A. Pawlik et al., STRUCTURAL CONDITIONS FOR SPONTANEOUS GENERATION OF OPTICAL-ACTIVITY IN J-AGGREGATES, JOURNAL OF PHYSICAL CHEMISTRY B, 101(29), 1997, pp. 5646-5651
Achiral molecules of 5,5',6,6'-tetrachlorobenzimidacarbocyanine dyes h
aving 1,1'-di-n-alkyl substituents longer than hexyl combined with 3,3
'-bis(2-acidoethyl) or 3,3'-bis(3-acido-n-propyl) substituents form J-
aggregates whose absorption spectrum exhibits Davydov-split subbands t
hat display strong circular dichroism, indicating the enantioselective
formation of chiral J-aggregates. In this way, for the first time, in
the liquid phase self-organization of achiral dye molecules to chiral
supramolecular aggregates has been realized which can be controlled b
y the molecular structure of the monomeric precursors, A helix-like, c
ylindric structure of the chiral J-aggregates is suggested, The result
s expose an interesting model for studying and understanding enantiose
lective processes in the biosphere.