Synthesis, crystal structure and thermal decomposition character of an environmentally-friendly energetic coordination compound of [Co(NH₃)₄(NO₃)](NO₃)•0.5H₂O

A new coordination compound of [Co(NH₃)₄(NO₃)]NO₃•0.5H₂O was synthesized by reacting Co(NO₃)₂ with NH₃•H₂O aqueous solution. It has been characterized by using elemental analysis, FT-IR technology, and X-ray single crystal diffraction analysis. It belongs to the monoclinic crystal system and P(2)/n space group with the unit cell: a=0.74618(1) nm, b=2.26114(4) nm, c=1.04282(2) nm, β=92.038(1)°. The central ion Co(II) displays a stable octahedral configuration, which was constructed with the central ion Co(II), four nitrogen atoms from NH₃ molecules and two oxygen atoms from NO^-₃. The outer sphere was NO^-₃ and a common crystalline water molecule, which connected the inner sphere by electrostatic force and the intermolecular force. The intermolecular and intramolecular hydrogen bonds constructed a three-dimensional network structure, which increased the stability of the whole crystal structure. In addition, thermal decomposition character of the title complex was investigated by using TG-DTG, DSC and FT-IR technologies. There are two endothermic peaks and one exothermic one in the process of thermal decomposition, and the decomposition residue at 300 °C is the mixture of CoO and Co₂O₃.