The chemistry of aliphatic unconjugated nitramines. III. Thermal, electrophilic, and nucleophilic reactions

Stals, J.

doi:10.1071/ch9692515

Cited by 10 publications

(4 citation statements)

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“…The HMX absorption shows a resolved electronic absorption band at *230 nm and an additional absorption band significantly below 200 nm. According to Stals et al, 44,45 the transition at 230 nm originates from the π→π* transition of the N-NO 2 group, and the broad band at *200 nm derives from an electronic transition between orbitals involving intimately mixed σ, π, σ*, π*, and n orbitals of similar energies.…”

Section: Resultsmentioning

confidence: 99%

Deep-Ultraviolet Resonance Raman Excitation Profiles of NH₄NO₃, PETN, TNT, HMX, and RDX

2012

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We measured the dispersion of the absolute-differential Raman crosssections of ammonium nitrate (NH4NO3), pentaerythritol tetranitrate (PETN), trinitrotoluene (TNT), nitroamine (HMX), and cyclotrimethylene-trinitramine (RDX) in acetonitrile and water solutions between 204 and 257 nm. The ultraviolet (UV) resonance Raman/differential Raman cross-sections of NH4NO3, PETN, TNT, HMX, and RDX dramatically increase as the excitation wavelength decreases deep into the UV to 204 nm. NH4NO3, PETN, and RDX are best resonance-enhanced by the 204 nm excitation used here, while the optimum excitation wavelength for TNT and HMX is ~230 nm. The excitation profile of TNT roughly follows its absorption band shape. The excitation profiles for the different Raman bands of each explosive molecule differ, indicating that multiple-excitation wavelength spectra are not redundant and can offer additional information on the species present. We see no evidence of any nonlinear spectral response or sample degradation at the fluences and spectral accumulation times used here. However, we previously observed such phenomena at longer spectral accumulation times and higher fluences. These results are promising for the development of standoff deep-UV Raman methods for explosive molecule determinations.

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Section: Resultsmentioning

confidence: 99%

Deep-Ultraviolet Resonance Raman Excitation Profiles of NH₄NO₃, PETN, TNT, HMX, and RDX

2012

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“…Thus, isomerization probably cannot compete with dissociation in the absence of cage effects . Dissociation of RDRONO to RDRO and NO, ,, reaction , requires only Δ H = 51 kJ/mol and has no additional barrier. The competing loss of HONO from RDRONO, reaction , has Δ H = −91 kJ/mol but Δ H ⧧ = 187 kJ/mol.…”

Section: Resultsmentioning

confidence: 99%

“…59 Thus, isomerization probably cannot compete with dissociation in the absence of cage effects. 16 Dissociation of RDRONO to RDRO and NO, 53,60,61 6,18 Three plausible structures have been suggested, 6,64 all based upon 1,3,5-triazine: the N-oxide (OST N ), the 2-hydroxide (OST C ), and the keto tautomer of the 2-hydroxide (OST K ). The last two of these isomers are of nearly equal stability, while the N-oxide is about 212 kJ/mol less stable (H 298 ).…”

Section: ■ Resultsmentioning

confidence: 99%

Aminoxyl (Nitroxyl) Radicals in the Early Decomposition of the Nitramine RDX

Irikura

2013

J. Phys. Chem. A

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The explosive nitramine RDX (1,3,5-trinitrohexahydro-s-triazine) is thought to decompose largely by homolytic N-N bond cleavage, among other possible initiation reactions. Density-functional theory (DFT) calculations indicate that the resulting secondary aminyl (R2N·) radical can abstract an oxygen atom from NO2 or from a neighboring nitramine molecule, producing an aminoxyl (R2NO·) radical. Persistent aminoxyl radicals have been detected in electron-spin resonance (ESR) experiments and are consistent with autocatalytic "red oils" reported in the experimental literature. When the O-atom donor is a nitramine, a nitrosamine is formed along with the aminoxyl radical. Reactions of aminoxyl radicals can lead readily to the "oxy-s-triazine" product (as the s-triazine N-oxide) observed mass-spectrometrically by Behrens and co-workers. In addition to forming aminoxyl radicals, the initial aminyl radical can catalyze loss of HONO from RDX.

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“…The latter transition mainly originates from a p!p* transition. 56,57 Stals et al 57 indicate that the assignment of the ;200 nm broad band is complicated by the ''intimate mixing'' of r, p, r*, p*, and n orbitals, which are of similar energies.…”

Section: Resultsmentioning

confidence: 99%

Deep Ultraviolet Resonance Raman Excitation Enables Explosives Detection

Tuschel

Mikhonin²,

Lemoff³

et al. 2010

Appl Spectrosc

122

171

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We measured the 229 nm absolute ultraviolet (UV) Raman cross-sections of the explosives trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), cyclotrimethylene-trinitramine (RDX), the chemically related nitroamine explosive HMX, and ammonium nitrate in solution. The 229 nm Raman cross-sections are 1000-fold greater than those excited in the near-infrared and visible spectral regions. Deep UV resonance Raman spectroscopy enables detection of explosives at parts-per-billion (ppb) concentrations and may prove useful for stand-off spectroscopic detection of explosives.

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The chemistry of aliphatic unconjugated nitramines. III. Thermal, electrophilic, and nucleophilic reactions

Cited by 10 publications

References 0 publications

Deep-Ultraviolet Resonance Raman Excitation Profiles of NH₄NO₃, PETN, TNT, HMX, and RDX

Deep-Ultraviolet Resonance Raman Excitation Profiles of NH₄NO₃, PETN, TNT, HMX, and RDX

Aminoxyl (Nitroxyl) Radicals in the Early Decomposition of the Nitramine RDX

Deep Ultraviolet Resonance Raman Excitation Enables Explosives Detection

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The chemistry of aliphatic unconjugated nitramines. III. Thermal, electrophilic, and nucleophilic reactions

Cited by 10 publications

References 0 publications

Deep-Ultraviolet Resonance Raman Excitation Profiles of NH4NO3, PETN, TNT, HMX, and RDX

Deep-Ultraviolet Resonance Raman Excitation Profiles of NH4NO3, PETN, TNT, HMX, and RDX

Aminoxyl (Nitroxyl) Radicals in the Early Decomposition of the Nitramine RDX

Deep Ultraviolet Resonance Raman Excitation Enables Explosives Detection

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Product

Resources

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Deep-Ultraviolet Resonance Raman Excitation Profiles of NH₄NO₃, PETN, TNT, HMX, and RDX

Deep-Ultraviolet Resonance Raman Excitation Profiles of NH₄NO₃, PETN, TNT, HMX, and RDX