Bishydrobis(tetrazol-1-yl)borate (BTB) based energetic ionic liquids with high density and energy capacity as hypergolic fuels

A new family of bishydrobis(tetrazol-1-yl)borate (BTB) based energetic ionic liquids were synthesized by a straightforward N-hydroboration of tetrazole followed by an ionic metathesis. The BTB-based ionic liquids are hypergolic with oxidizers and show superior energy capacity with high positive HOF (often >= 2.0 kJ g(-1)), high density (>= 1.2 g cm(-3)), high density impulse (often >= 367 s g cm(-3)) and short ignition delay times (<20 ms).