Hydrophobicity-induced aggregation of N-alkyl-4-aminophthalimides in aqueous media probed by solvatochromic fluorescence

The fluorescence response of a series of n-alkanes of different chain length, all labelled with an environmentally sensitive fluorophore, is reported in aqueous media. It is shown that solvent-sensitive fluorescence properties of 4-aminophthalimide allow one to monitor subtle changes in the microenvironment of the fluorophore resulting from aggregation or self-coiling of the molecules. A new fluorescence that is observed in aqueous media for the higher homologues of the series has been unambiguously assigned to the aggregates of the molecules.