The Ionization Energy of CF3: When Does Entropy Matter in Gas-Phase Reactions?
The Ionization Energy of CF3: When Does Entropy Matter in Gas-Phase Reactions?
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CF3 的电离能：熵何时在气相反应中发挥作用？
DOI：
10.1021/ja991350s
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发表时间：
1999
影响因子：
15
通讯作者：
["K. Irikura
中科院分区：
文献类型：
--
作者：
["K. Irikura
最近，关于三氟甲基自由基CF 3的电离能的值出现了一个小争议。可靠的证据似乎支持高值（IEa = 9.05 eV）和低值（IEa = 8.65 eV）。对各种实验结果分析中所作的假设进行检查，结果表明，差异的根源在于熵在低压气相离子化学中的作用。长期以来，熵的正确处理本身就是一个更基本的争论。在零压力极限下，分子碰撞中的能量守恒（ΔE）是主要考虑因素，但在高压极限下，自由能（ΔG）决定了反应的结果：什么压力符合“高”？（Henchman，M.;等人，《离子的结构/反应性和热化学》; Ausloos，P.，Lias，S. G.，编辑; Reidel：多尔德雷赫特，The Netherlands，1987，pp 381−399）.本论文并没有从根本上解决熵的问题。然而，它确实表明...
A minor controversy has emerged recently over the value of the ionization energy of the trifluoromethyl radical, CF3. Solid evidence appears to support both high values, IEa ≈ 9.05 eV, and low values, IEa ≈ 8.65 eV. Examining the assumptions made in the analysis of the various experimental results shows that the root of the discrepancy is the role of entropy in low-pressure, gas-phase ion chemistry. The proper treatment of entropy has, itself, been a more fundamental controversy for a long time. In the zero-pressure limit, conservation of energy (ΔE) in a molecular collision is the primary consideration, but at the high-pressure limit, the free energy (ΔG) dictates the outcome of a reaction: what pressures qualify as “high”? (Henchman, M.; et al. In Structure/Reactivity and Thermochemistry of Ions; Ausloos, P., Lias, S. G., Eds.; Reidel: Dordrecht, The Netherlands, 1987, pp 381−399). The present paper does not achieve any fundamental resolution of the entropy question. However, it does demonstrate that ...