Fluorescence properties of surface-active styrylcyanine molecular rotors

✍ Scribed by M.S.A. Abdel-Mottaleb; A.M.K. Sherief; A.A. Abdel-Azim; M.M. Habashy; L.F.M. Ismail

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 595 KB
• Volume: 44
• Category: Article
• ISSN: 1010-6030
• DOI: 10.1016/1010-6030(88)80088-1

✦ Synopsis

This paper reports on some photophysical properties of a newly synthesized styrylcyanine chromogen 1 of electron donor-acceptor type, namely l-cetyl-4-[ 4'-(NJV-dimethylamino)-styryl J -pyridinium bromide. The fluorescence properties of this self-organized surfactant chromogen were studied in non-homogeneous media. Its fluorescence shows a sensitivity to environmental factors which could be exploited profitably as a fluorescence probe in various systems of industrial and biological importance. A remarkable enhancement in its fluorescence efficiency was observed in a rigid ethanol matrix at 77 K and in micellar solutions. Moreover, a considerable edge-excitation red shift was observed in a PMMA matrix at room temperature similar to that found in glassy ethanol. The results provide some information on the free-volume distribution in a PMMA matrix, The changes noted can be rationalized, relative to the shortchain model compound 2, in terms of an enhanced sensitivity of the highly organized and tightly packed molecules 1 to viscosity-torsional reactions between solute and solvent.