Solvent Induced Helix Folding of Defined Indolenine Squaraine Oligomers
Please always quote using this 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.…
Author: | Arthur Turkin, Marco Holzapfel, Mohit Agarwal, David Fischermeier, Roland Mitric, Ralf Schweins, Franziska Gröhns, Christoph LambertORCiD |
---|---|
URN: | urn:nbn:de:bvb:20-opus-256869 |
Document Type: | Journal article |
Faculties: | Fakultät für Chemie und Pharmazie / Institut für Organische Chemie |
Fakultät für Chemie und Pharmazie / Institut für Physikalische und Theoretische Chemie | |
Language: | English |
Parent Title (English): | Chemistry—A European Journal |
Year of Completion: | 2021 |
Volume: | 27 |
Issue: | 32 |
Pagenumber: | 8380–8389 |
Source: | Chemistry—A European Journal 2021, 27(32):8380–8389. DOI: 10.1002/chem.202101063 |
DOI: | https://doi.org/10.1002/chem.202101063 |
Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 547 Organische Chemie |
Tag: | UV/Vis spectroscopy; dye chemistry; solvent effects; superstructure; supramolecular folding |
Release Date: | 2022/03/08 |
EU-Project number / Contract (GA) number: | 654000 |
OpenAIRE: | OpenAIRE |
Licence (German): | CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International |