Polarity effect on fluorescence of styryl derivatives of quinolizinium salts in micellar media

The styryl derivatives of quinolizinium salts show a marked solvatochromic effect. The p-amino and p-hydroxy derivatives exhibited the greatest effect. The fluorescent intensity of the salts dissolved in nine different solvents is shown to be related to their polarity parameters. The emission was highest for hydroxylic solvents. For all solvents the changes in the fluorescence of the styryl derivatives in the presence of various surfactants is also studied; a great increase in intensity was produced in the presence of sodium dodecylsulfate. This enhanced emission was not observed for non-ionic surfactants. This behaviour is discussed ansd also related to solvent polarity.