在过渡的-基团中添加C-H键,形成母基复合物
Kimberly C Mullane1, Ho Ryu2,3, Thibault Cheisson1
1Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia Pennsylvania 19104 , United States.
Journal of the American Chemical Society
|July 28, 2018
概括
研究人员使用特定的配体框架合成了+3和+4氧化状态的新复合物. 通过分子内C-H激活形成了新的化物复合物,揭示了受减剂影响的独特反应途径.
科学领域:
- 有机金属化学
- 无机化学
- 化学
背景情况:
- 复合物在各种化学应用中至关重要.
- 了解不同氧化状态下的的反应性对于开发新的催化和材料性质至关重要.
- 新型化合物的合成和表征为基本化学结合和反应机制提供了洞察力.
研究的目的:
- 在+3和+4氧化状态中合成和表征新的复合物.
- 调查化物中间体的反应性.
- 探讨模复合物的形成和阐明反应途径.
主要方法:
- 复合物的合成与阴离子PN联体框架.
- 使用光谱和分析技术对新化物和亚化物复合物的表征.
- 减少酸复合物的激活,以产生短暂的酸物种.
- 计算研究 (DFT) 用于计算反应能量概况.
主要成果:
- 成功合成 (III) 和 (IV) 复合物,包括 (PN) 2UIII I和 (PN) 2UIV Cl2.
- (IV) 化物复合物的形成 (PN) 2UIV (N3) 2.
- 通过短暂的化部分的分子内C-H激活产生一种罕见的母体imido复合体,[K(THF) 3[(PN) UIV (NH) [iPr2P(C6H3Me) N(C6H2Me2CH2].
- 计算分析表明减少剂不利于C-H插入,导致替代反应途径.
结论:
- 在+3和+4氧化状态下有效稳定.
- 已经确定了一种新的化物复合物的形成途径,涉及分子内C-H激活.
- 与之前研究的化系统相比,减少剂的存在显著改变了反应机制,防止了C-H的插入,并促进了不同的结果.
相关概念视频
03:45Formation of Complex Ions
26.2K
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...
26.2K
00:47Radical Formation: Addition
2.3K
Radicals can be formed by adding a radical to a spin-paired molecule. This is typically observed with unsaturated species, where the addition of a radical across the π bond leads to the production of a new radical by dissolving the π bond. For example, the addition of a Br radical to an alkene yields a carbon-centered radical.
Similar to charge conservation in chemical reactions, spin conservation is implicit for radical reactions. Accordingly, the product formed must possess an...
Similar to charge conservation in chemical reactions, spin conservation is implicit for radical reactions. Accordingly, the product formed must possess an...
2.3K
02:43Peptide Bonds
83.2K
A peptide bond covalently attaches amino acids through a dehydration reaction. One amino acid's carboxyl group and another amino acid's amino group combine, releasing a water molecule. The resulting bond is the peptide bond. The products that such linkages form are peptides. As more amino acids join this growing chain, the resulting chain is a polypeptide. Each polypeptide has a free amino group at one end. This end has the N-terminal, or the amino-terminal, and the other end has a free...
83.2K
02:49Bond Energies and Bond Lengths
31.5K
Stable molecules exist because covalent bonds hold the atoms together. The strength of a covalent bond is measured by the energy required to break it, that is, the energy necessary to separate the bonded atoms. Separating any pair of bonded atoms requires energy — the stronger a bond, the greater the energy required to break it.
31.5K
01:10C–C Bond Formation: Aldol Condensation Overview
16.3K
Aldol condensation is an important route in synthetic organic chemistry used to generate a new carbon–carbon bond under basic or acidic conditions. The aldol condensation reaction presented in Figure 1 constitutes an aldol addition reaction followed by the dehydration process.
16.3K
02:51Metal-Ligand Bonds
24.4K
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...
24.4K