使用X射线光谱学和计算,揭示酸离子液体的复杂物种化
J M Seymour1, E Gousseva1, F K Towers Tompkins1
1Department of Chemistry, University of Reading, Reading, UK. k.r.j.lovelock@reading.ac.uk.
Faraday discussions
|July 26, 2024
概括
这项研究揭示了使用X射线光谱和DFT计算在离子液体中的酸离子物种化. 它证实了特定离子的存在,并预测了各种分子分数的物种化.
科学领域:
- 材料化学 材料化学
- 物理化学 物理化学
- 频谱学是一种光谱学.
背景情况:
- 离子液体 (ILs) 是具有独特性质的多功能溶剂.
- 了解金属离子,如酸,在IL中的物种化对于它们的应用至关重要.
- 之前的研究往往缺乏在ILs中确定的物种识别.
研究的目的:
- 为了研究在离子液体中酸离子的物种化.
- 将实验光谱与理论计算相结合,以准确地确定特异性.
- 为了预测化离子在一系列化分子分数上的物种化.
主要方法:
- 液相X射线光电子光谱 (XPS) 和 Zn 1s X射线吸收近边结构 (XANES) 光谱.
- 密度函数理论 (DFT) 的计算,包括溶解模型 (SMD) 和气相计算.
- 分析光谱形状,宽度和实验和计算光谱之间的视觉匹配.
主要成果:
- 在所有研究的化分子分数中确定了2-酸离子.
- 特定的分子分数显示只有一个酸离子的存在,没有观察到平衡.
- 发现酸和酸离子的物种化在相当的分子分数下是一致的.
结论:
- 先进的光谱技术和DFT计算的结合,为酸离子的特异化提供了很高的信心.
- 对酸离子物种化的预测是以0.67.7的摩尔分数进行的.
- 建议谨慎不仅仅依赖DFT的总能量差异来进行种类判断.
相关概念视频
Mass Spectrometry: Alkyl Halide Fragmentation
1.0K
Chlorine isotopes exist as 35Cl and 37Cl in a 3:1 ratio, while bromine isotopes exist as 79Br and 81Br in a 1:1 ratio. The mass spectrum of alkyl halides typically produces two distinct molecular ion peaks, the molecular ion peak, [M], and the molecular ion plus two, [M + 2] peak. The relative heights of these two peaks are proportional to the isotopic abundance ratios of the halide. For example, 2‐chloropropane and 1‐bromopropane display two peaks with relative peak heights in a 3:1 and...
1.0K
Crystal Field Theory - Tetrahedral and Square Planar Complexes
41.9K
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
41.9K
Precipitation of Ions
27.9K
Predicting Precipitation
The equation that describes the equilibrium between solid calcium carbonate and its solvated ions is:
The equation that describes the equilibrium between solid calcium carbonate and its solvated ions is:
27.9K
Qualitative Analysis
22.1K
For solutions containing mixtures of different cations, the identity of each cation can be determined by qualitative analysis. This technique involves a series of selective precipitations with different chemical reagents, each reaction producing a characteristic precipitate for a specific group of cations. Metal ions within a group are further separated by varying the pH, heating the mixture to redissolve a precipitate, or adding other reagents to form complex ions.
For instance, group IV...
For instance, group IV...
22.1K
Extraction: Advanced Methods
436
Metal ions can be separated from one another by complexation with organic ligands–the chelating agent– to form uncharged chelates. Here, the chelating agent must contain hydrophobic groups and behave as a weak acid, losing a proton to bind with the metal. Since most organic ligands used in this process are insoluble or undergo oxidation in the aqueous phase, the chelating agent is initially added to the organic phase and extracted into the aqueous phase. The metal-ligand complex is...
436
Formation of Complex Ions
23.6K
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
23.6K


