Uncatalyzed N-Alkylation of Amines in Ionic Wind from Ambient Corona Discharge
Uncatalyzed N-Alkylation of Amines in Ionic Wind from Ambient Corona Discharge
复制标题
DOI：
10.1021/acs.analchem.0c04440
复制
发表时间：
2021-01-04
影响因子：
7.4
通讯作者：
Badu-Tawiah, Abraham K.
中科院分区：
文献类型：
--
作者：
Lee, Suji;Kulyk, Dmytro S.;Badu-Tawiah, Abraham K.
在放电存在下，由大量空气的拖曳组成的离子风使得能够在环境条件下进行N-烷基化反应。通过在电子加速阶段期间引入反应物蒸气作为放电气体的一部分，所选择的有机反应物的中性和带电物质通过离子-中性碰撞获得能量，这被认为有助于化学反应。通过在质谱仪前进行这个实验，在真实的时间内检查了离子风中发生的化学反应。反应能量学的特征在于通过使用苄胺，其在3.6 eV的临界能量下自由解离，得到作为反应中间体的共振稳定的苄基阳离子。苄胺和许多其它伯胺通过自交叉偶联离子-分子反应进行N-烷基化反应。由于所涉及的物质的高能量以及离子风在大气压下产生的事实，可以直接收集随后的反应产物，而无需使用复杂的仪器。水用作有效的收集溶剂，允许使用单个等离子体发射器在环境条件下收集>0.1 mg完整的N-烷基化产物。通过该离线产物收集实验发现了一种新的N-烷基化反应途径，包括N-苄基-1-（亚甲基氨基）-1-苯基甲烷胺的合成，为离子风中苄胺的解离提供了新的见解.
Ionic wind comprising of the drag of bulk air in the presence of electrical discharge enabled N-alkylation reactions under ambient conditions. By introducing reactant vapor as part of the discharge gas during the stages of electron acceleration, both neutral and charged species of the selected organic reactant gain energy through ion-neutral collisions, which is identified to facilitate chemical reactions. By performing this experiment in front of a mass spectrometer, chemical reactions occurring in the ionic wind were examined in real time. Reaction energetics were characterized via the use of benzylamine, which freely dissociates at a critical energy of 3.6 eV to give the resonance-stabilized benzyl cation as reaction intermediate. Benzylamine and many other primary amines were observed to undergo N-alkylation reactions by engaging in self-cross-coupling ion-molecule reactions. Because of the high energies of species involved and the fact that the ionic wind is generated at atmospheric pressure, it was straightforward to collect the ensuing reaction products without the use of complicated instrumentation. Water served as an effective collecting solvent allowing >0.1 mg of intact N-alkylated products to be collected under ambient conditions using a single plasma emitter. A novel N-alkylation reaction pathway involving the synthesis of N-benzyl-1-(methyleneamino)-1-phenylmethanaime was discovered through this offline product collection experiment, providing new insight into benzylamine dissociation in the ionic wind.