Heterogeneous solvent dynamics and time-resolved optical linewidths

Abstract The time resolved inhomogeneous optical linewidth observed in solvation dynamics experiments is sensitive to the nature of the solvent dynamics, homogeneous or heterogeneous. Linewidth data are assessed with regard to intrinsic non-exponentiality, the length scale of heterogeneity, and the time scale of rate exchange. For the glass-forming solvent under study, heterogeneity is found for average relaxation times in the range 3 ms to 54 s and in the regime of nanosecond dynamics.