Temperature dependent solvent shift of polyatomic molecules observed by ultrashort two-pulse spectroscopy

Abstract The high spectral resolution of the two-pulse excitation of polyatomic molecules allows the observation of small frequency shifts. A solution of nileblue-A-oxazone in CCl 4 shows a linear temperature dependent blue shift of the 0-0 transition frequency of 3.5 cm -1 /°C which can be attributed to the change of dielectric properties of the solvent.