复合物:结构,电子和机械的比较与交换和C-H激活过程相关的结构,电子和机械
J Christopher Thomas1, Jonas C Peters
1Division of Chemistry and Chemical Engineering, Arnold and Mabel Beckman Laboratories of Chemical Synthesis, California Institute of Technology, Pasadena, California 91125, USA.
Journal of the American Chemical Society
|July 17, 2003
概括
这项研究探讨了具有不同连接体的复合体,揭示了不同的反应机制和C-H键激活途径. 中性复合体表现出较快的C-H激活和独特的化过程,相比子对应物.
科学领域:
- 有机金属化学 有机金属化学
- 协调化学 协调化学
- 催化剂是一种催化剂.
背景情况:
- 复合物与双酸联体在催化和材料科学中至关重要.
- 了解连接体电子效应和反应机制是设计高效催化剂的关键.
- 金属复合体中的电荷差异化可以显著改变反应性和机械路径.
研究的目的:
- 通过使用新型素连接物合成和表征带电差异化的复合物.
- 为了研究不同双酸联体对中心的电子影响.
- 阐明这些系统中THF自我交换和CH键激活的机制.
主要方法:
- 复合物的合成,其中包括[Ph(2) BP(2) ],[Ph(2) SiP(2) ]和dppp配体.
- 使用和模型复合物的比较研究,以评估联体电子效应.
- 动力学研究 (温度和溶剂依赖性) 和NMR光谱 (包括同位素标记) 以确定反应机制.
主要成果:
- 与[Ph(2) SiP(2) ]和dppp相比,阳离子[Ph(2) BP(2) ]连接物赋予金属中心更大的电子丰富性.
- 中性和阴离子复合体表现出明显的THF自我交换机制 (配体辅助与协同).
- 中性白金复合物与的C-H键激活速度比阴离子对应物更快,具有不同的动态同位素效应和副产品分布.
- 观察到涉及[Ph(2) BP(2) ]联体的可逆联体金属化,导致(IV) 中间体.
结论:
- 双酸联体的电子和硬质性质对复合物的反应性有深远的影响.
- 电荷分化在决定溶剂交换和C-H激活的机械路径方面发挥着至关重要的作用.
- 这项研究提供了对溶液化学的详细机制理解,用于这些和系统.
相关概念视频
02:34Structural Isomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
02:16Resonance and Hybrid Structures
According to the theory of resonance, if two or more Lewis structures with the same arrangement of atoms can be written for a molecule, ion, or radical, the actual distribution of electrons is an average of that shown by the various Lewis structures.
Resonance Structures and Resonance Hybrids
The Lewis structure of a nitrite anion (NO2−) may actually be drawn in two different ways, distinguished by the locations of the N–O and N=O bonds.
Resonance Structures and Resonance Hybrids
The Lewis structure of a nitrite anion (NO2−) may actually be drawn in two different ways, distinguished by the locations of the N–O and N=O bonds.
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01:17Thermal Electrocyclic Reactions: Stereochemistry
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Selection Rules: Photochemical Activation
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