Hexanitroethane
Hexanitroethane is an organic compound with chemical formula C2N6O12 or 3C-C3. It is a solid matter with a melting point of 135 °C.
Hexanitroethane is used in some pyrotechnic compositions as a nitrogen-rich oxidizer, e.g. in some decoy flare compositions and some propellants. Like hexanitrobenzene, HNE has been investigated as a gas source for explosively pumped gas dynamic lasers.
A composition of HNE as oxidizer with boron as fuel is being investigated as a new explosive.
Preparation
The first synthesis was described by Wilhelm Will in 1914, using the reaction between the potassium salt of tetranitroethane with nitric acid.A practicable method for industrial use starts with furfural, which first undergoes oxidative ring-opening by bromine to mucobromic acid. In the following step, mucobromic acid is reacted with potassium nitrite at just below room temperature to form the dipotassium salt of 2,3,3-trinitropropanal. The final product is obtained by nitration with nitric acid and sulfuric acid at −60 °C.
Properties
The thermal decomposition of hexanitroethane has been detected at 60 °C upwards in both the solid and solution phases. Above 140 °C, this can occur explosively. The decomposition is first order and is significantly faster in solution than in the solid. For the solid, the following reaction can be formulated:For the decomposition in solution, tetranitroethylene is first formed and can be trapped and detected as a Diels–Alder adduct, for example with anthracene or cyclopentadiene.