Manganese‐Mediated Linkage of Perchlorate to Aminotetrazoles Produces Twice the Energy Density of the Unmetalated Salt

Abstract

New regimes of energy density in energetic materials may be achieved by replacement of oxidizing nitro groups with stronger oxidants such as oxychlorine species. We report the energetic material 1,3-di-tert-butyltetrazolium-5-imidoperchloratomanganese(II) 2, which crystallizes as an oligomeric cubane cluster. Bomb calorimetry on the amorphous, solvent-free phase gives an energy density of at least 40±3 MJ L , higher than hydrocarbon combustion in air, more than twice that of traditional energetic nitramines, and ≈70 % higher than that of the unmetalated tetrazolium perchlorate salt without metal linkage. The effects of solid-state structure, charge, and lattice energy on the energy of 2 are discussed.

Mesoionic tetrazolium-5-aminides: Synthesis, Molecular and Crystal Structures, UV-Vis Spectra, and DFT Calculations

“…Remaining bonds N1-N2 and N3-N4 show close lengths, ranged from 1.3333(7) to 1.3419(6) Å. In Table 2, we presented bond lengths of 1,3-di-tert-butyltetrazolium-5-aminide ligand in manganese complex [28], being the only structurally characterized complex with neutral 1,3-di-alkyltetrazolium-5-aminide. Therefore, it is of interest to compare its structural data with those for 8a to find the influence of the complexation on the ligand structure.…”

“…Earlier, we reported a facile preparation of 1,3-di-tert-butyltetrazolium-5-aminide [25], which was later used for synthesis of the first tetrazolium halocuprate [26]. Very recently, this aminide was found to be suitable ligand for manganese complexes [27] and the agent for preparation of the salt with high energy density [28]. Also, it is worth noting that today only a few examples of mesoionic tetrazole aminides X-ray structures are known [17,27].…”

Mesoionic tetrazolium-5-aminides: Synthesis, molecular and crystal structures, UV–vis spectra, and DFT calculations

“…In Table 2, we also included the bond lengths of the 1,3-di-tertbutyltetrazolium-5-aminide ligand in a manganese complex [29], being the only structurally characterized complex with a neutral 1,3-dialkyltetrazolium-5-aminide. Therefore, it is of interest to compare the structural data for this compound with those obtained for compound 8a to find the influence of the complexation on the ligand structure.…”

“…Earlier, we reported the facile preparation of 1,3-di-tert-butyltetrazolium-5aminide [25], which was later used for the synthesis of the first tetrazolium halocuprate [26] and also shown to react with bromine-containing alkylation reagents [27]. Very recently, this aminide was found to be a suitable ligand for manganese complexes [28] and used as the agent for the preparation of salts with high energy density [29]. Also, it is worth noting that today only a few examples of mesoionic tetrazole aminide X-ray structures are known [17,28].…”

“…The lengths of the tetrazole ring and exocyclic C-N bonds (Å) in compounds 8a, 10, and 11a, and in the 1,3-di-tert-butyltetrazolium-5aminide ligand in manganese complexes[29].…”