Fluorescence of acridine and acridine 9-carboxylic acid in anionic micelles

✍ Scribed by G.M.M. Medeiros; M.F. Leitão; Sílvia M.B. Costa

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 704 KB
• Volume: 72
• Category: Article
• ISSN: 1010-6030
• DOI: 10.1016/1010-6030(93)80018-5

✦ Synopsis

Using steady state and transient state fluorescence techniques, a comparative study of fluorescence parameters of acridine and acridine 9-carboxylic acid in water and sodium dodecyl sulphate (SDS) micelles, at controlled pH, is presented.

When fluorescence probes are micellized, the fluorescence quantum yields are low, ~=0.02~.06, and the fluorescence decays are complex. The radiative constants k, are (l-2) x 10' s-l in both media, but the nonradiative constants increase 20 times in acridine and twentyfold to thirtyfold in acridine 9-carboxylic acid.

The data point to a lowest excited state v**, with increased mixing of n-r* in acridine 9-carboxylic acid accounting for a significant increase in the non-radiative constants k,, (2x lo* s-') in Hz0 and SDS in spite of the efficiency of hydrogen bonding.