Characterizing Ionic Liquids as Reaction Media through a Chemical Probe

Autor: Dario Landini, Cecilia Betti, Angelamaria Maia, Valentina Dichiarante, Angelo Albini, Maurizio Fagnoni
Rok vydání: 2007
Předmět:
Zdroj: 13 (2007): 1834–1841.
info:cnr-pdr/source/autori:Dichiarante, V.; Betti, C.; Fagnoni, M.; Maia, A.; Landini, D.; Albini, A./titolo:Characterizing Ionic Liquids as Reaction Media through a Chemical Probe/doi:/rivista:/anno:2007/pagina_da:1834/pagina_a:1841/intervallo_pagine:1834–1841/volume:13
ISSN: 1521-3765
0947-6539
DOI: 10.1002/chem.200601078
Popis: The triplet N,N-dimethylaminophenyl cation, a highly reactive but chemospecific electrophile, has been used as a probe for characterizing the properties of reaction media for a series of imidazolium ILs. With the N-hexyl-N-methyl imidazolium derivatives (not with the N-butyl analogues), hydrogen transfer leading to the aniline was the main process. Trapping by iodide occurred with an inverse dependence on viscosity. Trapping by pi nucleophiles exhibited a more complex behavior. This was explained by the effect of both the bulk viscosity and the structure of the IL cation on both steps of the reaction, namely, initial electrophilic attack and ensuing cation elimination or nucleophile addition. However, with an excellent nucleophile, such as thiophene, or when the latter step was intramolecular, as with 4-pentenol, the difference was obliterated and trapping became uniform. Incorporation of the probe into the IL cation (through insertion into the C--H bond alpha to the imidazolium ring) was demonstrated, while no addition to the anion tested (including bis(trifluoromethanesulfonimide)) took place.
Databáze: OpenAIRE
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