An abnormal N-heterocyclic carbene-carbon dioxide adduct from imidazolium acetate ionic liquids: the importance of basicity.
Chemistry
; 20(40): 13002-8, 2014 Sep 26.
Article
em En
| MEDLINE
| ID: mdl-25137312
ABSTRACT
In the reaction of 1-ethyl-3-methylimidazolium acetate [C2C1Im][OAc] ionic liquid with carbon dioxide at 125 °C and 10â
MPa, 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.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Chemistry
Assunto da revista:
QUIMICA
Ano de publicação:
2014
Tipo de documento:
Article