From Concept to Synthesis: Developing Heat-Resistant High Explosives through Automated High-Throughput Virtual Screening

In
this paper, we investigate the utilization of high-throughput
virtual screening (HTVS) to identify and develop novel heat-resistant
high explosives (HRHEs) that possess a decomposition temperature exceeding
300 °C and a detonation velocity surpassing 8000 m·s–1. To achieve this, we constructed a molecular library
composed of pyrimidine as the parent ring and various five-membered
heterocycles as guest rings connected by an amino bridge. The GFN-xTB
method, an extended tight binding method, is employed to facilitate
geometry optimization and vibrational analysis, thereby enabling the
application of more precise and versatile quantum chemical calculation
in the HTVS workflow. Our screening efforts resulted in the synthesis
of three compounds that exhibited remarkable stability with decomposition
temperatures exceeding 320 °C, suggesting their potential as
HRHEs. Notably, compound K19-21 demonstrated a decomposition
temperature of 324.6 °C and a detonation velocity of 8293 m·s–1, surpassing both 2,2′,4,4′,6,6′-hexanitrostilbene
(HNS) and 2,6-bis(picrylamino)-3,5-dinitropyridine (PYX) and rivaling
l,3,5-triamino-2,4,6-trinitrobenzene (TATB). These results support
the efficacy of our molecular library design concepts and screening
workflow. Overall, our study underscores the importance and potential
of HTVS in accelerating the discovery of new materials possessing
the desired properties, especially in the field of energetic materials.