Calculation of Some Thermodynamic Properties and Detonation Parameters of 1‐Ethyl‐3‐Methyl‐H‐Imidazolium Perchlorate, [Emim][ClO4], on the Basis of CBS‐4M and CHEETAH Computations Supplemented by VBT Estimates

This paper estimates some thermochemical (in kcal mol–1) and detonation parameters for the ionic liquid, [emim][ClO4] and its associated solid in view of its investigation as an energetic material. The thermochemical values estimated, employing CBS‐4M computational methodology and volume‐based thermodynamics (VBT) include: lattice energy, UPOT([emim][ClO4]) ≈︁ 123 ± 16 kcal·mol–1; enthalpy of formation of the gaseous cation, ΔfH°([emim]+, g) = 144.2 kcal·mol–1 and anion, ΔfH°([ClO4]–, g) = –66.1 kcal·mol–1; the enthalpy of formation of the solid salt, ΔfH°([emim][ClO4],s) ≈︁ –55 ± 16 kcal·mol–1 and for the associated ionic liquid, ΔfHo([emim][ClO4],l) = –52 ± 16 kcal·mol–1 as well as the corresponding Gibbs energy terms: ΔfG°([emim][ClO4],s) ≈︁ +29 ± 16 kcal·mol–1 and ΔfGo([emim][ClO4],l) = +24 ± 16 kcal·mol–1 and the associated standard absolute entropies, of the solid [emim][ClO4], S°298([emim][ClO4],s) = 83 ± 4 cal·K–1·mol–1. The following combustion and detonation parameters are assigned to [emim][ClO4] in its (ionic) liquid form: specific impulse (Isp) = 228 s (monopropellant), detonation velocity (VoD) = 5466 m·s–1, detonation pressure (pC–J) = 99 kbar, explosion temperature (Tex) = 2842 K.