Resorc[4]arenes的复合物:光谱,运动和理论研究
Bruno Botta1, Ilaria D'Acquarica, Giuliano Delle Monache
1Dipartimento di Studi di Chimica e Tecnologia delle Sostanze Biologicamente Attive, Università La Sapienza, P.le A. Moro 5, 00185 Roma, Italy. bruno.botta@uniroma1.it
Journal of the American Chemical Society
|August 21, 2007
概括
树脂[4]乙烯乙烯形成稳定,有色的 (NO+) 复合物,在添加甲醇或水后会逆转. 光谱分析显示,NO+根据resorcarene结构和侧链不同地相互作用.
科学领域:
- 超分子化学 超分子化学
- 有机化学 有机化学
- 频谱学是一种光谱学.
背景情况:
- Resorc[4]arenes是具有篮状腔的宏环化合物.
- 酸 (NO+) 是一种有反应性的阴离子,在合成和传感方面具有应用.
- 了解宏观循环中的客宿主相互作用是设计新功能材料的关键.
研究的目的:
- 为了研究 (NO+) 与resorc[4]arene八甲基乙的复合.
- 阐明影响NO+结合的结构和电子因素.
- 探索这些复合物的可逆性和光谱性质.
主要方法:
- 合成了resorc[4]arene 八甲基乙烯 (1-3).
- 使用甲酸中的NOBF4盐进行复杂化研究.
- 紫外线可见光谱仪用于动力和光谱分析.
- 1H NMR光谱和分子建模.
主要成果:
- 形成了稳定,深色的1:1 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- 复杂性是可逆的,在甲醇或水中解离.
- Resorc[4]arenes 1和2显示了NO+在腔内外的相互作用,具有不同的光谱图案 (HEB和LEB).
- 在resorc[4]arene 2中,乙碳基组指导了外部的NO+结合,而在3,它们与电荷转移相互作用一起参与NO+捕获.
结论:
- Resorc[4]arenes可以与离子形成稳定的复合物.
- Resorc[4]arenes的形状和侧链功能决定了NO+相互作用的模式.
- 这些复合体表现出可逆行为和独特的光谱特征,表明在传感或分离方面的潜在应用.
相关概念视频
Resonance and Hybrid Structures
According to the theory of resonance, if two or more Lewis structures with the same arrangement of atoms can be written for a molecule, ion, or radical, the actual distribution of electrons is an average of that shown by the various Lewis structures.
Resonance Structures and Resonance Hybrids
The Lewis structure of a nitrite anion (NO2−) may actually be drawn in two different ways, distinguished by the locations of the N–O and N=O bonds.
Resonance Structures and Resonance Hybrids
The Lewis structure of a nitrite anion (NO2−) may actually be drawn in two different ways, distinguished by the locations of the N–O and N=O bonds.
2° Amines to N-Nitrosamines: Reaction with NaNO2
Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.
Resonance
The Lewis structure of a nitrite anion (NO2−) may actually be drawn in two different ways, distinguished by the locations of the N-O and N=O bonds.
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Overview
Nitrous acid and nitric acids are two types of acids containing nitrogen, among which nitrous acid is weaker than nitric acid. Nitrous acid with a pKa value of 3.37 ionizes in water to give a nitrite ion and the hydronium ion.
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by water loss...
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by water loss...
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
Nitrous acid is a relatively weak and unstable acid prepared in situ by the reaction of sodium nitrite and cold, dilute hydrochloric acid. In an acidic solution, the nitrous acid undergoes protonation when it loses water to form a nitrosonium ion—an electrophile. Nitrous acid reacts with primary amines to give diazonium salts. The reaction is called diazotization of primary amines.
Diazonium Group Substitution: –OH and –H
Nitrous acid, a weak acid, is prepared in situ via the reaction of sodium nitrite with a strong acid under cold conditions. This nitrous acid prepared in situ reacts with primary arylamines to form arenediazonium salts. Such reactions are known as diazotization reactions. As shown in Figure 1, the formation of arenediazonium salts begins with the decomposition of nitrous acid in an acidic solution to give nitrosonium ions.


