Time-resolved fluorescence studies of aminostyryl pyridinium dyes in organic solvents and surfactant solutions

摘要: Absorption, fluorescence emission spectra and lifetimes of N-alkyl-4-(p-N,N-dimethyl aminostyryl) pyridinium dyes varying lengths alkyl chain have been measured in different organic solvents (protic, dipolar aprotic aprotic) surfactant solutions. The for the are similar a single solvent but vary with type. Stokes shift dye does not parameter as predicted by Lippert–Mataga equation. decay shows two except few where or three were obtained. lifetime results interpreted terms from cis quinoid (or intramolecular charge transfer, ICT) forms excited state. isomer (synthesized stable compound) confirmed coexistence multiple species. In solutions, depend upon length concentration surfactant, namely, premicellar post micellar. Dye–surfactant complexes identified cases SDS CTAB TX-100 is found to stabilize all dyes, whereas both surfactants trans predominantly.