1. Stabilizing volatile azido in a 3D nitrogen-rich energetic metal–organic framework with excellent energetic performance
- Author
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Jian-Gang Xu, Jin-Fu Liu, Guo-Cong Guo, Yang-Hua Li, Jian-Di Lin, Fa-Kun Zheng, Wen-Cheng He, Ze-Nan Huang, and Rixin Lv
- Subjects
Materials science ,010405 organic chemistry ,Ligand ,Infrared spectroscopy ,Calorimetry ,010402 general chemistry ,Condensed Matter Physics ,01 natural sciences ,Standard enthalpy of formation ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,Thermogravimetry ,Materials Chemistry ,Ceramics and Composites ,Coordination polymerization ,Physical chemistry ,Metal-organic framework ,Physical and Theoretical Chemistry ,Single crystal - Abstract
The appearance of the nitrogen-rich energetic MOFs provides another opportunity for the new-generation of high energetic explosives. In this work, an insensitive energetic nitrogen-rich ligand, 3-amino-1, 2, 4-triazole (Hatz) was imported into the system of transition-metal azides via the coordination polymerization strategy in the hope to prepare mixed-ligand nitrogen-rich high energetic MOF materials with low sensitivity and finally a solvent-free 3D energetic compacted metal-organic framework (MOF), Cd3(atz)4(N3)2 (1) was successfully isolated under hydrothermal conditions. Compound 1 was characterized by single crystal X-ray diffraction, IR spectroscopy, elemental analysis (EA), different scanning calorimetry (DSC), and thermogravimetry analysis (TGA). Topological analysis shows that the 3D framework of 1 can be abstracted into a ten-connected topological network. The volatile azido ion can be viewed as a counter anion to be stabilized in a 3D framework as the connection of Cd(II) ions with two independent atz− ligands still remains a 3D framework. Compound 1 has a high calculated density (ρ) of 2.517 g cm−3. The standard molar enthalpy of formation (ΔfHo) of 1 was calculated to be 1330.10 kJ mol−1, which is higher than those of most of the previously 3D energetic MOFs. Sensitivity tests demonstrate that 1 is insensitive to external mechanical stimuli. TGA demonstrates that 1 has an excellent thermostability which can be stable up to 372 °C. Compound 1 can be served as a high-energy-density material with a favorable level of safety due to its excellent energetic performances, low sensitivities and excellent thermostability.
- Published
- 2018