极化器-分析器配置对FTIR光谱学的影响:对多重极化算法的影响
Callum Gassner1, Ankit Dodla1,2, Aaron Mclean1
1Monash Biospectroscopy Group, School of Chemistry, Monash University, Clayton 3800, Australia.
The journal of physical chemistry. B
|April 23, 2024
概括
在极化里叶变换红外光谱 (p-FTIR) 中添加第二个极化器可以改变光谱数据. 这项研究探讨了这些效应,揭示了分析样本异性质的新方法,即使对于更厚的材料.
科学领域:
- 频谱学是一种光谱学.
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
背景情况:
- 极化里叶变换红外光谱 (p-FTIR) 对于分析有机材料中的分子方向至关重要.
- 传统的p-FTIR使用单个偏振器,但第二个偏振器 (分析器) 可以引入意想不到的光谱变化.
- 这些取决于偏振的变异,源于样本诱导的光偏振变化,尚未在p-FTIR中得到充分研究.
研究的目的:
- 为了研究第二个偏光器对p-FTIR光谱的异性质有机样本的影响.
- 在p-FTIR中探索极化器-分析器配置的理论和实验效应.
- 确定p-FTIR的新分析可能性,特别是用于检测样本异性质.
主要方法:
- 利用理论建模和实验测量.
- 在薄薄的异性质有机样本中分析了由双折射引起的光谱变异.
- 研究了交叉和并行偏振器配置的影响.
主要成果:
- 由于薄样本中的二重折射,最显著的光谱变异出现在二重峰的肩膀上.
- 交叉偏振器配置使得在通常太厚的样本中检测到异性质.对于标准的p-FTIR来说.
- 吸收率的标准平方-小关系与第二个并行偏振器是不准确的.
结论:
- 在p-FTIR中加入第二个偏振器可以显著影响光谱数据和分析结果.
- 使用交叉偏振器利用二合色峰肩上的光谱特征,为分析更厚的异性质材料提供了一种新的方法.
- 提出了一个修改后的函数,用于p-FTIR分析,准确地描述多个极化器配置中的吸收率.
更多相关视频
05:54Author Spotlight: Non-Invasive Imaging of Complex Bio-Structures Using Polarization-Sensitive Two-Photon Microscopy
Published on: September 8, 2023
1.2K
00:07A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
8.5K
相关概念视频
03:09Measuring Reaction Rates
25.0K
Polarimetry finds application in chemical kinetics to measure the concentration and reaction kinetics of optically active substances during a chemical reaction. Optically active substances have the capability of rotating the plane of polarization of linearly polarized light passing through them—a feature called optical rotation. Optical activity is attributed to the molecular structure of substances. Normal monochromatic light is unpolarized and possesses oscillations of the electrical...
25.0K
01:25IR Spectrometers
1.1K
There are two main infrared (IR) spectrophotometers: dispersive IR spectrometers and Fourier transform infrared (FTIR) spectrometers. In a dispersive IR spectrometer, a beam of infrared radiation produced by a hot wire is divided into two parallel equal-intensity beams using mirrors. One beam passes through the sample, while another is a reference beam. The beams then move through the monochromator, which separates the radiations into a continuous spectrum of different frequencies. The...
1.1K
01:20¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
1.0K
When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
1.0K
01:03IR Frequency Region: Fingerprint Region
873
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...
873
01:12Double Resonance Techniques: Overview
199
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
Spin decoupling is usually achieved by...
199
02:24Properties of Enantiomers and Optical Activity
17.0K
It is essential to understand the difference between chiral and achiral interactions and the implications thereof in optical activity and their applications. Just as our feet, which are chiral, interact uniquely with chiral objects, such as a pair of shoes, but identically with achiral socks, enantiomers of a molecule exhibit different properties only when they interact with other chiral media. An example of a significant implication from this facet is the phenomenon known as optical activity,...
17.0K