Pressure as a Tool to Investigate Vibrational Fermi Resonance in Molecular Liquids: Study of Liquid Methanol up to 20 kbar by Raman Microscopy

摘要

Vibrational Fermi resonance often occurs in the 2900 cm~(-1) spectral region of many organic compounds. Coupling between the CH symmetric stretch and a HCH bend overtone yields two mixed states. The relative splitting continuously changes with pressure and produces frequency shifts and intensity changes of the mixed bands. Raman Microscopy allows us to investigate the pressure-induced changes over a range of frequencies by measuring changes in relative positions and intensities in the Raman spectra. In the present study we examine the vibrational coupling as a function of pressure of liquid methanol up to 20 kbar in a Sapphire Anvil Cell (SAC) by Raman scattering at room temperature.