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Full-Text Articles in Life Sciences
Concerted Ho2 Elimination From Alpha-Aminoalkylperoxyl Free Radicals: Experimental And Theoretical Evidence From The Gas-Phase Nh2 Chco2 - + O2 Reaction, Gabriel Da Silva, Benjamin Kirk, Celli Lloyd, Adam Trevitt, Stephen Blanksby
Concerted Ho2 Elimination From Alpha-Aminoalkylperoxyl Free Radicals: Experimental And Theoretical Evidence From The Gas-Phase Nh2 Chco2 - + O2 Reaction, Gabriel Da Silva, Benjamin Kirk, Celli Lloyd, Adam Trevitt, Stephen Blanksby
Adam Trevitt
We have investigated the gas-phase reaction of the α- aminoacetate (glycyl) radical anion (NH2 •CHCO2−) with O2 using ion trap mass spectrometry, quantum chemistry, and statistical reaction rate theory. This radical is found to undergo a remarkably rapid reaction with O2 to form the hydroperoxyl radical (HO2 •) and an even-electron imine (NHCHCO2−), with experiments and master equation simulations revealing that reaction proceeds at the ion−molecule collision rate. This reaction is facilitated by a low-energy concerted HO2 • elimination mechanism in the NH2CH(OO•)CO2− peroxyl radical. These findings can explain the widely observed free-radical-mediated oxidation of simple amino acids to amides …
Pyrolysis Of Fulvenallene (C7h6) And Fulvenallenyl (C7h5): Theoretical Kinetics And Experimental Product Detection, Adam Trevitt, G Da Silva, M Steinbauer, P Hemberger
Pyrolysis Of Fulvenallene (C7h6) And Fulvenallenyl (C7h5): Theoretical Kinetics And Experimental Product Detection, Adam Trevitt, G Da Silva, M Steinbauer, P Hemberger
Adam Trevitt
Fulvenallene and fulvenallenyl are the respective C7H6 and C7H5 global minima, yet their importance to combustion has only recently emerged. We have studied the pyrolysis of these species theoretically to obtain rate constants and compare our results to pyrolysis mass spectrometry experiments for product identification. Master equation modeling reveals that fulvenallene rapidly dissociates to fulvenallenyl + H, and that fulvenallenyl dissociates to form propargyl plus diacetylene, with lesser amounts of i-C5H3 (CH2CCCCH)/n-C5H3 (CHCCHCCH) plus acetylene. Photoionization mass spectrometry experiments using a pyrolysis source on the fulvenallene precursor phthalide identify products consistent with those proposed theoretically for both fulvenallene and fulvenallenyl …
Gas-Phase Reactions Of Aryl Radicals With 2-Butyne: An Experimental And Theoretical Investigation Employing The N-Methyl-Pyridinium-4-Yl Radical Cation, Adrian Lam, Cong Li, George Khairallah, Benjamin Kirk, Stephen Blanksby, Adam Trevitt, Uta Wille, Richard O'Hair, Gabriel Da Silva
Gas-Phase Reactions Of Aryl Radicals With 2-Butyne: An Experimental And Theoretical Investigation Employing The N-Methyl-Pyridinium-4-Yl Radical Cation, Adrian Lam, Cong Li, George Khairallah, Benjamin Kirk, Stephen Blanksby, Adam Trevitt, Uta Wille, Richard O'Hair, Gabriel Da Silva
Adam Trevitt
Aromatic radicals form in a variety of reacting gas-phase systems, where their molecular weight growth reactions with unsaturated hydrocarbons are of considerable importance. We have investigated the ion–molecule reaction of the aromatic distonic N-methyl-pyridinium-4-yl (NMP) radical cation with 2-butyne (CH3C≡CCH3) using ion trap mass spectrometry. Comparison is made to high-level ab initio energy surfaces for the reaction of NMP and for the neutral phenyl radical system. The NMP radical cation reacts rapidly with 2-butyne at ambient temperature, due to the apparent absence of any barrier. The activated vinyl radical adduct predominantly dissociates via loss of a H atom, with lesser …