SYNTHESIS, STRUCTURE, AND EXCIMER FORMATION OF A VESICULAR ASSEMBLY CARRYING CHIRAL 9-ANTHRYL CHROMOPHORES

A new chiral amphiphile carrying two octadecyl chains and a 9-anthryl group was synthesized from d-9-anthrylalanine: (CH3)3N+(CH2)6CONHCH(CH2-9Ant)CON(Ci8H37)2. The amphiphile formed a vesicular assembly in aqueous dispersion, which shows a gel-liquid crystalline transition at 26.5°C. Absorption and CD spectra indicated no strong ground-state interaction between the anthryl groups. Fluorescence spectra showed a strong excimer emission around 548 nm. The excimer to monomer emission intensity ratio increased monotonically with decreasing temperature. The excimer was found to form within ca. 1 ns after photoexcitation. The excimer emission showed a right-handed circular polarization, but the magnitude of the circular polarization was insensitive to the temperature. These results are consistent with an efficient energy migration along the two-dimensional array of anthryl chromophores followed by trapping into a relatively small number of excimer-forming sites. © 1990, American Chemical Society. All rights reserved.