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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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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
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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] [What about the content of this article? (0)] [Affiliation(s)] [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.![]()
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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
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Lehmann M, Dechant M, Weh D, Freytag E. Metal Phthalocyanine−Fullerene Dyads: Promising Lamellar Columnar Donor−Acceptor Liquid Crystal Phases. Chempluschem 2020; 85:1934-1938. [DOI: 10.1002/cplu.202000540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/01/2020] [Indexed: 11/08/2022]
Affiliation(s)
- Matthias Lehmann
- Institute of Organic ChemistryUniversity of Würzburg Am Hubland 97074 Würzburg Germany
- Center for Nanosystems Chemistryand Bavarian Polymer Institute Theodor-Boveri-Weg 4 97074 Würzburg Germany
| | - Moritz Dechant
- Institute of Organic ChemistryUniversity of Würzburg Am Hubland 97074 Würzburg Germany
| | - Dominik Weh
- Institute of Organic ChemistryUniversity of Würzburg Am Hubland 97074 Würzburg Germany
| | - Emely Freytag
- Institute of Organic ChemistryUniversity of Würzburg Am Hubland 97074 Würzburg Germany
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Fuchs C, Dorn D, Doht B, Freytag E, Fuchs CA, Henning HV, Scheler F. [Aluminum poisoning by phosphate binders in kidney insufficiency]. Verh Dtsch Ges Inn Med 1977; 83:1313-5. [PMID: 611842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Freytag E. Measurement of high doses with glass dosimeters. Health Phys 1971; 20:93-94. [PMID: 5559159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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