Novel method for selective probing of ground-state rotational dynamics of solutes in solvents

摘要

We introduce an optical pump/probe method that allows selective measurement of ground-state rotational dynamics of solutes in liquids.It relies on employing two successive pump pulses that are adjusted to create an optical anisotropy due to the orientational distribution of only the ground-state solute molecules.Measurement on a dye-solvent system shows a large difference between the rotational diffusion rates of the ground state and the excited state of the dye molecules due to different solute-solvent interactions.