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Luo W, Bian L, Dong F, Nie J, Yang J. MD-DFT Calculations on Dissociative Absorption Configurations of FOX-7 on (001)- and (101)-Oriented Crystalline Parylene Protective Membranes. Polymers (Basel) 2024; 16:438. [PMID: 38337327 DOI: 10.3390/polym16030438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 09/29/2023] [Accepted: 10/07/2023] [Indexed: 02/12/2024] Open
Abstract
Crystalline poly-para-xylylene (parylene) has the potential for use as a protective membrane to delay the nucleation of explosives by separating the explosives and their decomposition products to decrease the explosive sensitivity. Here, molecular dynamics (MD) and density functional theory (DFT) techniques were used to calculate the dissociative adsorption configurations of 1,1-diamino-2,2-dinitroethylene (FOX-7) on (001)- and (101)-oriented crystalline parylene membranes. Based on the results of the calculations, this work demonstrates that the -NO2-π electrostatic interactions are the dominant passivation mechanism of FOX-7 on these oriented surfaces. FOX-7 can dissociatively adsorb on oriented parylene membranes due to the interactions between the LUMO of the toluene (or methyl) groups on parylene and the HOMO of the -NO2 (or -NH2) groups on FOX-7. The formation of a new intermolecular H-bond with the ONO group leads to FOX-7 decomposition via intramolecular C-NO2 bond fission and nitro-to-nitrite rearrangement. The most likely adsorption configurations are described in terms of the decomposition products, surface active groups of parylene, binding behaviors, and N charge transfer. Importantly, the (001)-oriented parylene AF8 membrane is promising for use as a protective membrane to passivate the high-energy -NO2 bonds during the dissociative adsorption of FOX-7. This study offers a new perspective on the development of protective membranes for explosives.
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Affiliation(s)
- Weihui Luo
- Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, South West University of Science and Technology, Mianyang 621010, China
| | - Liang Bian
- Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, South West University of Science and Technology, Mianyang 621010, China
- Institute of Gem and Material Technology, Hebei GEO University, Shijiazhuang 050000, China
- State Key Laboratory of Environment-friendly Energy Materials, South West University of Science and Technology, Mianyang 621010, China
- Tianfu Institute of Research and Innovation, Southwest University of Science and Technology, Chengdu 610299, China
| | - Faqin Dong
- Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, South West University of Science and Technology, Mianyang 621010, China
| | - Jianan Nie
- Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, South West University of Science and Technology, Mianyang 621010, China
| | - Jingjie Yang
- Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, South West University of Science and Technology, Mianyang 621010, China
- State Key Laboratory of Environment-friendly Energy Materials, South West University of Science and Technology, Mianyang 621010, China
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2
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Chen K, Edgar AS, Jung J, Kress JD, Wong CH, Yang D. Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry Analysis of Eutectic Bis(2,2-dinitropropyl) Acetal/Formal Degradation Profile: Nontargeted Identification of Antioxidant Derivatives. ACS OMEGA 2022; 7:35316-35325. [PMID: 36211031 PMCID: PMC9535708 DOI: 10.1021/acsomega.2c05011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 08/30/2022] [Indexed: 05/17/2023]
Abstract
In the eutectic mixture of bis(2,2-dinitropropyl) acetal (BDNPA) and bis(2,2-dinitropropyl) formal (BDNPF), also known as nitroplasticizer (NP), n-phenyl-β-naphthylamine (PBNA), an antioxidant, is used to improve the long-term storage of NP. PBNA scavenges nitrogen oxides (e.g., NO x radicals) that are evolved from NP decomposition, hence slowing down the degradation of NP. Yet, little is known about the associated chemical reaction between NP and PBNA. Herein, using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF), we thoroughly characterize nitrated PBNA derivatives with up to five NO2 moieties in terms of retention time, mass verification, fragmentation pattern, and correlation with NP degradation. The propagation of PBNA nitration is found to depend on the temperature and acidity of the NP system and can be utilized as an indirect, yet reliable, means of determining the extent of NP degradation. At low temperatures (<55 °C), we find that the scavenging efficiency of PBNA is nullified when three NO2 moieties are added to PBNA. Hence, the dinitro derivative can be used as a reliable indicator for the onset of hydrolytic NP degradation. At elevated temperatures (≥55 °C) and especially in the dry environment, the trace amount of water in the condensed NP (<700 ppm) is essentially removed, which accelerates the production of reactive species (e.g., HONO, HNO3 and NO x ). In return, the increased acidity due to HNO3 formation catalyzes the hydrolysis of NP and PBNA nitro derivatives into 2,2-dinitropropanol (DNPOH) and nitrophenol/dinitrophenol, respectively.
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Affiliation(s)
- Kitmin Chen
- MST-7: Engineered Materials Group
of Materials Science and Technology
Division and T-1: Physics and Chemistry of Materials Group of Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico87545, United States
| | - Alexander S. Edgar
- MST-7: Engineered Materials Group
of Materials Science and Technology
Division and T-1: Physics and Chemistry of Materials Group of Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico87545, United States
| | - Julie Jung
- MST-7: Engineered Materials Group
of Materials Science and Technology
Division and T-1: Physics and Chemistry of Materials Group of Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico87545, United States
| | - Joel D. Kress
- MST-7: Engineered Materials Group
of Materials Science and Technology
Division and T-1: Physics and Chemistry of Materials Group of Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico87545, United States
| | - Camille H. Wong
- MST-7: Engineered Materials Group
of Materials Science and Technology
Division and T-1: Physics and Chemistry of Materials Group of Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico87545, United States
| | - Dali Yang
- MST-7: Engineered Materials Group
of Materials Science and Technology
Division and T-1: Physics and Chemistry of Materials Group of Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico87545, United States
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Freye CE, Snyder CJ. Investigation into the Decomposition Pathways of an Acetal-Based Plasticizer. ACS OMEGA 2022; 7:30275-30280. [PMID: 36061734 PMCID: PMC9434789 DOI: 10.1021/acsomega.2c03494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 08/08/2022] [Indexed: 05/17/2023]
Abstract
Until now, it has been assumed that the primary decomposition pathway for the liquid plasticizer bis(2,2-dinitropropyl)acetal and bis(2,2-dinitropropyl)formal (BDNPA/F) was nitrous acid elimination (NAE). An ultrahigh-performance liquid chromatography (UHPLC) coupled to quadrupole time-of-flight mass spectrometry (QTOF) methodology was developed to discover and identify the degradation products of BDNPA/F. No evidence of NAE was found. However, two other degradation pathways were found: (1) hydrolysis of the acetal/formal functional group and (2) radical-based homolysis of the C-N bond, followed by hydrogen atom abstraction. Hydrolysis of BDNPA/F proceeds by the formation of 2,2-dinitropropanol (DNPOH) and 2,2-dinitropropyl hemiacetal/hemiformal, which further decompose into DNPOH and ethanal/methanal, respectively. Hydrolysis is the dominant decomposition pathway in all samples; however, at higher temperatures, C-N homolysis becomes more significant. Also, the solid PBX 9501 has different ratios of decomposition products than the liquid BDNPA/F due to the slower rate of diffusion through solids than liquids.
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4
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Yang D, Upshaw DA, Edgar AS, Rosales CJ. The Behavior of Antioxidant Irganox 1010 during the Thermal Degradation of a Plastic Bonded Explosive. Polym Degrad Stab 2022. [DOI: 10.1016/j.polymdegradstab.2022.109928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Booth RS, Annesley CJ. Photoinduced Intermolecular Electron Transfer in Gas Phase Ion Pairs of the 1-Ethyl-3-methylimidazolium Cation and the Bis(trifluoromethylsulfonyl)imide Anion. J Phys Chem A 2020; 124:9683-9691. [PMID: 33185452 DOI: 10.1021/acs.jpca.0c06018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study, the UV photodissociation of gas phase ion pairs of the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [emim]+[tf2n]-, is shown to proceed primarily through radical intermediates. [emim]+[tf2n]- ion pairs have been shown previously to undergo two-photon-dependent dissociation, but the mechanisms of this have not been probed in detail. By employing a two-laser pump probe spectroscopy and time-dependent density functional theory (TD-DFT) calculations, we have illustrated that one of the major UV photodissociation pathways in [emim]+[tf2n]- ion pairs is an intermolecular electron transfer wherein the anion transfers an electron to the cation resulting in two neutral open-shelled products. These products were observable for at least 1.6 μs post photodissociation, the experimental limit, via detection of the [emim]+ cation. This data demonstrates that the likely photoproducts of [emim]+[tf2n]- UV photodissociation are two neutral species that separate spatially, demonstrated through lack of observed relaxation pathways such as electron recombination. TD-DFT and frontier molecular orbital analysis calculations at the MN15/6-311++G(d,p) level are employed to aid in identifying excited state characteristics and support the interpretations of the experimental data. The energetic onset of the intermolecular electron transfer is consistent with previously observed [emim]+[tf2n]- absorption spectra in the bulk and gas phases. The similarities between bulk and gas phase UV spectra imply that this electron-transfer pathway may be a major photodissociation channel in both phases.
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Affiliation(s)
- Ryan S Booth
- Institute for Scientific Research, Boston College, Chestnut Hill, Boston, Massachusetts 02467, United States
| | - Christopher J Annesley
- Space Vehicles Directorate, Air Force Research Laboratory, Kirtland AFB, Albuquerque, New Mexico 87117, United States
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6
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Dynamics of CBr bond dissociation in methyl 2-bromopropionate at 235 nm: A resonance-enhanced multiphoton ionization study. Chem Phys Lett 2016. [DOI: 10.1016/j.cplett.2015.11.050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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7
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Booth RS, Butler LJ. Thermal decomposition pathways for 1,1-diamino-2,2-dinitroethene (FOX-7). J Chem Phys 2015; 141:134315. [PMID: 25296814 DOI: 10.1063/1.4896165] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this study, we computationally investigate the initial and subsequent steps in the chemical mechanism for the gas-phase thermal decomposition of 1,1-diamino-2,2-dinitroethene (FOX-7). We determine the key exothermic step in the gas-phase thermal decomposition of FOX-7 and explore the similarities and differences between FOX-7 and other geminal dinitro energetic materials. The calculations reveal a mechanism for NO loss involving a 3-member cyclic intermediate, rather than a nitro-nitrite isomerization, that occurs in the radical intermediates formed throughout the decomposition mechanism.
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Affiliation(s)
- Ryan S Booth
- The James Franck Institute and Department of Chemistry, University of Chicago, Chicago, Illinois 60637, USA
| | - Laurie J Butler
- The James Franck Institute and Department of Chemistry, University of Chicago, Chicago, Illinois 60637, USA
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Kawade MN, Saha A, Upadhyaya HP, Kumar A, Naik PD. Photodissociation dynamics of 2-chloro-6-nitrotoluene and nitrocyclopentane in gas phase: Laser-induced fluorescence detection of OH. Chem Phys 2014. [DOI: 10.1016/j.chemphys.2014.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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9
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Kiselev VG, Gritsan NP. Unexpected Primary Reactions for Thermolysis of 1,1-Diamino-2,2-dinitroethylene (FOX-7) Revealed by ab Initio Calculations. J Phys Chem A 2014; 118:8002-8. [DOI: 10.1021/jp507102x] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Vitaly G. Kiselev
- Institute of Chemical Kinetics and Combustion SB RAS, 3, Institutskaya Street, Novosibirsk 630090, Russia
- Novosibirsk State University, 2, Pirogova Street, Novosibirsk 630090, Russia
| | - Nina P. Gritsan
- Institute of Chemical Kinetics and Combustion SB RAS, 3, Institutskaya Street, Novosibirsk 630090, Russia
- Novosibirsk State University, 2, Pirogova Street, Novosibirsk 630090, Russia
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Booth RS, Brynteson MD, Lee SH, Lin JJ, Butler LJ. Further studies into the photodissociation pathways of 2-bromo-2-nitropropane and the dissociation channels of the 2-nitro-2-propyl radical intermediate. J Phys Chem A 2014; 118:4707-22. [PMID: 24947044 DOI: 10.1021/jp502277v] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
These experiments investigate the decomposition mechanisms of geminal dinitro energetic materials by photolytically generating two key intermediates: 2-nitropropene and 2-nitro-2-propyl radicals. To characterize the unimolecular dissociation of each intermediate, we form them under collision-free conditions using the photodissociation of 2-bromo-2-nitropropane; the intermediates are formed at high internal energies and undergo a multitude of subsequent unimolecular dissociation events investigated herein. Complementing our prior work on this system, the new data obtained with a crossed-laser molecular beam scattering apparatus with VUV photoionization detection at Taiwan's National Synchrotron Radiation Research Center (NSRRC) and new velocity map imaging data better characterize two of the four primary 193 nm photodissociation channels. The C-Br photofission channel forming the 2-nitro-2-propyl radicals has a trimodal recoil kinetic energy distribution, P(ET), suggesting that the 2-nitro-2-propyl radicals are formed both in the ground electronic state and in two low-lying excited electronic states. The new data also revise the HBr photoelimination P(ET) forming the 2-nitropropene intermediate. We then resolved the multiple competing unimolecular dissociation channels of each photoproduct, confirming many of the channels detected in the prior study, but not all. The new data detected HONO product at m/e = 47 using 11.3 eV photoionization from both intermediates; analysis of the momentum-matched products allows us to establish that both 2-nitro-2-propyl → HONO + CH3CCH2 and 2-nitropropene → HONO + C3H4 occur. Photoionization at 9.5 eV allowed us to detect the mass 71 coproduct formed in OH loss from 2-nitro-2-propyl; a channel missed in our prior study. The dynamics of the highly exothermic 2-nitro-2-propyl → NO + acetone dissociation is also better characterized; it evidences a sideways scattered angular distribution. The detection of some stable 2-nitropropene photoproducts allows us to fit signal previously assigned to H loss from 2-nitro-2-propyl radicals. Overall, the data provide a comprehensive study of the unimolecular dissociation channels of these important nitro-containing intermediates.
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Affiliation(s)
- Ryan S Booth
- Department of Chemistry and the James Franck Institute, The University of Chicago , Chicago, Illinois 60637, United States
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Veals JD, Thompson DL. Thermal decomposition of 1,3,3-trinitroazetidine (TNAZ): A density functional theory andab initiostudy. J Chem Phys 2014. [DOI: 10.1063/1.4870652] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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12
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Straus DB, Butler LM, Alligood BW, Butler LJ. Analyzing angular distributions for two-step dissociation mechanisms in velocity map imaging. J Phys Chem A 2013; 117:7102-6. [PMID: 23464815 DOI: 10.1021/jp400368f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Increasingly, velocity map imaging is becoming the method of choice to study photoinduced molecular dissociation processes. This paper introduces an algorithm to analyze the measured net speed, P(vnet), and angular, β(vnet), distributions of the products from a two-step dissociation mechanism, where the first step but not the second is induced by absorption of linearly polarized laser light. Typically, this might be the photodissociation of a C-X bond (X = halogen or other atom) to produce an atom and a momentum-matched radical that has enough internal energy to subsequently dissociate (without the absorption of an additional photon). It is this second step, the dissociation of the unstable radicals, that one wishes to study, but the measured net velocity of the final products is the vector sum of the velocity imparted to the radical in the primary photodissociation (which is determined by taking data on the momentum-matched atomic cophotofragment) and the additional velocity vector imparted in the subsequent dissociation of the unstable radical. The algorithm allows one to determine, from the forward-convolution fitting of the net velocity distribution, the distribution of velocity vectors imparted in the second step of the mechanism. One can thus deduce the secondary velocity distribution, characterized by a speed distribution P(v1,2°) and an angular distribution I(θ2°), where θ2° is the angle between the dissociating radical's velocity vector and the additional velocity vector imparted to the product detected from the subsequent dissociation of the radical.
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Affiliation(s)
- Daniel B Straus
- Department of Chemistry and the James Franck Institute, University of Chicago, Chicago, Illinois 60637, USA
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Booth RS, Lam CS, Butler LJ. A Novel Mechanism for Nitric Oxide Production in Nitroalkyl Radicals that Circumvents Nitro-Nitrite Isomerization. J Phys Chem Lett 2013; 4:547-550. [PMID: 26281753 DOI: 10.1021/jz302138n] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this study, we present a novel mechanism for NO loss from nitroalkyl radicals that circumvents the traditional higher-energy nitro-nitrite isomerization. We characterize the intrinsic reaction coordinate at the B3LYP/6-311++g(3df,2p) level of theory and calculate the transition-state energies using the G4 composite method; the subsequent dynamics en route to the highly exothermic NO + acetone product channel proceeds through a three-membered ring intermediate. Crossed laser-molecular beam scattering experiments on the 2-nitro-2-propyl radical confirm the importance of this new mechanism in determining the product branching.
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Affiliation(s)
- Ryan S Booth
- The James Franck Institute and Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Chow-Shing Lam
- The James Franck Institute and Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Laurie J Butler
- The James Franck Institute and Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
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