In Situ Cyclization/Reduction of Polynitro Azides into Insensitive High-Energy Compounds

Polynitro azide compounds have attracted considerable attention owing to their high energy content and large positive heats of formation. However, excessive sensitivity to external stimuli severely limits their practical application. Therefore, it remains a formidable challenge to reduce its sensitivity so as to enhance the safety. In this work, we report an in situ cyclization/reduction strategy that enables effective desensitization of polynitro azide compounds while preserving their high energy output, thereby affording a new class of insensitive high-performance energetic materials. Notably, the in situ cyclization effectively transforms the azide and trinitromethyl moieties into a fused ring system; the underlying mechanism is investigated in detail. All of the newly synthesized compounds exhibit good energetic properties.