On the Mechanism of the Reactivity of 1,3-Dialkylimidazolium Salts under Basic to Acidic Conditions: A Combined Kinetic and Computational Study

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Abstract

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 35wt% 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.

Original languageEnglish
JournalAngewandte Chemie (International Edition)
Volume57
Issue number36
Pages (from-to)11613-11617
Number of pages5
ISSN1433-7851
DOIs
Publication statusPublished - 3 Sep 2018
MoE publication typeA1 Journal article-refereed

Fields of Science

  • 116 Chemical sciences
  • carbenes
  • hydrogen bonds
  • ionic liquids
  • kinetics
  • transition states
  • N-HETEROCYCLIC CARBENES
  • ACETATE IONIC LIQUIDS
  • BASIS-SETS
  • UNWANTED ACETYLATION
  • HYDROGEN-BONDS
  • H/D EXCHANGE
  • CELLULOSE
  • POLYSACCHARIDES
  • CHEMISTRY
  • CATALYSIS

Cite this

@article{0457693003c4431dbbbf5bee48b1a5ab,
title = "On the Mechanism of the Reactivity of 1,3-Dialkylimidazolium Salts under Basic to Acidic Conditions: A Combined Kinetic and Computational Study",
abstract = "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 35wt{\%} 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.",
keywords = "116 Chemical sciences, carbenes, hydrogen bonds, ionic liquids, kinetics, transition states, N-HETEROCYCLIC CARBENES, ACETATE IONIC LIQUIDS, BASIS-SETS, UNWANTED ACETYLATION, HYDROGEN-BONDS, H/D EXCHANGE, CELLULOSE, POLYSACCHARIDES, CHEMISTRY, CATALYSIS",
author = "{Rico del Cerro}, Daniel and Ra{\'u}l Mera-Adasme and King, {Alistair W. T.} and Perea-Buceta, {Jesus E.} and Sami Heikkinen and Tapio Hase and Dage Sundholm and Kristiina W{\"a}h{\"a}l{\"a}",
year = "2018",
month = "9",
day = "3",
doi = "10.1002/anie.201805016",
language = "English",
volume = "57",
pages = "11613--11617",
journal = "Angewandte Chemie (International Edition)",
issn = "1433-7851",
publisher = "Wiley-VCH",
number = "36",

}

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

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 35wt% 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 35wt% 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 - 116 Chemical sciences

KW - carbenes

KW - hydrogen bonds

KW - ionic liquids

KW - kinetics

KW - transition states

KW - N-HETEROCYCLIC CARBENES

KW - ACETATE IONIC LIQUIDS

KW - BASIS-SETS

KW - UNWANTED ACETYLATION

KW - HYDROGEN-BONDS

KW - H/D EXCHANGE

KW - CELLULOSE

KW - POLYSACCHARIDES

KW - CHEMISTRY

KW - CATALYSIS

U2 - 10.1002/anie.201805016

DO - 10.1002/anie.201805016

M3 - Article

VL - 57

SP - 11613

EP - 11617

JO - Angewandte Chemie (International Edition)

JF - Angewandte Chemie (International Edition)

SN - 1433-7851

IS - 36

ER -