Helical aggregates chiral amplification

Keywords Chiral amplification Chirality sensing Helical aggregates ... 

This concept of the chiral amplification has been applied to supramole-cular systems that involve self-assemblies composed of chiral-achiral and chiral-chiral (R/S) components, resulting in the formation of chiral supra-molecules [20] including helical aggregates. 

Nuckolls and Katz have synthesized discotic liquid crystalline molecules in which the core is a helix in its own right.37 Nonracemic helicene 33 was found to assemble into a columnar mesophase in which the helicenes stack on top of each other. CD spectroscopy showed a strong increase of the Cotton effect upon going from the molecularly dissolved state to the aggregated state, exhibiting an amplification of chirality. These helical columns give rise to a strong expression of chirality because the intrinsic shape of the helicenes... 

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