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

Abstract

The experimental vapor pressures of thermally modified energetic materials 2-(fluoromethyl)-1H-tetrazol-5-amine and its isomer 1-(fluoromethyl)-1H-tetrazol-5-amine were measured for the first time with the chromatography-assisted transpiration method and compared with the unsubstituted 1H-tetrazol-5-amine as well as with the methylated analogues. The resulting p–T fitting equations based on the Clausius–Clapeyron equation and the enthalpy of sublimation at the reference temperature of 298.15 K were determined for the five compounds under study, and the results are as follows: (93.8 ± 1.0) kJ·mol–1 for 2-(fluoromethyl)-1H-tetrazol-5-amine, (88.7 ± 1.3) kJ·mol–1 for 2-methyl-1H-tetrazol-5-amine, (112.6 ± 2.6) kJ·mol–1 for 1-(fluoromethyl)-1H-tetrazol-5-amine, (118.1 ± 2.0) kJ·mol–1 for 1-methyl-1H-tetrazol-5-amine, and (116.6 ± 2.2) kJ·mol–1 for 1H-tetrazol-5-amine. The p–T fitting equations were used to extrapolate to 298.15 K, and the corresponding vapor pressure results were reported in this work.