Iodocuprate-containing ionic liquids as promoters for green propulsion

In this work, we prepared and comprehensively characterized four novel iodocuprate-containing ionic liquids, CuILs 1-4. In addition to their interesting molecular structures and physical properties CuILs exhibited capability to efficiently promote hypergolic reactions between boron-containing [EMIM⁺][H₃BCN^-] and [MIM]·[BH₃] fuels and a highly concentrated H₂O₂ (95%) oxidizer. The most promising promoter CuIL 3 has the decomposition temperature well above the decomposition temperature of the fuels, was stable in promoter-in-fuel mixtures for weeks and showed ignition delay times down to 14 ms. We believe that further development of our new iodocuprate ionic liquids can lead to promising "green" H₂O₂-based bipropellant systems for space applications.