高氧物种的快速和氧原子转移
Teresa Corona1, Apparao Draksharapu2, Sandeep K Padamati2
1Grup de Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT), Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Facultat de Ciències, Universitat de Girona, C/ Maria Aurèlia Capmany 69 , E17003 Girona, Catalonia, Spain.
Journal of the American Chemical Society
|September 7, 2016
概括
研究人员开发了一种新的催化剂, 活性物种,一个-低化合物,挑战了"Oxo Wall"概念,尽管它处于正式的氧化状态,但仍具有反应性.
科学领域:
- 协调化学
- 催化剂
- 氧化化学
背景情况:
- 末端高价值金属氧物种是酶和合成氧化催化中的关键中间体.
- 晚期过渡金属 (Co,Ni,Cu) 的表征很少,部分原因是"Oxo Wall"概念预测四角环境中的不稳定性.
- 了解这些物种对于设计高效的合成氧化催化剂至关重要.
研究的目的:
- 在C-H键功能化中研究 (II) 复合物的催化活性.
- 用酸盐作为氧化剂识别和描述在催化过程中形成的活性氧物种.
- 探索这些发现对"Oxo Wall"概念和晚期过渡金属催化的影响.
主要方法:
- 使用 (II) 复合物和酸盐的催化氧化和化C-H键.
- 低温光谱研究 (UV-vis,共振拉曼,EPR) 和质谱 (ESI-MS) 捕获和分析反应性中间体.
- 用于结构和电子表征的X射线吸收光谱 (XAS) 和密度功能理论 (DFT) 计算.
主要成果:
- (II) 复合物有效催化了化和氧化反应.
- 一种低酸盐物种 (3) 被确定为关键的中间物质,尽管有"Oxo Wall"的预测,但仍表现出反应性.
- 谱学和计算分析表明,物种3最好被描述为具有非定位电子密度的Ni (III) 复合体.
结论:
- 这项研究证明了反应性-酸盐物种的成功生成和表征,挑战了"Oxo Wall"概念.
- 已识别的Ni (III) 种直接参与C-H键的催化氧化和化,包括强有力的异质键.
- 这项工作扩大了对晚期过渡金属高价值物种及其在氧化化学中的催化潜力的理解.
更多相关视频
相关概念视频
Catalysis
31.7K
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
31.7K
Radical Formation: Homolysis
4.6K
A bond is formed between two atoms by sharing two electrons. When this bond is broken by supplying sufficient energy, either two electrons can be taken up by one atom forming ions by the cleavage called heterolysis, or the two electrons are shared by two atoms, with one each creating radicals by the cleavage called homolysis.
4.6K
Reduction of Alkenes: Catalytic Hydrogenation
14.7K
Alkenes undergo reduction by the addition of molecular hydrogen to give alkanes. Because the process generally occurs in the presence of a transition-metal catalyst, the reaction is called catalytic hydrogenation.
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
14.7K
Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
7.8K
Diols are compounds with two hydroxyl groups. In addition to syn dihydroxylation, diols can also be synthesized through the process of anti dihydroxylation. The process involves treating an alkene with a peroxycarboxylic acid to form an epoxide. Epoxides are highly strained three-membered rings with oxygen and two carbons occupying the corners of an equilateral triangle. This step is followed by ring-opening of the epoxide in the presence of an aqueous acid to give a trans diol.
7.8K
Oxidative Cleavage of Alkenes: Ozonolysis
13.4K
In ozonolysis, ozone is used to cleave a carbon–carbon double bond to form aldehydes and ketones, or carboxylic acids, depending on the work-up.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.
13.4K
Hydroboration-Oxidation of Alkenes
12.0K
In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
12.0K

![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)
