捕获具有异常反应性的三角双 (IV) 氧物种
Guilherme L Tripodi1,2, Jindou Yang3, Ying Xing3,4
1Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, Nijmegen 6525 AJ, The Netherlands.
Journal of the American Chemical Society
|November 25, 2025
概括
这项研究引入了一种高反应性 (IV) 氧复合物用于C-H化,通过独特的三角形双金字塔几何形态克服了"氧墙". 这一发现提升了氧化化学和金属氧复合物的反应性.
科学领域:
- 协调化学
- 氧化催化
- 生物有机化学
背景情况:
- 金属氧复合物 (MO) 在氧化反应中对激活C-H键至关重要.
- 高价值铁 (IV) 氧物质挑战了已有的氧化强度概念.
- (IV) 氧物种正在成为有前途的替代品, 但面临着"氧墙"等挑战.
研究的目的:
- 通过Me3NTB配体合成和表征一种新的 (IV) 氧复合物.
- 在C-H化反应中研究这种复合物的反应性.
- 探索控制高价值氧反应性的电子和结构因素.
主要方法:
- 一个前体的合成: [{Me3NTB}Co{MeCN}{OTf}2].
- 通过与PhIO反应生成高价值的氧中间体.
- 使用流化学加上电喷离离子质谱 (FC-ESI-MS) 和红外光解离谱 (IRPD) 的表征.
主要成果:
- 一个短暂的 (IV) -oxo物种,Me3NTB) CoIV (O) (OTf) +,产生并被检测出来.
- 这种复合体呈现出三角形双金字塔形状,具有完全的Co-O双键 (在812 cm-1处的νCoO).
- 尽管四旋状态,但该复合物对C-H化具有高度反应性,通过几何扭曲和双重状态的稳定.
结论:
- 合成的 (IV) 氧复合体在C-H化中表现出显著的反应性,挑战了"氧墙"的限制.
- 三角二形几何在稳定反应中间体和促进反应途径方面发挥着关键作用.
- 这项工作扩大了晚期过渡金属氧化化学的范围,以挑战氧化反应.
相关概念视频
03:02Colors and Magnetism
13.9K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
13.9K
02:42Valence Bond Theory
11.1K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
11.1K
01:33Radical Reactivity: Intramolecular vs Intermolecular
2.1K
Radical reactions can occur either intermolecularly or intramolecularly. In an intermolecular radical reaction, a nucleophilic radical adds to an electrophilic alkene or vice versa. In such reactions, the radical and generally the alkene, which is also called the radical trap, are two different molecules. Additionally, for such intermolecular reactions to occur, the radical trap must be active, present in an excess concentration, and the radical starting material must have a weak...
2.1K
02:34Structural Isomerism
21.4K
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...
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...
21.4K
01:16Radical Reactivity: Nucleophilic Radicals
2.6K
Radicals adjacent to electron-donating groups are called nucleophilic radicals. These radicals readily react with electrophilic alkenes. The SOMO–LUMO interactions are the driving force for the reaction, where the high-energy SOMO of the electron-rich, nucleophilic radicals interacts with the low-energy LUMO of the electron-deficient, electrophilic alkenes. Such SOMO–LUMO interactions are the basis of reactive radical traps, affecting the selectivity in radical reactions. For...
2.6K
02:51Metal-Ligand Bonds
23.9K
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...
23.9K