ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Novel Bis(dimethinemerocyanine) Dyes with Isolated Chromophores in the Molecule Containing the Sulfobutyl Group and their Aggregation Tendency in Aqueous SolutionThe bis(dimethinemerocyanine) dyes 7a-c with Chromophores separated by a polymethylene chain as ‘isolator’ are synthesized in good yield. Their aggregation tendency in organic solvents, organic solvents/H2O mixtures, and in H2O is investigated. In organic solvents, the dyes 7a-b show a splitted absorption band, due to interaction of the two Chromophores of the dye. In H2O, 7a exhibits an intense absorption band at 496 nm (∊ = 224 300 1·mol-1·cm-1) with a small width \documentclass{article}\pagestyle{empty}\begin{document}$ (\tilde v_{{\raise0.7ex\hbox{$1$} \!\mathord{\left/ {\vphantom {1 2}}\right.\kern-\nulldelimiterspace} \!\lower0.7ex\hbox{$2$}}} = 1000\;{\rm cm}^{ - 1}) $\end{document} and shoulders at 552 and 580 nm. In presence of starch, this absorption band shifts to 617 nm, probably due to J-aggregation. The dye 7b shows the same spectral behaviour as 7a. In contrast, 7c exhibits an absorption band without splitting in organic solvents; the interaction of the Chromophores has disappeared. In H2O and in H2O containing starch, 7c shows a wide absorption band, due to interaction of the Chromophores of the dye.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19890720403
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