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Updated: Jul 30, 2025
10:37
Spatial Separation of Molecular Conformers and Clusters
Published on: January 9, 2014
9.0K
The intermolecular polar bond interaction and coupling induced spectral splitting phenomenon for a binary mixture
Huigang Wang1, Zian Wang2, Jiwen Jian1
1Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang, P. R. China. zdwhg@163.com.
Physical Chemistry Chemical Physics : PCCP
|May 17, 2023
Summary
Aggregation-induced spectral splitting theory explains vibrational splitting in polar bonds. This study demonstrates the theory using cryogenic isolation and spectral analysis of acetone and beta-propiolactone, confirming monomer-dimer dynamics.
Area of Science:
- Spectroscopy
- Chemical Physics
- Physical Chemistry
Background:
- The polarization Raman noncoincidence effect and spectral discrepancies between FT-Raman and FT-IR spectra of polar bonds remain areas of interest.
- Aggregation-induced spectral splitting theory offers a potential explanation for these phenomena.
Purpose of the Study:
- To demonstrate the vibration splitting theory using experimental and theoretical approaches.
- To investigate the spectral splitting phenomenon in specific molecules and its dependence on aggregation state and concentration.
Main Methods:
- Cryogenic matrix isolation techniques to improve spectral resolution.
- Acquisition of polarization Raman and two-dimensional infrared (2D-IR) spectra.
- Density Functional Theory (DFT) calculations.
- Analysis of Fourier Transform Infrared (FT-IR) and Fourier Transform Raman (FT-Raman) spectra.
- Concentration-dependent 2D-Correlation Spectroscopy (2D-COS).
Main Results:
- Monomer and dimer splitting bands of acetone were detected using Ar matrix isolation.
- Spectral splitting was clearly observed in beta-propiolactone (PIL)/CCl4 mixtures, with dynamic monomer-dimer transformations detected by adjusting PIL concentration.
- DFT calculations corroborated the observed splitting phenomenon for PIL.
- Concentration-triggered 2D-COS spectra confirmed the splitting and provided insights into dilution kinetics.
Conclusions:
- The vibration splitting theory is effectively demonstrated through experimental spectral analysis and theoretical calculations.
- Spectral splitting is a measurable phenomenon linked to molecular aggregation and concentration.
- The study provides a comprehensive understanding of spectral noncoincidence effects in polar molecules.
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