Surface Orientation of 1-methyl-, 1-ethyl-, and 1-butyl-3-methylimidazolium Methyl Sulfate as Probed by Sum-Frequency Generation Vibrational Spectroscopy

Cherry S Santos, Steven Baldelli

J Phys Chem B. 2007 May 10;111(18):4715-23.

PMID: 17474698

Abstract:

The orientation of the ions at the surface of ionic liquids has been determined by the surface-sensitive technique sum-frequency generation vibrational spectroscopy. The results indicate that both ions are present at the first layer of the gas-liquid interface. Furthermore, the alkyl chains are found to be extended toward the gas phase and away from the liquid phase. The proposed models for the preferred orientation of the ions are in good agreement in comparison with the results obtained from the recent MD simulation studies. The salts considered here are 1,3-dimethylimidazolium methylsulfate, 1-ethyl-3-methylimidazolium methylsulfate, and 1-butyl-3-methylimidazolium methylsulfate.

Chemicals Related in the Paper:

Catalog Number	Product Name	Structure	CAS Number	Price
AP516474014	1-Ethyl-3-methylimidazolium methyl sulfate		516474-01-4	Price