在化学空间中分子液体中的核量子效应
Baris E Ugur1, Michael A Webb2
1Department of Chemical and Biological Engineering, Princeton University Princeton, Princeton, NJ, USA.
Nature communications
|July 1, 2025
概括
核量子效应 (NQE) 显著影响有机液体的热物理性质,改变多达5%的摩尔体积. 这些量子效应可以通过摩尔质量,密度和热膨胀率来预测.
科学领域:
- 物理化学 物理化学
- 计算化学计算化学
- 材料科学 材料科学 材料科学
背景情况:
- 核量子效应 (NQE) 对轻原子和低温至关重要,但很少被广泛研究.
- 对NQE的量化是有限的,水是值得注意的例外.
研究的目的:
- 系统地研究NQEs对92种有机液体的热物理性质的影响.
- 为了确定预测NQE的大小的关键分子特征.
主要方法:
- 采用了途径整体分子动力学模拟.
- 使用数据驱动分析将分子特征与NQE相关联.
主要成果:
- NQE显著影响热膨胀率,压缩性,介电常数,蒸发度和体积 (高达5%的差异).
- 化显示出不那么明显的同位素效应,类似于NQEs.
- 摩尔质量,经典密度和经典热膨胀率被确定为NQE的关键预测因素.
结论:
- 在水以外的分子液体中,NQE具有广泛的相关性.
- 提供了一个框架,以预测和理解NQEs基于分子特征,如分支和异质原子含量.
相关概念视频
Molecular Orbital Theory I
33.0K
Overview of Molecular Orbital Theory
33.0K
Chemical Shift: Internal References and Solvent Effects
790
In an NMR sample, precise measurement of the absolute absorption frequencies of nuclei is difficult. A standard internal reference compound is added, and the frequency difference between the reference signal and sample signals is measured.
The internal reference compound generally used in NMR spectroscopy is tetramethylsilane (TMS). TMS is preferred because it is chemically inert, soluble in NMR solvents, and easily removable. Also, the highly shielded methyl protons in TMS yield an intense...
The internal reference compound generally used in NMR spectroscopy is tetramethylsilane (TMS). TMS is preferred because it is chemically inert, soluble in NMR solvents, and easily removable. Also, the highly shielded methyl protons in TMS yield an intense...
790
π Electron Effects on Chemical Shift: Overview
1.2K
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0,...
1.2K
Nuclear Overhauser Enhancement (NOE)
844
Irradiation of a spin-active nucleus causes an increase or decrease in the signal intensity of neighboring nuclei that are not necessarily chemically bonded or involved in J-coupling. This phenomenon, called the Nuclear Overhauser Enhancement (NOE), results from through-space interactions between the nuclear spins. The NOE effect decreases with increasing internuclear distance and is generally not observed beyond 4 angstroms. In NOE, dipole-dipole interactions between neighboring...
844
UV–Vis Spectroscopy: Molecular Electronic Transitions
1.8K
In Ultraviolet–Visible (UV–Vis) spectroscopy, the absorption of electromagnetic radiation is used to probe the electronic structure of molecules. This technique provides insights into molecular electronic transitions, particularly the movement of electrons between different molecular orbitals. Radiation is absorbed if the energy of the electromagnetic radiation passing through the molecule is precisely equal to the energy difference between the excited and ground states. During this...
1.8K
Molecular Orbital Theory II
19.8K
Molecular Orbital Energy Diagrams
19.8K


