Designing and synthesizing new energetic materials is a challenging endeavor. Indeed, there is a continued push to synthesize high performing compounds while avoiding extreme sensitivity. In this defense, two avenues will be explored: (1) stabilizing high-nitrogen energetic materials and (2) improving the synthetic accessibility of furoxans – a desirable energetic heterocycle. For the first topic, several theories regarding the stabilization of high-nitrogen content heterocyclic systems will be discussed, followed by experimental evaluation of their veracity. These theories include alternating negative-positive charge theory, specific substitution patterns in tetrazoles, incorporation of N-oxides, and incorporation of zwitterions. All aforementioned design considerations have previously afforded improvements but have yet to be evaluated as thoroughly in tetrazole-based energetic materials. Application of these theories to design several new energetic materials is conducted, and several new tetrazole-based energetic materials are reported herein.

 

The second topic, improving the synthetic accessibility of furoxans, is discussed with respect to an improved synthesis of diethyl furoxan dicarboxylate. Furoxans are a critical energetic heterocycle, but are typically synthesized by the oxidation of dioximes or by dimerization of nitrile oxides, making their accessibility challenging. Previous interest in diethyl furoxan dicarboxylate has been established by Lawrence Livermore National Laboratory (LLNL), who published an improved synthesis in 2019. Our improved synthesis of diethyl furoxan dicarboxylate is discussed, which boasts an order of magnitude cost reduction relative to LLNL’s previously published synthesis.