The crystal structure and thermal decomposition kinetics of cis-hexanitrostilbene

Hexanitrostilbene (HNS) is an energetic material with wide application and excellent comprehensive performance. cis -HNS is successfully prepared using crude HNS with a purity of 95% as the raw material and N -methyl pyrrolidone (NMP) as the solvent. After separation and purification, acetone is used as a solvent to obtain light-yellow crystals at room temperature. The molecular structure of cis -HNS is determined through analysis of Fourier transform infrared, 13 C NMR and 1 H NMR spectroscopy and single-crystal X-ray diffraction data. The thermal decomposition properties of cis and trans -HNS are studied using differential scanning calorimetry (DSC). When the heating rate is low, cis -HNS will undergo a crystal transformation after melting, from liquid cis -HNS to liquid trans -HNS, and then it will solidify and release heat. According to the results of DSC data, the apparent kinetic parameters of thermal decomposition of cis - and trans -HNS were obtained by Kissinger method [Kissinger (1957). Anal. Chem. 29 , 1702–1706] and Ozawa method [Ozawa (1965). Bull. Chem. Soc. Jpn. 38 , 1881–1886], respectively. The spontaneous combustion temperature and self-accelerating decomposition temperature of cis and trans -HNS are calculated by the Zhang-Hu-Xie-Li method [Zhang et al. (1994). Thermochim. Acta , 244 , 171–176].