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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 …
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 …
Reactions Of Simple And Peptidic Alpha-Carboxylate Radical Anions With Dioxygen In The Gas Phase, Tony Ly, Benjamin B. Kirk, Pramesh I. Hettiarachchi, Berwyck L. Poad, Adam J. Trevitt, Gabriel Da Silva, Stephen J. Blanksby
Reactions Of Simple And Peptidic Alpha-Carboxylate Radical Anions With Dioxygen In The Gas Phase, Tony Ly, Benjamin B. Kirk, Pramesh I. Hettiarachchi, Berwyck L. Poad, Adam J. Trevitt, Gabriel Da Silva, Stephen J. Blanksby
Adam Trevitt
α-Carboxylate radical anions are potential reactive intermediates in the free radical oxidation of biological molecules (e.g., fatty acids, peptides and proteins). We have synthesised well-defined α-carboxylate radical anions in the gas phase by UV laser photolysis of halogenated precursors in an ion-trap mass spectrometer. Reactions of isolated acetate (CH2CO 2-) and 1-carboxylatobutyl (CH3CH 2CH2CHCO2-) radical anions with dioxygen yield carbonate (CO3-) radical anions and this chemistry is shown to be a hallmark of oxidation in simple and alkyl-substituted cross-conjugated species. Previous solution phase studies have shown that Cα-radicals in peptides, formed from free radical damage, combine with dioxygen to form …