A fluorochrome from aniline blue: structure,synthesis and fluorescence properties

Abstract

A fluorochrome has been isolated in analytically pure form from a commercial sample of the triaryl-methane dye aniline blue. Its structure has been shown to be sodium 4,4'-[carbonylbis(benzene-4,1-diyl)bis(imino)]bisbenzenesulfonate by spectroscopic means and confirmed by synthesis. Its fluorescence emission, which is markedly solvent-dependent, is 150 times greater in butan-1-ol than in water (however, the wavelength of the emission maximum is not altered significantly). In the presence of a cationic surfactant, hexadecyltrimethylammonium bromide, the fluorescence intensity reaches a maximum at approximately the critical micelle concentration of the surfactant.