相关实验视频
Updated: Jul 5, 2025

10:37
Spatial Separation of Molecular Conformers and Clusters
Published on: January 9, 2014
9.0K
分子气相形态组合的组合
1Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, Michigan 48824, United States.
Journal of chemical information and modeling
|January 11, 2024
概括
这项研究比较了四个结构搜索引擎 (Auto3D,CREST,气球,ETKDG) 寻找分子全球最小值. 来自离子流动性质谱学的实验碰撞截面 (CCS) 数据验证了它们的有效性,有助于精确的分子结构确定.
科学领域:
- 计算化学计算化学
- 分子建模分子建模
- 分析化学 分析化学
背景情况:
- 准确确定全球分子最小值对于药物设计,材料科学和化学合成至关重要.
- 规格搜索引擎探索分子规格空间以识别稳定的结构.
研究的目的:
- 为了比较四个自由可用的构造搜索引擎的有效性:Auto3D,CREST,气球和ETKDG (RDKit).
- 引入实验性气相碰撞截面 (CCS) 值,作为对形状搜索准确性的验证度量.
- 建立一个气相对应图库 (GPCL) 用于验证对应搜索引擎.
主要方法:
- 比较Auto3D,CREST,气球和ETKDG的形状搜索引擎.
- 使用基于潜力,半经验和基于力场的机器学习 (ML) 方法.
- 使用从离子运动质谱学实验气相碰撞截面 (CCS) 值进行验证.
主要成果:
- 评估不同结构搜索引擎在定位全球最小值方面的性能.
- 证明CCS值作为可靠的实验验证工具,用于构造性搜索.
- 建立了含有20个小分子的气相形态图书馆 (GPCL),供社区使用.
结论:
- 该研究提供了对各种结构性搜索引擎的优势和局限性的见解.
- 实验CCS数据提供了一个可靠的方法来验证计算预测的全球最小值.
- GPCL和拟议的验证工作流程提高了分子结构确定的准确性,特别是用于代谢物识别和未知的化合物预测.
相关概念视频
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
847
At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...
847
Conformations of Ethane and Propane
14.0K
In an organic molecule, free rotation about the carbon-carbon single bond results in energetically different conformers of the molecule. Due to this rotation, called the internal rotation, ethane has two major conformations — staggered and eclipsed.
Staggered conformation is a low energy and more stable conformation with the C-H bonds on the front carbon placed at 60°dihedral angles relative to the C-H bonds on the back carbon, leading to a reduced torsional strain. In staggered...
Staggered conformation is a low energy and more stable conformation with the C-H bonds on the front carbon placed at 60°dihedral angles relative to the C-H bonds on the back carbon, leading to a reduced torsional strain. In staggered...
14.0K
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
1.1K
The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.
1.1K
Conformations of Butane
14.3K
Unlike ethane and propane that have only two major conformations, butane has more than two conformers. The staggered form of butane in which the bulky methyl groups on the two carbons are placed on opposite sides, that is, at a dihedral angle of 180°, is the lowest energy, most stable form — called the anti conformer. This conformation is stabilized due to the absence of steric repulsion between the largely spaced out methyl groups. The other two staggered conformations are...
14.3K
Kinetic Molecular Theory and Gas Laws Explain Properties of Gas Molecules
32.7K
The test of the kinetic molecular theory (KMT) and its postulates is its ability to explain and describe the behavior of a gas. The various gas laws (Boyle’s, Charles’s, Gay-Lussac’s, Avogadro’s, and Dalton’s laws) can be derived from the assumptions of the KMT, which have led chemists to believe that the assumptions of the theory accurately represent the properties of gas molecules.
32.7K
Molecular Comparison of Gases, Liquids, and Solids
41.2K
Particles in a solid are tightly packed together (fixed shape) and often arranged in a regular pattern; in a liquid, they are close together with no regular arrangement (no fixed shape); in a gas, they are far apart with no regular arrangement (no fixed shape). Particles in a solid vibrate about fixed positions (cannot flow) and do not generally move in relation to one another; in a liquid, they move past each other (can flow) but remain in essentially constant contact; in a gas, they move...
41.2K

