Solid-solid synthesis, characterization and thermal decomposition of a homodinuclear cobalt(II) complex

The homodinuclear cobalt(II) complex [Co-2(dipic)(2)(H2O)(5)]center dot 2H(2)O was synthesized using pyridine-2,6-dicarboxylic acid (H(2)dipic) and cobalt(II) acetate as raw materials by room temperature solid-solid reaction. The complex was characterized by elemental analyses, single crystal X-ray diffraction, X-ray powder diffraction, Fourier transform infrared spectroscopy, UV spectroscopy, thermogravimetry and differential scanning calorimetry. Its crystal structure belongs to monoclinic system and space group P2(1)/c. There are two types of six-coordinated Co(II) ions, one Co(II) is coordinated by four carboxyl O atoms and two pyridine N atoms from two dipic(2-) anions, and another Co(II) is coordinated by five O atoms from five H2O molecules and one bridged carboxyl O atom from the dipic(2)- anion. The possible pyrolysis reactions in the thermal decomposition processes of the complex, the experimental and calculated percentage mass loss are also given.