title: Fluorescence decay of singlet excited-state of safranine T and its interaction with ground-state of pyridinthiones in micelles and homogeneous media.
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 homogeneous 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) < kq(TX-100) < 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.
authors.affiliation: Chemistry Department, Faculty of Education, Tanta University, Kafr El-Sheikh 33516, Egypt. elkemary@yahoo.com
authors.forename: Maged A
authors.initials: MA
authors.lastname: El-Kemar
authors.forename: Rehab A
authors.initials: RA
authors.lastname: Khedr
authors.forename: Safaa El-Din H
authors.initials: Sel-D
authors.lastname: Etaiw
mesh_terms: D005453:Fluorescence; D010619:Phenazines / Q000737:chemistry*; D013871:Thiones / Q000737:chemistry*
chemical_list: D010619:Phenazines; D013871:Thiones; C009195:safranine T