MICELLAR EFFECTS ON THE TWISTED INTRAMOLECULAR CHARGE-TRANSFER

Micellar Effects on the twisted intramolecular charge transfer (TICT) of p-N, N-dimethylaminobenzaldehyde (DMABA) in aqueous solution is investigated. It is observed that micelle promotes the TICT process of DMABA, increases the total fluorescence quantum yield of DMABA, and shifts TICT fluorescence band dramatically to blue. The ratio of the intensity of TICT fluorescence to that of normal fluorescence is proportional to DMABA concentration, and the presence of micelle increases the slope of the line of the ratio versus DMABA concentration, It is concluded that the TICT state of DMABA may concern with two DMABA molecules and the key factors that affect the relative population of TICT excited state of DMABA are the energy gaps between the TICT state and the corresponding triplet state and between the TICT state and the ground state. The probable structure of the TICT state of DMABA and the intrinsic properties of micellar effects are discussed.