Highly Promising Primary Explosive: A Metal-Free, Fluoro-Substituted Azo-Triazole with Unmatched Safety and Performance

A primary explosive is a perfect chemical compound for starting ignition in military and commercial uses. Over the past century, the quest for lead-free, environmentally friendly primary explosives has been a significant challenge and a long-standing goal. Here, an innovative organic primary explosive, (<i>E</i>)-1,2-bis(3-azido-5-(trifluoromethyl)-4<i>H</i>-1,2,4-triazol-4-yl)diazene (<b>4</b>), has been designed and synthesized through a straightforward three-step reaction from commercially available reagents. Importantly, this compound integrated two trifluoromethyl and azido groups into the <i>N</i>,<i>N</i>'-azo-1,2,4-triazole backbone to enhance the performance and safety. With this combination, it meets stringent criteria for safer, environmentally friendly primary explosives: being metal and perchlorate-free, possessing high density, excellent priming ability, and unique sensitivities to nonexplosive stimuli. It shows robust environmental resistance, good thermal stability, and effective detonation performance and also can be effectively initiated with a laser. Moreover, in the detonation test, compound <b>4</b> successfully detonated 500 mg of PETN with an ultralow minimum primer charge (MPC) of 40 mg, similar to traditional primary explosive LA (MPC: 40 mg) and outperforming organic metal-free primary explosives ICM-103 (MPC: 60 mg) and DDNP (MPC: 70 mg). The high detonation power, combined with its straightforward synthesis, cost-effectiveness, and easy large-scale manufacturing, makes it a superior alternative to currently used primary explosives such as lead azide (LA) and diazodinitrophenol (DDNP).