The interplay of configuration and conformation in helical perylenequinones: Insights from chirality induction in liquid crystals and calculations

• Elisa Frezza,
• Silvia Pieraccini,
• Stefania Mazzini,
• Alberta Ferrarini and
• Gian Piero Spada

Beilstein J. Org. Chem. 2012, 8, 155–163, doi:10.3762/bjoc.8.16

• is that which is expected for helicoidal disc-like dopants, as binaphthyl derivatives [20] and helicene-like molecules [22][24], i.e., left-handed for the M and right-handed for the P molecular helicity. In view of the similar molecular shape of 1 and 2, the difference between the absolute values of

Chiral amplification in a cyanobiphenyl nematic liquid crystal doped with helicene-like derivatives

• Alberta Ferrarini,
• Silvia Pieraccini,
• Stefano Masiero and
• Gian Piero Spada

Beilstein J. Org. Chem. 2009, 5, No. 50, doi:10.3762/bjoc.5.50

• efficient chiral inducers in biaryl nematic mesophases. In this paper, we focus on a new series of helicene-like molecules of known absolute configuration. We have integrated cholesteric pitch measurements with geometry optimization by DFT calculations and analysis of the twisting ability by the Surface

• , allows us to extend our knowledge of the molecular origin of the chirality amplification in liquid crystals and to confirm the simple relationship “molecular P-helicity” → “cholesteric P-handedness” for helical-shaped helicene-like derivatives. Keywords: chirality; cholesteric; helical twisting power

• ; helicene; nematic liquid crystal; Surface Chirality model; Introduction Nematic liquid crystals (LCs) are fluid phases formed by anisometric molecules which, though free to rotate as in ordinary liquids, are preferentially aligned along a common axis, called director. The addition of a chiral non-racemic