title: Prediction of CL-20 chemical degradation pathways, theoretical and experimental evidence for dependence on competing modes of reaction.
abstract: Highest occupied and lowest unoccupied molecular orbital energies, formation energies, bond lengths and FTIR spectra all suggest competing CL-20 degradation mechanisms. This second of two studies investigates recalcitrant, toxic, aromatic CL-20 intermediates that absorb from 370 to 430 nm. Our earlier study (Struct. Chem., 15, 2004) revealed that these intermediates were formed at high OH(-) concentrations via the chemically preferred pathway of breaking the C-C bond between the two cyclopentanes, thereby eliminating nitro groups, forming conjugated pi bonds, and resulting in a pyrazine three-ring aromatic intermediate. In attempting to find and make dominant a more benign CL-20 transformation pathway, this current research validates hydroxylation results from both studies and examines CL-20 transformations via photo-induced free radical reactions. This article discusses CL-20 competing modes of degradation revealed through: computational calculation; UV/VIS and SF spectroscopy following alkaline hydrolysis; and photochemical irradiation to degrade CL-20 and its byproducts at their respective wavelengths of maximum absorption.
authors.affiliation: U.S. Army ERDC, 3909 Halls Ferry Road, Vicksburg, MS 39180, USA. Mohammad.M.Qasim@erdc.usace.army.mil
authors.forename: M
authors.initials: M
authors.lastname: Qasim
authors.forename: H
authors.initials: H
authors.lastname: Fredrickson
authors.forename: P
authors.initials: P
authors.lastname: Honea
authors.forename: J
authors.initials: J
authors.lastname: Furey
authors.forename: J
authors.initials: J
authors.lastname: Leszczynski
authors.forename: S
authors.initials: S
authors.lastname: Okovytyy
authors.forename: J
authors.initials: J
authors.lastname: Szecsody
authors.forename: Y
authors.initials: Y
authors.lastname: Kholod
mesh_terms: D001372:Aza Compounds / Q000737:chemistry* / Q000378:metabolism*; D006571:Heterocyclic Compounds / Q000737:chemistry* / Q000378:metabolism*; D006868:Hydrolysis; D006900:Hydroxylation; D008962:Models, Theoretical; D010777:Photochemistry / Q000379:methods; D011237:Predictive Value of Tests; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: C482139:2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaaza-isowurtzitane; D001372:Aza Compounds; D006571:Heterocyclic Compounds