Kinetic Study of the OH Radical Reaction with Phenylacetylene

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• 作者：Ranjith Kumar Abhinavam Kailasanathan ; Juddha Thapa ; Fabien Goulay
• 刊名：Journal of Physical Chemistry A
• 出版年：2014
• 出版时间：September 11, 2014
• 年：2014
• 卷：118
• 期：36
• 页码：7732-7741
• 全文大小：483K
• ISSN：1520-5215

文摘

The reaction of the OH radical with phenylacetylene is studied over the 298鈥?23 K temperature range and 1鈥?.5 Torr pressure range in a quasi-static reaction cell. The OH radical is generated by 266 nm photolysis of hydrogen peroxide (H₂O₂) or 355 nm photolysis of nitrous acid (HONO), and its concentration monitored using laser-induced fluorescence. The measured reaction rates are found to strongly depend on laser fluence at 266 nm. The 266 nm absorption cross-section of phenylacetylene is measured to be 1.29 (卤0.71) 脳 10^鈥?7 cm², prohibiting any accurate kinetic measurements at this wavelength. The rates are independent of laser fluence at 355 nm with an average value of 8.75 (卤0.73) 脳 10^鈥?1 cm³ s^鈥?. The reaction exhibits no pressure or temperature dependence over the studied experimental conditions and is much faster than the estimated values presently used in combustion models. These results are consistent with the formation of a short lifetime intermediate that stabilizes by collisional quenching with the buffer gas. The structures of the most likely formed products are discussed based on both the computed energies for the OH-addition intermediates and previous theoretical investigations on similar chemical systems.