Dual fluorescence of 2-phenoxyaniline

818-8242-Phenoxyaniline (2POA) shows a dual fluorescence in hydrogen bonding solvents. The increase in Stokes shift with increase in polarity is much more for longer wavelength abnormal fluorescence band (FA) than for shorter wavelength fluorescence band (FN). It is found that FA band arises only due to bulk properties of solvent and not due to complex formation. A mechanism involving twisted intramolecular charge transfer (TICT) state is proposed for the dual fluorescence of 2POA. pHstudies indicate that the stretched sigmoid curve obtained for the neutral-monocation equilibrium is due to overlap of proton induced fluorescence quenching and monocation formation curves