fe3O4, CoO, ZnO and mixtures of Ni, NiO and Cu, Cu2O.
The thermal, spectral and magnetic studies of succinic acid compounds of some transition metal ions
Abstract Compounds of succinic acid with cobalt, nickel, copper and zinc have been prepared in aqueous solution. The compounds have been characterised by analyses, magnetic moments, and by vibrational and electronic spectra. The nickel, copper and zinc compounds have octahedral structures while the cobalt compound has a tetrahedral structure. The thermal behaviour of the compounds has been studied by thermogravimetry and differential thermal analysis. The compounds, which are hydrated, lose water of crystallisation followed by the organic ligand to give the metal oxide.
The thermal decomposition of copper(II) nicotinate and isonicotinate
Abstract The thermal decomposition of copper(II) nicotinate and isonicotinate yields, in a sharp transition, metallic copper as the final solid residue along with the release of carbon dioxide and pyridine. In the case of the nicotinate, small amounts of nicotinic acid are also detected. The decomposition is started by homolytic RC(O)O-Cu bond scission, which is equivalent to electron transfer from RC(O)O− to Cu(II).