在液晶中溶解物-溶剂相互作用和奇拉感应
Giorgio Celebre1, Giuseppina De Luca, Michela Maiorino
1Dipartimento di Chimica, Università della Calabria, via P. Bucci, 87036 Rende (CS), Italy. giorgio.celebre@unical.it
Journal of the American Chemical Society
|August 18, 2005
概括
奇拉溶液通过分子间相互作用在液晶中诱导胆固醇相. 甲基硫化物 (MPS) 在不同溶剂中表现出相反的手性,揭示了溶剂对性诱导的影响.
科学领域:
- 超分子化学 超分子化学
- 液晶科学 液晶科学
- 奇拉性研究 奇拉性研究
背景情况:
- 液晶中的奇拉放大是由分子间相互作用引起的.
- 灵活的性剂对相性的影响是复杂的,涉及溶液顺序和剂构成.
- 溶剂对液晶中奇拉诱导的溶剂作用尚未完全理解.
研究的目的:
- 调查溶剂对液晶中奇拉感应的影响.
- 解开溶剂对溶液构成和方向顺序的影响.
- 阐明溶剂在调解从分子到相的奇拉性转移中的作用.
主要方法:
- 测量甲基硫氧化物 (MPS) 在各种阴性溶剂中的扭转功率.
- 核磁共振 (NMR) 实验,包括1H-1H和13C-1H双极合.
- 分子场理论模拟分子间相互作用的奇拉性.
主要成果:
- 甲基硫氧化物 (MPS) 诱导胆固醇阶段与相反的手性取决于内马性溶剂.
- 核磁共振分析揭示了溶剂依赖的溶解物构成和定向顺序.
- 从溶液到液晶相的奇拉性转移在很大程度上是由溶剂相互作用介导的.
结论:
- 溶剂在调节液晶中性感应方面发挥着至关重要的作用.
- 嵌合剂的形状灵活性和它们的方向顺序是受溶剂影响的关键因素.
- 这项研究提供了关于超分子系统中性放大分子机制的见解.
相关概念视频
Van der Waals Interactions
Atoms and molecules interact with each other through intermolecular forces. These electrostatic forces arise from attractive or repulsive interactions between particles with permanent, partial, or temporary charges. The intermolecular forces between neutral atoms and molecules are ion–dipole, dipole–dipole, and dispersion forces, collectively known as van der Waals forces.Polar molecules have a partial positive charge on one end and a partial negative charge on the other end of the molecule,...
Intermolecular Forces
Atoms and molecules interact through bonds (or forces): intramolecular and intermolecular. The forces are electrostatic as they arise from interactions (attractive or repulsive) between charged species (permanent, partial, or temporary charges) and exist with varying strengths between ions, polar, nonpolar, and neutral molecules. The different types of intermolecular forces are ion–dipole, dipole–dipole, hydrogen bonds, and dispersion; among these, dipole–dipole, hydrogen bonds, and dispersion...
Intermolecular Forces in Solutions
The formation of a solution is an example of a spontaneous process, a process that occurs under specified conditions without energy from some external source.
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Such a solution is called an ideal solution. A mixture of ideal gases (or gases such as helium and argon,...
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Such a solution is called an ideal solution. A mixture of ideal gases (or gases such as helium and argon,...
Aqueous Solutions and Heats of Hydration
Water and other polar molecules are attracted to ions. The electrostatic attraction between an ion and a molecule with a dipole is called an ion-dipole attraction. These attractions play an important role in the dissolution of ionic compounds in water.
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
Solvating Effects
An understanding of the solvating effect helps rationalize the relation between solvation and acidity of the compound. In addition, this also explains the relative stability of conjugate bases for compounds with different pKa values. This lesson details, in-depth, the principle of solvating effects. The strength of an acid and the stability of its corresponding conjugate base are determined using pKa values. This observed relationship is a consequence of solvation, which is the interaction...
Colloidal precipitates
The high insolubility of some precipitates can result in an unfavorable relative supersaturation. This can lead to colloidal particles with a large surface-to-mass ratio, where adsorption is promoted. For instance, in the precipitation of silver chloride, silver ions are adsorbed on the surface of the colloidal particles, forming a primary layer. This layer attracts ions of opposite charge (such as nitrate ions), forming a diffuse secondary layer of adsorbed ions. This electric double layer...


