کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1195717 964406 2006 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Reactivity of Aromatic σ,σ-Biradicals Toward Riboses
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Reactivity of Aromatic σ,σ-Biradicals Toward Riboses
چکیده انگلیسی

The gas-phase reactions of sugars with aromatic, carbon-centered σ,σ-biradicals with varying polarities [as reflected by their calculated electron affinities (EA)] and extent of spin-spin coupling [as reflected by their calculated singlet-triplet (S-T) gaps] have been studied. The biradicals are positively charged, which allows them to be manipulated and their reactions to be studied in a Fourier-transform ion cyclotron resonance mass spectrometer. Hydrogen atom abstraction from sugars was found to be the dominant reaction for the biradicals with large EA values, while the biradicals with large S-T gaps tend to form addition/elimination products instead. Hence, not all σ,σ-biradicals may be able to damage DNA by hydrogen atom abstraction. The overall reaction efficiencies of the biradicals towards a given substrate were found to be directly related to the magnitude of their EA values, and inversely related to their S-T gaps. The EA of a biradical appears to be a very important rate-controlling factor, and it may even counterbalance the reduced radical reactivity characteristic of singlet biradicals that have large S-T gaps.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of the American Society for Mass Spectrometry - Volume 17, Issue 10, October 2006, Pages 1325–1334
نویسندگان
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