Solvent Induced Helix Folding of Defined Indolenine Squaraine Oligomers
Zitieren Sie bitte immer diese URN: urn:nbn:de:bvb:20-opus-256869
- A protecting group strategy was employed to synthesise a series of indolenine squaraine dye oligomers up to the nonamer. The longer oligomers show a distinct solvent dependence of the absorption spectra, that is, either a strong blue shift or a strong red shift of the lowest energy bands in the near infrared spectral region. This behaviour is explained by exciton coupling theory as being due to H- or J-type coupling of transition moments. The H-type coupling is a consequence of a helix folding in solvents with a small Hansen dispersity index.A protecting group strategy was employed to synthesise a series of indolenine squaraine dye oligomers up to the nonamer. The longer oligomers show a distinct solvent dependence of the absorption spectra, that is, either a strong blue shift or a strong red shift of the lowest energy bands in the near infrared spectral region. This behaviour is explained by exciton coupling theory as being due to H- or J-type coupling of transition moments. The H-type coupling is a consequence of a helix folding in solvents with a small Hansen dispersity index. DOSY NMR, small angle neutron scattering (SANS), quantum chemical and force field calculations agree upon a helix structure with an unusually large pitch and open voids that are filled with solvent molecules, thereby forming a kind of clathrate. The thermodynamic parameters of the folding process were determined by temperature dependent optical absorption spectra.…
Autor(en): | Arthur Turkin, Marco Holzapfel, Mohit Agarwal, David Fischermeier, Roland Mitric, Ralf Schweins, Franziska Gröhns, Christoph LambertORCiD |
---|---|
URN: | urn:nbn:de:bvb:20-opus-256869 |
Dokumentart: | Artikel / Aufsatz in einer Zeitschrift |
Institute der Universität: | Fakultät für Chemie und Pharmazie / Institut für Organische Chemie |
Fakultät für Chemie und Pharmazie / Institut für Physikalische und Theoretische Chemie | |
Sprache der Veröffentlichung: | Englisch |
Titel des übergeordneten Werkes / der Zeitschrift (Englisch): | Chemistry—A European Journal |
Erscheinungsjahr: | 2021 |
Band / Jahrgang: | 27 |
Heft / Ausgabe: | 32 |
Seitenangabe: | 8380–8389 |
Originalveröffentlichung / Quelle: | Chemistry—A European Journal 2021, 27(32):8380–8389. DOI: 10.1002/chem.202101063 |
DOI: | https://doi.org/10.1002/chem.202101063 |
Allgemeine fachliche Zuordnung (DDC-Klassifikation): | 5 Naturwissenschaften und Mathematik / 54 Chemie / 547 Organische Chemie |
Freie Schlagwort(e): | UV/Vis spectroscopy; dye chemistry; solvent effects; superstructure; supramolecular folding |
Datum der Freischaltung: | 08.03.2022 |
EU-Projektnummer / Contract (GA) number: | 654000 |
OpenAIRE: | OpenAIRE |
Lizenz (Deutsch): | CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International |