Simple synthesis produces environmentally friendly energetic material

Chemists looking to make explosives will often load their molecules with nitrogen atoms, which release energy as they break apart to form N₂ and other small molecules. Researchers have now prepared the first example of a nitrogen-packed [5,6,5]-tricyclic bistetrazole-fused compound. The potassium salt of this molecule, which the researchers named DTAT-K, has properties that could make it an environmentally friendly primary explosive (ACS Cent. Sci. 2023, DOI: 10.1021/acscentsci.3c00219).

Guangbin Cheng and Hongwei Yang at Nanjing University of Science and Technology and Chuan Xiao at Norinco led the researchers who discovered DTAT-K. The chemists were simply trying to substitute azides for the chlorides on 4,6-dichloro-5-nitropyrimidine—an inexpensive and commercially available starting material. But they were surprised to find that after the substitution occurred, the molecule spontaneously cyclized to form the [5,6,5]-tricyclic bistetrazole-fused motif and appended an additional azide group.

Swapping the sodium ion for potassium produced DTAT-K. The compound has detonation properties that are comparable to lead azide, a commonly used primary explosive that’s a source of heavy metal contamination at military training grounds. DTAT-K is safer to handle than lead azide, so it could be a replacement free of heavy metals.