极化嵌入对于计算光学旋转的重要性:珀在乙醇中的案例
Michele Nottoli1, Edoardo Vanich2, Lorenzo Cupellini2
1Institute of Applied Analysis and Numerical Simulation, Universität Stuttgart, Pfaffenwaldring 57, D-70569, Stuttgart, Germany.
The journal of physical chemistry letters
|July 30, 2024
概括
计算化学家现在可以准确地模拟溶剂中的光学旋转. 使用量子力学/分子力学 (QM/MM) 与AMOEBA力场的新极化嵌入方法与实验结果密切相匹配.
科学领域:
- 计算化学计算化学
- 物理化学 物理化学
- 频谱学是一种光谱学.
背景情况:
- 光学旋转对溶剂效应敏感,这给计算建模带来了挑战.
- 准确预测分子光学旋转需要考虑溶剂极化.
研究的目的:
- 开发和应用一个可偏化的嵌入式QM/MM方法来计算光学旋转.
- 为了研究溶剂极化对乙醇中坎佛光学旋转的影响.
主要方法:
- 密度函数理论 (DFT) 与AMOEBA极化力场相结合.
- 量子力学/分子力学 (QM/MM) 具有连续,静电嵌入和极化嵌入模型.
- 经典的分子动力学模拟.
主要成果:
- QM/AMOEBA极化嵌入模型与实验光学旋转值取得了定量一致.
- 与静电嵌入相比,可极化嵌入提供了明显不同的质量图像.
- 静电嵌入结果在统计学上与可极化描述结果无关.
结论:
- 可极化嵌入QM/MM对于精确的溶液光学旋转计算至关重要.
- 考虑到环境两极分化对于可靠地预测溶剂对分子性质的影响至关重要.
相关概念视频
Properties of Enantiomers and Optical Activity
16.9K
It is essential to understand the difference between chiral and achiral interactions and the implications thereof in optical activity and their applications. Just as our feet, which are chiral, interact uniquely with chiral objects, such as a pair of shoes, but identically with achiral socks, enantiomers of a molecule exhibit different properties only when they interact with other chiral media. An example of a significant implication from this facet is the phenomenon known as optical activity,...
16.9K
Measuring Reaction Rates
24.9K
Polarimetry finds application in chemical kinetics to measure the concentration and reaction kinetics of optically active substances during a chemical reaction. Optically active substances have the capability of rotating the plane of polarization of linearly polarized light passing through them—a feature called optical rotation. Optical activity is attributed to the molecular structure of substances. Normal monochromatic light is unpolarized and possesses oscillations of the electrical...
24.9K
Fischer Projections
13.1K
Learning to draw Fischer projections of molecules and understanding their relevance plays a crucial role in the visual depiction of organic molecules. A Fischer projection is a two-dimensional projection on a planar surface to simplify the three-dimensional wedge–dash representation of molecules. This is especially helpful in the case of molecules with multiple chiral centers that can be difficult to draw. Here, all the bonds of interest are represented as horizontal or vertical lines.
13.1K
Thermal Electrocyclic Reactions: Stereochemistry
2.0K
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
2.0K
Stereoisomerism of Cyclic Compounds
8.7K
In this lesson, we delve into the role of ring conformation and its stability, which determines the spatial arrangement and, consequently, the molecular symmetry and stereoisomerism of cyclic compounds. 1,2-Dimethylcyclohexane is used as a case study to evaluate the possible number of stereoisomers. Here, given the multiple (n = 2) chiral centers, there are 2n = 4 possible configurations that lack a plane of symmetry, as the ring skeleton exists in a non-planar chair conformation. In addition,...
8.7K
Photochemical Electrocyclic Reactions: Stereochemistry
1.8K
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
1.8K


