Počet záznamů: 1
Helicene-based π-conjugated macrocycles: their synthesis, properties, chirality and self-assembly into molecular stripes on a graphite surface
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SYSNO ASEP 0564865 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Helicene-based π-conjugated macrocycles: their synthesis, properties, chirality and self-assembly into molecular stripes on a graphite surface Tvůrce(i) Houska, Václav (UOCHB-X) RID, ORCID
Ukraintsev, Egor (FZU-D) RID, ORCID
Vacek, Jaroslav (UOCHB-X) RID, ORCID
Rybáček, Jiří (UOCHB-X) RID, ORCID
Bednárová, Lucie (UOCHB-X) RID, ORCID
Pohl, Radek (UOCHB-X) RID, ORCID
Stará, Irena G. (UOCHB-X) RID, ORCID
Rezek, B. (CZ)
Starý, Ivo (UOCHB-X) RID, ORCIDZdroj.dok. Nanoscale. - : Royal Society of Chemistry - ISSN 2040-3364
Roč. 15, č. 4 (2023), s. 1542-1553Poč.str. 12 s. Jazyk dok. eng - angličtina Země vyd. GB - Velká Británie Klíč. slova helicene-based macrocycle ; ambient AFM ; “molecular Velcro” in self-assembly on HOPG Obor OECD Organic chemistry CEP GA20-23566S GA ČR - Grantová agentura ČR Výzkumná infrastruktura CzechNanoLab - 90110 - Vysoké učení technické v Brně Způsob publikování Omezený přístup Institucionální podpora UOCHB-X - RVO:61388963 ; FZU-D - RVO:68378271 UT WOS 000885656700001 EID SCOPUS 85142525577 DOI 10.1039/d2nr04209f Anotace Fully aromatic helicenes are attractive building blocks for the construction of inherently chiral π-conjugated macrocyclic nanocarbons. These hitherto rare molecular architectures are envisaged to exhibit remarkable (chir)optical properties, self-assembly, charge/spin transport, induced ring current or a fascinating Möbius topology. Here the synthesis of helically chiral macrocycles that combine angular dibenzo[5]helicene units as corners and linear trans-stilbene-4,4′-diyl linkers as edges is reported. By subjecting a racemic or enantiopure divinyl derivative of dibenzo[5]helicene to olefin metathesis, which was catalysed by a 2nd generation Piers catalyst under kinetic control, a π-conjugated helicene cyclic trimer (33%) and a tetramer (22%) were obtained, which were separated by GPC. Combining racemic/asymmetric synthesis with the resolution of enantiomers/diastereomers by SFC/HPLC on a chiral column, both homochiral (+)-(M,M,M)/(−)-(P,P,P) and heterochiral (+)-(M,M,P)/(−)-(M,P,P) stereoisomers of the helicene cyclic trimer could be obtained in an enantio- and diastereomerically enriched form. The complete energy profile of their interconversion was compiled on the basis of kinetic measurements and numerical solution of the proposed kinetic model. In equilibrium, the heterochiral diastereomer predominates over the homochiral one (ca. 75 : 25 at 76 °C). π-Conjugation along a large, twisted circuit in the helicene cyclic trimer is rather disrupted, stabilising this formally antiaromatic molecule. Using an optimised PeakForce mode of ambient AFM, the self-assembly of otherwise highly mobile stereoisomers of the helicene cyclic trimer on the HOPG surface could be studied. Irrespective of the stereochemistry, strong preferences for the edge-to-edge interaction of these macrocycles were found to form very long parallel 1D molecular stripes in ordered 2D nanocrystals, a result also supported by molecular dynamics simulations. Six trityl groups, initially introduced to the macrocycle to enhance solubility, serve as a key “molecular Velcro” system in the self-assembly of macrocycles to maximise their mutual van der Waals interactions. Pracoviště Ústav organické chemie a biochemie Kontakt asep@uochb.cas.cz ; Kateřina Šperková, Tel.: 232 002 584 ; Jana Procházková, Tel.: 220 183 418 Rok sběru 2024 Elektronická adresa https://doi.org/10.1039/D2NR04209F
Počet záznamů: 1