Strategy for Extending the Nitrogen Chain: The Bis(1,2,3-triazole) Formation Reaction from Tosylhydrazones and N-Amino Azole.

A facile and versatile synthesis strategy for the bis(1,2,3-triazole) formation reaction was developed from tosylhydrazones and N-amino (N-NH2) azole instead of C-amino amine derivatives. The novel energetic compounds containing the bicycle catenated six-nitrogen chain (N6) and the first example of N7 neutral compounds were synthesized in a moderate or high yield. The possible mechanism of bis(1,2,3-triazole) formation reaction based on amino azole of N-NH2 was verified by the X-ray crystal structure of key intermediates. In addition, four energetic compounds 4aa, 4ba, 4ac, and 4ad containing N6 and N7 structures possess acceptable decomposition temperatures (150.1-201.6 °C) and moderate calculated detonation performances (6850-7727 m/s). Among them, 4aa (N6 structure) and 4ad (N7 structure) could be used as the melt-cast explosive candidate and the gas generation agent candidate, respectively. This type of nitrogen-nitrogen bonding formation opens a new method for discovery of novel high-nitrogen energetic compounds containing catenated multiple nitrogen atoms especially odd number nitrogen compounds.