Synchrotron Photoionization Measurements of OH-Initiated Cyclohexene Oxidation: Ring-Preserving Products in OH + Cyclohexene and Hydroxycyclohexyl + O2 Reactions

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• 作者：Amelia W. Ray ; Craig A. Taatjes ; Oliver Welz ; David L. Osborn ; Giovanni Meloni
• 刊名：The Journal of Physical Chemistry A
• 出版年：2012
• 出版时间：June 28, 2012
• 年：2012
• 卷：116
• 期：25
• 页码：6720-6730
• 全文大小：616K
• 年卷期：v.116,no.25(June 28, 2012)
• ISSN：1520-5215

文摘

Earlier synchrotron photoionization mass spectrometry experiments suggested a prominent ring-opening channel in the OH-initiated oxidation of cyclohexene, based on comparison of product photoionization spectra with calculated spectra of possible isomers. The present work re-examines the OH + cyclohexene reaction, measuring the isomeric products of OH-initiated oxidation of partially and fully deuterated cyclohexene. In particular, the directly measured photoionization spectrum of 2-cyclohexen-1-ol differs substantially from the previously calculated Franck鈥揅ondon envelope, and the product spectrum can be fit with no contribution from ring-opening. Measurements of H₂O₂ photolysis in the presence of C₆D₁₀ establish that the addition鈥揺limination product incorporates the hydrogen atom from the hydroxyl radical reactant and loses a hydrogen (a D atom in this case) from the ring. Investigation of OH + cyclohexene-4,4,5,5-d₄ confirms this result and allows mass discrimination of different abstraction pathways. Products of 2-hydroxycyclohexyl-d₁₀ reaction with O₂ are observed upon adding a large excess of O₂ to the OH + C₆D₁₀ system.