AbstractThe rapid thermal decomposition (dT/dt ≥ 70°C/s) of eubylammonium nitrate (CUBAN) and cubane‐1, 4‐diammonium dinitrate (CUBDAN) is described in terms of the temperature profile and gas products as a function of pressure (1‐200 psi Ar). In this environment the full strain energy of cubane is not released simultaneously with the redox reactions that involve the ammonium nitrate site because C2H4and/or C2H2are evolved. No large hydrocarbons form during rapid thermolysis, although both salts sublime to some extent below 7 psi Ar. CUBDAN is the only alkyldiammonium dinitrate salt that we have found to sublimduring fast thermolysis. An estimated gas phase basicity of about 215 kcal/mol for the cubylamines is obtained from the tendency to release HNO3(g). This value is surprising in light of the basicity values for other primar