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Stability and CO 2 Capture Ability of Electrogenerated N ‐Heterocyclic Carbene in Parent 1‐Butyl‐3‐methylimidazoliun Ionic Liquid (BMIm‐X): The Role of X −
Author(s) -
Feroci Marta,
Chiarotto Isabella,
Forte Gianpiero,
Vecchio Ciprioti Stefano,
Inesi Achille
Publication year - 2014
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201300269
Subject(s) - ionic liquid , carbene , reactivity (psychology) , adduct , chemistry , electrochemistry , thermogravimetric analysis , medicinal chemistry , cyclic voltammetry , benzaldehyde , ion , inorganic chemistry , catalysis , organic chemistry , electrode , medicine , alternative medicine , pathology
The electrochemical reduction of imidazolium‐based ionic liquids (BMIm‐X) leads to the formation of corresponding N ‐heterocyclic carbenes (NHCs). Owing to the peculiar reactivity of NHCs, solutions containing NHC in ionic liquid (IL) can be used in CO 2 capture or in organocatalyzed reactions. It is thus important to know the stability of the carbene in the parent IL. In fact, the NHC lifetime can be influenced by the nature of the anion (X − ) of the IL. To better understand the relationship between NHC lifetime (and reactivity towards CO 2 ) and IL medium, the presence of electrogenerated NHC in the parent IL is studied by using voltammetric, infrared, and thermogravimetric analyses and by isolation of the adduct between NHC and benzaldehyde. It is thus possible to estimate the actual NHC concentration and its lifetime through voltammetric peak‐current measurements. Moreover, NHC in BMIm‐X is able to catch CO 2 (yielding the adduct NHC–CO 2 ) and, triggered by heating (60‐150 °C), to release CO 2 . It is proven that the half‐life of NHC and the rate of CO 2 capture are both affected by the nature of X − .