Preparation, Crystal Structure, and Thermal Decomposition of the Four‐coordinated Zinc Compound Based on 1,5‐Diaminotetrazole

Abstract

AbstractThe environmental friendly energetic coordination compound Zn(DAT)2(Ac)2 (1) (Ac = acetic) was synthesized from 1,5‐diaminotetrazole (DAT), and characterized by elemental analysis and FT‐IR spectroscopy. The crystal structure was determined by X‐ray single crystal diffraction. The crystallographic data showed that compound 1 belongs to the monoclinic system, space group Cc, with cell parameters: a = 17.595(5) Å, b = 7.3060(18) Å, c = 14.076(4) Å, β = 123.449(4)°, V = 1509.7(7) Å3, Z = 4, Dc = 1.688 g·cm–3. In 1, the zinc cation is four‐coordinated with two oxygen atoms from the two acetic carboxyl groups and two 4‐nitrogen atoms of DAT molecules, and exhibits a distorted‐tetrahedron configuration. Thermal decomposition mechanism was determined based on differential scanning calorimeter (DSC) and thermogravimetry‐derivative thermogravimetry (TG‐DTG) analysis. Kinetic parameters of the first exothermic process were studied by using Kissinger's method and Ozawa's method, respectively. The critical temperature of thermal explosion, entropy of activation (ΔS≠), enthalpy of activation (ΔH≠), and free energy of activation (ΔG≠) were calculated and obtained as 519.71 K, –144.04 J·(K·mol)–1, 152.20 kJ·mol–1 and 224.99 kJ·mol–1, respectively. The constant‐volume energy of combustion (9.78 MJ·kg–1) was measured by oxygen bomb calorimetry, which was equal to that of RDX. In the end, the sensitivities properties were also determined with standard method.