Amino functionalized [B12H12]2− salts as hypergolic fuels

Abstract

A series of hypergolic salts based on [B₁₂H₁₁NH₃]⁻ anion were synthesized. The resulting six salts were characterized by ¹H and ¹³C NMR, IR, ESI-MS and EA. Their key properties were measured or calculated, including melting points (133.9–210.7 °C), decomposition temperatures (215.6–278.2 °C), and heats of formation (−40.1 to 1073.0 J g⁻¹). As expected, the [B₁₂H₁₁NH₃]⁻ salts (1–6) possess higher specific impulses (274.9–276.8 s) than the corresponding [B₁₂H₁₂]²⁻ salts (269.8–272.6 s). When the fuel/oxidizer combinations range from 20% to 50%, specific impulse values of the salts are still maintained at a high level of above 269 s.