对于HYDRA项目而言,碳酸微的振动特征
Noah O Evers1, Sophie M Schweer1, Martin A Suhm1
1Institute of Physical Chemistry, University of Goettingen, Tammannstr. 6, 37077 Goettingen, Germany. noah-oriol.evers@uni-goettingen.de.
Physical chemistry chemical physics : PCCP
|July 22, 2025
概括
这项研究使用光谱学描述了和酸的微溶解,为量子化学基准测试的HyDRA数据库添加了关键数据. 研究人员确定了一种稳定的乙酸二聚体单酸,增强了对酸水相互作用的理解.
科学领域:
- 物理化学 物理化学
- 频谱学是一种光谱学.
- 计算化学计算化学
背景情况:
- 海德拉数据库系统地描述了微溶解中的水振动,用于量子化学的基准测试.
- 目前的HYDRA数据缺乏关于酸微溶解的全面信息.
研究的目的:
- 通过描述酸和酸中性微水合物来扩大HYDRA数据库.
- 用实验数据对量子化学方法进行基准测试.
主要方法:
- 超音速喷射FTIR光谱学超音速喷射FTIR光谱学
- 拉曼光谱法 拉曼光谱法
主要成果:
- 有特征的酸和酸中性微水合物.
- 位于酸单水化合物中基本延伸的结合水OH的位在3535(4) cm-1 .
- 鉴定了一种转移稳定的乙酸二聚体的单酸,并证实了酸单酸的文献谱.
结论:
- 碳酸复合物的计算和实验OH拉伸转移之间的经验关系是强大的.
- 这项工作显著增强了HYDRA数据库,增加了新的酸微溶解数据.
相关概念视频
NMR and Mass Spectroscopy of Carboxylic Acids
4.3K
In ¹H NMR spectroscopy, acidic protons (–COOH) of carboxylic acids are highly deshielded and absorb far downfield, at around 9–12 ppm. The chemical shift value depends on the concentration and solvent used.
While α protons of carboxylic acids absorb at 2–2.5 ppm, β protons absorb further upfield.
Carboxylic acids are easily identified by dissolving them in deuterium oxide, which results in a rapid exchange of the acidic protons with deuterium. This leads to the...
While α protons of carboxylic acids absorb at 2–2.5 ppm, β protons absorb further upfield.
Carboxylic acids are easily identified by dissolving them in deuterium oxide, which results in a rapid exchange of the acidic protons with deuterium. This leads to the...
4.3K
IR and UV–Vis Spectroscopy of Carboxylic Acids
4.6K
In IR spectroscopy of carboxylic acids, the C=O bond shows a characteristic band between 1710 and 1760 cm⁻¹, and the O–H bond exhibits a broad band between 2500 and 3300 cm⁻¹.
However, the stretching absorptions for the C=O bond vary depending on the structure of carboxylic acids. The C=O bond of the free carboxylic acids shows a higher stretching frequency, 1760 cm−1, while H-bonded carboxylic acids (dimers) exhibit stretching absorptions at a lower frequency,...
However, the stretching absorptions for the C=O bond vary depending on the structure of carboxylic acids. The C=O bond of the free carboxylic acids shows a higher stretching frequency, 1760 cm−1, while H-bonded carboxylic acids (dimers) exhibit stretching absorptions at a lower frequency,...
4.6K
Spectroscopy of Carboxylic Acid Derivatives
2.6K
Infrared spectroscopy is primarily used to determine the types of bonds and functional groups. In carboxylic acid derivatives, a typical carbonyl bond absorption is observed around 1650–1850 cm−1. For esters, the absorption is recorded at around 1740 cm−1, while acid halides show the absorption at about 1800 cm−1. Another acid derivative, the acid anhydrides, exhibit two carbonyl absorption around 1760 cm−1 and 1820 cm−1, arising from the symmetrical and...
2.6K
NMR Spectroscopy and Mass Spectrometry of Aldehydes and Ketones
4.4K
In aldehydes, the hydrogen atom connected to the carbonyl carbon helps distinguish aldehydes from other carbonyl compounds using ¹H NMR spectroscopy. The closeness of aldehydic hydrogen to the electrophilic carbonyl carbon highly deshields the hydrogen atom causing its signal to appear around 10 ppm in the ¹H NMR spectra. α hydrogens split the aldehydic proton signal, which helps identify the number of α hydrogens in the molecule. For instance, one α hydrogen creates a...
4.4K
Aldehydes and Ketones with Water: Hydrate Formation
3.6K
An oxygen-based nucleophile, like water, can undergo addition reactions with aldehydes and ketones. The reaction leads to the formation of hydrates, also referred to as 1,1-diols or geminal diols.
The formation of hydrates is a reversible reaction. Hydrate formation is influenced by steric and electronic factors accompanying the alkyl substituents on the carbonyl group: The rate of hydrate formation increases with a decrease in the number of alkyl groups attached to the carbonyl carbon. Hence,...
The formation of hydrates is a reversible reaction. Hydrate formation is influenced by steric and electronic factors accompanying the alkyl substituents on the carbonyl group: The rate of hydrate formation increases with a decrease in the number of alkyl groups attached to the carbonyl carbon. Hence,...
3.6K
Acid Halides to Carboxylic Acids: Hydrolysis
2.9K
Hydrolysis of acid halides is a nucleophilic acyl substitution reaction in which acid halides react with water to give carboxylic acids. The reaction occurs readily and does not require acid or a base catalyst.
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic...
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic...
2.9K


