相关实验视频

Updated: Jun 21, 2025

Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives

Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives

Published on: January 19, 2016

圆角量化并预测三甲酸和刚性宏循环之间的阴离子复合体的亲和力和反应力

Zhao Zhang¹, Edward G Sheetz¹, Maren Pink¹

¹Department of Chemistry, Indiana University Address, 800 East Kirkwood Avenue, Bloomington, Indiana, 47405, United States.

Angewandte Chemie (International ed. in English)

|July 5, 2024

概括

我们为有机三化酸盐开发了一个硬质角,以预测受体-阴离子结合亲和力. 这种固态参数也与结合离子的反应性相关,为分子识别提供了新的见解.

科学领域:

超分子化学超分子化学
有机金属化学有机金属化学
物理有机化学有机化学

背景情况:

立体效应在分子识别中至关重要,但缺乏与受体-离子复合体稳定性和离子反应性的定量关系.
托尔曼角已为子建立,但对于离子,特别是有机三甲酸,需要类似的度量.
了解体质量如何影响离子结合和反应性是设计选择性分子受体的关键.

研究的目的:

定义和关联有机三化酸盐 (R-BF3-) 与星离子结合亲缘关系的固态角 (θ).
为了研究受体结合对复合离子反应性的影响,特别是化物交换.
为了在离子识别中建立一个线性自由能量关系,用于固态效应.

主要方法:

合成和表征十个有机三甲酸离子与不同的固态替代剂 (乙烯基,乙烯,乙烯).
使用定位方法测量cyanostar和合成的离子之间的结合亲和力.
根据有机三二酸盐上的替代物的硬质体积来确定形角.
量化化物从结合离子转移到三乙的产量,以评估反应性.

主要成果:

在角和结合亲和力之间建立了线性相关性,该亲和力是对比-BF3-组更大的替代体的离子的结合亲和力.
开发的角模型准确地预测了两个新的离子的亲和力在±5%以内.
发现化物转移的产量,表明离子反应性,与角相关,在增加硬质体量时显示反应性降低.

结论:

对有机三化酸盐的立体圆角为预测和理解受体-离子复合体稳定性提供了有价值的工具.
阳离子反应,特别是化物交换,是由受体内的固体阻碍调节的.
建立的线性自由能量关系表明,类似的硬体相关性可能适用于其他受体系统,如竹.

关键词:

结合阳离子的阳离子圆的角度圆的角度圆的角度蓝星星星星星星星星星星星星线性相关性线性相关性反应性反应性反应性

更多相关视频

Qualitative Identification of Carboxylic Acids, Boronic Acids, and Amines Using Cruciform Fluorophores

Qualitative Identification of Carboxylic Acids, Boronic Acids, and Amines Using Cruciform Fluorophores

Published on: August 19, 2013

Preparation of 6-aminocyclohepta-2,4-dien-1-one Derivatives via Tricarbonyltroponeiron

Preparation of 6-aminocyclohepta-2,4-dien-1-one Derivatives via Tricarbonyltroponeiron

Published on: August 12, 2019

相关概念视频

ortho–para-Directing Activators: –CH3, –OH, –&NoBreak;NH2, –OCH3

ortho–para-Directing Activators: –CH₃, –OH, –⁠NH₂, –OCH₃

All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...

ortho–para-Directing Deactivators: Halogens

ortho–para-Directing Deactivators: Halogens

Halogens are ortho–para directors. They are more electronegative than carbon. Therefore, as ring substituents, they can withdraw electrons through the inductive effect and deactivate the aromatic ring towards electrophilic substitution. Halogens also have an electron-donating resonance effect on the ring, which influences the orientation of the incoming electrophile. If an electrophile attacks at the ortho or the para position, the halogen donates electrons and stabilizes the intermediate...

Valence Bond Theory

Valence Bond Theory

Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...

Electrophilic Addition to Alkynes: Halogenation

Electrophilic Addition to Alkynes: Halogenation

Introduction
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.

Predicting Molecular Geometry

Predicting Molecular Geometry

VSEPR Theory for Determination of Electron Pair Geometries

Woodward–Hoffmann Selection Rules and Microscopic Reversibility

Woodward–Hoffmann Selection Rules and Microscopic Reversibility

Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for...