INTRAMOLECULAR CHARGE-TRANSFER NEAR A HYDROPHOBIC SURFACE - 2,6-P-TOLUIDINONAPHTHALENE SULFONATE IN A REVERSE MICELLE

Intramolecular charge transfer (ICT) processes of 2,6-p-toluidinonapht halene sulfonate (TNS) in the water pool of sodium dioctyl sulfosuccin ate (AOT) reverse micelle in heptane, is studied using picosecond emis sion spectroscopy. It is observed that while in aqueous solutions the lifetime (tau(f)) of TNS is 80 ps, tau(f) increases to 4 ns in the mic roemulsion with water to AOT ratio, w(0)=4. With increase in w(0) as t he water pool swells in size, the lifetime and quantum yield of emissi on decrease and the rate of the ICT process increases. However, the ma gnitude of the change (at most approximate to 70 times at w(0)=4) in t he rate of the ICT process of TNS compared to ordinary water is smalle r than the several thousand fold retardation in the solvation dynamics of water in such a water pool relative to bulk water. This is attribu ted to the fact that while the solvation dynamics in the water pool is governed by the dielectric relaxation, dynamics of the ICT process is controlled by the static polarity of the medium.