Woodcock K R S, Vondrak T, Meech S R, Plane J M C
School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
Phys Chem Chem Phys. 2006 Apr 21;8(15):1812-21. doi: 10.1039/b518155k. Epub 2006 Mar 6.
These gas-phase reactions were studied by pulsed laser ablation of an iron target to produce Fe(+) in a fast flow tube, with detection of the ions by quadrupole mass spectrometry. Fe(+).N(2) and Fe(+).O(2) were produced by injecting N(2) and O(2), respectively, into the flow tube. FeO(+) was produced from Fe(+) by addition of N(2)O, or by ligand-switching from Fe(+).N(2) following the addition of atomic O. The following rate coefficients were measured: k(FeO(+) + O --> Fe(+) + O(2), 186-294 K) = (3.2 +/- 1.5) x 10(-11); k(Fe(+).N(2) + O --> FeO(+)+ N(2), 294 K) = (4.6 +/- 2.5) x 10(-10); k(Fe(+).O(2) + O --> FeO(+) + O(2), 294 K) = (6.3 +/- 2.7) x 10(-11); and k(FeO(+) + CO --> Fe(+) + CO(2), 294 K) = (1.59 +/- 0.34) x 10(-10) cm(3) molecule(-1) s(-1), where the quoted uncertainties are a combination of the 1sigma standard errors in the kinetic data and the systematic experimental errors. The surprisingly slow reaction between FeO(+) and O is examined using ab initio quantum calculations of the relevant potential energy surfaces. The importance of this reaction for controlling the lifetime of sporadic E layers is then demonstrated using a model of the upper mesosphere and lower thermosphere.
通过脉冲激光烧蚀铁靶在快速流动管中产生Fe(+)，并用四极杆质谱法检测离子，对这些气相反应进行了研究。分别通过向流动管中注入N₂和O₂来产生Fe(+).N₂和Fe(+).O₂。通过添加N₂O由Fe(+)产生FeO(+)，或者在添加原子O之后通过Fe(+).N₂的配体交换产生FeO(+)。测量了以下速率系数：k(FeO(+) + O --> Fe(+) + O₂, 186 - 294 K) = (3.2 +/- 1.5) x 10⁻¹¹；k(Fe(+).N₂ + O --> FeO(+) + N₂, 294 K) = (4.6 +/- 2.5) x 10⁻¹⁰；k(Fe(+).O₂ + O --> FeO(+) + O₂, 294 K) = (6.3 +/- 2.7) x 10⁻¹¹；以及k(FeO(+) + CO --> Fe(+) + CO₂, 294 K) = (1.59 +/- 0.34) x 10⁻¹⁰ cm³ molecule⁻¹ s⁻¹，其中所引用的不确定性是动力学数据中1σ标准误差与系统实验误差的组合。使用相关势能面的从头算量子计算研究了FeO(+)与O之间惊人缓慢的反应。然后使用中层顶和低热层模型证明了该反应对于控制偶发性E层寿命的重要性。
