Effect of counter-ion on packing and crystal density of 5,5'-(3,3'-bi[1,2,4-oxa-diazole]-5,5'-di-yl)bis-(1H-tetra-zol-1-olate) with five different cations.

ABSTRACT: In energetic materials, the crystal density is an important parameter that affects the performance of the material. When making ionic energetic materials, the choice of counter-ion can have detrimental or beneficial effects on the packing, and therefore the density, of the resulting energetic crystal. Presented herein are a series of five ionic energetic crystals, all containing the dianion 5,5'-(3,3'-bi[1,2,4-oxa-diazole]-5,5'-di-yl)bis-(1H-tetra-zol-1-olate), with the following cations: hydrazinium (1) (2N₂H₅⁺·C₆N₁₂O₄^2-), hydroxyl-ammonium (2) 2NH₄O⁺·C₆N₁₂O₄^2- [Pagoria et al.. (2017). Chem. Heterocycl. Compd, 53, 760-778; included for comparison], di-methyl-ammonium (3) (2C₂H₈N⁺·C₆N₁₂O₄^2-), 5-amino-1H-tetra-zol-4-ium (4) (2CH₄N₅⁺·C₆N₁₂O₄^2-·4H₂O), and amino-guanidinium (5) (2CH₇N₄⁺·C₆N₁₂O₄^2-). Both the supra-molecular inter-actions and the sterics of the cation play a role in the density of the resulting crystals, which range from 1.544 to 1.873 Mg m^-1. In 5, the tetra-zolate ring is disordered over two positions [occupancy ratio 0.907 (5):0.093 (5)] due to a 180° rotation in the terminal tetra-zole rings.

SUBMITTER: Giles ID 

PROVIDER: S-EPMC5946978 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature