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Full-Text Articles in Social and Behavioral Sciences
Oxidation Of 4-Substituted Tempo Derivatives Reveals Modifications At The 1- And 4-Positions, David Marshall, M L. Christian, G Gryn'ova, M L. Coote, Philip J. Barker, Stephen J. Blanksby
Oxidation Of 4-Substituted Tempo Derivatives Reveals Modifications At The 1- And 4-Positions, David Marshall, M L. Christian, G Gryn'ova, M L. Coote, Philip J. Barker, Stephen J. Blanksby
Stephen Blanksby
Potenital pathways for the deactivation of hindered amine light stabilisers (HALS) have been investigated by observing reactions of model compounds - based on 4-substituted derivatives of 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) - with hydroxyl radicals. In these reactions, dilute aqueous suspensions of photocatalytic nanoparticulate titanium dioxide were irradiated with UV light in the presence of water-soluble TEMPO derivatives. Electron spin resonance (ESR) and electrospray ionisation mass-spectrometry (ESI-MS) data were acquired to provide complementary structural elucidation of the odd- and even-electron products of these reactions and both techniques show evidence for the formation of 4-oxo-TEMPO (TEMPONE). TEMPONE formation from the 4-substituted TEMPO compounds is …
Ion-Molecule Reactions Of O,S-Dimethyl Methylphosphonothioate: Evidence For Intramolecular Sulfur Oxidation During Vx Perhydrolysis, Jilliarne Williams, Martin Paine, Stephen J. Blanksby, Michael L. Rogers, Andrew M. Mcanoy
Ion-Molecule Reactions Of O,S-Dimethyl Methylphosphonothioate: Evidence For Intramolecular Sulfur Oxidation During Vx Perhydrolysis, Jilliarne Williams, Martin Paine, Stephen J. Blanksby, Michael L. Rogers, Andrew M. Mcanoy
Stephen Blanksby
The alkaline perhydrolysis of the nerve agent O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate (VX) was investigated by studying the ion-molecule reactions of HOO- with O,S-dimethyl methylphosphonothioate in a modified linear ion-trap mass spectrometer. In addition to simple proton transfer, two other abundant product ions are observed at m/z 125 and 109 corresponding to the S-methyl methylphosphonothioate and methyl methylphosphonate anions, respectively. The structure of these product ions is demonstrated by a combination of collision-induced dissociation and isotope-labeling experiments that also provide evidence for their formation by nucleophilic reaction pathways, namely, (i) S(N)2 at carbon to yield the S-methyl methylphosphonothioate anion and (ii) nucleophilic …