揭示液晶的低THz动力学:确定分子内模式之间的分子间相互作用
Patrick Friebel1, Daria Ruth Galimberti2, Matteo Savoini3
1Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, Heidelberg 69117, Germany.
The journal of physical chemistry. B
|January 8, 2024
概括
研究人员利用光谱学探索液晶中的太赫兹 (THz) 动态. 他们发现,虽然一些THz反应来自单个分子,但其他反应,特别是低于3 THz的反应,表明这些光学材料中的分子间相互作用.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 频谱学是一种光谱学.
背景情况:
- 液晶是可见光谱和近红外光谱的可调光学材料.
- 目前的研究重点是将液晶应用扩展到太赫兹 (THz) 频率 (1-10 THz).
- 在液晶中理解THz触发的动力学仍然不完整.
研究的目的:
- 为了研究在不同的中相中液晶中THz触发的动力学.
- 为了阐明THz在液晶中吸收的分子起源.
- 区分单分子和分子间对THz反应的贡献.
主要方法:
- 宽带THz时间域光谱测试对4--4'-基双 (nCB) 和5-环 (PCH5) 进行了测试.
- 密度函数理论 (DFT) 的计算用于孤立的分子,二分体和三分体.
- 分析了光谱数据,以确定特有的THz吸收模式.
主要成果:
- 对孤立分子的DFT计算准确地预测了大约4.5和5.5 THz的明显THz模式,这归因于蓝色群曲.
- 与链模式相关的低于3 THz的宽THz响应与单分子计算不一致.
- 分析显示,低频THz反应具有显著的分子间特征,由二次和三次数计算证实.
结论:
- 该研究成功地描述了nCB和PCH5液晶中的THz动态.
- 分子间相互作用在液晶的低频THz反应中起着至关重要的作用.
- 结合实验光谱和理论计算,提供了对THz触发动态的全面了解.
相关概念视频
03:00Intermolecular vs Intramolecular Forces
87.4K
Intermolecular forces (IMF) are electrostatic attractions arising from charge-charge interactions between molecules. The strength of the intermolecular force is influenced by the distance of separation between molecules. The forces significantly affect the interactions in solids and liquids, where the molecules are close together. In gases, IMFs become important only under high-pressure conditions (due to the proximity of gas molecules). Intermolecular forces dictate the physical properties of...
87.4K
02:56Intermolecular Forces and Physical Properties
20.8K
20.8K
03:13Intermolecular Forces
58.3K
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...
58.3K
02:34Comparing Intermolecular Forces: Melting Point, Boiling Point, and Miscibility
44.4K
Intermolecular forces are attractive forces that exist between molecules. They dictate several bulk properties, such as melting points, boiling points, and solubilities (miscibilities) of substances. Molar mass, molecular shape, and polarity affect the strength of different intermolecular forces, which influence the magnitude of physical properties across a family of molecules.
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
44.4K
01:24Van der Waals Interactions
64.0K
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.
64.0K
02:57Surface Tension, Capillary Action, and Viscosity
27.8K
Surface Tension
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
27.8K