Crystal structure evolution of the high energetic compound carbonic dihydrazidinium bis[3-(5-nitroimino-1,2,4-triazolate)] induced by solvents

Abstract

The crystal structures and stability of energetic compounds are closely related to the energy, safety and reliability of weapons. Searching for new solid forms of an energetic compound has become an integral part of its development. The studied compound, carbonic dihydrazidinium bis[3-(5-nitroimino-1,2,4-triazolate)] (CBNT), is a recently synthesized high energy and low sensitivity energetic ionic salt with promising applications. Herein, we have investigated the crystal structure evolution and searched for new solid forms of CBNT under different conditions via the solvent induction method. The phase composition of all screened samples was analysed by powder or single-crystal X-ray diffraction. Four new solid forms of CBNT·2H₂O (1), H₂BNT·2DMSO (2), H₂BNT·2H₂O (3) and [NH₂(CH₃)₂⁺]₂[BNT²⁻]·2H₂O (4) (BNT²⁻ = bis[3-(5-nitroimino-1,2,4-triazolate)²⁻]) were obtained from water, DMSO, BL/H₂O and DMF/H₂O, respectively. Their molecular interactions were analysed by theoretical simulations of the Hirshfeld surface and molecular electrostatic potentials. Furthermore, the energetic properties have been verified through EXPLO5.