TY - JOUR
T1 - On the Mechanism of the Reactivity of 1,3-Dialkylimidazolium Salts under Basic to Acidic Conditions
T2 - A Combined Kinetic and Computational Study
AU - Rico del Cerro, Daniel
AU - Mera-Adasme, Raúl
AU - King, Alistair W.T.
AU - Perea-Buceta, Jesus E.
AU - Heikkinen, Sami
AU - Hase, Tapio
AU - Sundholm, Dage
AU - Wähälä, Kristiina
N1 - Funding Information:
This research has been supported by the Academy of Finland through project 275845, Magnus Ehrnrooth Foundation and Suomen Kulttuurirahasto (125971-16702). R.M.-A. thanks CONICYT-Chile for financial support under FONDECYT N. 11160032 and PAI 79150043. CSC the Finnish IT Center for Science as well as the Finnish Grid and Cloud Infrastructure (urn:nbn:fi:research infras-2016072533) are acknowledged for computational resources.
Publisher Copyright:
© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2018/9/3
Y1 - 2018/9/3
N2 - 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 (D2O) and acidic conditions (DCl/D2O 35 wt % solution). The deuteration of high purity [bmim]Cl in D2O 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.
AB - 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 (D2O) and acidic conditions (DCl/D2O 35 wt % solution). The deuteration of high purity [bmim]Cl in D2O 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.
KW - carbenes
KW - hydrogen bonds
KW - ionic liquids
KW - kinetics
KW - transition states
UR - http://www.scopus.com/inward/record.url?scp=85052510551&partnerID=8YFLogxK
U2 - 10.1002/anie.201805016
DO - 10.1002/anie.201805016
M3 - Article
C2 - 29987916
AN - SCOPUS:85052510551
SN - 1433-7851
VL - 57
SP - 11613
EP - 11617
JO - Angewandte Chemie: International Edition
JF - Angewandte Chemie: International Edition
IS - 36
ER -