Anorganische Chemie I-Festkörperchemie und Materialien, Ruhr-Universität Bochum, D-44780 Bochum, Germany.
Phys Chem Chem Phys. 2010 Jul 14;12(26):7056-63. doi: 10.1039/b925606g. Epub 2010 May 18.
The concept of optical basicities initially developed by Duffy for solid oxides was successfully transferred to low melting salts such as ionic liquids (ILs). Several ionic liquids (ILs) were doped with Mn(NTf(2))(2) (NTf(2) = bis(trifluoromethanesulfonyl)imide) as a probe to investigate the IL anion basicity by means of UV-Vis spectroscopy. The (6)A(1)-->(4)A, (4)E(G) transition band of Mn(2+) is influenced by the electron donor properties, i.e., Lewis basicity, of the coordinating ligands but remains-to the first order-independent from the ligand field. The change in the optical spectra for various Mn(NTf(2))(2) doped ILs is predominantly dependent on the anion. No significant influence of the IL cation could be detected for the ILs under investigation except for functionalized cations with electron donor functionalities. This allows ranking the ILs with respect to their (optical) anion basicities. For the most prominent IL anions an order of BF(4)(-) < ClO(4)(-) < NTf(2)(-) approximately MeSO(3)(-) < NO(3)(-) < DCA(-) < TFA(-) < EtSO(4)(-) approximately OTos(-) < Cl(-) < Br(-) with respect to rising optical basicity could be established.
最初由 Duffy 为固体氧化物开发的光学碱度概念成功地转移到低熔点盐，如离子液体（ILs）。几种离子液体（ILs）被掺杂了 Mn(NTf(2))(2)（NTf(2)=双（三氟甲烷磺酰基）亚胺）作为探针，通过紫外可见光谱法研究 IL 阴离子的碱度。Mn(2+)的 (6)A(1)-->(4)A、(4)E(G)跃迁带受配位配体的电子给体性质（即路易斯碱度）的影响，但在第一级上与配体场无关。各种 Mn(NTf(2))(2)掺杂 IL 的光学光谱的变化主要取决于阴离子。除了具有电子给体官能团的功能化阳离子外，对于所研究的 IL 阳离子，没有检测到 IL 阳离子的显著影响。这允许根据它们的（光学）阴离子碱度对 IL 进行排序。对于最突出的 IL 阴离子，可以建立一个顺序 BF(4)(-) < ClO(4)(-) < NTf(2)(-) approximately MeSO(3)(-) < NO(3)(-) < DCA(-) < TFA(-) < EtSO(4)(-) approximately OTos(-) < Cl(-) < Br(-)，随着光学碱度的升高。
