Premium
Competing Reactions of CO 2 with Cations and Anions in Azolide Ionic Liquids
Author(s) -
Gohndrone Thomas R.,
Bum Lee Tae,
DeSilva M. Aruni,
QuirozGuzman Mauricio,
Schneider William F.,
Brennecke Joan F.
Publication year - 2014
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201400009
Subject(s) - phosphonium , ionic liquid , chemistry , inorganic chemistry , ammonium , ion , reactivity (psychology) , ylide , proton , ionic bonding , organic chemistry , catalysis , medicine , physics , alternative medicine , pathology , quantum mechanics
We show that phosphonium azolide ionic liquids of interest for CO 2 capture applications react with CO 2 both through the normal anion channel and, at elevated temperatures, through a previously unrecognized cation channel. The reaction is caused by an interaction between the anion and cation that allows proton transfer, and involves a phosphonium ylide intermediate. The cation reaction can be mitigated by using ammonium rather than phosphonium cations. Thus, phosphonium and ammonium cations paired with aprotic heterocyclic anions (AHAs) react with CO 2 through different mechanisms at elevated temperatures. This work shows that careful consideration of both physical properties and chemical reactivity of ILs based on AHA anions is needed when designing ionic liquids for CO 2 separations.