Deciphering decomposition pathways of high explosives with cryogenic X-ray Raman spectroscopy

Published

June 3, 2025

Author(s)

Oscar Parades Mellone, Michael Nielsen, Jeffrey Babicz, John Vinson, Trevor Willey, Dimosthenis Sokaras

Abstract

We employed cryogenic X-ray Raman spectroscopy to investigate the early-stage decomposition of the high explosive molecule hexanitrohexaazaisowurtzitane (CL-20). By systematically varying the radiation dose under cryogenic conditions, we induced the decomposition of the molecule using ionizing radiation and observed the evolution of spectral features at the carbon, nitrogen, and oxygen K edges. Through extensive first-principles calculations, we identified key intermediates in the early stages of the decomposition process, resulting from C–C and C–N bond cleavage which leads to the opening of the internal cage structure. A detailed analysis of spectral trends and fingerprints provided evidence supporting N–NO2 homolytic cleavage as the primary initial decomposition pathway. The combination of advanced core-level spectroscopy methods and state-of-the-art theoretical calculations enabled a comprehensive characterization of the molecular changes induced by controlled radiation dose exposures. Our findings establish a benchmark for understanding the decomposition chemistry of high-explosive materials, offering important insights into their stability and reactivity under extreme conditions.

Citation

Proceedings of the National Academy of Sciences

Volume

122

Pub Type

Journals

Download Paper

https://doi.org/10.1073/pnas.2426320122

Local Download

Citation

Parades Mellone, O. , Nielsen, M. , Babicz, J. , Vinson, J. , Willey, T. and Sokaras, D. (2025), Deciphering decomposition pathways of high explosives with cryogenic X-ray Raman spectroscopy, Proceedings of the National Academy of Sciences, [online], https://doi.org/10.1073/pnas.2426320122, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=958765 (Accessed June 29, 2025)