Intramolecular Charge Transfer and Solvation Dynamics of Coumarin 152 in Aerosol-OT, Water-Solubilizing Reverse Micelles, and Polar Organic Solvent Solubilizing Reverse Micelles

Abstract

The relative retardation of intramolecular charge transfer (ICT) and the solvation dynamics of coumarin 152 in pure AOT, water, methanol, acetonitrile, and formamide reverse micelles have been investigated using picosecond time-resolved emission spectroscopy. The rate of ICT has been retarded almost 7 times at w0 = 4 and 4 times at w0 = 32 compared to that in pure water. The rate of retardation of ICT is also observed in the methanol and acetonitrile reverse micelles in comparison to that in pure methanol and acetonitrile. In pure AOT, the solvation time is 12.22 ns, but at w0 = 4 of water reverse micelles the solvation time is 7.27 ns. The slow dynamics in methanol, acetonitrile, and formamide reverse micelles is also observed. The relative retardation of the ICT rate is much smaller compared to the several thousand fold decrease in the solvation dynamics in the pool of the reverse micelles. The w dependency of solvation time is observed for water and methanol reverse micelles, but it is little for aceto...