DFT Study of the Decomposition Pathways of 5,5'-bitetrazole-1,1'-diide as a Parent Anion in the Family of Highly Energetic Green Explosives

Abstract

Abstract:The decomposition pathways of the anionic parts of the 5,5'-bitetrazole-related energetic salts are studied theoretically using highly-symmetric 5,5'-bitetrazole-1,1'-diide (point group D2d) as a model compound. The relaxed scans for all the four symmetry unique bonds elongation have been performed at the wB97XD/6-311+G(d,p) level of theory. The results have revealed that the most preferable decomposition route is the C5-N1 bond elongation. Breaking of the bonds has been tracked using the QTAIM analysis at each point along the reaction coordinate. Another decomposition mechanism of 5,5'-bitetrazole-1,1'-diide can be triggered by its oxidation, which results in breaking of the N2-N3 bond.

The σ+π dual aromaticity of typical bi‐tetrazole ring molecule TKX‐50

“…A few studies have only concomitantly mentioned the variation of aromaticity in studying other problems but no further step. [107,108] Owing to the close relationship between aromaticity and stability, we employ two complexes as shown in Figure 1, where complex I is the most common molecular structure corresponding to the crystal structure of TKX-50 [109][110][111] and complex II is the most stable one in ten possible complexes obtained by Talawar et al [112] through complex searching at ωb97xd/6-311 + + g-(3df,3pd) level of theory in the gas phase, to deep study the aromaticity of TKX-50 molecules and first found that the aromaticity of TKX-50 is constituted by π-aromaticity and a comparable amount of σ-aromaticity. This provides a new and deeper perspective on the aromaticity of TKX-50 and its related properties as a promising energetic material such as stability, impact sensitivity, and heat decomposition.…”

“…However, the aromaticity of the bi‐tetrazole ring in TKX‐50 has not attracted much attention from researchers. A few studies have only concomitantly mentioned the variation of aromaticity in studying other problems but no further step [107,108] . Owing to the close relationship between aromaticity and stability, we employ two complexes as shown in Figure 1, where complex I is the most common molecular structure corresponding to the crystal structure of TKX‐50 [109–111] and complex II is the most stable one in ten possible complexes obtained by Talawar et al [112] .…”