Synthesis, crystal structure, and thermal properties of Ni(NH3)4(AFT)2

Article abstract of DOI:10.1177/1747519820939475

Ni(NH₃)₄(AFT)₂ [NiC₆H₁₆N₁₈O₂, AFT = 4-amino-3-(5-tetrazolate)furazan] is synthesized and characterized by elemental analysis and Fourier-transform infrared spectroscopy for the first time. X-ray diffraction measurements are used to determine the crystal structure of compound 1. The results demonstrate that compound 1 crystallized in the orthorhombic crystal system. The nickel(II) ion is six-coordinated by N atoms from two AFT-ligands and four NH₃ molecules. Its thermal properties are investigated by differential scanning calorimetry and thermogravimetry-derivative thermogravimetry methods, with the results demonstrating that the differential scanning calorimetry curve exhibits two endothermic and one exothermic processes. The endothermic processes are in the range of 130–510 °C with a peak temperature of 188 °C. The temperature from 230 to 400 °C is the exothermic process in which the peak temperature is 314.58 °C. In addition, Kissinger’s and Ozawa-Doyle’s methods are used for calculating the non-isothermal kinetics parameters. Moreover, the apparent activation energy (E), safety, and thermal stability parameters (T_SADT, T_TIT, T_b) for Ni(NH₃)₄(AFT)₂ are calculated. In addition, the calculated thermodynamic functions (?S^≠, ?H^≠, and ?G^≠) for the exothermic decomposition process of Ni(NH₃)₄(AFT)₂ are 55.07 J mol^?1 K^?1, 196.18 kJ mol^?1, and 164.90 kJ mol^?1, respectively.