Publication: Kinetics for Tautomerizations and Dissociations of Triglycine Radical Cations
All || By Area || By YearTitle | Kinetics for Tautomerizations and Dissociations of Triglycine Radical Cations | Authors/Editors* | Chi-Kit Siu, Junfang Zhao, Julia Laskin, Ivan K. Chu, Alan C. Hopkinson, K.W. Michael Siu |
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Where published* | Journal of the American Society for Mass Spectrometry |
How published* | Journal |
Year* | 2009 |
Volume | 20 |
Number | |
Pages | 996-1005 |
Publisher | |
Keywords | |
Link | http://dx.doi.org/10.1016/j.jasms.2009.01.014 |
Abstract |
Fragmentations of tautomers of the alpha-centered radical triglycine radical cation, [GGGâ¢]+, [GGâ¢G]+, and [Gâ¢GG]+, are charge-driven, giving b -type ions; these are processes that are facilitated by a mobile proton, as in the fragmentation of protonated triglycine (Rodriquez, C.F. et al. J. Am. Chem. Soc.2001, 123, 3006 â 3012). By contrast, radical centers are less mobile. Two mechanisms have been examined theoretically utilizing density functional theory and Rice-Ramsperger-Kassel-Marcus modeling: (1) a direct hydrogen-atom migration between two ?-carbons, and (2) a two-step proton migration involving canonical [GGG]⢠+ as an intermediate. Predictions employing the latter mechanism are in good agreement with results of recent CID experiments (Chu, I.K. et al. J. Am. Chem. Soc.2008, 130, 7862 â 7872). |
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