1
|
Freytag E, Kreimendahl L, Holzapfel M, Petersen J, Lackinger H, Stolte M, Würthner F, Mitric R, Lambert C. Chiroptical Properties of Planar Benzobisthiazole-Bridged Squaraine Dimers. J Org Chem 2023. [PMID: 37487529 DOI: 10.1021/acs.joc.3c00821] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/26/2023]
Abstract
Five chiral squaraine dimers were synthesized by fusing chiral indolenine semisquaraines with three different benzobisthiazole bridges. The thereby created squaraine dimers show a strong splitting of the lowest energy absorption bands caused by exciton coupling. The intensities of the two exciton transitions and the energetic splitting depend on the angle of the two squaraine moieties within the chromophore dimer. The electric circular dichroism spectra of the dimers show intense Cotton effects whose sign depends on the used squaraine chromophores. Sizable anisotropies gabs of up to 2.6 × 10-3 could be obtained. TD-DFT calculations were used to partition the rotational strength into the three Rosenfeld terms where the electric-magnetic coupling turned out to be the dominant contribution while the exciton chirality term is much smaller. This is because the chromophore dimers are essentially planar but the angle between the electric transition dipole moment of one squaraine and the magnetic transition dipole moment of the other squaraine strongly deviates from 90°, which makes the dot product between the two moment vectors and, thus, the rotational strength substantial.
Collapse
Affiliation(s)
- Emely Freytag
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Lasse Kreimendahl
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Marco Holzapfel
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Jens Petersen
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Heiko Lackinger
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Matthias Stolte
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Frank Würthner
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Roland Mitric
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Christoph Lambert
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| |
Collapse
|
2
|
Selby J, Holzapfel M, Radacki K, Swain AK, Braunschweig H, Lambert C. Polymeric Indolenine–Squaraine Foldamers with a Preferred Helix Twist Sense and Their Chiroptical Absorption and Emission Properties. Macromolecules 2022. [DOI: 10.1021/acs.macromol.1c02155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joshua Selby
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Marco Holzapfel
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Krzysztof Radacki
- Institut für Anorganische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Asim Kumar Swain
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Holger Braunschweig
- Institut für Anorganische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Christoph Lambert
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| |
Collapse
|
3
|
Freytag E, Holzapfel M, Swain A, Bringmann G, Stolte M, Würthner F, Lambert C. Axially chiral indolenine derived chromophore dimers and their chiroptical absorption and emission properties. Chem Sci 2022; 13:12229-12238. [PMID: 36349102 PMCID: PMC9601394 DOI: 10.1039/d2sc04600h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 10/05/2022] [Indexed: 11/23/2022] Open
Abstract
Yamamoto homocoupling of two chiral oxindoles led to the atropo-diastereoselective formation of an axially chiral oxindole dimer. This building block served as the starting material for the syntheses of axially chiral squaraine and merocyanine chromophore dimers. These dimers show pronounced chiroptical properties, this is, outstandingly high ECD signals (Δε up to ca. 1500 M−1 cm−1) as a couplet with positive Cotton effect for the P-configuration around the biaryl axis and a negative Cotton effect for the M-configuration. All investigated dimers also exhibit pronounced circularly polarised emission with anisotropy values of ca. 10−3 cgs. Time-dependent density functional calculations were used to analyse the three contributions (local one electron, electric–magnetic coupling, and exciton coupling) to the rotational strength applying the Rosenfeld equation to excitonically coupled chromophores. While the exciton coupling term proves to be the dominant one, the electric–magnetic coupling possesses the same sign and adds significantly to the total rotational strength owing to a favourable geometric arrangement of the two chromophores within the dimer. From an axially chiral oxindole, squaraine and merocyanine chromophore dimers with pronounced chiroptical properties were prepared.![]()
Collapse
Affiliation(s)
- Emely Freytag
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Marco Holzapfel
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Asim Swain
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Gerhard Bringmann
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Matthias Stolte
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, Würzburg 97074, Germany
- Center for Nanosystems Chemistry, Universität Würzburg, Theodor-Boveri-Weg, Würzburg 97074, Germany
| | - Frank Würthner
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, Würzburg 97074, Germany
- Center for Nanosystems Chemistry, Universität Würzburg, Theodor-Boveri-Weg, Würzburg 97074, Germany
| | - Christoph Lambert
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, Würzburg 97074, Germany
- Center for Nanosystems Chemistry, Universität Würzburg, Theodor-Boveri-Weg, Würzburg 97074, Germany
| |
Collapse
|
4
|
Balzer F, Schumacher MF, Mattiello S, Schulz M, Zablocki J, Schmidtmann M, Meerholz K, Serdar Sariciftci N, Beverina L, Lützen A, Schiek M. The Impact of Chiral Citronellyl‐Functionalization on Indolenine and Anilino Squaraine Thin Films. Isr J Chem 2021. [DOI: 10.1002/ijch.202100079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Frank Balzer
- SDU Centre for Photonics Engineering Mads Clausen Institute University of Southern Denmark Alsion 2 DK-6400 Sønderborg Denmark
| | - Marvin F. Schumacher
- Kekulé-Institute for Organic Chemistry and Biochemistry University of Bonn Gerhard-Domagk-Str. 1 D-53121 Bonn Germany
| | - Sara Mattiello
- Department of Materials Chemistry and INSTM University of Milano-Bicocca Via R. Cozzi 53 I-20125 Milano Italy
| | - Matthias Schulz
- Kekulé-Institute for Organic Chemistry and Biochemistry University of Bonn Gerhard-Domagk-Str. 1 D-53121 Bonn Germany
| | - Jennifer Zablocki
- Kekulé-Institute for Organic Chemistry and Biochemistry University of Bonn Gerhard-Domagk-Str. 1 D-53121 Bonn Germany
| | - Marc Schmidtmann
- Department of Chemistry University of Oldenburg Carl-von-Ossietzky-Str. 9–11 D-26129 Oldenburg Germany
| | - Klaus Meerholz
- Physical Chemistry University of Cologne Greinstr. 4–6 D-50939 Cologne Germany
| | - N. Serdar Sariciftci
- Linz Institute for Solar Cells Johannes Kepler University Altenberger Str. 69 A-4040 Linz Austria
| | - Luca Beverina
- Department of Materials Chemistry and INSTM University of Milano-Bicocca Via R. Cozzi 53 I-20125 Milano Italy
| | - Arne Lützen
- Kekulé-Institute for Organic Chemistry and Biochemistry University of Bonn Gerhard-Domagk-Str. 1 D-53121 Bonn Germany
| | - Manuela Schiek
- Linz Institute for Solar Cells Johannes Kepler University Altenberger Str. 69 A-4040 Linz Austria
- Center for Surface- and Nanoanalytics and Linz Institute for Solar Cells Johannes Kepler University Altenberger Str. 69 A-4040 Linz Austria
- Institute of Physics University of Oldenburg Carl-von-Ossietzky-Str. 9–11 D-26129 Oldenburg Germany
| |
Collapse
|