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dc.contributor.authorZhang, L.
dc.contributor.authorLaborda, E.
dc.contributor.authorDarwish, Nadim
dc.contributor.authorNoble, B.
dc.contributor.authorTyrell, J.
dc.contributor.authorPluczyk, S.
dc.contributor.authorLe Brun, A.
dc.contributor.authorWallace, G.
dc.contributor.authorGonzalez, J.
dc.contributor.authorCoote, M.
dc.contributor.authorCiampi, Simone
dc.date.accessioned2018-02-19T07:58:19Z
dc.date.available2018-02-19T07:58:19Z
dc.date.created2018-02-19T07:13:34Z
dc.date.issued2018
dc.identifier.citationZhang, L. and Laborda, E. and Darwish, N. and Noble, B. and Tyrell, J. and Pluczyk, S. and Le Brun, A. et al. 2018. Electrochemical and Electrostatic Cleavage of Alkoxyamines. Journal of the American Chemical Society. 140 (2): pp. 766-774.
dc.identifier.urihttp://hdl.handle.net/20.500.11937/65431
dc.identifier.doi10.1021/jacs.7b11628
dc.description.abstract

© 2017 American Chemical Society. Alkoxyamines are heat-labile molecules, widely used as an in situ source of nitroxides in polymer and materials sciences. Here we show that the one-electron oxidation of an alkoxyamine leads to a cation radical intermediate that even at room temperature rapidly fragments, releasing a nitroxide and carbocation. Digital simulations of experimental voltammetry and current-time transients suggest that the unimolecular decomposition which yields the "unmasked" nitroxide (TEMPO) is exceedingly rapid and irreversible. High-level quantum computations indicate that the collapse of the alkoxyamine cation radical is likely to yield a neutral nitroxide radical and a secondary phenylethyl cation. However, this fragmentation is predicted to be slow and energetically very unfavorable. To attain qualitative agreement between the experimental kinetics and computational modeling for this fragmentation step, the explicit electrostatic environment within the double layer must be accounted for. Single-molecule break-junction experiments in a scanning tunneling microscope using solvent of low dielectric (STM-BJ technique) corroborate the role played by electrostatic forces on the lysis of the alkoxyamine C-ON bond. This work highlights the electrostatic aspects played by charged species in a chemical step that follows an electrochemical reaction, defines the magnitude of this catalytic effect by looking at an independent electrical technique in non-electrolyte systems (STM-BJ), and suggests a redox on/off switch to guide the cleavage of alkoxyamines at an electrified interface.

dc.publisherAmerican Chemical Society
dc.titleElectrochemical and Electrostatic Cleavage of Alkoxyamines
dc.typeJournal Article
dcterms.source.volume140
dcterms.source.number2
dcterms.source.startPage766
dcterms.source.endPage774
dcterms.source.issn0002-7863
dcterms.source.titleJournal of the American Chemical Society
curtin.departmentNanochemistry Research Institute
curtin.accessStatusFulltext not available


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