Influence of the N-alkyl chain length on the J-aggregation behavior of a cyanine dye.
A new series of benzimidocarbocyanine dyes having diffeerent N-alkyl chain lengths (C2-C12) but the same chromophoric system was synthesized to investigate the effect of the dye structure on the photophysical properties of J-aggregate-forming dyes. For these dyes, the number of J-absorption band depends on the chain length of the alkyl substiuents, whereas the fluorescence emission spectra exhibit only a single J-band. Furthermore, an increase in the N-alkyl-chain length leads to a strong decrease in the bandwidth of the J-absorption and emission bands.
Laboratory for Time-Resolved Spectroscopy, Federal Institute for Matcrials Research and Testing, Rudower Chaussee 5, D-12489, Berlin, Germany.
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U
De Rossi
J
J
Moll
J
J
Kriwanek
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Daehne