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Ionic liquids based on the bis(trifluoromethylsulfonyl)imide anion for high‐pressure Raman spectroscopy measurements
Author(s) -
Faria Luiz F. O.,
Nobrega Marcelo M.,
Temperini Marcia L. A.,
Ribeiro Mauro C. C.
Publication year - 2013
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.4220
Subject(s) - imide , raman spectroscopy , ionic liquid , ion , ionic bonding , chemistry , high pressure , analytical chemistry (journal) , materials science , polymer chemistry , organic chemistry , physics , thermodynamics , optics , catalysis
Assembling a diamond anvil cell for high‐pressure measurements involves placing in a gasket hole the sample of interest, a pressure transmitting fluid, and a material for pressure calibration. In this communication, we propose the use of ionic liquids containing the bis(trifluoromethylsulfonyl)imide anion ([Tf 2 N] ‐ ), [(CF 3 SO 2 ) 2 N] ‐ , as a simultaneous pressure transmitting and calibrant material for high‐pressure Raman spectroscopy measurements of solid samples that are not soluble in ionic liquids. The position of the characteristic Raman band of the [Tf 2 N] ‐ anion at 740 cm −1 exhibits linear frequency shift for pressures up to 2.5 GPa. High‐pressure Raman spectra of different ionic liquids containing the same anion indicate that the actual magnitude of the pressure‐induced frequency shift of the [Tf 2 N] ‐ normal mode depends on the counterion, the typical shift being 4.2 cm −1 /GPa. Ionic liquids based on the [Tf 2 N] ‐ anion are also good pressure transmitting mediums because hydrostatic condition is kept at high pressure, and no crystallization is observed up to 4.0 GPa. Copyright © 2012 John Wiley & Sons, Ltd.