Synthesis, structure and thermochemical study of a cobalt energetic coordination compound incorporating 3,5-diamino-1,2,4-triazole and pyridine-2,6-dicarboxylic acid

• An energetic coordination compound with dinuclear cobalt unit has been synthesized and structurally characterized.
• The standard molar enthalpy of formation of the compound was determined by a designed thermochemical cycle.
• The specific heat capacity of the compound at T = 298.15 K was determined to be 1.13 ± 0.02 J · mol−1 · K−1.

An energetic coordination compound [Co2(C2H5N5)2(C7H3NO4)2(H2O)2]·2H2O (Hdatrz(C2H5N5) = 3,5-diamino-1,2,4-triazole, H2pda(C7H5NO4) = pyridine-2,6-dicarboxylic acid) has been synthesized and characterized by elemental analysis, chemical analysis, IR spectroscopy, single-crystal X-ray diffraction and thermal analysis. X-ray diffraction analysis confirmed that the compound possessed a di-nuclear unit and featured a 3D super-molecular structure. Furthermore, a reasonable thermochemical cycle was designed based on the preparation reaction of the compound and the standard molar enthalpy of dissolution of reactants and products was measured by the RD496-2000 calorimeter. Finally, the standard molar enthalpy of formation of the compound was determined to be −(2475.0 ± 3.1) kJ · mol−1 in accordance with Hess’s law. In addition, the specific heat capacity of the compound at T = 298.15 K was determined to be (1.13 ± 0.02) J · K−1 · g−1 by RD496-2000 calorimeter.