Synthesis and Improved Properties of Hypergolic Boronium‐Based Ionic Liquids

Abstract

A series of asymmetric monoimidazolium dihydroboronium-based ionic liquids (ILs) were synthesized from amine-boranes. All the resulting ILs were fully characterized by 1 H and 13 C NMR, IR spectroscopy, elemental analysis or high resolution mass spectrum. Compared with the symmetric bisimidazolium dihydroboronium-based ILs, these new ILs exhibited improved properties with shorter ignition delay times (IDs), higher densities, and lower phase transition temperature showing the promising application potential as green propellants.

Synthesis, structures, and solid-state photoresponsive color change behavior of boronium complexes bearing a pyridine-imine, diimine, or pyridine-ketone bidentate ligand

“…1 These complexes are of interest as research targets in various fields because of their characteristic molecular structures and properties, for example, they are key intermediates in some catalytic reactions. [2][3][4][5] They also act as functional compounds such as hypergolic ionic liquids, [6][7][8] anion receptors, 9 fluorescent materials, 10,11 and disinfectants. 12 Among them, bipyridine-boronium complexes have attracted attention as redox-active compounds in 4,4′-bipyridine-boronium 13 or 2,2′-bipyridine-boronium complexes, 10,[14][15][16][17][18][19][20][21] because their bi( pyridinium) structures resemble viologens or diquats, which makes them easily reducible.…”