在IR,NIR和可见范围内推进VCD光谱的测量和解释,以达到可检测性和计算复杂性的极限
Marco Fusè1, Giuseppe Mazzeo1, Julien Bloino2
1Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Viale Europa 11, 25123, Brescia, Italy.
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy
|October 13, 2023
概括
这项研究分析了 (R) - 烯.
科学领域:
- 频谱学是一种光谱学.
- 计算化学的计算化学
- 有机化学 有机化学
背景情况:
- 振动循环二极化 (VCD) 和红外 (IR) 光谱对于分子结构的阐明至关重要.
- 了解像 (R) - 氨这样的奇拉分子的光谱模式,可以了解立体化学.
- 纳菲等人之前的研究. 和布雷西亚集团在烯光谱学方面奠定了基础.
研究的目的:
- 解释 (R) - 烯的VCD和IR吸收光谱在一个广泛的光谱范围 (90016000厘米-1).
- 在高音和组合区域调查新的VCD数据.
- 为特定的分子振动赋予光谱特征,特别是CH拉伸模式.
主要方法:
- 利用现有的VCD和IR数据,补充了特定频谱区域的新测量.
- 使用密度函数理论 (DFT) 采用GVPT2的无方法进行光谱解释.
- 在DFT中应用了局部模式 (LM) 方法,以详细分析CH延伸区域.
主要成果:
- 在GVPT2方法成功地解释基本和高音/组合模式高达9000厘米-1.1.
- 局部模式模型准确地复制了所有CH-stretching区域 (基本和附加色) 中观察到的光谱.
- 对于所有泛音,观察到一个恒定的VCD模式,由局部模式模型支持.
结论:
- 局部模式模型为 (R) - 烯的观察到的VCD光谱提供了可靠的解释.
- 双信号VCD频谱的特定组件被分配给轴向和赤道CH键拉伸.
- 这种详细的光谱分析增强了对性分子振动的理解.
相关概念视频
01:02Ultraviolet and Visible (UV–Vis) Spectroscopy: Overview
2.8K
Ultraviolet–visible (UV–visible or UV–Vis) spectroscopy is an analytical technique that investigates the interaction between matter and UV–Vis light within the electromagnetic spectrum. This method is widely used for its versatility, simplicity, and relatively quick data acquisition, making it valuable for both qualitative and quantitative analysis. When UV–Vis radiation passes through a material, molecules absorb light depending on the energy required for...
2.8K
01:09Infrared (IR) Spectroscopy: Overview
1.9K
When electromagnetic radiation passes through a material, atoms or molecules transition from a lower to a higher energy state by absorbing radiation corresponding to the energy difference between the two states. The absorption of infrared (IR) radiation causes transitions between vibrational energy levels in a molecule. Therefore, IR spectroscopy is a useful analytical tool for determining the molecular structure of molecules.
Different compounds display unique properties due to their...
Different compounds display unique properties due to their...
1.9K
01:24IR Spectroscopy: Molecular Vibration Overview
2.4K
When Infrared (IR) radiation passes through a covalently bonded molecule, the bonds transition from lower to higher vibrational levels. The fundamental vibrational motions that result in infrared absorption can be classified as stretching or bending vibrations.
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
2.4K
01:11Applications of IR Spectroscopy: Overview
773
The non-destructive nature and ability to provide valuable chemical information make IR spectroscopy a versatile technique with broad applications in various scientific and industrial fields. IR spectroscopy is commonly used to identify and characterize organic and inorganic compounds. It provides information about the functional groups present in a molecule and the bonding between atoms. This helps in the structural elucidation of compounds during organic synthesis, pharmaceutical research,...
773
01:03IR Frequency Region: Fingerprint Region
919
IR spectra are divided into two main regions: the diagnostic region and the fingerprint region. The diagnostic region of the spectrum lies above 1500 cm−1. The absorptions resulting from single-bond vibrations of the N–H, C–H, and O–H stretch at higher wavenumbers and appear on the left side of the spectrum. The stretching absorptions of the C≡C and C≡N occur between 2100–2300 cm−1. In contrast, those arising from stretching absorptions of the...
919
01:14UV–Vis Spectrometers
1.4K
The absorbance of UV and visible (UV–visible) radiations is measured using a UV–visible spectrophotometer. Deuterium lamps, which emit UV radiation, and tungsten lamps, which produce radiation in the visible region, are used as light sources in UV–visible spectrophotometers. A monochromator or prism is used for diffraction grating, i.e., to split the incoming radiation into different wavelengths. A system of slits is used to focus the desired wavelength on the sample cell.
1.4K