An abnormal N-heterocyclic carbene-carbon dioxide adduct from imidazolium acetate ionic liquids

The importance of basicity

Zsolt Kelemen, Barbara Péter-Szabõ, Edit Székely, Oldamur Hollõczki, Dzmitry S. Firaha, Barbara Kirchner, Jõzsef Nagy, L. Nyulászi

Research output: Contribution to journalArticle

41 Citations (Scopus)

Abstract

In the reaction of 1-ethyl-3-methylimidazolium acetate [C2C1Im][OAc] ionic liquid with carbon dioxide at 125 C and 10MPa, not only the known N-heterocyclic carbene (NHC)-CO2 adduct I, but also isomeric aNHC-CO2 adducts II and III were obtained. The abnormal NHC-CO2 adducts are stabilized by the presence of the polarizing basic acetate anion, according to static DFT calculations and ab initio molecular dynamics studies. A further possible reaction pathway is facilitated by the high basicity of the system, deprotonating the initially formed NHC-CO2 adduct I, which can then be converted in the presence of the excess of CO2 to the more stable 2-deprotonated anionic abnormal NHC-CO2 adduct via the anionic imidazolium-2,4-dicarboxylate according to DFT calculations on model compounds. This suggests a generalizable pathway to abnormal NHC complex formation.

Original languageEnglish
Pages (from-to)13002-13008
Number of pages7
JournalChemistry - A European Journal
Volume20
Issue number40
DOIs
Publication statusPublished - Sep 26 2014

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Ionic Liquids
Alkalinity
Ionic liquids
Discrete Fourier transforms
Carbon Dioxide
Carbon dioxide
Acetates
Molecular dynamics
Negative ions
Anions
carbene

Keywords

  • basicity
  • density functional calculations
  • ionic liquids
  • N-heterocyclic carbenes
  • supercritical CO

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

An abnormal N-heterocyclic carbene-carbon dioxide adduct from imidazolium acetate ionic liquids : The importance of basicity. / Kelemen, Zsolt; Péter-Szabõ, Barbara; Székely, Edit; Hollõczki, Oldamur; Firaha, Dzmitry S.; Kirchner, Barbara; Nagy, Jõzsef; Nyulászi, L.

In: Chemistry - A European Journal, Vol. 20, No. 40, 26.09.2014, p. 13002-13008.

Research output: Contribution to journalArticle

Kelemen, Zsolt ; Péter-Szabõ, Barbara ; Székely, Edit ; Hollõczki, Oldamur ; Firaha, Dzmitry S. ; Kirchner, Barbara ; Nagy, Jõzsef ; Nyulászi, L. / An abnormal N-heterocyclic carbene-carbon dioxide adduct from imidazolium acetate ionic liquids : The importance of basicity. In: Chemistry - A European Journal. 2014 ; Vol. 20, No. 40. pp. 13002-13008.
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