Bond-forming and electron-transfer reactivity between Ar2+ and O2.
Bond-forming and electron-transfer reactivity between Ar2+ and O2.
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DOI：
10.1039/d0cp01194k
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发表时间：
2020-04
期刊：
影响因子：
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通讯作者：
Sam Armenta Butt;S. Price
中科院分区：
文献类型：
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作者：
Sam Armenta Butt;S. Price
用位置敏感符合方法研究了Ar2+与O2在碰撞能量为4.4 eV下的双分子反应的反应性、能量学和动力学。观察到生成产物离子对的四种双分子反应通道，形成：Ar+ + O2+、Ar+ + O+、ArO+ + O+和O+ + O+。Ar+ + O2+的形成是一个次要的通道，涉及前向散射，并产生处于基电子态的O2+。通过Landau-Zener论证，这种单电子转移过程是容易的，但由于电子转移途径涉及多电子过程，因此该通道的强度较低。Ar2+与O2相互作用后形成的ar++ o++ O是最强烈的通道，与前人的实验结果一致。许多不同的Ar2+和产物电子态的组合促成了该通道中的产物通量。新生O2+*离子的主要解离途径涉及离子的第一和第二解离极限。不同寻常的是，实验结果清楚地表明，在这个通道中存在一个短暂的碰撞复合体[ArO2]2+。O+和ArO+的形成涉及到Ar2+直接从O2中提取O-。很少有证据表明碰撞复合体参与了这种键形成途径。ArO+产物似乎是在第一激发态形成的（2Π）。O+ + O+的形成是通过O22+中间体离解双电子转移的结果。新生O22+中间体解离的放能性与先前研究该指示的单分子解离的工作很好地一致。
The reactivity, energetics and dynamics of the bimolecular reactions between Ar2+ and O2 have been studied using a position sensitive coincidence methodology at a collision energy of 4.4 eV. Four bimolecular reaction channels generating pairs of product ions are observed, forming: Ar+ + O2+, Ar+ + O+, ArO+ + O+ and O+ + O+. The formation of Ar+ + O2+ is a minor channel, involving forward scattering, and generates O2+ in its ground electronic state. This single electron transfer process is expected to be facile by Landau-Zener arguments, but the intensity of this channel is low because the electron transfer pathways involve multi-electron processes. The formation of Ar+ + O+ + O, is the most intense channel following interactions of Ar2+ with O2, in agreement with previous experiments. Many different combinations of Ar2+ and product electronic states contribute to the product flux in this channel. Major dissociation pathways of the nascent O2+* ion involve the ion's first and second dissociation limits. Unusually, the experimental results clearly show the involvement of a short-lived collision complex [ArO2]2+ in this channel. The formation of O+ and ArO+ involves direct abstraction of O- from O2 by Ar2+. There is scant evidence of the involvement of a collision complex in this bond forming pathway. The ArO+ product appears to be formed in the first excited electronic state (2Π). The formation of O+ + O+ results from dissociative double electron transfer via an O22+ intermediate. The exoergicity of the dissociation of the nascent O22+ intermediate is in good agreement with previous work investigating the unimolecular dissociation of this dication.