Study of molecular association in acetic acid-water binary solution by Raman spectroscopy

Bo Yang; Yeqiu Li; Nan Gong; Xianwen Cao; Shenghan Wang; Chenglin Sun

doi:10.1016/j.saa.2018.08.029

Study of molecular association in acetic acid-water binary solution by Raman spectroscopy

Spectrochim Acta A Mol Biomol Spectrosc. 2019 Apr 15:213:463-466. doi: 10.1016/j.saa.2018.08.029. Epub 2018 Aug 17.

Authors

Bo Yang¹, Yeqiu Li², Nan Gong¹, Xianwen Cao¹, Shenghan Wang³, Chenglin Sun⁴

Affiliations

¹ Coherent Light and Atomic and Molecular Spectroscopy Laboratory, College of Physics, Jilin University, Changchun 130012, China.
² Coherent Light and Atomic and Molecular Spectroscopy Laboratory, College of Physics, Jilin University, Changchun 130012, China; Key Laboratory of Physics and Technology for Advanced Batteries, College of Physics, Jilin University, Changchun 130012, China. Electronic address: yeqiuli@sylu.edu.cn.
³ Coherent Light and Atomic and Molecular Spectroscopy Laboratory, College of Physics, Jilin University, Changchun 130012, China; Key Laboratory of Physics and Technology for Advanced Batteries, College of Physics, Jilin University, Changchun 130012, China. Electronic address: shenghan@jlu.edu.cn.
⁴ Coherent Light and Atomic and Molecular Spectroscopy Laboratory, College of Physics, Jilin University, Changchun 130012, China; Key Laboratory of Physics and Technology for Advanced Batteries, College of Physics, Jilin University, Changchun 130012, China. Electronic address: chenglin@jlu.edu.cn.

PMID: 30772663
DOI: 10.1016/j.saa.2018.08.029

Abstract

Raman spectra of acetic acid-water binary solutions with different concentrations have been measured in order to study molecular association of acetic acid. We find that the symmetric and asymmetric OH stretching vibration of water (3242 and 3443 cm^-1) have marked changes of Raman shift when the volume fraction of acetic acid (V_AA) is 0.3 and 0.8, respectively, which demonstrates that the hydrogen bonding of the water is affected, causing association molecule (acetic acid-water structure) to undergo two phase transitions. Furthermore, the peak of the HCH bending vibration is blue-shifted at V_AA = 0.8, which shows that the acetic acid-acetic acid structure undergoes a phase transition and the acetic acid side-on dimer is formed. These results also indicate that the CH vibration mode in CH⋯O is HCH bending vibration. Finally, the phase transition process of association molecules (hydrated monomer, linear dimer, acetic acid side-on dimer and water-separated dimer) has been obtained in acetic acid-water binary solutions through theoretical analysis.

Keywords: Acetic acid-water binary solution; Hydrogen bond; Molecular association; Phase transition; Raman spectroscopy.