The mechanism of decarbonylation of [M  ROH]+˙ ions formed from dialkyl phenylsuccinates upon electron ionization. Alkoxy group migration between two carbonly groups

1992 ◽  
Vol 27 (7) ◽  
pp. 847-849
Author(s):  
I. Vidavsky ◽  
A. Mandelbaum
Keyword(s):  
Alkoxy Group ◽  
Electron Ionization ◽  
Group Migration

Isomerization of the Isoprene Hydroxy Nitrates and Formation of Orthonitrite Compounds

2019 ◽  
Author(s):  
Gabriel da Silva
Keyword(s):  
Hydroxy Group ◽  
Peroxyl Radical ◽  
Branching Fractions ◽  
Membered Ring ◽  
Low Energy ◽  
Peroxyl Radicals ◽  
Aerosol Formation ◽  
Subsequent Removal ◽  
Ring Compounds ◽  
Group Migration

Atmospheric oxidation of isoprene produces significant yields of eight unique nitrate 11 compounds, each with a β- or δ-hydroxy group. These isoprene hydroxy nitrates (ISOPNs) 12 significantly impact upon global NOx budgets, O3 levels, and aerosol formation. 13 Uncertainties exist, however, in our understanding of ISOPN chemistry, particularly in their 14 yields from the reaction of isoprene peroxyl radicals with NO. This study describes novel 15 isomerization reactions of the ISOPNs, identified through the application of computational 16 chemistry techniques. These reactions produce saturated polycyclic orthonitrite compounds 17 via attack of the R–NO2 group on the vinyl moiety. For the δ-hydroxy nitrates, low-energy 18 isomerization pathways exist to six-membered ring compounds that are around 5 kcal mol-1 19 exothermic. These reactions proceed with barriers around 15 kcal mol-1 below the 20 respective peroxyl radical + NO reactants and yield orthonitrites that can further isomerize 21 to β-hydroxy ISOPNs. Moreover, the δ-hydroxy nitrates can directly interconvert with their β 22 substituted counterparts via NO3 group migration, with barriers that are lower yet. It follows 23 that β-hydroxy nitrates may be stabilized in the δ-hydroxy form, and vice versa. Moreover, 24 the lowest-energy pathway for dissociation of the δ-hydroxy ISOPNs is for the formation of 25 β-hydroxy alkoxyl radicals, and because of this established branching fractions between the 26 various isoprene peroxyl radicals may require re-evaluation. The results presented here also 27 suggest that ISOPNs may be stabilized to some extent in their saturated orthonitrite forms, 28 which has implications for both the total nitrate yield and for their subsequent removal by 29 OH, O3, and photolysis.<br><br>

Reduction Reactions in the Ion Source in Electron Ionization Mass Spectrometry

2020 ◽  
Vol 75 (13) ◽  
pp. 1685-1692
Author(s):  
D. M. Mazur ◽  
M. E. Zimens ◽  
Th. B. Latkin ◽  
N. V. Ul’yanovskii ◽  
V. B. Artaev ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Ion Source ◽  
Electron Ionization ◽  
Electron Ionization Mass Spectrometry ◽  
Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Reduction Reactions

A novel rearrangement in the gas phase under electron ionization for 3-glycosyl-5-aryl-2-isoxazolines

1999 ◽  
Vol 34 (9) ◽  
pp. 915-921 ◽  
Author(s):  
Norma D’Accorso ◽  
Mirta Fascio ◽  
Carlos Gustavo Arabehety ◽  
Alicia M. Seldes
Keyword(s):  
Gas Phase ◽  
Electron Ionization

scholarly journals Kinetic Studies of Acetyl Group Migration between the Saccharide Units in an Oligomannoside Trisaccharide Model Compound and a Native Galactoglucomannan Polysaccharide

ChemBioChem ◽  
2021 ◽  
Author(s):  
Robert Lassfolk ◽  
Sara Bertuzzi ◽  
Ana Ardá ◽  
Johan Wärnå ◽  
Jesús Jiménez‐Barbero ◽  
...  
Keyword(s):  
Model Compound ◽  
Kinetic Studies ◽  
Acetyl Group ◽  
Group Migration
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