N‐Fluoromethylated (Amino)Tetrazoles: Manipulating Thermal and Energetic Properties

Abstract

Fluoroiodomethane was allowed to react with the sodium salts of 5H‐tetrazole and 5‐aminotetrazole to give in each case the two corresponding isomers 1‐fluoromethyl‐5H‐tetrazole (1a) and 2‐fluoromethyl‐5H‐tetrazole (1b), as well as 1‐fluoromethyl‐5‐aminotetrazole (2a) and 2‐fluoromethyl‐5‐aminotetrazole (2b). The new tetrazoles were isolated and characterized by spectroscopic methods (IR, Raman, multinuclear NMR), mass spectrometry, and in the case of fluoromethyl‐5‐aminotetrazole the crystal structures of both isomers were obtained and discussed. Differential thermal analysis (DTA) gave insight in how a FCH2 moiety attached to a tetrazole effects the thermal behavior compared to its CH3 analog. In addition, the detonation parameters were calculated and compared to those of the corresponding methyltetrazoles. In addition, the preparation of energetic copper complexes of the new ligands was attempted. Complexes of copper(II) perchlorate and chlorate are crystallographically described and their energetic properties discussed.

Thermochemical Investigation of Tetrazole-Based Green Explosive Motifs: Experimental Vapor Pressures of N-(Fluoro)methylated Aminotetrazoles

“…The 2-substituted 5-aminotetrazole is less polar than the 1-substituted ones, and this description was corroborated by the work of Reichel using Hirshfeld analysis, where the sum of intermolecular interactions is stronger in the 1FM-5AT crystal than in the 2FM-5AT. 12 This result reassures the influence of polarity on the thermodynamic properties.…”

“…10,11 Further, the heterocycle offers a promising manipulation potential in terms of thermal and energetic properties via suitable functionalization�like the investigated (fluoro)methylation. 12 Therefore, this class of compounds finds applications in primary and secondary explosive research as well as in pyrotechnics. 11,13 Since diverse fluoromethylating agents are available for different nucleophiles, access to a broad class of compounds is ensured.…”

“…These substances can be conveniently synthesized following a route via [3 + 2] cycloaddition of azides and nitriles in the presence of a proton source. 12 Alternatively, the easily accessible compound 1H-tetrazole or the commonly available compound 1H-tetrazol-5-amine can be functionalized with amines, Noxides, or even with (fluoro)alkanes. 16 compounds can be synthesized in a straightforward way, no thermodynamic characteristics are available in the literature for fluoromethylated aminotetrazoles.…”

“…In the search for environmentally compatible alternatives for high-performance explosives, the scientific community became aware of tetrazoles as a motif. − Tetrazole compounds are important and well-investigated pharmaceutical agents, and in combination with various cations they represent auspicious energetic materials. , That is because these nitrogen-rich heterocycles combine the desired endothermic and kinetic properties with high combustion rates and high temperatures during decomposition with simultaneous formation of environmentally benign reaction products. , Further, the heterocycle offers a promising manipulation potential in terms of thermal and energetic properties via suitable functionalizationlike the investigated (fluoro)­methylation . Therefore, this class of compounds finds applications in primary and secondary explosive research as well as in pyrotechnics. , Since diverse fluoromethylating agents are available for different nucleophiles, access to a broad class of compounds is ensured .…”

“…These substances can be conveniently synthesized following a route via [3 + 2] cycloaddition of azides and nitriles in the presence of a proton source . Alternatively, the easily accessible compound 1 H -tetrazole or the commonly available compound 1 H -tetrazol-5-amine can be functionalized with amines, N -oxides, or even with (fluoro)­alkanes .…”