Men Shuang, Sun Yusheng, Licence Peter, Qu Jun
School of Materials Science and Engineering, Shenyang Ligong University, Shenyang, 110159, P. R. China.
Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, 37830, USA.
Phys Chem Chem Phys. 2022 Oct 19;24(40):24845-24851. doi: 10.1039/d2cp03674f.
In this study, X-ray photoelectron spectroscopy is used to analyse nine morpholinium ionic liquids, which are of great interest in green chemistry because of their low toxicity and high recyclability. The effect of the alkyl chain length on the aliphatic C 1s binding energy and the impact of the anion basicity on the cationic N 1s and O 1s binding energies are investigated. It is concluded that by changing the basicity of the anion, there is a more notable change in the electronic environment of the oxygen centre. The impact of a long alkyl side substituent on the cation-anion interactions is also discussed. It is observed that there is an intense charge shielding effect of the alkyl side chain in the cases of octyl and dodecyl substituents, which is reflected in the reduced Br 3d binding energy.
在本研究中，采用X射线光电子能谱对九种吗啉鎓离子液体进行了分析，这些离子液体因其低毒性和高可回收性而在绿色化学领域备受关注。研究了烷基链长度对脂肪族C 1s结合能的影响以及阴离子碱性对阳离子N 1s和O 1s结合能的影响。得出的结论是，通过改变阴离子的碱性，氧中心的电子环境会发生更显著的变化。还讨论了长烷基侧链取代基对阳离子-阴离子相互作用的影响。观察到，在辛基和十二烷基取代的情况下，烷基侧链存在强烈的电荷屏蔽效应，这反映在Br 3d结合能降低上。
