Chirality‐Controlled Self‐Assembly of Amphiphilic Dibenzo[6]helicenes into Langmuir–Blodgett Thin Films

• Published in: Chemistry : a European journal 2019-09, Vol.25 (49), p.11494-11502
• Main Authors: Holec, Jan, Rybáček, Jiří, Vacek, Jaroslav, Karras, Manfred, Bednárová, Lucie, Buděšínský, Miloš, Slušná, Michaela, Holý, Petr, Schmidt, Bernd, Stará, Irena G., Starý, Ivo
• Format: Article
• Language: English
• Subjects: arenes; chirality; helical structures; Langmuir–Blodgett films; self-assembly
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201901695

Racemic and highly enantioenriched 3‐methoxycarbonyl, 3‐carboxy, and 3‐hydroxymethyl derivatives of dibenzo[6]helicene were prepared. The Langmuir layers of these helicenes were formed at the air–water interface and transferred onto solid substrates to afford Langmuir–Blodgett films, which were then studied by ambient atomic force microscopy and (chir)optical spectroscopy. Significant differences were found in the behaviour of the Langmuir layers as well as in the morphology, UV/Vis, electronic circular dichroism (ECD), and fluorescence spectra of the Langmuir–Blodgett thin films depending on the molecular chirality and nature of the polar group. The experimental results were supported by molecular dynamics simulations. Dibenzo[6]helicene derivatives: Racemic and highly enantioenriched 3‐CO2CH3, 3‐CO2H, and 3‐CH2OH derivatives of dibenzo[6]helicene were prepared. The corresponding Langmuir layers were formed at the air–water interface and transferred onto solid substrates to afford Langmuir–Blodgett films. Significant differences were found in their stability, morphology, UV/Vis, electronic circular dichroism, and fluorescence spectra depending on the molecular chirality and nature of the polar group.