相关实验视频
Updated: Jul 14, 2026

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Determination of the Gas-phase Acidities of Oligopeptides
Published on: June 24, 2013
酸氨基的N-H和α (C-H) 键解离热量是酸氨基的解离热量
Jacques Lalevée1, Xavier Allonas, Jean-Pierre Fouassier
1Contribution from the Département de Photochimie Générale, CNRS UMR 7525, Ecole Nationale Supérieure de Chimie de Mulhouse, 3, rue Alfred Werner, France.
Journal of the American Chemical Society
|August 9, 2002
概括
由于电子相互作用,阿里法胺中的键解离度 (BDE) 非常稳定,接近91kcal/mol. 像循环化和硬质障碍等结构因素通过改变轨道对齐和应变来影响BDE.
科学领域:
- 物理化学 物理化学
- 计算化学的计算化学
背景情况:
- 纽带解离度 (BDE) 对于理解化学反应性至关重要.
- 亚利法胺呈现出多样化的结构,影响其电子性质和键强度.
研究的目的:
- 使用光声热度计测量各种异形胺的BDE.
- 调查控制氨基中的C-H和N-H键强度的电子和结构因素.
- 为了将实验BDE与理论计算相关联.
主要方法:
- 采用光声热度计来实验性地确定BDE.
- 计算化学方法 (CBS水平) 用于理论验证.
- 分析电子相互作用 (例如,两轨三电子,超) 和几何效应.
主要成果:
- 不受约束的阿里法胺的α ((C-H) BDEs始终在91kcal/mol左右.
- N-化,O-化和基组的引入对alpha (C-H) BDEs的影响很小.
- 由于氨基基基稳定,N-H BDE从初级氨基减少到二级氨基.
- 循环和固态阻碍的氨基体表现出与轨道几何学和应变放松相关的BDE变异.
结论:
- 柔性氨基酸中alpha ((C-H) BDEs的主要因子是N-alphaC相互作用.
- 在C-C键中的过度结合稳定了氨基基基,影响N-H BDEs.
- 循环和拥挤氨基的几何约束通过轨道相互作用和应变调节BDE.
相关概念视频
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Acid-catalyzed hydrolysis:
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NMR Spectroscopy and Mass Spectrometry of Aldehydes and Ketones
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 doublet for an aldehydic...

