Electron Attachment to C7F14, Thermal Detachment from C7F14鈥?/sup>, the Electron Affinity of C7F14, and Neutralization of C7

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• 作者：Thomas M. Miller ; Jeffrey F. Friedman ; Nicholas S. Shuman ; Shaun G. Ard ; Joshua J. Melko ; A. A. Viggiano
• 刊名：The Journal of Physical Chemistry A
• 出版年：2012
• 出版时间：October 25, 2012
• 年：2012
• 卷：116
• 期：42
• 页码：10293-10300
• 全文大小：341K
• 年卷期：v.116,no.42(October 25, 2012)
• ISSN：1520-5215

文摘

Rate coefficients and branching fractions have been measured for electron attachment to perfluoromethylcyclohexane, Cb>7b>Fb>14b>, along with thermal detachment rate coefficients for Cb>7b>Fb>14b>^{鈥?/sup>, from 300 to 630 K, using a flowing-afterglow Langmuir-probe apparatus. The attachment rate coefficient at room temperature is 4.5 卤 1.2 脳 10鈥? cm3 s鈥? and increases with temperature at a rate described by an activation energy of 50 卤 25 meV. Thermal electron detachment is negligible at room temperature, but measurable at 600 K and above, reaching 2300 卤 1300 s鈥? at 630 K. Analysis of the attachment鈥揹etachment equilibrium yields EA(Cb>7b>Fb>14b>) = 1.02 卤 0.06 eV, in agreement with the literature value while more than halving the uncertainty. Implications of the measurement for the electron affinity of SFb>6b> are discussed. The dominant product of electron attachment is the parent anion, but Cb>6b>Fb>11b>鈥?/sup> and Cb>7b>Fb>13b>鈥?/sup> are also observed at very low levels (<0.1%) at room temperature and increase in importance as the temperature is increased, reaching 10% each at 630 K. In the course of this work we have also measured rate coefficients for the neutralization of Cb>7b>Fb>14b>鈥?/sup> by Ar+ at 300, 400, and 500 K: 4.8, 3.5, and 3.1 脳 10鈥? cm3 s鈥?, respectively, with uncertainties of 卤5 脳 10鈥? cm3 s鈥?.}