相关实验视频

Updated: Sep 15, 2025

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Published on: April 8, 2020

在气相星际介质中形成胺和胺的计算预测

Mohamad Akbar Ali^1,2, Sorakayala Thripati^1,2

¹Department of Chemistry, Khalifa University of Science and Technology, Abu Dhabi, United Arab Emirates.

Frontiers in chemistry

|July 15, 2025

概括

这项研究表明thioamides可以在星际条件下形成,与胺不同,并确定了四个新的分子用于潜在的检测. 这有助于我们对前生物化学和太空中硫循环的理解.

科学领域:

天体化学和天体生物学
量子化学和理论建模理论建模
生命的起源研究研究研究

背景情况:

氨基酸和胺键是生命的基础,使它们在太空中的形成途径对生命起源研究至关重要.
在寒冷的星际介质 (ISM) 中,含有的化合物,包括胺和胺的形成机制尚不清楚.
益生菌化学和星际化学是理解生命构建块的合成的关键领域.

研究的目的:

通过使用计算方法,从简单的星际前体中研究胺和胺的气相形成路径.
在星际介质 (ISM) 条件下确定这些形成路径的动力可行性.
为了确定天文观测的潜在新分子,并了解硫在天体生物学中的作用.

主要方法:

采用 ab initio 密度函数理论 (DFT) 计算来预测反应路径和能量障碍.
利用统计速率理论,包括微规范变量过渡状态理论 (μVTST) 和RRKM/主方程 (ME) 模拟,计算无障碍反应的速率常数 (k).
评估了使用常见星际前体的形成路径:一氧化碳 (CO),单硫化碳 (CS),氨基原 (NH ₂),分子 (H ₂) 和氨 (NH _3).

主要成果:

胺 (HCSNH₂,NH₂CSNH₂) 在ISM条件下显示出形成的潜力.
胺形成 (HCONH₂,NH₂CONH₂) 由于显著的能量障碍 (>5 kcal/mol) 的可能性较小.
四个新的分子 (·CSNH₂,HCSN·H,HCSNH₂,NH₂CSNH₂) 是基于计算的度和速率常数在ISM环境中进行潜在检测的建议.

结论:

包括新发现的胺体在内的有机硫分子可以作为铁硫化物颗粒和关键的天体生物学化合物如甲和氨酸的前体.
阐明这些形成机制对于连接深空中的碳,,氧和硫循环至关重要.
这项研究扩大了我们对银河系硫循环和导致生命起源的化学进化过程的理解.

关键词:

在一开始,从一开始.氨基酸是氨基酸中的一种.天文化学天文化学星际化学反应是星际化学反应.键是一种键.反应性中间体反应性中间体铁胺酸的使用方法

更多相关视频

Curation of Computational Chemical Libraries Demonstrated with Alpha-Amino Acids

Curation of Computational Chemical Libraries Demonstrated with Alpha-Amino Acids

Published on: April 13, 2022

Conducting Miller-Urey Experiments

Conducting Miller-Urey Experiments

Published on: January 21, 2014

相关概念视频

Preparation of Amides

Preparation of Amides

Amides are synthesized by treating carboxylic acids with amines in the presence of dehydrating agents like dicyclohexylcarbodiimide (DCC).
The DCC-promoted synthesis of amides begins with the protonation of DCC by carboxylic acid. The protonation makes it a better acceptor. Next, the addition of carboxylate to the protonated carbodiimide gives a reactive acylating agent.
Subsequently, the amine acts as a nucleophile that attacks the acylating agent to form a tetrahedral intermediate. In the...

Aldehydes and Ketones with Amines: Imine Formation Mechanism

Aldehydes and Ketones with Amines: Imine Formation Mechanism

Imine formation involves the addition of carbonyl compounds to a primary amine. It begins with the generation of carbinolamine through a series of steps involving an initial nucleophilic attack and then several proton transfer reactions. The second part includes the elimination of water, as a leaving group, to give the imine.
Imines are formed under mildly acidic conditions. A pH of 4.5 is ideal for the reaction.
If the pH is low or the solution is too acidic, the reaction slows down in the...

Preparation of 1° Amines: Gabriel Synthesis

Preparation of 1° Amines: Gabriel Synthesis

Direct alkylation is not a suitable method for synthesizing amines because it produces polyalkylated products. Gabriel synthesis is the most preferred method to exclusively make primary amines. The method uses phthalimide, which contains a protected form of nitrogen that participates in alkylation only once to predominantly give primary amines.
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...

Mass Spectrometry of Amines

Mass Spectrometry of Amines

In mass spectroscopy, amines undergo fragmentation to give parent ions with odd molecule weights. This observed mass spectrum follows the nitrogen rule: a molecule with an odd number of nitrogen atoms produces a parent ion with an odd molecular weight. The remaining fragments have an even mass.
Amines undergo fragmentation through α cleavage, producing nitrogen-containing cations—iminium ions—and alkyl radicals. Mass spectra of aromatic and cyclic aliphatic amines exhibit...

Acid Halides to Amides: Aminolysis

Acid Halides to Amides: Aminolysis

Aminolysis is a nucleophilic acyl substitution reaction, where ammonia or amines act as nucleophiles to give the substitution product. Acid halides react with ammonia, primary amines, and secondary amines to yield primary, secondary, and tertiary amides, respectively.
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...

Preparation of Amines: Reduction of Amides and Nitriles

Preparation of Amines: Reduction of Amides and Nitriles

Nitriles can be reduced to primary amines using reducing agents like lithium aluminum hydride or catalytic hydrogenation. The reduction introduces an amino group with an extra carbon in the skeleton. Nitriles are formed from the reaction between alkyl halides and sodium cyanide through the SN2 mechanism. Primary alkyl halides are the preferred substrates to prepare nitriles.
Amides can be reduced to primary, secondary, and tertiary amines using catalytic hydrogenation, active metals like Fe,...