在共价有机框架中π-链接的影响 - - 催化光采集提奥化反应
Ayan Jati1, Durba Chanda1, Biplab Maji1
1Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, India.
ACS applied materials & interfaces
|February 24, 2025
概括
为了光催化,合成了两种基于烯的共价有机框架 (COF). 与烯酸相关的COF在铁化中表现出优异的性能,证明了广泛的适用性和可回收性.
科学领域:
- 材料科学 材料科学 材料科学
- 有机化学 有机化学
- 光催化作用的光催化
背景情况:
- 联有机框架 (COF) 是异质光催化剂的有希望的材料.
- 基于Pyrene的2D COF与π结合网络提供了独特的电子特性.
研究的目的:
- 合成和比较两种类似的以烯为基础的COF,具有不同的链接 (CN与CC).
- 为了研究链接类型对可见光介导的化中光催化活性的影响.
主要方法:
- 使用希夫基和诺维纳格尔凝结反应,分别合成因胺结合和烯结合的COF.
- 使用可见光介导的硫乙化作为模型反应来评估光催化性能.
主要成果:
- 与因胺结合的COF相比,烯结合的COF显示出更高的光催化活性.
- 该协议实现了高达95%的铁产量,具有广泛的基质范围,包括多种碳酸和药物分子.
- 光催化剂被证明是强大的,可以在多个循环中重复使用,而不会失去活动.
结论:
- 基于烯的COF中的链接类型显著影响了它们的光催化效率.
- 开发的COF光催化剂通过减少光催化循环实现了高效和可回收的硫合成.
- 碳化合物骨干为交叉合反应提供了增强的电子转移.
![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)
相关概念视频
01:26Photochemical Electrocyclic Reactions: Stereochemistry
1.8K
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
1.8K
01:17Thermal Electrocyclic Reactions: Stereochemistry
2.0K
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
2.0K
01:12Cycloaddition Reactions: MO Requirements for Photochemical Activation
2.0K
Some cycloaddition reactions are activated by heat, while others are initiated by light. For example, a [2 + 2] cycloaddition between two ethylene molecules occurs only in the presence of light. It is photochemically allowed but thermally forbidden.
2.0K
01:29Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
4.6K
Diels–Alder reactions between cyclic dienes locked in an s-cis configuration and dienophiles yield bridged bicyclic products.
4.6K
01:28Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
3.7K
The Diels–Alder reaction is one of the robust methods for synthesizing unsaturated six-membered rings. The reaction involves a concerted cyclic movement of six π electrons: four π electrons from the diene and two π electrons from the dienophile.
3.7K
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
2.3K
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
2.3K