Solid state synthesis, thermodynamics and catalytic combustion effect of a high energy nickel(II) coordination compound

Abstract

Self-assembly of Ni(II) with 3,5-diamino-1,2,4-triazole resulted in a 3D supramolecular compound [Ni3(Hdatrz)6(fma)2(H2O)4]fma·11H2O (1) in the presence of coligand fumaric acid (Hdatrz=3,5-diamino-1,2,4-triazole, H2fma=fumaric acid). X-ray structural analysis reveals that three nickel ions are bridged by six neutral Hdatrz ligands, and abundant lattice water molecules exist in 1. Based on the structural framework and TG curve of 1, a new energetic compound [Ni3(Hdatrz)6(fma)2(H2O)4]fma (2) with 35.5% of nitrogen content was readily prepared through dehydration of 1 at 398K under N2 atmosphere. The enthalpy change of the reaction of formation for 1 was determined to be (−23.24±0.05)kJmol−1 by microcalorimetry at (298.15±0.01)K. Thermodynamic and thermokinetic parameters k, E, n, ΔS≠θ, ΔH≠θ and ΔG≠θ of the reaction of formation for 1 were obtained. Thermoanalytical kinetics of the reaction of formation for 2 was further investigated. The sensitivity experiment results indicated that 2 was more sensitive to impact and friction stimuli that 1. As an additive, 2 effectively promoted the thermal decomposition of ammonium perchlorate (AP), which projected the potential application of the compound 2 as combustion modifier in solid propellants.