Molecular structure, theoretical calculation and thermal behavior of 2-(1,1-dinitromethylene)-1,3-diazepentane

A new compound, 2-(1,1-dinitromethylene)-1,3-diazepentane, was synthesized and its structure was determined by single-crystal X-ray diffraction. The crystal is orthorhombic, space group C2/c with crystal parameters of a = 21.707(9) Å, b = 8.572(3) Å, c = 7.431(3) Å, α = 90°, β = 98.776(12)°, γ = 90°, V = 1366.5(9) Å3, Z = 4, μ = 0.125 mm−1, F(0 0 0) = 536, and Dc = 1.284 g cm−3. The theoretical investigation on the title compound was carried out by B3LYP, MP2 and HF methods with 6-311+G(d) basis set. Thermal decomposition of the title compound was studied under the non-isothermal conditions by DSC and TG/DTG methods. The enthalpy, apparent activation energy and pre-exponential constant of the exothermic decomposition reaction are 317.13 kJmol−1, 269.7 kJ mol−1 and 1024.51 s−1, respectively. The critical temperature of thermal explosion is 261.04 °C.