集中硫酸中的二酸的一般不稳定性,这与金星云的可居住性有关
相关实验视频
Updated: Jun 19, 2025

11:00
Determination of the Gas-phase Acidities of Oligopeptides
Published on: June 24, 2013
11.1K
Janusz J Petkowski1,2,3, Maxwell D Seager4,5, William Bains6,7,8
1Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA. jjpetkow@mit.edu.
Scientific reports
|July 24, 2024
概括
蛋白质前体二,在金星上大多是不稳定的.
科学领域:
- 天体生物学 天体生物学
- 有机化学 有机化学
- 行星科学 行星科学
背景情况:
- 对金星云层生命的重新兴趣促使人们对缩硫酸中的有机化学进行研究.
- 之前的研究证实了维纳斯云中硫酸度 (81%和98%重/重) 的氨基酸稳定性.
研究的目的:
- 为了确定二的稳定性,蛋白质的前体,在缩的硫酸环境.
- 评估键在假设的金星生命中发挥作用的潜力.
主要方法:
- 通过使用20种不同的同型,研究了键的反应性.
- 在81%和98%重/重硫酸度下测试的二稳定性.
- 监测分解过程并将其与标准的酸催化水解进行比较.
主要成果:
- 大多数同型在两个测试的硫酸度下,在几周内发生溶解 (分解).
- 例外:HH和GG二在98%的硫酸中稳定约4个月;II,LL,VV,PP,RR,KK在81%的硫酸中稳定约5周.
- 在98%的硫酸中分解二酸不同于标准的酸解,不仅释放单体氨基酸.
结论:
- 没有同型在81%和98%的硫酸度中表现出稳定性.
- 假设金星上的生命可能需要替代生物化学结构来稳定标准键.
相关概念视频
Solvating Effects
7.4K
An understanding of the solvating effect helps rationalize the relation between solvation and acidity of the compound. In addition, this also explains the relative stability of conjugate bases for compounds with different pKa values. This lesson details, in-depth, the principle of solvating effects. The strength of an acid and the stability of its corresponding conjugate base are determined using pKa values. This observed relationship is a consequence of solvation, which is the interaction...
7.4K
Molecular Structure and Acidity
17.2K
An acid can be deprotonated to form a conjugate base or an anion. If the produced anion is more stable, then the acid is stronger. On the contrary, if the anion is unstable, then the acid is weaker. Hence, to determine the acidity of the compound, the stability of its conjugate base is studied using various factors.
The size effect explains the change in atomic size on acidity. When comparing the acids formed from elements that belong to the same column in the periodic table, their atomic sizes...
The size effect explains the change in atomic size on acidity. When comparing the acids formed from elements that belong to the same column in the periodic table, their atomic sizes...
17.2K
Stability of Conjugated Dienes
3.3K
Introduction
A comparison of the enthalpies of hydrogenation of dienes reveals that conjugated dienes release less heat on hydrogenation, rendering them more stable than their nonconjugated analogs.
A comparison of the enthalpies of hydrogenation of dienes reveals that conjugated dienes release less heat on hydrogenation, rendering them more stable than their nonconjugated analogs.
3.3K
Entropy and Solvation
7.0K
The process of surrounding a solute with solvent is called solvation. It involves evenly distributing the solute within the solvent. The rule of thumb for determining a solvent for a given compound is that like dissolves like. A good solvent has molecular characteristics similar to those of the compound to be dissolved. For example, polar solutions dissolve polar solutes, and apolar solvents dissolve apolar solutes. A polar solvent is a solvent that has a high dielectric constant (ϵ...
7.0K
Mixtures of Acids
676
The pH of a solution containing an acid can be determined using its acid dissociation constant and initial concentration. If a solution contains two different acids, then its pH can be determined using one of several methods depending on the relative strength of the acids and their dissociation constants.
In a strong and weak acid mixture, the strong acid dissociates completely and becomes a source of almost all the hydronium ions present in the solution. In contrast, the weak acid shows...
In a strong and weak acid mixture, the strong acid dissociates completely and becomes a source of almost all the hydronium ions present in the solution. In contrast, the weak acid shows...
676
Acid Halides to Carboxylic Acids: Hydrolysis
2.6K
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...
2.6K

