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Updated: Jun 15, 2026

Interfacial Molecular-level Structures of Polymers and Biomacromolecules Revealed via Sum Frequency Generation Vibrational Spectroscopy
Published on: August 13, 2019
The microscopic structure of liquid methanol from Raman spectroscopy
1Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
Abstract:
The microscopic structure of liquid methanol has been systematically investigated with Raman spectroscopy in a temperature range of 15-55 degrees C. The unbonded free -OH stretching vibrational band has been observed at approximately 3660 cm(-1) in pure liquid. With the aid of depolarization measurements and theoretical calculations, four featured spectral components have been unambiguously identified and assigned to four well-defined vibrational modes of clusters in chain or ring forms. Furthermore, the cluster size distribution and its temperature dependence have been derived from the spectral fittings for the first time, which lead to the conclusion that the trimer, tetramer, and pentamer are the dominant clusters in liquid methanol, taking up more than 50% of total clusters.
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