Synthesis of hydrazinium azide

Sodium azide (NaN3) and hydrazine sulfate (N2H4 ·H2SO4) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Hydrazine monohydrate (N2H4·H2O) was obtained from Tokyo Chemical Industry Co. (Tokyo, Japan) and n-butanol was purchased from Daejung (Seoul, Korea). They were used without further purification. Hydrazinium azide (HA) was obtained by the reaction of sodium azide and hydrazine. A three-neck round-bottom flask with a magnetic stirring bar was charged with sodium azide (1.690 g), hydrazine sulfate (1.692 g), and hydrazine monohydrate (0.65 ml), after which 250 ml of n-butanol was slowly added under N2. The mixture was reacted for 30 min at 120 ◦C. The solvent was decanted and was cooled to 0 ◦C. The resulting product was washed three times with ether and dried under vacuum to yield 1.440 g of crystalline HA powder.

J. Chem. Phys. 148, 134310 (2018)