XPS Investigation of A3 Coupling Reaction in Room Temperature Ionic Liquids

We herein report a new analytical application of XPS to the identification of organic molecules in room temperature ionic liquid for the first time. An organic compound, propargylamine (1), produced in 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][ PF₆ ]), which is one of the room temperature ionic liquids (RTILs), via A³ coupling reaction, is characterized by means of x-ray photoelectron spectroscopy (XPS) rather than using conventional organic compound analysis techniques. There are four non-equivalent carbons in RTILs and 1 each. The ratios of normalized integrated areas of the deconvoluted binding energy of core electron of carbon (C1s) peaks are well matched to the number of carbons in those compounds. The binding energies of C1s of the featured carbons in 1, C4 (sp carbons in acetylene group) and C5 ( sp² carbons in benzene ring), are assigned 286.2 and 285.4 eV, respectively. These results will be able to provide an important tool and a new strategy for the analysis of organic molecules