Preparation of the 1-Methylimidazole Borane/Tetrazole System for Hypergolic Fuels

Based on the acid–base neutralization, the (1-methylimidazolium)(tetrazol-1-yl)borane was successfully synthesized by taking advantage of the acidity of the tetrazole and the basicity of the 1-methylimidazole borane complex. Through HRMS, NMR, and FT−IR, the structure of synthetic compounds was characterized in detail. Concerning about the (1-methylimidazolium)(tetrazol-1-yl)borane, it had an ignition−delay time of about 25 ms and a density specific impulse over 351 s·g/cm³, making it a suitable candidate for green hypergolic fuels. Moreover, it also demonstrated that introducing tetrazole into the borane could be an appropriate strategy to adjust the performance of the energy of those borane compounds.