Differences in Performance\namong ECPs with Different\nMetal Centers Based on Highly Stable TzTO

The stability and detonation properties of energetic\ncoordination\npolymers (ECPs) are usually directly related to the selection of ligands.\nHowever, different metals and ligands may form different structures,\nwhich will greatly affect the stability and detonation performance\nof ECPs. Three-dimensional (3D) energetic metal–organic frameworks\n(EMOFs) usually exhibit enhanced energetic performances and modest\nstability compared with one-dimensional (1D) and two-dimensional (2D)\nECPs. In this work, an energetic internal salt H<sub>2</sub>TzTO (5-(1<i>H</i>-1,2,4-triazol-4-ium-3-yl)-1<i>H</i>-tetrazol-1-olate)\nwith high stability was selected as the ligand and coordinated with\nfour metal centers, Na(I), K(I), Co(II), and Ni(II), to form three\nECPs, named [Na(HTzTO)(H<sub>2</sub>O)]<sub><i>n</i></sub>·0.5H<sub>2</sub>O, Co(HTzTO)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>, and Ni(HTzTO)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>·2H<sub>2</sub>O, and one EMOF [K(HTzTO)]<sub><i>n</i></sub>, respectively.\nThe four compounds showed excellent thermal stability [decomposition\ntemperature (<i>T</i><sub>d</sub>) ≥ 263 °C]\nand detonation properties [detonation velocity (<i>D</i>) ≥ 8587 m·s–<sup>1</sup> and detonation pressure\n(<i>P</i>) ≥ 33.8 GPa], but their properties are\ndifferent due to the influence of the metal center and structure.\nAmong them, [K(HTzTO)]<sub><i>n</i></sub> and Co(HTzTO)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub> exhibit surprising thermal stability\n(<i>T</i><sub>d</sub> = 344 and 347 °C, respectively)\ndue to the formation of face-to-face π–π stacking\nin their structures, which greatly enhances the stability of the molecules.