Reaction of Aniline with Singlet Oxygen (O2 1Δg)
Reaction of Aniline with Singlet Oxygen (O2 1Δg)
复制标题
DOI：
10.1021/acs.jpca.7b00765
复制
发表时间：
2017-05-04
影响因子：
2.9
通讯作者：
Dlugogorski, Bogdan Z.
中科院分区：
文献类型：
--
作者：
Al-Nu'airat, Jomana;Altarawneh, Mohammednoor;Dlugogorski, Bogdan Z.
溶解有机物 (DOM) 作为一种有效的光化学敏化剂，可产生单线态 δ 分子氧 (O-2 (1)Delta(g))，这是一种强氧化剂，可从水溶液中去除苯胺。然而，该反应的确切模式、对亚氨基苯醌与邻亚氨基苯醌的比例以及其中一种反应相对于另一种的选择性在很大程度上仍然是推测性的。这一贡献解决了这些不确定性。我们首次报告了在气相和水相中使用 B3LYP 和 M06 泛函对苯胺与单线态 δ 氧氧化的综合机理和动力学解释。反应机制已在 E、H 和 G 尺度上绘制出来。 O-2 (1)Delta(g) 与苯胺进行 1,4-环加成，形成 1,4-过氧化物中间体 (M1)，该中间体通过闭壳机制异构化，生成对亚氨基苯醌分子。另一方面，当氢过氧基键断裂时，O-2 (1)Delta(g) 烯型反应会形成邻亚氨基苯醌产物，从而从 1,2-氢过氧化物 (M3) 部分分裂出羟基。气相模型预测了对亚氨基苯醌和邻亚氨基苯醌的形成。在后一个模型中，M1 加合物的选择性高达 96%。水溶剂化模型预测 M1 进一步分解，仅形成对亚氨基苯醌，在 T = 313 K 时速率常数为 k = 1.85 X 10(9) (L/(mol s))。这些结果证实了最近的产物浓度分布实验结果，其中对亚氨基苯醌代表唯一检测到的产物。
Dissolved organic matter (DOM) acts as an effective photochemical sensitizer that produces the singlet delta state of molecular oxygen (O-2 (1)Delta(g)), a powerful oxidizer that removes aniline from aqueous solutions. However, the exact mode of this reaction, the p- to o-iminobenzoquinone ratio, and the selectivity of one over the other remain largely speculative. This contribution resolves these uncertainties. We report, for the first time, a comprehensive mechanistic and kinetic account of the oxidation of aniline with the singlet delta oxygen using B3LYP and M06 functionals in both gas and aqueous phases. Reaction mechanisms have been mapped out at E, H, and G scales. The 1,4-cycloaddition of O-2 (1)Delta(g) to aniline forms a 1,4-peroxide intermediate (M1), which isomerizes via a closed-shell mechanism to generate a p-iminobenzoquinone molecule. On the other hand, the O-2 (1)Delta(g) ene-type reaction forms an o-iminobenzoquinone product when the hydroperoxyl bond breaks, splitting hydroxyl from the 1,2-hydroperoxide (M3) moiety. The gas-phase model predicts the formation of both p- and o-iminobenzoquinones. In the latter model, the M1 adduct displays the selectivity of up to 96%. A water-solvation model predicts that M1 decomposes further, forming only p-iminobenzoquinone with a rate constant of k = 1.85 X 10(9) (L/(mol s)) at T = 313 K. These results corroborate the recent experimental findings of product concentration profile in which p-iminobenzoquinonine represents the only detected product.