Ab Initio Study of Unimolecular Decomposition of Nitroethylene

Gindulytė, Asta; Massa, Lou; Huang, Lulu; Karle, J.

doi:10.1021/jp991793i

Cited by 45 publications

(57 citation statements)

References 22 publications

(33 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Our data in section IIIE do evidence vinoxy radicals from the photolysis of this sample (the spectroscopic experiment of Miller and co-workers definitively detect vinoxy), but our HBr + data show that there is most certainly not enough HBr + signal from HBr to assign the vinoxy to the BrCH 2 CH 2 O → vinoxy + HBr reaction. Miller and co-workers also considered, and rejected, the possibility that the vinoxy results from a competing HBr photoelimination channel in the precursor that would produce CH 2 CHONO (that product would efficiently dissociate to vinoxy + NO, as shown in the calculations of Gindulyte et al 32 ). The present study concurs that vinoxy cannot be from this source, again because the signal at HBr + is far too small to form in a 1:1 (or larger) ratio with vinoxy.…”

Section: The Journal Of Physical Chemistry Amentioning

confidence: 99%

Imaging and Scattering Studies of the Unimolecular Dissociation of the BrCH₂CH₂O Radical from BrCH₂CH₂ONO Photolysis at 351 nm

et al. 2014

View full text Add to dashboard Cite

We report a study of the unimolecular dissociation of BrCH 2 CH 2 O radicals produced from the photodissociation of BrCH 2 CH 2 ONO at 351/355 nm. Using both a crossed laser-molecular beam scattering apparatus with electron bombardment detection and a velocity map imaging apparatus with tunable VUV photoionization detection, we investigate the initial photodissociation channels of the BrCH 2 CH 2 ONO precursor and the subsequent dissociation of the vibrationally excited BrCH 2 CH 2 O radicals. The only photodissociation channel of the precursor we detected upon photodissociation at 351 nm was O−NO bond fission. C−Br photofission and HBr photoelimination do not compete significantly with O−NO photofission at this excitation wavelength. The measured O−NO photofission recoil kinetic energy distribution peaks near 14 kcal/mol and extends from 5 to 24 kcal/mol. There is also a small signal from lower kinetic energy NO product (it would be 6% of the total if it were also from O−NO photofission). We use the O−NO photofission P(E T ) peaking near 14 kcal/mol to help characterize the internal energy distribution in the nascent ground electronic state BrCH 2 CH 2 O radicals. At 351 nm, some but not all of the BrCH 2 CH 2 O radicals are formed with enough internal energy to unimolecularly dissociate to CH 2 Br + H 2 CO. Although the signal at m/e = 93 (CH 2 Br + ) obtained with electron bombardment detection includes signal both from the CH 2 Br product and from dissociative ionization of the energetically stable BrCH 2 CH 2 O radicals, we were able to isolate the signal from CH 2 Br product alone using tunable VUV photoionization detection at 8.78 eV. We also sought to investigate the source of vinoxy radicals detected in spectroscopic experiments by Miller and co-workers (J. Phys. Chem. A 2012, 116, 12032) from the photodissociation of BrCH 2 CH 2 ONO at 351 nm. Using velocity map imaging and photodissociating the precursor at 355 nm, we detected a tiny signal at m/e = 43 and a larger signal at m/e = 15 that we tentatively assign to vinoxy. An underlying signal in the time-of-flight spectra at m/e = 29 and m/e = 42, the two strongest peaks in the literature electron bombardment mass spectrum of vinoxy, is also apparent. Comparison of those signal strengths with the signal at HBr + , however, shows that the vinoxy product does not have HBr as a cofragment, so the prior suggestion by Miller and co-workers that the vinoxy might result from a roaming mechanism is contraindicated.

show abstract

Section: The Journal Of Physical Chemistry Amentioning

confidence: 99%

Imaging and Scattering Studies of the Unimolecular Dissociation of the BrCH₂CH₂O Radical from BrCH₂CH₂ONO Photolysis at 351 nm

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Some stabilization of nitroethylene would be expected under the present conditions. The thermal dissociation of C 2 H 3 NO 2 has been studied theoretically [30,31], but no rate constants have been reported. We have assumed that the C 2 H 3 +NO 2 recombination reaction (R6) proceeds with an estimated rate constant of 10 13 cm 3 mole -1 s -1 .…”

Section: Chemical Kinetic Modelmentioning

confidence: 99%

High pressure oxidation of C2H4/NO mixtures

Giménez-López

Alzueta

Rasmussen

et al. 2011

Proceedings of the Combustion Institute

View full text Add to dashboard Cite

An experimental and kinetic modeling study of the interaction between C 2 H 4 and NO has been performed under flow reactor conditions in the intermediate temperature range (600-900 K), high pressure (60 bar), and for stoichiometries ranging from reducing to oxidizing conditions. The main reaction pathways of the C 2 H 4 /O 2 /NO x conversion, the capacity of C 2 H 4 to remove NO, and the influence of the presence of NO x on the C 2 H 4 oxidation are analyzed. Compared to the C 2 H 4 /O 2 system, the presence of NO x shifts the onset of reaction 75-150 K to lower temperatures. The mechanism of sensitization involves the reaction HOCH 2 CH 2 OO + NO → CH 2 OH + CH 2 O + NO 2 , which pushes a complex system of partial equilibria towards products. This is a confirmation of the findings of Doughty et al. [Proc. Combust. Inst. 26 (1996) 589-596] for a similar system at atmospheric pressure. Under reducing conditions and temperatures above 700 K, a significant fraction of the NO x is removed. This removal is partly explained by the reaction C 2 H 3 + NO → HCN + CH 2 O. However, a second removal mechanism is active in the 700-850 K range, which is not captured by the chemical kinetic model. With the present thermochemistry and kinetics, neither formation of nitro-hydrocarbons

show abstract

“…Decomposition of these compounds is particularly important, first, because it occurs at relatively low temperatures and, second, it plays a role in the detonation of explosives [1,2]. The considerable experimental difficulties to investigate the complex chemical processes taking place during the decomposition of nitro molecules, especially when excited states are involved [3], make theoretical studies particularly relevant in this field.…”

Section: Introductionmentioning

confidence: 99%

“…C 2 H 3 NO 2 is also the simplest member of the nitro-olefin series and show conjugation effects between the ethylenic p electrons and those on the nitro group [10], thereby affecting the electronic spectra. Investigations on nitroethylene should provide relevant information on 1,1-diamino-2,2-dinitro-ethylene (DADNE) as well, a recently synthesized and promising explosive [2].…”

Section: Introductionmentioning

confidence: 99%

Electronic spectra of nitroethylene

Borges

Barbatti

Aquino

et al. 2011

Int J of Quantum Chemistry

View full text Add to dashboard Cite

A systematic study of the electronic excited states of nitroethylene (C₂H₃NO₂) was carried out using the approximate coupled-cluster singles-and-doubles approach with the resolution of the identity (RI-CC2), the time dependent density functional theory with the CAMB3LYP functional (TDDFT/CAMB3LYP) and the DFT multireference configuration interaction (DFT/MRCI) method. Vertical transition energies and optical oscillator strengths were computed for a maximum of 20 singlet transitions. Semiclassical simulations of the ultraviolet (UV) spectra were performed at the RI-CC2 and DFT/MRCI levels. The main features in the UV spectrum were assigned to a weak n-π* transition, and two higher energy π_CC+O−π* bands. These characteristics are common to molecules containing NO2 groups. Simulated spectra are in good agreement with the experimental spectrum. The energy of the bands in the DFT/MRCI simulation agrees quite well with the experiment, although it overestimates the band intensities. RI-CC2 produced intensities comparable to the experiment, but the bands were blue shifted. A strong π_CC+O−π* band, not previously measured, was found in the 8–9 eV range

show abstract

Ab Initio Study of Unimolecular Decomposition of Nitroethylene

Cited by 45 publications

References 22 publications

Imaging and Scattering Studies of the Unimolecular Dissociation of the BrCH₂CH₂O Radical from BrCH₂CH₂ONO Photolysis at 351 nm

Imaging and Scattering Studies of the Unimolecular Dissociation of the BrCH₂CH₂O Radical from BrCH₂CH₂ONO Photolysis at 351 nm

High pressure oxidation of C2H4/NO mixtures

Electronic spectra of nitroethylene

Contact Info

Product

Resources

About

Ab Initio Study of Unimolecular Decomposition of Nitroethylene

Cited by 45 publications

References 22 publications

Imaging and Scattering Studies of the Unimolecular Dissociation of the BrCH2CH2O Radical from BrCH2CH2ONO Photolysis at 351 nm

Imaging and Scattering Studies of the Unimolecular Dissociation of the BrCH2CH2O Radical from BrCH2CH2ONO Photolysis at 351 nm

High pressure oxidation of C2H4/NO mixtures

Electronic spectra of nitroethylene

Contact Info

Product

Resources

About

Imaging and Scattering Studies of the Unimolecular Dissociation of the BrCH₂CH₂O Radical from BrCH₂CH₂ONO Photolysis at 351 nm

Imaging and Scattering Studies of the Unimolecular Dissociation of the BrCH₂CH₂O Radical from BrCH₂CH₂ONO Photolysis at 351 nm