Photosensitized Production of Atmospherically Reactive Organic Compounds at the Air/Aqueous Interface.
Photosensitized Production of Atmospherically Reactive Organic Compounds at the Air/Aqueous Interface.
复制标题
DOI：
10.1021/jacs.5b04051
复制
发表时间：
2015-07-08
影响因子：
15
通讯作者：
George C
中科院分区：
文献类型：
--
作者：
Fu H;Ciuraru R;Dupart Y;Passananti M;Tinel L;Rossignol S;Perrier S;Donaldson DJ;Chen J;George C
我们报告了在空气/水界面上探测光敏化学的实验，该界面不仅连接两相，而且显示其自身的特定化学。在这里，我们跟踪了辛醇的反应，辛醇是一种与环境相关的可溶性表面活性剂的代表，由三态羰基化合物的攻击引发，这些化合物本身在这种表面活性剂的存在下集中在界面上。气相产物采用PTR-ToF-MS测定，残留在有机层的产物采用ATR-FTIR和HPLC-HRMS测定。我们观察到羧酸以及不饱和和支链含氧产物的光敏生产，这些化合物作为有机气溶胶前体，被认为是完全由生物活性产生的。这里详细介绍了与观察结果一致的机制，并使用量子化学方法计算了几个关键反应的能量学。结果表明，界面的浓缩性质导致其成为自由基反应的有利场所，产生复杂和功能化的产物，这些产物本身可以在大气环境中引发进一步的二次化学和新粒子的形成。
We report on experiments that probe photosensitized chemistry at the air/water interface, a region that does not just connect the two phases but displays its own specific chemistry. Here, we follow reactions of octanol, a proxy for environmentally relevant soluble surfactants, initiated by an attack by triplet-state carbonyl compounds, which are themselves concentrated at the interface by the presence of this surfactant. Gas-phase products are determined using PTR-ToF-MS, and those remaining in the organic layer are determined by ATR-FTIR spectroscopy and HPLC-HRMS. We observe the photosensitized production of carboxylic acids as well as unsaturated and branched-chain oxygenated products, compounds that act as organic aerosol precursors and had been thought to be produced solely by biological activity. A mechanism that is consistent with the observations is detailed here, and the energetics of several key reactions are calculated using quantum chemical methods. The results suggest that the concentrating nature of the interface leads to its being a favorable venue for radical reactions yielding complex and functionalized products that themselves could initiate further secondary chemistry and new particle formation in the atmospheric environment.