Fragmentations of Hydroxymethyl Radical Cation: An Ab Initio Study |
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Authors: | Fu‐Der Mai Hsiu‐Feng Lu Feng‐Yin Li Sheng‐Hsien Lin |
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Affiliation: | 1. Department of Applied Chemistry, Chung‐Shan Medical University, Taichung, Taiwan 402, R.O.C.;2. The Institute of Atomic and Molecular Sciences, Academia Sinica, P. O. Box 23–166, Taipei, Taiwan 106, R.O.C.;3. Department of Chemistry, National Chung Hsing University, Taichung, Taiwan 402, R.O.C. |
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Abstract: | The probable fragmentation channels of hydroxymethyl radical cation were studied through the H‐and H2‐abstraction and C‐O bond breaking reactions including their related isomerization reactions. The energy barriers for hydroxymethyl cation undergoing isomerization reactions are generally higher than those undergoing the concerted 1,2‐elimination reactions to generate CHO+ and H2. The fragmentation reaction to form CHO+ and H2 through the 1,2‐elimination pathways is the major fragmentation channel for hydroxymethyl cation, consistent with the experimental observation. H abstraction from the hydroxyl group of CH2OH+ is more difficult than that from the methylene group. The feasible path to lose H is to generate CHOH2+ through hydrogen transfer reaction as the first step and then to undergo H‐elimination to generate trans‐CHOH+. Among all the reactions found in this study, the OH‐elimination to generate CH2+ has the highest energy barrier. Our calculation results indicate that the major signals contributed from the related species of hydroxymethyl cation found in the mass spectrum should be m/e 29, m/e 30. |
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Keywords: | Hydroxymethyl cation Conformation Fragmentation |
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