Cyanotetrazolylborohydride (CTB) anion-based ionic liquids with low viscosity and high energy capacity as ultrafast-igniting hypergolic fuelsElectronic supplementary information (ESI) available: Detailed experimental protocols and spectroscopic characterization data. CCDC 1548762. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7cc03766j

A series of hypergolic cyanotetrazolylborohydride ( CTB ) anion-based ionic liquids have been synthesized by a straightforward N -hydroboration of tetrazole followed by a salt metathesis reaction, which exhibited remarkably low viscosity (1.1 g cm −3 ), and ultra-short ignition delay time (as short as 1.4 ms) upon contact with white fuming nitric acid (WFNA). Hypergolic CTB -based ionic liquids exhibited remarkable low viscosity, high density, and ultra-short IDs (as short as 1.4 ms).