Alkali Metals-Based Energetic Coordination Polymers as Promising Primary Explosives: Crystal Structures, Energetic Properties, and Environmental Impact

Coordination polymers (CPs) consisting of alkali metals (Na, K, Rb, and Cs) and a powerful nitrogen- and oxygen-rich energetic ligand (4,4′-bis(dinitromethyl)-3,3′-bisnitramide-methylene-furazanate, DBMF²⁻) were developed. Molecular structures of these CPs, confirmed by single-crystal X-ray diffraction analysis, indicated that the same ligand takes on a U-shaped state for Na and an N-shaped state for K, Rb, and Cs. Explosion tests demonstrated that both Na₂DBMF and K₂DBMF efficiently detonated the secondary explosive RDX. This indicates that they are both effective primary explosives. K₂DBMF exhibits better calculated detonation performance (D: 8227 m s⁻¹; P: 32.5 GPa) than the primary explosive Pb(N₃)₂. In addition, toxicity tests and evaluation of their decomposition products reveal their low impact on the environment. Both experimental results and theoretical analyses indicate that the combination of alkali metals and a powerful energetic ligand can stimulate the development of primary explosives.