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

Abstract

A facile and versatile synthesis strategy for the bis(1,2,3-triazole) formation reaction was developed from tosylhydrazones and <i>N</i>-amino (<i>N</i>-NH₂) azole instead of <i>C</i>-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 <i>N</i>-NH₂ was verified by the X-ray crystal structure of key intermediates. In addition, four energetic compounds <b>4aa, 4ba, 4ac</b>, and <b>4ad</b> 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, <b>4aa</b> (N₆ structure) and <b>4ad</b> (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.