| Abstract | The fluorescence decays of safranine T were studied in different homogeneous solvents and heterogeneous micellar
solutions. It has been found that micellization leads to an increase in the lifetime. The lifetime distributions were studied
in micelles and homogenous media. It was found that the different half-width distributions of the dye in different
micelles are related to the different orientation of the dye in different micelles. Also, the fluorescence quenching of
safranine T by 4,6-disubstituted-3-cyanopyridin-2(1H)-thiones was studied in chloroform, methanol and acetonitrile as
well as in different micelles. In heterogeneous media the kq values for quenching of safranine T by thiones in various
micelles increase on the following order: kq(CTAB)B/kq(TX-100)B/kq(SDS). This is due to the electrostatic
interactions between the anionic SDS and the cationic moiety of safranine T and therefore the quenching process
will be less significant. |