Photophysics, Electrochemistry, Morphology, and Bioimaging Applications of New 1,8-Naphthalimide Derivatives Containing Different Chromophores.

A series of 1,8-naphthalimide-based fluorophores containing different chromophores with varying conjugation and electron richness at the imidic nitrogen atom are synthesized and characterized. These amine-functionalized naphthalimides are bipolar in nature and exhibit interesting optical and morphological variations attributable to the nature of the N substituents. Despite the fact that the dyes are structurally different owing to variation of the substituent on the imidic nitrogen atom, their electronic characteristics are similar and originate from the 4-aminonaphthalimide segment. Nevertheless, they exhibit variations in morphology in the microscopic domain, and this is attributable to structural differences. Further, these fluorescent dyes display biocompatibility and are used in the bioimaging of cells.