Kinetics for Tautomerizations and Dissociations of Triglycine Radical Cations
Fragmentations of tautomers of the α-centered radical triglycine radical cation, [GGG*]+, [GG*G]+, and [G*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 - 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 α-carbons, and (2) a two-step proton migration involving a 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 - 7872).
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 952904
- Report Number(s):
- PNNL-SA-64060; JAMSEF; 24494; KC0302020; TRN: US0902610
- Journal Information:
- Journal of the American Society for Mass Spectrometry, 20(6):996-1005, Vol. 20, Issue 6; ISSN 1044-0305
- Country of Publication:
- United States
- Language:
- English
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