Exciplex and ion pair quenching in a chiral hexahelicene-amine system
- Publikations-Art
- Zeitschriftenbeitrag
- Autoren
- Rau, H.; Totter, F.
- Erscheinungsjahr
- 1992
- Veröffentlicht in
- J. Photochem. Photobiol., A
- Band/Volume
- 63/3
- Seite (von - bis)
- 337-47
Quenching of the fluorescence of hexahelicene (HH) by N-methyl-N-(2-methylbutyl)aniline (MMBA) is strongly dependent on the solvent: no quenching is obsd. in nonpolar solvents, exciplex quenching is seen in medium polar solvents (.epsilon. in the range 10-24) and ion pair quenching is found in highly polar solvents (acetonitrile, .epsilon. = 37). Exciplex and ion pair quenching are parallel pathways in the quenching of the fluorescence of HH* as demonstrated in methanol soln. (.epsilon. = 32); the solvent dets. which is preferred. The asymmetry of the quenching of the enantiomers of HH by (S)-(+)-MMBA is, if present, only small and within exptl. error.