深入的XANES和EXAFS在二甲基硫氧化物溶液中的Ag+离子协调的表征
Alessandro Tofoni1, Matteo Busato1, Andrea Colella1
1Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza", P.le A. Moro 5, I-00185 Rome, Italy.
The journal of physical chemistry. B
|August 12, 2024
概括
射线吸收光谱揭示了二甲基硫氧化物 (DMSO) 中银离子的协调结构. 一个四面体[Ag(DMSO) 4+复合体被证实,澄清银.
科学领域:
- 协调化学 协调化学
- 材料科学 材料科学 材料科学
- 频谱学是一种光谱学.
背景情况:
- 了解溶液中的金属离子的协调结构对于各种化学应用至关重要.
- 像二甲基硫氧化物 (DMSO) 这样的协调溶剂中的银(I) 离子具有复杂的结构行为.
- 之前的研究已经提供了一些见解,但缺乏明确的结构阐释.
研究的目的:
- 为了确定DMSO溶液中的Ag+离子的精确协调结构.
- 阐明DMSO中由Ag+形成的四重协调复合物的几何.
- 使用X射线吸收光谱技术进行详细的结构分析.
主要方法:
- 使用X射线吸收近边结构 (XANES) 光谱学.
- 扩展的X射线吸收细结构 (EXAFS) 光谱学与XANES一起使用.
- 对XANES区域进行了定量分析,以确定复杂几何形状.
主要成果:
- 在EXAFS分析中,第一个协调外中的Ag-O键距离为2.31(3) Å,大约有4.1(5) 氧原子.
- 对XANES数据的分析证实了四个协调的银复合物的形成.
- 该研究明确确定了一个正规的四面体[Ag(DMSO) 4+复合体.
结论:
- EXAFS和XANES的组合提供了一种强大的方法来表征溶液中的金属离子协调.
- 一个正规的四面体[Ag(DMSO) 4+复合物在银三酸盐的DMSO溶液中最终形成.
- 这一发现澄清了DMSO中Ag+的协调环境,有助于理解溶液化学.
相关概念视频
Formation of Complex Ions
23.5K
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...
23.5K
Preparation and Reactions of Sulfides
4.8K
Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.
4.8K
Masking and Demasking Agents
2.4K
EDTA titrations may necessitate masking and demasking agents to temporarily protect a particular metal ion in a mixture from the EDTA reaction. These agents facilitate the sequential analysis of the metal ions by forming stable complexes with some—but not all—metal ions during certain steps.
There are many masking agents, such as cyanide, fluoride, triethanolamine, thiourea, and 2,3-bis(sulfanyl)propan-1-ol (formerly 2,3-dimercapto-1-propanol), with the masking agent chosen based on...
There are many masking agents, such as cyanide, fluoride, triethanolamine, thiourea, and 2,3-bis(sulfanyl)propan-1-ol (formerly 2,3-dimercapto-1-propanol), with the masking agent chosen based on...
2.4K
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
EDTA: Auxiliary Complexing Reagents
572
EDTA titrations are usually carried out in highly basic conditions, where the fully deprotonated form of EDTA, Y4−, actively complexes with the free metal ions in the solution. Several metal ions precipitate as hydrous oxide (hydroxides, oxides, or oxyhydroxides) under these conditions, lowering the concentration of free metal ions in the solution. For this reason, auxiliary complexing agents or ligands such as ammonia, tartrate, citrate, or triethanolamine are used in EDTA titrations to...
572
Metal-Ligand Bonds
20.7K
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
20.7K


