Jove
Visualize
联系我们
JoVE
x logofacebook logolinkedin logoyoutube logo
关于 JoVE
概览领导团队博客JoVE 帮助中心
作者
出版流程编辑委员会范围与政策同行评审常见问题投稿
图书馆员
用户评价订阅访问资源图书馆顾问委员会常见问题
研究
JoVE JournalMethods CollectionsJoVE Encyclopedia of Experiments存档
教育
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab Manual教师资源中心教师网站
使用条款与条件
隐私政策
政策

相关概念视频

Stability of Substituted Cyclohexanes02:30

Stability of Substituted Cyclohexanes

This lesson discusses the stability of substituted cyclohexanes with a focus on energies of various conformers and the effect of 1,3-diaxial interactions.
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
Combustion Energy: A Measure of Stability in Alkanes and Cycloalkanes02:14

Combustion Energy: A Measure of Stability in Alkanes and Cycloalkanes

The low reactivity in alkanes can be attributed to the non-polar nature of C–C and C–H σ bonds. Alkanes, therefore, were  initially termed as “paraffins,” derived from the Latin words: parum, meaning “too little,” and affinis, meaning “affinity.”
Alkanes undergo combustion in the presence of excess oxygen and high-temperature conditions to give carbon dioxide and water. A combustion reaction is the energy source in natural gas, liquified petroleum gas (LPG), fuel oil, gasoline, diesel fuel, and...
Stereoisomerism of Cyclic Compounds02:33

Stereoisomerism of Cyclic Compounds

In this lesson, we delve into the role of ring conformation and its stability, which determines the spatial arrangement and, consequently, the molecular symmetry and stereoisomerism of cyclic compounds. 1,2-Dimethylcyclohexane is used as a case study to evaluate the possible number of stereoisomers. Here, given the multiple (n = 2) chiral centers, there are 2n = 4 possible configurations that lack a plane of symmetry, as the ring skeleton exists in a non-planar chair conformation. In addition,...
Distillation: Vapor–Liquid Equilibria01:01

Distillation: Vapor–Liquid Equilibria

Distillation is a separation technique that takes advantage of the boiling point properties of disparate elements in a mixture. To perform distillation, we begin by heating a miscible mixture of two liquids with a significant difference in boiling points (at least 20°C). As the solution heats up and reaches the bubble point of the more volatile component, some molecules of the more volatile component transition into the gas phase and travel upward into the condenser, which is a glass tube with...
Aromatic Compounds: Overview01:25

Aromatic Compounds: Overview

In general, the term ‘aromatic’ indicates a pleasant smell or fragrance from fresh flowers, freshly prepared coffee, etc. In the early history of organic chemistry, many benzene derivatives were isolated from the pleasant odor oils of the plants. For example, vanillin was isolated from the oil of vanilla, methyl salicylate from the oil of wintergreen, and cinnamaldehyde from the oil of cinnamon. They all had a pleasant odor; hence the name aromatic was given.
In 1825, Faraday isolated benzene...
Stability of Conjugated Dienes01:28

Stability of Conjugated Dienes

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.

您也可能阅读

相关文章

通过共同作者、期刊和引用图与本文相关的文章。

排序
Same author

Gastrointestinal bypass surgery for non-strangulated adhesive small bowel obstruction.

Surgery today·2026
Same author

Diagnosing method conditioned bias in mineral resource estimation using a mutual information and entropy uncertainty indicator.

Scientific reports·2026
Same author

H<sub>2</sub>O‑Dissociative Adsorption on Mg(0001) SurfaceCorrosion Process under Atmospheric Conditions.

ACS omega·2026
Same author

Megacolon Associated with Multiple Endocrine Neoplasia Type 2B: A Case Successfully Managed with Ileostomy.

Surgical case reports·2026
Same author

Selective Hydrogenation of Formamide to Methanol Over Supported Platinum Catalysts.

Angewandte Chemie (International ed. in English)·2026
Same author

Cobalt-Catalyzed Highly Regioselective Alkoxycarbonylation of Olefins Driven by Light.

Journal of the American Chemical Society·2026

相关实验视频

Updated: Jul 17, 2026

Rapid Collection of Floral Fragrance Volatiles using a Headspace Volatile Collection Technique for GC-MS Thermal Desorption Sampling
05:22

Rapid Collection of Floral Fragrance Volatiles using a Headspace Volatile Collection Technique for GC-MS Thermal Desorption Sampling

Published on: December 10, 2019

稳定性和芳香度的循环-合的烯同源物.

Remco W A Havenith1, Haijun Jiao, Leonardus W Jenneskens

  • 1Department of Physical Organic Chemistry, Debye Institute, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.

Journal of the American Chemical Society
|March 7, 2002
PubMed
概括

环和化烯化合物的芳香度随着化环的数量增加而下降. 西格玛菌株,不仅仅是电子因素,影响稳定性,导致独特的磁性和复杂的同源体中的碗形结构.

更多相关视频

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy
07:36

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy

Published on: November 9, 2019

Tea Aroma Analysis Based on Solvent-Assisted Flavor Evaporation Enrichment
04:36

Tea Aroma Analysis Based on Solvent-Assisted Flavor Evaporation Enrichment

Published on: May 26, 2023

相关实验视频

Last Updated: Jul 17, 2026

Rapid Collection of Floral Fragrance Volatiles using a Headspace Volatile Collection Technique for GC-MS Thermal Desorption Sampling
05:22

Rapid Collection of Floral Fragrance Volatiles using a Headspace Volatile Collection Technique for GC-MS Thermal Desorption Sampling

Published on: December 10, 2019

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy
07:36

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy

Published on: November 9, 2019

Tea Aroma Analysis Based on Solvent-Assisted Flavor Evaporation Enrichment
04:36

Tea Aroma Analysis Based on Solvent-Assisted Flavor Evaporation Enrichment

Published on: May 26, 2023

科学领域:

  • 计算化学计算化学
  • 有机化学 有机化学
  • 材料科学 材料科学 材料科学

背景情况:

  • 烯及其化衍生物是具有独特电子和结构性质的多环芳.
  • 了解复杂的化系统的芳香度和稳定性对于设计新型有机材料至关重要.

研究的目的:

  • 通过使用理论方法,研究循环-化烯同源的芳香性.
  • 为了将热力学稳定性与磁性相关联,并分析化环对芳香度的影响.

主要方法:

  • 使用了不同级别的理论计算.
  • 计算了共振能量,磁性特性 (例如,delta{1}H,磁性敏感性异质,NICS值) 和总能量 (E{2}tot).
  • 为了评估稳定性,计算了同位素反应能量和芳香稳定能量 (ASE(isom)).

主要成果:

  • 芳香度随着合的五个环数量的增加而减少.
  • 双cyclopentapyrenes的热力学稳定性顺序不同于从磁性标准获得的芳香度顺序.
  • 西格玛压力对这些融合系统的稳定性产生重大影响,在某些情况下会超过电子效应.
  • 四环环[cd,fg,jk,mn]烯采用碗形结构,其平面形式是过渡状态.

结论:

  • 这项研究揭示了循环-化烯中结构,稳定性和芳香度之间的微妙关系.
  • 西格玛菌株是确定这些复杂的多环芳的热力学稳定性的关键因素.
  • 理论计算为潜在难以捉摸的化烯系统的特性提供了洞察力.