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Insights into temperature-induced phase transition mechanism of CL-20 using terahertz spectroscopy
Yongwei Duan1, Quancheng Liu1, Minchang Wang2
1School of Information Engineering, Southwest University of Science and Technology, Mianyang, China.
Abstract:
Understanding the phase transition mechanism of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) is crucial for ensuring its safe applications. In this study, we observed the temperature-induced phase transition of CL-20 using terahertz spectroscopy. Subsequently, quantum chemical calculations were employed to assign the vibrations to experimental absorptions. Finally, the variations of intra- and intermolecular vibrations before and after phase transition were analyzed. The results indicated hydrogen bonds formed by the rotation of 5-nitro promoted hydrogen transfer, resulting in the decrease in thermal stability.
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