Rico Del Cerro Daniel, Mera-Adasme Raúl, King Alistair W T, Perea-Buceta Jesus E, Heikkinen Sami, Hase Tapio, Sundholm Dage, Wähälä Kristiina
Department of Chemistry, University of Helsinki, P.O. Box 55, A.I. Virtasen aukio 1, 00014, Helsinki, Finland.
Departamento de Ciencias del Ambiente, Facultad de Química y Biología, Universidad de Santiago de Chile, Av. Libertador Bernardo O'Higgins 3363, 9170022, Estacion Central, Chile.
Angew Chem Int Ed Engl. 2018 Sep 3;57(36):11613-11617. doi: 10.1002/anie.201805016. Epub 2018 Jul 31.
Comprehensive spectroscopic kinetic studies illustrate an alternative mechanism for the traditional free-carbene intermediated H/D exchange reaction of 1,3-dialkylimidazolium salts under neutral (D O) and acidic conditions (DCl/D O 35 wt % solution). The deuteration of high purity [bmim]Cl in D O is studied at different temperatures, in absence of catalyst or impurities, to yield an activation energy. DFT transition-state modelling, of a small water cluster and [bmim] cation, also yields an activation energy which strongly supports the proposed mechanism. The presence of basic impurities are shown to significantly enhance the exchange reaction, which brings into question the need for further analysis of technical purities of ionic liquids and the implications for a wide range of chemical reactions in such media.
全面的光谱动力学研究表明，在中性（D₂O）和酸性条件（DCl/D₂O 35 wt%溶液）下，1,3 - 二烷基咪唑鎓盐传统的自由卡宾介导的H/D交换反应存在另一种机制。在不同温度下，于无催化剂或杂质的情况下，研究了高纯度[bmim]Cl在D₂O中的氘代反应，以得出活化能。对一个小水簇和[bmim]阳离子进行的DFT过渡态建模也得出了一个活化能，这有力地支持了所提出的机制。结果表明，碱性杂质的存在会显著增强交换反应，这使得有必要进一步分析离子液体的技术纯度以及此类介质中广泛化学反应的影响。
