Microviscosity inside a Nanocavity: A Femtosecond Fluorescence Up-Conversion Study of Malachite Green

摘要: Femtosecond fluorescence up-conversion measurements of malachite green (MG) have been carried out to confirm the relaxation pathway and subsequently probe microviscosity water trapped in a nanoconfined environment using an AOT (sodium dioctylsulfosuccinate, aerosol-OT) reverse micelle as model system. The experimental results reveal strong dependence S(1) state dynamics MG on solvent viscosity while very weak has observed for S(2) relaxation. time-dependent density functional theory (TD-DFT) calculations used construct potential energy surfaces by pursuing intramolecular rotation along torsional coordinate phenyl rings. On synchronization with observations, computational comprehend existence conical intersection S(0) surfaces, which leads mixed vibrational levels characteristics. suggest that is N,N-dimethyl substituted ring. Correlating confined system time different glycerol-water mixtures, we assert determination inside micelle. data confer pool w(0) = 2 (9 cP) almost 9 times higher than bulk water. As increase from 40, decreases monotonically 5.68 cP, decrease be exponential nature.