Synthesis, crystal structure and thermal behavior of Bis(3,4-diaminofurazan)methane

Abstract

A new energetic compound bis(3,4-diaminofurazan)methane (BDAFM) was synthesized and structurally characterized by X-ray diffraction. Theoretical calculation on BDAFM was carried out by B3LYP with 6-311+G(d) basis set. The crystal of BDAFM belongs to orthorhombic system with space group Pnn2. The BDAFM molecule is composed of two diaminofurazan groups linked by a methylene group, and the two diaminofurazan groups are centrosymmetric about the central C1 atom. Thermal decomposition of BDAFM was studied by DSC and TG/DTG methods. Results show that the thermal behavior of BDAFM presents a continuous melting-decomposition process, and the peak temperatures of melting and thermal decomposition are 251.8 and 276.4 °C, respectively. The molar heat capacity of BDAFM was determined as 245.7 J mol−1 K−1 at 298.15 K. The standard molar enthalpy of combustion and enthalpy of formation were obtained as −3362 and 259 kJ mol−1, respectively. The impact sensitivity of BDAFM is > 12.5 J, which is higher than that of DAF (>23.5 J) but lower than that of RDX and HMX (>7.4 J). The detonation velocity (D) and detonation pressure (P) for BDAFM were 7629 m s−1 and 24.38 GPa respectively, which are higher than that of TNT and close to that of DAAF.