The ultrafast dynamics of liquid 1-octanol measured by femtosecond optical Kerr effect

The ultrafast dynamics of pure 1-octanol, occurring in the first ten picoseconds, is investigated as a function of temperature by time-resolved Optical Kerr Effect (OKE) and the results compared to data obtained by Rayleigh scattering (DRS) and Molecular Dynamics (MD) simulations. Distinct time regimes are detected using both OKE spectroscopy and DRS measurements. A relaxation process of ~ 2 ps observed in the present work is comparable to that assigned, for similar systems, to the breaking and reforming of H-bonds. A short relaxation mechanism of ~ 0:3 ps is also clearly identified. The relative amplitude of this process increases with increasing temperature. The ultrafast dynamics, corresponding in the frequency domain to a band centered at 50 cm^-1 is attributed to the librations of the molecules within the cages formed inside the liquid.