由于协调数的变化,Cu(aq) +/Cu(aq) 2+氧化还原反应表现出强烈的非线性溶剂反应
1Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom. jb376@cam.ac.uk
Journal of the American Chemical Society
|November 27, 2008
概括
这项研究揭示了铜在水中具有5倍的协调,与假定的八面体结构不同. 这种结构差异解释了铜 (I) 和铜 (II) 离子之间的电子转移速度缓慢.
科学领域:
- 无机化学 无机化学 有机化学
- 计算化学计算化学
- 物理化学 物理化学
背景情况:
- 在水溶液中的铜离子的协调环境对于理解它们的反应性至关重要.
- 以前的研究通常假定Cu的八面体协调是(2+),但最近的实验表明不是这样.
研究的目的:
- 用模拟来描述铜 (I) /铜 (II) 氧化还原对的结构和能量.
- 研究协调变化对电子转移理论,特别是马库斯理论的影响.
主要方法:
- 使用了广泛的波恩-奥本海默分子动力学模拟.
- 对协调数,带结合和糖尿病自由能量曲线的分析.
主要成果:
- 在水溶液中的Cu2+) 采用5倍协调,而不是八面体.
- (((+) 形成一个线性二水化合物结构.
- 协调数的不对称变化导致非抛物线自由能量曲线和Cu(+) 与Cu(2+) 之间的重组自由能量1.0 eV的差异.
结论:
- 模拟的结构和能量支持对铜离子协调的实验发现.
- 计算的重组自由能量解释了实验观察到的Cu(+) 和Cu(2+) 之间的缓慢电子自我交换速率.
- 由于协调变化,从马库斯理论的线性响应假设的偏差是显著的.
更多相关视频
11:04Ion Mobility-Mass Spectrometry Techniques for Determining the Structure and Mechanisms of Metal Ion Recognition and Redox Activity of Metal Binding Oligopeptides
Published on: September 7, 2019
06:01EPR Monitored Redox Titration of the Cofactors of Saccharomyces cerevisiae Nar1
Published on: November 26, 2014
相关概念视频
Leveling Effect
In acid-base chemistry, the leveling effect refers to the limitation imposed by the solvent on the strength of acids and bases in solution. When a base stronger than the solvent's conjugate base is used, it deprotonates the solvent until the base is entirely consumed, making it ineffective against weaker acids. Conversely, an acid stronger than the solvent's conjugate acid protonates the solvent until the acid is depleted, rendering it ineffective against weaker bases. Essentially, the solvent...
Complexation Equilibria: Overview
Complexation reactions take place when dative or coordinate covalent bonds form between metal ions and ligands. The compounds formed in these reactions are called coordination compounds. The number of bonds formed between the metal ion and the ligands is called its coordination number. Generally, most metal ions in an aqueous solution are solvated by water molecules and thus exist as aqua complexes.
The equilibrium constant of the complexation reaction is represented as the formation constant...
The equilibrium constant of the complexation reaction is represented as the formation constant...
Leveling Effect and Non-Aqueous Acid-Base Solutions
This lesson defines the leveling effect in acidic and basic solutions and its role in aqueous and non-aqueous solutions. It is essential to understand the competing nature of various species in a chemical system.
The Leveling Effect of a Solvent
A generic acid (HA) reacts with the generic base (B-) to yield the corresponding conjugate base (A-) and conjugate acid (HB):
The Leveling Effect of a Solvent
A generic acid (HA) reacts with the generic base (B-) to yield the corresponding conjugate base (A-) and conjugate acid (HB):
Titration in Nonaqueous Solvents
Most acid-base titrations are performed in an aqueous medium. In aqueous titrations, water competes with weaker acids or bases for proton donation or acceptance, leading to ambiguous endpoints in the titration curve. Water also affects the partial ionization of weak acids or bases. For example, water accepts a proton from acetic acid to form hydronium and acetate ions. The hydronium ion formed is a stronger acid than acetic acid, and the acetate ion is a stronger base than water. As a result,...
Chemical Reactions in Aqueous Solutions
Chemical substances interact in many different ways. Certain chemical reactions exhibit common patterns of reactivity. Due to the vast number of chemical reactions, it becomes necessary to classify them based on the observed patterns of interaction.
Redox Equilibria: Overview
A reduction-oxidation reaction is commonly called a redox reaction. In a redox reaction, electrons are transferred from one species to another rather than being shared between or among atoms. The reducing agent or reductant is the species that loses electrons and gets oxidized in the process. The species that gains electrons and gets reduced in the process is the oxidizing agent or oxidant. Redox reactions are represented as two separate equations called half-reactions, where one equation...
