溶剂在确定二在水中的结构偏好的作用中的作用
Alexander N Drozdov1, Alan Grossfield, Rohit V Pappu
1Department of Biomedical Engineering, Washington University in St. Louis, Campus Box 1097, St. Louis, Missouri 63130, USA.
Journal of the American Chemical Society
|February 26, 2004
概括
短的氨酸在水中更喜欢聚二 (P(II)) 结构. 然而,这项研究揭示了水相互作用有利于紧的构造,而不是P(II),通过最大限度地减少化冲突在.
科学领域:
- 生物物理学的生物物理.
- 计算化学计算化学
- 分子动力学分子动力学
背景情况:
- 谱学研究表明,短氨酸在水中有利于聚二 (P(II)) 构造.
- 这种偏好被认为源于有利的-溶剂相互作用,特别是水桥.
研究的目的:
- 为了明确分析化结构和氨酸二合体的热力学.
- 调查-溶剂相互作用在确定P(II) 螺旋偏好的作用.
主要方法:
- 蒙特卡洛模拟在正统的合奏中.
- 使用全原子OPLS参数用于氨酸二和水的TIP5P模型.
- 在液态水中分析了N-乙氨酸-N'-甲基胺的16种低能度对象.
主要成果:
- 与结合的水分子数量没有影响溶解热力学.
- 溶解热力学是由完全水化所需的工作决定的.
- 有利的-溶剂相互作用有利于紧的形状,而不是类似于P (II) 的几何形状.
结论:
- 在实验中观察到的对P (II) 的偏好并不是由于直接的-水相互作用.
- 水分子有助于揭示内在的形状偏好,这种偏好是通过最小化内硬质冲突来驱动的.
相关概念视频
Solvents
A solvent is a substance, most often a liquid, that can dissolve other substances. Here, the substance being dissolved is called a solute. When a solvent and a solute combine, they form a solution - a homogenous mixture of both the solvent and the solute. Water is a universal biological solvent. Its polar structure allows it to dissolve many other polar compounds. The ability of water to dissolve is governed by a balance between water molecules binding to each other and binding to the solute.
A...
A...
Molecular Shape and Polarity
Dipole Moment of a Molecule
Solution Formation
There is no one solvent that can dissolve every type of solute. Some substances that readily dissolve in a certain solvent might be insoluble in a different solvent. A simple way to predict which substances dissolve in which solvent is the phrase "like dissolves like". This means that polar substances, such as salt and sugar, dissolve in a polar substance like water. In contrast, non-polar substances are more soluble in non-polar solvents such as carbon tetrachloride.
This selective solubility...
This selective solubility...
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...
Factors Affecting Solubility
Compared with pure water, the solubility of an ionic compound is less in aqueous solutions containing a common ion (one also produced by dissolution of the ionic compound). This is an example of a phenomenon known as the common ion effect, which is a consequence of the law of mass action that may be explained using Le Chȃtelier’s principle. Consider the dissolution of silver iodide:
Solubility
Solution, Solubility, and Solubility Equilibrium
A solution is a homogeneous mixture composed of a solvent, the major component, and a solute, the minor component. The physical state of a solution—solid, liquid, or gas—is typically the same as that of the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
In a solution, the solute particles (molecules, atoms, and/or ions)...
A solution is a homogeneous mixture composed of a solvent, the major component, and a solute, the minor component. The physical state of a solution—solid, liquid, or gas—is typically the same as that of the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
In a solution, the solute particles (molecules, atoms, and/or ions)...


