相关实验视频
Updated: Jun 29, 2026

10:40
High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
Published on: June 28, 2016
碳甲基化碳:光谱学,理论,化学和运动学
I Likhotvorik1, Z Zhu, E L Tae
1Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210, USA.
Journal of the American Chemical Society
|June 21, 2001
概括
甲基的光解产生了一种持久的碳基物种. 这种碳化合物.
科学领域:
- 有机化学 有机化学
- 摄影化学的使用.
- 频谱学是一种光谱学.
背景情况:
- 碳是有机合成中至关重要的高度反应性的中间体.
- 了解碳稳定性和反应性是开发新合成方法的关键.
- 甲基8-chloro-3a,7a-methanoindan-8-carboxylate作为一种特定的碳素的前体.
研究的目的:
- 为了表征光化学生成的碳素甲基化碳素 (6).
- 在各种溶剂中研究碳6的反应性和运动参数.
- 确定碳消失的激活能量及其与沃尔夫重排的关系.
主要方法:
- 甲基8--3a,7a-甲胺-8-碳酸盐 (5) 在 254 nm 和 300 nm 的光解.
- 红外 (IR) 和紫外线光谱学用于碳化合物的表征.
- 密度函数理论 (DFT) 的计算 (B3-LYP/6-31G).
- 激光闪光光解 (LFP) 使用XeCl排泄激光 (308nm).
- 在弗里昂-113和 perfluorohexane 的动力学研究,以确定碳的寿命和反应速率常数.
主要成果:
- 碳甲基化碳素 (6) 在 14 K. 产生为持久物种.
- 红外光谱显示卡尔6的非平面单片基态.
- 在溶液中的光解产生了印丹 (97%的产量).
- 碳6通过CH插入和双键添加表现出捕获反应.
- 激光闪光光解使得可以测量碳的寿命 (114 ns在-113中) 和与金的反应速率 (2 x 10^9 M^-1 s^-1).
- 在不同的溶剂中确定了碳消失的激活能量,这表明了沃尔夫重排的下限.
结论:
- 碳甲基化碳素 (6) 是一种稳定,可特征的碳素物种.
- 碳6的反应性取决于溶剂,表现出插入和添加反应.
- 动力学数据提供了关于碳化合物的稳定性和潜在的重排路径的见解.
- 这项研究为在合成应用中利用这种碳素奠定了基础.
相关概念视频
UV–Vis Spectrum
When light passes through a substance, a portion of the light is absorbed while the remaining light is reflected or transmitted. If the molecule absorbs light between the wavelengths of 180–400 nm range, the UV spectrum is obtained, and if it absorbs light in the 400–780 nm wavelength range, the visible spectrum is obtained.
The UV–Vis spectrum of a molecule is the plot of its absorbance versus wavelength. The plot is drawn by taking molar absorptivity (ε) or log ε on the y-axis (ordinate)...
The UV–Vis spectrum of a molecule is the plot of its absorbance versus wavelength. The plot is drawn by taking molar absorptivity (ε) or log ε on the y-axis (ordinate)...
IR and UV–Vis Spectroscopy of Carboxylic Acids
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, 1710 cm−1. The C=O bond of the...
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, 1710 cm−1. The C=O bond of the...
Spectroscopy of Carboxylic Acid Derivatives
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 unsymmetrical carbonyl vibration.
In the...
In the...
Molecular Spectroscopy: Absorption and Emission
Molecules possess discrete energy levels called quantum states. Unlike atoms, which have simpler energy levels, molecules possess additional rotational and vibrational energy levels. Each energy level is separated by an energy gap, with the gaps between adjacent electronic, vibrational, and rotational levels varying significantly. The three types of energy levels in a diatomic molecule are shown in Figure 1.
UV–Vis Spectroscopy: Molecular Electronic Transitions
In Ultraviolet–Visible (UV–Vis) spectroscopy, the absorption of electromagnetic radiation is used to probe the electronic structure of molecules. This technique provides insights into molecular electronic transitions, particularly the movement of electrons between different molecular orbitals. Radiation is absorbed if the energy of the electromagnetic radiation passing through the molecule is precisely equal to the energy difference between the excited and ground states. During this process,...
Atomic Spectroscopy: Absorption, Emission, and Fluorescence
Atomic spectroscopy is a vital tool in elemental analysis, both qualitatively and quantitatively. It can be broadly divided into optical spectroscopy, mass spectroscopy, and X-ray spectroscopy methods. The optical spectroscopic methods are atomic absorption spectroscopy (AAS), atomic emission spectroscopy (AES), and atomic fluorescence spectroscopy (AFS). The first step in all three methods is atomization, where the solid, liquid, or solution-phase samples are converted into gas-phase atoms and...

