Oxamate-based Cobalt(II) Complex and dpss: Assembling of the {[Co(H2O)6][Co2(H2mpba)3]}·2,2-dpss·2H2O complex in the solid.

Oxamate-based coordination compounds are described with an extensive variety of structural arrangements and can be used as precursors in the synthesis of heterometallic systems, which have several potential applications in molecular magnetism and spintronics, for instance1. In this sense, cobalt(II) presents spinorbit coupling, which could be responsible for fascinating magnetic behavior. Among the N/O-donor ligands, the oxamate-type stand out in the synthesis of metallic complexes, because they present different coordination modes, and two of them is depicted in Figure 1. In this work is presented a complex salt of formula {[Co(H2O)6][Co2(H2mpba)3]}·2,2dpss·2H2O (1). The anion is a dinuclear mesocate in which three partially deprotonated H2mpba2− ligands chelate the cobalt(II) ions in a bisbidentade mode thorough the carbonyl groups (Figure 1). The cation is the hexaaquacobalt(II) complex, [Co(H2O)6]2+ and the crystal structure is stabilized by the non-coordinated dpss ligand and water molecules. The three cobalt(II) ions in the structure exhibit an octahedral geometry connected to six oxygen atoms from oxamate (C=O) or from water molecules (Ow). Besides the single crystal X-ray diffraction (SXRD), 1 was characterized in a polycrystalline sample by FTIR, TG/DTA and PXRD and all the analysis are in agreement with the structure determined by the SXRD. Thermal analyses show a first mass loss near 100 ºC, corroborating the presence water molecules as crystallization solvents and the following losses were assigned to thermal decomposition of the ligands until de formation of cobalt(II) oxide (CoO).