Solvation dynamics of Coumarin 153 in aqueous and non-aqueous reverse micelles

The solvation dynamics of water, methanol and acetonitrile in n-heptane/AOT/water, n-heptane/AOT/methanol and n-heptane/AOT/acetonitrile reverse micelles have been investigated by picosecond time-resolved emission spectroscopy using rigid and neutral probe, Coumarin 153 (C-153). We have observed a substantially slow dynamics (order of few nanosecond) in all the three reverse micelles compared to pure solvents. The w dependency of solvation time is observed in case of water and methanol reverse micelles. However, a very little w dependency is observed in case of acetonitrile reverse micelles. Moreover, fluorescence anisotropy measurements are used to characterize rotational motion of C-153 in all the three reverse micelles.