Institute of Chemistry-, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, Porto Alegre, 91501-970, RS, Brazil.
i3N|Cenimat, Materials Science Department, School of Science and Technology (FCT), NOVA University of Lisbon, Caparica, 2829-516, Portugal.
ChemSusChem. 2020 Jun 19;13(12):3101-3109. doi: 10.1002/cssc.202000574. Epub 2020 May 11.
Ionic liquids (ILs) are among the most studied and promising materials for selective CO capture and transformation. The high CO sorption capacity associated with the possibility to activate this rather stable molecule through stabilization of ionic/radical species or covalent interactions either with the cation or anion has opened new avenues for CO functionalization. However, recent reports have demonstrated that another simpler and plausible pathway is also involved in the sorption/activation of CO by ILs associated with basic anions. Bare ILs or IL solutions contain almost invariable significant amounts of water and through interaction with CO generate carbonates/bicarbonates rather than carbamic acids or amidates. In these cases, the IL acts as a base and not a nucleophile and yields buffer-like solutions that can be used to shift the equilibrium toward acid products in different CO reutilization reactions. In this Minireview, the emergence of IL buffer-like solutions as a new reactivity paradigm in CO capture and activation is described and analyzed critically, mainly through the evaluation of NMR data.
离子液体 (ILs) 是最受关注和最有前途的用于选择性 CO 捕获和转化的材料之一。与通过稳定离子/自由基物种或通过与阳离子或阴离子的共价相互作用来激活这种相当稳定的分子的可能性相关联的高 CO 吸附能力为 CO 的功能化开辟了新途径。然而，最近的报道表明，另一种更简单且合理的途径也与碱性阴离子相关的 ILs 对 CO 的吸附/活化有关。裸 IL 或 IL 溶液几乎始终含有大量的水，并且通过与 CO 的相互作用生成碳酸盐/碳酸氢盐而不是氨基甲酸或酰胺。在这些情况下，IL 作为碱而不是亲核试剂起作用，并产生缓冲类似的溶液，可用于在不同的 CO 再利用反应中将平衡推向酸产物。在这篇综述中，主要通过 NMR 数据的评估，对 IL 缓冲溶液作为 CO 捕获和活化中的新反应性范例的出现进行了批判性地描述和分析。
