Electronic Effects in the Structure of 1-Ethyl-3-Methylimidazolium Ionic Liquids

In this study, ten 1-ethyl-3-methylimidazolium ionic liquids are analyzed by X-ray photoelectron spectroscopy. A reliable charge correction method is established based upon the binding energy difference between cationic N 1 s and C 2 1 s . It is found that the C aliphatic 1 s component is applicable for charge correction only if the Kamlet-Taft hydrogen bond acceptor ability value is larger than 0.77. The electronic environment of nitrogen and sulfur atoms is demonstrated in detail. The impact of the substituent on the binding energy of P 2 p and B 1 s is discussed.