三硝基间苯三酚5-氨基四唑盐的晶体结构及热分解

摘要

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) nm3, 7.=4, and Dc=1.849 g. cm-3. The molecular formula was confirmed to be (ATZ)TNPG. 2H20. 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), rnthermogravimetry-thermogravimetric analysis (TG-DTG), and Fourier transform-infrared (FT-IR) spectroscopy techniques. rnwith peak temperature of 76 ℃ and one exothermal process with peak temperature of 203 ℃. The former was confirmed to be a dehydrate process. The latter was the decomposition of TNPG- and ATZ+ in the compound. The method were, E=132.1 KJ. 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.%制备得到标题化合物并对其进行了元素分析与红外光谱分析.用X射线衍射方法测得其晶体结构属于正交晶系,空间群Pbca,晶胞参数a=0.6624(2)nm,b=1.7933(4)nm,c=2.3117(5)nm,V=2.7458(9)nm3,Z=4,Dc=1.849 g·cm-3.其分子式可写作(ATZ)TNPG·2H2O.5-氨基四唑阳离子(ATZ+)和三硝基间苯三酚阴离子(TNPG-)通过氢键在b轴和C轴方向上联成二维层面,然后在α轴方向通过不同层中的水分子之间的氢键联接起来.用差示扫描量热法(DSC),TG-DTG结合傅立叶变换红外光谱(FT-IR)分析了其热分解过程.在氮气气氛下用10℃·min-1的升温速率测定发现,该化合物经历一个峰温为76℃的吸热过程及一个峰温为203℃的放热过程.前者为脱除结晶水的过程,后者为产物中的TNPG-与ATZ+的热分解过程,放热的焓变为-212.10 kJ·mol-1.对该过程估算动力学参数:采用Kissinger法得活化能E=132.1 kJ·mol-1,ln(A/s-1)=12.54,r=0.9990;采用Ozawa-Doyle法得E=133.1 kJ·mol-1.r=0.9992.