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The combination of Energetic Ionic Liquid (EIL) "green" fuels and high test peroxide (>90% H2O2; HTP), as a "green" oxidizer, is a very promising platform for the development of fully "green" bipropellants for space exploration. In this work, two new "tandem-action" promoters – [FcCH2N(CH3)3+]2[Cu2I42−] (P1) and [FcCH2N(CH3)3+]n[Cu2I3−]n (P2) – and two reference "single-action" promoters, [FcCH2N(CH3)3+][H3BCN−] (P3) and [CH3N(CH2CH3)3+]n[Cu2I3−]n (P4), were prepared, comprehensively characterized and evaluated for their ability to significantly shorten the Ignition Delay (ID) times of hypergolic reactions between a series of EILs and H2O2. These promoters exhibited high solubility and long-term chemical stability in a typical EIL fuel – 1-ethyl-3-methylimidazolium dicyanamide (F1). Upon screening the performance of promoter–EIL formulations, the best ID result of 31 ms was observed for the combination of 1-ethyl-3-methylimidazolium cyanoborohydride (F2) fuel and promoter P2 (10 wt%), with H2O2 (95%), whereas an ID time of 58 ms was observed for the F2/P2 formulation with commercially available H2O2 (70%), respectively. Remarkably, the latter formulation remained fully homogeneous even at −40 °C, and showed an ID time of 66 ms at this temperature with H2O2 (95%), indicating the advantages of our approach for the development of novel fully "green" bipropellants. [ABSTRACT FROM AUTHOR]

Due to a significant and prolific activity in the field of design and synthesis of new energetic molecules, it becomes increasingly difficult to introduce new explosophore structures with attractive properties. In this work, we synthesized a trans-bimane-based energetic material—3,7-diamino-2,6-dinitro-1H,5H-pyrazolo-[1,2-a]pyrazole-1,5-dione (4), the structure of which was comprehensively analyzed by a variety of advanced spectroscopic methods and by X-ray crystallo-graphy (with density of 1.845 g·cm−3 at 173 K). Although obtained crystals of 4 contained solvent molecules in their structure, state-of-the-art density functional theory (DFT) computational techniques allowed us to predict that solvent-free crystals of this explosive would preserve a similar tightly packed planar layered molecular arrangement, with the same number of molecules of 4 per unit cell, but with a smaller unit cell volume and therefore higher energy density. Explosive 4 was found to be heat resistant, with an onset decomposition temperature of 328.8 °C, and was calculated to exhibit velocity of detonation in a range of 6.88–7.14 km·s−1 and detonation pressure in the range of 19.14–22.04 GPa, using for comparison both HASEM and the EXPLO 5 software. Our results indicate that the trans-bimane explosophore could be a viable platform for the development of new thermostable energetic materials. [ABSTRACT FROM AUTHOR]