在电化学活性核修饰的扩展型氨酸体的拓多样性
Hosahalli S Udaya1, Vishnu Mishra1, Tullimilli Y Gopalakrishna1
1Department of Chemistry, Indian Institute of Science Education and Research, Pune, Maharashtra 411008, India.
Organic letters
|September 5, 2023
概括
基于烯的扩展烯酸随着添加更多的烯单位而扭曲. 八氨酸在溶液中表现出形状变化,但在固态中是刚性的,更大的系统表现出独特的电子性质.
科学领域:
- 有机化学 有机化学
- 超分子化学 超分子化学
- 材料科学 材料科学 材料科学
背景情况:
- 扩展型氨酸是具有可调节电子和光物理性质的宏环化合物.
- 提奥芬的结合影响了这些宏观循环的形状灵活性和电子结构.
研究的目的:
- 为了研究基于烯的扩大烯酸的结构变化,增加了越来越多的烯酸单位.
- 描述较大的硫基氨酸的电子性质和氧化还原行为.
主要方法:
- 合成和表征基于蒂奥芬的扩展型氨酸.
- 可变温度NMR光谱学用于研究形状动力学.
- 谱电化学测量以探测氧化还原特性.
主要成果:
- 观察到从平面到扭曲形状的过渡随着提奥芬单位的增加.
- 八素 (40π电子) 在溶液中表现出取决于温度的形状交换,与其刚性固态结构不同.
- 60π-dodecaphyrin和70π-tetradecaphyrin表现出易于,可逆的两电子氧化与不稳定的激素阴离子中间体.
结论:
- 构造灵活性是基于硫的扩展型氨酸的关键特征,受π电子数量和结合的影响.
- 这些系统为需要动态分子架构和可调整的氧化还原特性的应用提供了潜力.
相关概念视频
Thermal and Photochemical Electrocyclic Reactions: Overview
2.4K
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.
2.4K
Photochemical Electrocyclic Reactions: Stereochemistry
1.9K
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
1.9K
Regioselectivity of Electrophilic Additions-Peroxide Effect
8.7K
In the presence of organic peroxides, the addition of hydrogen bromide to an alkene yields the isomer that is not predicted by Markovnikov’s rule. For example, the addition of hydrogen bromide to 2-methylpropene in the presence of peroxides gives 1-bromo-2-methylpropane. This addition reaction proceeds via a free radical mechanism, which reverses the regioselectivity. The free radical reaction mechanism involves three stages: initiation, propagation, and termination.
8.7K
Aromatic Hydrocarbon Cations: Structural Overview
2.8K
Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group...
Removing one hydrogen from the intervening CH2 group...
2.8K
Electrochemistry: Overview
2.1K
Electrochemistry is the branch of chemistry that studies the relationship between electrical quantities and chemical reactions, particularly oxidation and reduction. Oxidation is the loss of electrons from a substance, whereas reduction refers to the gain of electrons. A substance with a strong electron affinity is called an oxidizing agent (oxidant), and a reducing agent (reductant) is a species that donates electrons. Oxidation and reduction processes are pivotal to electrochemical reactions,...
2.1K
Aromatic Hydrocarbon Anions: Structural Overview
2.8K
Neutral hydrocarbons like cyclopentadiene with an odd number of carbon atoms and one intervening CH2 group in the ring are not aromatic. Cyclopentadiene with 4 π electrons does not satisfy the 4n + 2 π electron rule. Additionally, the intervening CH2 group is sp3 hybridized and lacks a vacant p orbital, thereby interrupting the overlap of p orbitals in a continuous manner and preventing the delocalization of π electrons throughout the ring.
Due to the absence of continuous...
Due to the absence of continuous...
2.8K


![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)