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.
Thermal behavior of glycolic acid, sodium glycolate and its compounds with some bivalent transition metal ions in the solid state
Synthesis, characterization and thermal behavior of some transition metal glycolates, M(C2H3O3)2 [M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II)], as well as the thermal behavior of glycolic acid and its sodium salt (NaC2H3O3) were investigated employing simultaneous thermogravimetry and differential thermal analysis, infrared spectroscopy (FTIR), simultaneous thermogravimetry–differential scanning calorimetry coupled to FTIR (evolved gas analysis), complexometry and high-resolution electrospray ionization mass spectrometry. The lowest energy model structure of each complex has been proposed by using the density functional theory at the B3LYP/6-311++g(d) level of theory. The results provided information concerning the composition, dehydration, thermal stability, thermal decomposition and identification of the gaseous products evolved during the thermal decomposition of these compounds in dynamic dry air atmosphere.
Structural versatility of the malonate ligand as a tool for crystal engineering in the design of molecular magnets
The synthesis of ferro- and ferri-magnetic systems with a tunable Tc and three-dimensional (3-D) ordering from molecular precursors implying transition metal ions is one of the active branches of molecular inorganic chemistry. The nature of the interactions between the transition metal ions (or transition metal ions and radicals) is not so easy to grasp by synthetic chemists working in this field since it may be either electrostatic (orbital) or magnetic (mainly dipolar). Therefore, the systems fulfilling the necessary requirements to present the expected magnetic properties are not so easy to design on paper and realize in the beaker. In this work we show how the design of one-, two- and three-dimensional materials can strongly benefit from the use of crystal engineering techniques, which can give rise to structures of different shapes, and how these differences can give rise to different properties. We will focus on the networks constructed by assembling malonate ligands and metal centres. The idea of using malonate (dianion of propanedioic acid, H2mal) is that it can give rise to different coordination modes with the metal ions it binds. 
 Extended magnetic networks of dimensionalities one (1-D), two (2-D) and three (3-D) can be chemically constructed from malonate-bridged metallic complexes. These coordination polymers behave as ferro-, ferri- or canted antiferro-magnets. We are currently trying to obtain analogous compounds using magnetically anisotropic ions, such as cobalt(II), in order to explore how structural differences influence the magnetic properties. In this case the control of the spatial arrangement of the magnetic building blocks is of paramount importance in determining the strength of the magnetic interaction. The possibility of controlling the shape of the networks depends on the coordination bond between the metal ion and the ligands and on supramolecular interactions such as stacking interactions or hydrogen bonding.