Redox-Switchable Aromaticity in a Helically Extended Indeno[2,1-c]fluorene DOI Creative Commons
Eric Sidler, Robert Hein, Daniel Doellerer

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(28), P. 19168 - 19176

Published: July 2, 2024

Molecular switches have received major attention to enable the reversible modulation of various molecular properties and been extensively used as trigger elements in diverse fields, including machines, responsive materials, photopharmacology. Antiaromaticity is a fascinating property that has attracted not only significant fundamental interest but also increasingly relevant different applications, particular organic (opto)electronics. However, designing systems which (anti)aromaticity can be judiciously reversibly switched ON OFF remains challenging. Herein, we report helicene featuring an indenofluorene-bridged bisthioxanthylidene novel switch wherein simultaneous two-electron (electro)chemical redox process allows highly its (anti)aromatic character. Specifically, two thioxanthylidene rotors, attached initially aromatic indenofluorene scaffold via overcrowded alkenes, adopt anti-folded structure, upon oxidation convert singly bonded, twisted conformations. This associated with (chir)optical changes importantly results formation fully conjugated, formally antiaromatic as-indacene motif helical core switch. proceeds without buildup radical cation intermediates thus enables switching geometry, aromaticity, absorbance, chiral expression under ambient conditions, evidenced by NMR, UV–vis, CD, (spectro)electrochemical analyses, supported DFT calculations. We expect this concept extendable wide range robust antiaromatic–aromatic provide basis for structure these inherently polycyclic π-scaffolds.

Language: Английский

Redox-Switchable Aromaticity in a Helically Extended Indeno[2,1-c]fluorene DOI Creative Commons
Eric Sidler, Robert Hein, Daniel Doellerer

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(28), P. 19168 - 19176

Published: July 2, 2024

Molecular switches have received major attention to enable the reversible modulation of various molecular properties and been extensively used as trigger elements in diverse fields, including machines, responsive materials, photopharmacology. Antiaromaticity is a fascinating property that has attracted not only significant fundamental interest but also increasingly relevant different applications, particular organic (opto)electronics. However, designing systems which (anti)aromaticity can be judiciously reversibly switched ON OFF remains challenging. Herein, we report helicene featuring an indenofluorene-bridged bisthioxanthylidene novel switch wherein simultaneous two-electron (electro)chemical redox process allows highly its (anti)aromatic character. Specifically, two thioxanthylidene rotors, attached initially aromatic indenofluorene scaffold via overcrowded alkenes, adopt anti-folded structure, upon oxidation convert singly bonded, twisted conformations. This associated with (chir)optical changes importantly results formation fully conjugated, formally antiaromatic as-indacene motif helical core switch. proceeds without buildup radical cation intermediates thus enables switching geometry, aromaticity, absorbance, chiral expression under ambient conditions, evidenced by NMR, UV–vis, CD, (spectro)electrochemical analyses, supported DFT calculations. We expect this concept extendable wide range robust antiaromatic–aromatic provide basis for structure these inherently polycyclic π-scaffolds.

Language: Английский

Citations

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