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Full-Text Articles in Social and Behavioral 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 Jul 2013

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 …


Isomer-Specific Product Detection Of Cn Radical Reactions With Ethene And Propene By Tunable Vuv Photoionization Mass Spectrometry, Adam Trevitt, Fabien Goulay, Giovanni Meloni, David Osborn, Craig Taatjes, Stephen Leone Jul 2013

Isomer-Specific Product Detection Of Cn Radical Reactions With Ethene And Propene By Tunable Vuv Photoionization Mass Spectrometry, Adam Trevitt, Fabien Goulay, Giovanni Meloni, David Osborn, Craig Taatjes, Stephen Leone

Adam Trevitt

No abstract provided.


Coalescence Of Levitated Polystyrene Microspheres, Adam Trevitt, Philip Wearne, Evan Bieske Jul 2013

Coalescence Of Levitated Polystyrene Microspheres, Adam Trevitt, Philip Wearne, Evan Bieske

Adam Trevitt

No abstract provided.


Differentiation Of Complex Lipid Isomers By Radical-Directed Dissociation Mass Spectrometry, Huong Pham, Tony Ly, Adam Trevitt, Todd Mitchell, Stephen Blanksby Jul 2013

Differentiation Of Complex Lipid Isomers By Radical-Directed Dissociation Mass Spectrometry, Huong Pham, Tony Ly, Adam Trevitt, Todd Mitchell, Stephen Blanksby

Adam Trevitt

Contemporary lipidomics protocols are dependent on conventional tandem mass spectrometry for lipid identification. This approach is extremely powerful for determining lipid class and identifying the number of carbons and the degree of unsaturation of any acyl-chain substituents. Such analyses are however, blind to isomeric variants arising from different carbon−carbon bonding motifs within these chains including double bond position, chain branching, and cyclic structures. This limitation arises from the fact that conventional, low energy collision-induced dissociation of even-electron lipid ions does not give rise to product ions from intrachain fragmentation of the fatty acyl moieties. To overcome this limitation, we have …


Pyrolysis Of Fulvenallene (C7h6) And Fulvenallenyl (C7h5): Theoretical Kinetics And Experimental Product Detection, Adam Trevitt, G Da Silva, M Steinbauer, P Hemberger Jul 2013

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 …


Comment On The Ionization Energy Of B2f4, Bun Chan, Adam J. Trevitt, Stephen J. Blanksby, Leo Radom Jul 2013

Comment On The Ionization Energy Of B2f4, Bun Chan, Adam J. Trevitt, Stephen J. Blanksby, Leo Radom

Adam Trevitt

The Gn test sets(1) of accurate (uncertainty ≤ 1 kcal mol–1 ≈ 4 kJ mol–1) experimental data are widely employed in the development and assessment of quantum chemistry procedures. However, while all the data in the Gn sets nominally carry a sub-kcal mol–1 uncertainty, several of the experimental values show uncharacteristically large discrepancies when compared with values determined by high-level theoretical calculations. One of these questionable values is the adiabatic ionization energy (IE) of B2F4, for which the theoretical values calculated, for example, with the high-level G2 (1133.9, kJ mol–1),(1b) G3 (1135.4 kJ mol–1),(2) and G4 (1127.2 kJ mol–1)(3) procedures …


Cyclic Versus Linear Isomers Produced By Reaction Of The Methylidyne Radical (Ch) With Small Unsaturated Hydrocarbons, Adam Trevitt, Talitha Selby, Luc Vereecken, Fabien Goulay, Giovanni Meloni, David Osborn, Craig Taatjes, Stephen Leone Jul 2013

Cyclic Versus Linear Isomers Produced By Reaction Of The Methylidyne Radical (Ch) With Small Unsaturated Hydrocarbons, Adam Trevitt, Talitha Selby, Luc Vereecken, Fabien Goulay, Giovanni Meloni, David Osborn, Craig Taatjes, Stephen Leone

Adam Trevitt

No abstract provided.


Direct Detection Of Pyridine Formation By The Reaction Of Ch (Cd) With Pyrrole: A Ring Expansion Reaction, Satchin Soorkia, Craig Taatjes, David Osborn, Talitha Selby, Adam Trevitt, Kevin Wilson, Stephen Leone Jul 2013

Direct Detection Of Pyridine Formation By The Reaction Of Ch (Cd) With Pyrrole: A Ring Expansion Reaction, Satchin Soorkia, Craig Taatjes, David Osborn, Talitha Selby, Adam Trevitt, Kevin Wilson, Stephen Leone

Adam Trevitt

No abstract provided.


Reactions Of Small Carbon-Bearing Radicals With Unsaturated Hydrocarbons: Product Detection And Low Temperature Kinetics, Adam Trevitt, Fabien Goulay, Stephen Leone Jul 2013

Reactions Of Small Carbon-Bearing Radicals With Unsaturated Hydrocarbons: Product Detection And Low Temperature Kinetics, Adam Trevitt, Fabien Goulay, Stephen Leone

Adam Trevitt

We report on results from two experimental techniques concerned with the reactions of small carbon based radicals (CN and CH) with unsaturated hydrocarbons. First, low temperature (100-300K) kinetic studies using a pulse Laval nozzle technique probe the reactions of the CN radical with benzene and toluene. The CN + benzene is found to be a fast, barrierless reaction. But in the case of toluene, two reaction pathways are in competition, one of which back dissociates to the reactants. The implications for the atmosphere of Titan are discussed. Product detection studies undertaken at the Advanced Light Source (ALS) using synchrotron coupled …


Branching Fractions Of The Cn + C3h6 Reaction Using Synchrotron Photoionization Mass Spectrometry: Evidence For The 3-Cyanopropene Product, Adam Trevitt, Talitha Selby, Craig Taatjes, Satchin Soorkia, J Savee, D L Osborn, S R Leone Jul 2013

Branching Fractions Of The Cn + C3h6 Reaction Using Synchrotron Photoionization Mass Spectrometry: Evidence For The 3-Cyanopropene Product, Adam Trevitt, Talitha Selby, Craig Taatjes, Satchin Soorkia, J Savee, D L Osborn, S R Leone

Adam Trevitt

The gas-phase CN + propene reaction is investigated using synchrotron photoionization mass spectrometry (SPIMS) over the 9.8 - 11.5 eV photon energy range. Experiments are conducted at room temperature in 4 Torr of He buffer gas. The CN + propene addition reaction produces two distinct product mass channels, C3H3N and C4H5N, corresponding to CH3 and H elimination, respectively. The CH3 and H elimination channels are measured to have branching fractions of 0.59 + 0.15 and 0.41 + 0.10, respectively. The absolute photoionization cross sections between 9.8 and 11.5 eV are measured for the three considered H-elimination coproducts: 1-, 2-, and …


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 Jul 2013

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 …


Biophyschem2011: A Joint Meeting Of The Australian Society For Biophysics And The Raci Physical Chemistry Division Foreword, Adam Trevitt, Jeffrey Reimers, Ronald Clarke, Jamie Vandenberg Jul 2013

Biophyschem2011: A Joint Meeting Of The Australian Society For Biophysics And The Raci Physical Chemistry Division Foreword, Adam Trevitt, Jeffrey Reimers, Ronald Clarke, Jamie Vandenberg

Adam Trevitt

[extract] This Research Front of the Australian Journal of Chemistry is aligned with the BIOPHYSCHEM2011 meeting, a joint conference of the Australian Society for Biophysics and the Physical Chemistry Division of the RACI, which was held at the University of Wollongong from 3 to 6 December 2011. Just shy of 200 delegates made the journey to the Illawarra as these two societies came together for the first time for a national meeting. The idea for this collaboration sprang from the inaugural Australian Biophysical Chemistry Workshop, coordinated by Dr Ron Clarke (U. Sydney) and Dr Tak Kee (U. Adelaide) in 2010. …