Spectroscopic characterization of the interaction of lithium with thin films of the ionic liquid 1-octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide
Spectroscopic characterization of the interaction of lithium with thin films of the ionic liquid 1-octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide
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DOI：
10.1039/c4cp03091e
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发表时间：
2014-01-01
影响因子：
3.3
通讯作者：
Endres, Frank
中科院分区：
文献类型：
--
作者：
Olschewski, Mark;Gustus, Rene;Endres, Frank
本实验研究显示了锂与1-辛基-3-甲基咪唑双（三氟甲基磺酰基）酰胺（[OMIm]Tf2N）的相互作用。为此，锂和[OMIm]Tf2N薄膜相继气相沉积在铜衬底上，并通过x射线光电子能谱（XPS）和紫外光电子能谱（UPS）进行分析。当[OMIm]Tf2N在薄锂膜上蒸发时，XPS光谱的化学位移分析显示了多种反应产物，如LiF， Li2O和LixCHy，这揭示了IL对锂的不稳定性。讨论了时间分辨XPS光谱，以区分阳离子反应和光束损伤效应。在第二步中，锂沉积在[OMIm]Tf2N层上。XPS光谱与前一步的结果一致，但在[OMIm]阳离子方面存在一些差异。在第三步[OMIm]中，Tf2N沉积在钝化的锂层上。XPS结果显示[Tf2N]（-）阴离子几乎未受影响，[OMIm]（+）阳离子部分分解。有趣的是，与[C(4)C(1)Pyrr]Tf2N（1-丁基-1-甲基吡咯烷二[三氟甲基磺酰]酰胺）和锂的相互作用相比，阳离子反应显示出相似之处。
In this experimental investigation the interaction of lithium with 1-octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([OMIm]Tf2N) is shown. For this purpose thin films of lithium and [OMIm]Tf2N were successively vapor deposited on a copper substrate and analyzed by X-ray Photoelectron Spectroscopy (XPS) as well as by Ultraviolet Photoelectron Spectroscopy (UPS). When [OMIm]Tf2N is evaporated on top of a thin lithium film a chemical shift analysis of XPS spectra shows a variety of reaction products like LiF, Li2O and LixCHy which reveals the instability of the IL against lithium. Time resolved XPS spectra were discussed to distinguish cation reactions from beam damage effects. In a second step lithium is deposited on a [OMIm]Tf2N layer. The XPS spectra are in agreement with the results of the previous step, but show some differences concerning the [OMIm] cation. In a third step [OMIm]Tf2N has been deposited on a passivated lithium layer. XPS results show nearly unaffected [Tf2N](-) anions and partially decomposed [OMIm](+) cations. Interestingly the cation reactions show similarities when compared to the interaction of [C(4)C(1)Pyrr]Tf2N (1-butyl-1-methylpyrrolidinium bis[trifluoromethylsulfonyl]amide) and lithium.