The School of Chemistry, The University of Nottingham, Nottingham NG7 2RD, UK.
Chemphyschem. 2012 May 14;13(7):1917-26. doi: 10.1002/cphc.201100829. Epub 2012 Jan 27.
X-ray photoelectron spectroscopy (XPS) is used to study a series of five 1-(ferrocenylmethyl)-3-methylimidazolium- and 1-(ferroceniummethyl)-3-methylimidazolium-based salts. All samples emit good photoelectron fluxes with sharp, well-resolved photoelectron peaks. Due to the low volatility of imidazolium-salts at ambient temperature, no modification of the XP spectrometer was required. Two of the salts exhibit supercooling behaviour, allowing XPS to be recorded at room temperature on liquid samples without the need for charge neutralisation. The photoelectron peaks can be assigned to the component atoms of the salts, based on previous studies on ferrocene, ferrocenium-compounds and ionic liquids. Oxidation of the ferrocenyl moiety to ferrocenium shiftsthe Fe 2p and cyclopentadienyl C 1s photoelectron peaks to higher binding energy but does not affect the imidazolium and anion peaks. Under charge-neutralisation conditions, in which the sample is flooded with low-energy electrons, the ferrocenium moiety of the salt 1-(ferroceniummethyl)-3-methylimidazolium di(hexafluorophosphate) is partially reduced.
X 射线光电子能谱（XPS）用于研究一系列五种 1-(二茂铁基甲基)-3-甲基咪唑鎓-和 1-(二茂铁基甲基)-3-甲基咪唑鎓盐。所有样品都发出良好的光电子通量，具有尖锐、分辨率良好的光电子峰。由于室温下咪唑鎓盐的挥发性低，因此不需要对 XP 光谱仪进行修改。两种盐表现出过冷行为，允许在室温下对液体样品进行 XPS 记录，而无需进行电荷中和。根据之前对二茂铁、二茂铁化合物和离子液体的研究，光电子峰可以分配给盐的组成原子。茂铁部分氧化为二茂铁将 Fe 2p 和环戊二烯基 C 1s 光电子峰移至更高的结合能，但不影响咪唑鎓和阴离子峰。在电荷中和条件下，即用低能电子淹没样品时，盐 1-(二茂铁基甲基)-3-甲基咪唑鎓双（六氟磷酸盐）的二茂铁部分被部分还原。
