离子亲和关系的复习:我们是否需要点方法?
Morten Lehmann1, Salimot Natalie Balogun1, Marc Reimann1,2
1Technische Universität Berlin, Institut für Chemie, 10623, Berlin, Germany.
Chemistry (Weinheim an der Bergstrasse, Germany)
|March 3, 2025
概括
直接计算离子亲和度 (FIA) 优于现代DFT计算的间接方法. 这一发现挑战了以前的假设,为评估易斯酸提供了更准确的方法.
科学领域:
- 计算化学的计算化学
- 量子化学 是一个量子化学.
- 理论化学 理论化学
背景情况:
- 精确计算气相离子亲缘关系 (FIAs) 对于理解易斯酸相互作用至关重要.
- 传统的间接点方法在密度函数理论 (DFT) 计算中比直接的FIA计算更受青.
- 这些间接方法旨在规避与模拟自由离子相关的挑战.
研究的目的:
- 量化评估各种DFT函数和FIA计算的复合方法.
- 将直接FIA计算的准确性与广泛使用的间接点方法进行比较.
- 挑战普遍的假设,即间接方法对于DFT级别的FIA计算总是优越.
主要方法:
- 对于71个主要组的易斯酸,使用了计算的气相FIA的基准数据集.
- 评估了52个DFT函数和4个复合方法.
- 直接的FIA计算与两种使用光和三甲基酸的间接点方法进行了比较.
主要成果:
- 现代的DFT函数具有较低的自我交互错误和适当的基础集,减少了间接方法的优势.
- 基于三甲基酸的点方法通常会比直接计算更糟糕.
- 点方法中的错误取消在先进的计算设置中崩,否定了它们的好处.
结论:
- 当使用现代DFT函数和具有扩散函数的合适基础集时,FIA的直接计算是首选的方法.
- 对间接点方法的广泛偏好并不普遍适用.
- 优化的直接FIA计算为易斯酸表征提供了更可靠的结果.
相关概念视频
Electron Affinity
35.1K
The electron affinity (EA) is the energy change for adding an electron to a gaseous atom to form an anion (negative ion).
35.1K
Alkyl Halides
15.8K
Structural Properties
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...
15.8K
Valence Bond Theory
31.7K
Overview of Valence Bond Theory
31.7K
Calculating pH Changes in a Buffer Solution
52.5K
A buffer can prevent a sudden drop or increase in the pH of a solution after the addition of a strong acid or base up to its buffering capacity; however, such addition of a strong acid or base does result in the slight pH change of the solution. The small pH change can be calculated by determining the resulting change in the concentration of buffer components, i.e., a weak acid and its conjugate base or vice versa. The concentrations obtained using these stoichiometric calculations can be used...
52.5K
Hydrogen Bonds
7.8K
A hydrogen bond is formed when a weakly positive hydrogen atom already bonded to one electronegative atom (for example, the oxygen in the water molecule) is attracted to another electronegative atom from another polar molecule, such as water (H2O), hydrogen fluoride (HF), or ammonia (NH3). The huge electronegativity difference between the H atom (2.1) and the atom to which it is bonded (4.0 for an F atom, 3.5 for an O atom, or 3.0 for an N atom), combined with the very small size of an H atom...
7.8K
Intermolecular Forces
57.0K
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...
57.0K


