Low-Frequency Raman Scattering in Colliding Benzene Droplets.

Low-frequency intermolecular motions are of importance for understanding the structure of molecular liquids, which can be elucidated by Raman spectroscopy. A liquid droplet provides a field where stimulated Raman scattering (SRS) readily proceeds. Our previous study showed that multiorder SRS is more effectively generated in colliding droplets than a single droplet. Here we report that the multiorder SRS generated in colliding benzene droplets included low-frequency bands of the liquid benzene, which is considered to represent a temporal state of liquid emerging in the course of the droplet collision. This method enables measurements of the low-frequency intermolecular motions of the novel liquid state emerging at the mixed region of the colliding droplet without suffering from background of Rayleigh scattering.