Energetic complexes as promoters for the green hypergolic bipropellant of EIL-H2O2 combinations

In this work, six energetic complexes were prepared and used as promoters for the hypergolic reaction of 1-ethyl-3-methylimidazolium cyanoborohydride [EMIM][BH3CN] and 90% H2O2. The structures of these compounds were studied by FT-IR spectroscopy, powder XRD, and single crystal X-ray diffraction. The results revealed that all the compounds were isostructural and each metal center was coordinated with four organic ligands and two counter ions. The decomposition temperatures of these compounds ranged from 169.6–255.9 °C. After adding 10 wt.% of prepared complexes to an ionic liquid, [EMIM][BH3CN], the shortest ignition delay time achieved was 94 ms. Moreover, the formed homogenous catalytic fuels had similar densities, thermal stabilities, as well as specific impulses similar to that of pure [EMIM][BH3CN]. The simple preparation method, excellent yield, as well as high performance of these compounds make them promising promoters for use in green hypergolic bipropellants.