[en] X-ray photoelectron spectroscopy is used to detect the formation of different chlorometallate anions and to differentiate the electronic environment of each element present in chlorometallate anions. The impact of the degree of the charge delocalization of chlorometallate anions on the Cl 2p binding energy is demonstrated in detail. The basicity of chlorostannate and chloroferrate anions is estimated based upon the measured N 1s binding energy. It is found that chlorostannate and chloroferrate anions can be considered as the least basic anions.

[en] We investigate two imidazolium zwitterionic salts, 1,3-dimethylimidazolium-2-carboxylate and 1-butyl-3-methylimidazolium-2-carboxylate, together with 1-butyl-3-methylimidazolium acetate using X-ray photoelectron spectroscopy. The electronic environment of each element for the two zwitterionic salts is analyzed. Due to the electron-withdrawing effect of the imidazoliumcation, the binding energies of Ccarboxyl 1s and O 1s for zwitterionic salts are higher than those of 1-butyl-3-methylimidazolium acetate. The impact of the alkyl chain length on the charge distribution is also illustrated. It suggests that the electron-withdrawing effect of the imidazoliumcation decreases along with the increasing of the alkyl chain length.