Crystal structure and thermal decomposition of 5-aminotetrazole trinitrophloroglucinolate

5-Aminotetrazole trinitrophloroglucinolate ((ATZ) TNPG) was prepared and characterized by elemental analysis and FT-IR spectroscopy. The crystal structure was determined by X-ray diffraction analysis and it belonged to orthorhombic system and Pbca space group with a=0.6624(2) nm, b=1.7933(4) nm, c=2.3117(5) nm, V=2.7458(9) nm, Z=4, and Dc=1.849 g center dot cm(-3). The molecular formula was confirmed to be (ATZ)TNPG center dot 2H(2)O. 5-Aminotetrazole cation (ATZ(+)) and trinitrophloroglucinol anion (TNPG(-)) were linked into 2-D layers along b-axis and c-axis by hydrogen bonds. Then the layers were linked along a-axis by hydrogen bonds between the water molecules belonging to different layers. The thermal decomposition mechanism of the compound was studied by differential scanning calorimetry (DSC), thermogravimetry-thermogravimetric analysis (TG-DTG), and Fourier transform-infrared (FT-IR) spectroscopy techniques. Under nitrogen atmosphere with a heating rate of 10 degrees C center dot min(-1), the compound experienced one endothermic process with peak temperature of 76 degrees C and one exothermal process with peak temperature of 203 degrees C. The former was confirmed to be a dehydrate process. The latter was the decomposition of TNPG(-) and ATZ(+) in the compound. The exothermic enthalpy change of this process was -212.10 kJ center dot mol(-1). The kinetic parameter calculation from Kissinger's method were, E=132.1 kJ center dot mol(-1), In (A/s(-1))=12.54 with r=0.9990, and the calculation results from Ozawa-Doyle's method were, E=133.1 kJ mol(-1) with r=0.9992.