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Brockmann M, Glotz G, von Glasenapp JS, Unterriker L, Neshchadin D, Gescheidt G, Herges R. Highly Sensitive, Easy-to-Use, One-Step Detection of Peroxide-, Nitrate- and Chlorate-Based Explosives with Electron-Rich Ni Porphyrins. J Am Chem Soc 2024. [PMID: 38690970 DOI: 10.1021/jacs.3c14118] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
Homemade explosives, such as peroxides, nitrates, and chlorates, are increasingly abused by terrorists, criminals, and amateur chemists. The starting materials are easily accessible and instructions on how to make the explosives are described on the Internet. Safety considerations raise the need to detect these substances quickly and in low concentrations using simple methods. Conventional methods for the detection of these substances require sophisticated, electrically operated, analytical equipment. The simpler chemical detection methods are multistep and require several chemicals. We have developed a simple, one-step method that works similarly to a pH test strip in terms of handling. The analytical reaction is based on an acid-catalyzed oxidation of an electron-rich porphyrin to an unusually stable radical cation and dication. The detection limit for the peroxide-based explosive triacetone triperoxide (TATP), which is very frequently used by terrorists, is 40 ng and thus low enough to detect the substance without direct contact via the gas phase. It is sufficient to bring the stick close to the substance to observe a color change from red to green. Nitrates and chlorates, such as ammonium nitrate, urea nitrate, or potassium chlorate, are detected by direct contact with a sensitivity of 85-350 ng. A color change from red to dark brown is observed. The test thus detects all homemade explosives and distinguishes between the extremely impact-, shock-, and friction-sensitive peroxides and the less sensitive nitrates and chlorates by color change of a simple test strip.
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Affiliation(s)
- Mike Brockmann
- Otto Diels-Institute of Organic Chemistry, Christian-Albrechts-Universität zu Kiel, Otto Hahn Platz 4, 24118 Kiel, Germany
| | - Gabriel Glotz
- Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Jan-Simon von Glasenapp
- Otto Diels-Institute of Organic Chemistry, Christian-Albrechts-Universität zu Kiel, Otto Hahn Platz 4, 24118 Kiel, Germany
| | - Lara Unterriker
- Otto Diels-Institute of Organic Chemistry, Christian-Albrechts-Universität zu Kiel, Otto Hahn Platz 4, 24118 Kiel, Germany
| | - Dmytro Neshchadin
- Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Georg Gescheidt
- Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Rainer Herges
- Otto Diels-Institute of Organic Chemistry, Christian-Albrechts-Universität zu Kiel, Otto Hahn Platz 4, 24118 Kiel, Germany
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2
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Businski A, Ta TC, Gindullis N, Näther C, Herges R. Synthesis and crystal structure of tetra-methyl ( E)-4,4'-(ethene-1,2-di-yl)bis-(5-nitro-benzene-1,2-di-carboxyl-ate). Acta Crystallogr E Crystallogr Commun 2024; 80:435-438. [PMID: 38584740 PMCID: PMC10993603 DOI: 10.1107/s2056989024002676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 03/22/2024] [Indexed: 04/09/2024]
Abstract
The title compound, C22H18N2O12, was obtained as a by-product during the planned synthesis of 1,2-bis-(2-nitro-4,5-dimethyl phthalate)ethane by oxidative dimerization starting from dimethyl-4-methyl-5-nitro phthalate. To identify this compound unambiguously, a single-crystal structure analysis was performed. The asymmetric unit consists of half a mol-ecule that is located at a centre of inversion. As a result of symmetry restrictions, the mol-ecule shows an E configuration around the double bond. Both phenyl rings are coplanar, whereas the nitro and the two methyl ester groups are rotated out of the ring plane by 32.6 (1), 56.5 (2) and 49.5 (2)°, respectively. In the crystal, mol-ecules are connected into chains extending parallel to the a axis by pairs of C-H⋯O hydrogen bonds that are connected into a tri-periodic network by additional C-H⋯O hydrogen-bonding inter-actions.
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Affiliation(s)
- Artjom Businski
- Otto-Diels-Institut für Organische Chemie, Universität Kiel, Otto-Hahn-Platz 4, D-24098 Kiel, Germany
| | - Thuy C. Ta
- Otto-Diels-Institut für Organische Chemie, Universität Kiel, Otto-Hahn-Platz 4, D-24098 Kiel, Germany
| | - Niklas Gindullis
- Institut für Organische Chemie, Leibniz Universität Hannover, Schneiderberg 1 B, D-30167 Hannover, Germany
| | - Christian Näther
- Institut für Anorganische Chemie, Universität Kiel, Max-Eyth-Str. 2, D-24118 Kiel, Germany
| | - Rainer Herges
- Otto-Diels-Institut für Organische Chemie, Universität Kiel, Otto-Hahn-Platz 4, D-24098 Kiel, Germany
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3
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Wages F, Brandt T, Martin HJ, Herges R, Maser E. Light-switchable diazocines as potential inhibitors of testosterone-synthesizing 17β-hydroxysteroid dehydrogenase 3. Chem Biol Interact 2024; 390:110872. [PMID: 38244963 DOI: 10.1016/j.cbi.2024.110872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Revised: 12/24/2023] [Accepted: 01/12/2024] [Indexed: 01/22/2024]
Abstract
In patients with prostate carcinoma as well as in some other cancer types, the reduction of testosterone levels is desired because the hormone stimulates cancer cell growth. One molecular target for this goal is the inhibition of 17β-hydroxysteroid dehydrogenase type 3 (17βHSD3), which produces testosterone from its direct precursor androstenedione. Recent research in this field is trying to harness photopharmacological properties of certain compounds so that the inhibitory effect could be turned on and off by irradiation. Seven new light-switchable diazocines were investigated with regard to their inhibition of 17βHSD3. For this purpose, transfected HEK-293 cells and isolated microsomes were treated with the substrate and the potential inhibitors with and without irradiation for an incubation period of 3 or 5 h. The amount of generated testosterone was measured by UHPLC and compared between samples and control as well as between irradiated and non-irradiated samples. There was no significant difference between samples with and without irradiation. However, four of the seven diazocines led to a significantly lower testosterone production both in cell and in microsome assays. In some of the irradiated samples, a partial destruction of the diazocines was observed, indicated by an additional UHPLC peak. However, the influence on the inhibition is negligible, because the majority of the substance remained intact. In conclusion, new inhibitors of 17βHSD3 have been found, but so far without the feature of a light switch, since the configurational alteration of the diazocines by irradiation did not lead to a change in bioactivity. Further modification might help to find a light-switching molecule that inhibits only in one configuration.
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Affiliation(s)
- F Wages
- Institute of Toxicology and Pharmacology for Natural Scientists, University Medical School Schleswig-Holstein, Campus Kiel, Brunswiker Str. 10, 24105 Kiel, Germany
| | - T Brandt
- Otto Diels Institute of Organic Chemistry, Christian-Albrecht University of Kiel, Otto Hahn Platz 4, 24118 Kiel, Germany
| | - H-J Martin
- Institute of Toxicology and Pharmacology for Natural Scientists, University Medical School Schleswig-Holstein, Campus Kiel, Brunswiker Str. 10, 24105 Kiel, Germany
| | - R Herges
- Otto Diels Institute of Organic Chemistry, Christian-Albrecht University of Kiel, Otto Hahn Platz 4, 24118 Kiel, Germany
| | - E Maser
- Institute of Toxicology and Pharmacology for Natural Scientists, University Medical School Schleswig-Holstein, Campus Kiel, Brunswiker Str. 10, 24105 Kiel, Germany.
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4
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Meng X, Möller J, Menchón RE, Weismann A, Sánchez-Portal D, Garcia-Lekue A, Herges R, Berndt R. Kondo Effect of Co-Porphyrin: Remarkable Sensitivity to Adsorption Sites and Orientations. Nano Lett 2024; 24:180-186. [PMID: 38150551 DOI: 10.1021/acs.nanolett.3c03669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
We investigated the Kondo effect of cobalt(II)-5-15-bis(4'-bromophenyl)-10,20-bis(4'-iodophenyl)porphyrin (CoTPPBr2I2) molecules on Au(111) with low-temperature scanning tunneling microscopy under ultrahigh vacuum conditions. The molecules exhibit four adsorption configurations at the top and bridge sites of the surface with different molecular orientations. The Kondo resonance shows extraordinary sensitivity to the adsorption configuration. By switching the molecule between different configurations, the Kondo temperature is varied over a wide range from ≈8 up to ≈250 K. Density functional theory calculations reveal that changes of the adsorption configuration lead to distinct variations of the hybridization between the molecule and the surface. Furthermore, we show that surface reconstruction plays a significant role for the molecular Kondo effect.
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Affiliation(s)
- Xiangzhi Meng
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098 Kiel, Germany
| | - Jenny Möller
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität, 24098 Kiel, Germany
| | - Rodrigo E Menchón
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Spain
- Facultad de Ciencias Exactas, Ingeniría y Agrimensura (FCEIA), Instituto de Física Rosario (IFIR), 2000 Rosario, Argentina
- Universidad Nacional de Rosario (UNR), 2000 Rosario, Argentina
| | - Alexander Weismann
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098 Kiel, Germany
| | - Daniel Sánchez-Portal
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Spain
- Centro de Física de Materiales CSIC-UPV/EHU, 20018 Donostia-San Sebastián, Spain
| | - Aran Garcia-Lekue
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
| | - Rainer Herges
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität, 24098 Kiel, Germany
| | - Richard Berndt
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098 Kiel, Germany
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5
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Thaggard GC, Park KC, Lim J, Maldeni Kankanamalage BKP, Haimerl J, Wilson GR, McBride MK, Forrester KL, Adelson ER, Arnold VS, Wetthasinghe ST, Rassolov VA, Smith MD, Sosnin D, Aprahamian I, Karmakar M, Bag SK, Thakur A, Zhang M, Tang BZ, Castaño JA, Chaur MN, Lerch MM, Fischer RA, Aizenberg J, Herges R, Lehn JM, Shustova NB. Breaking the photoswitch speed limit. Nat Commun 2023; 14:7556. [PMID: 37985777 PMCID: PMC10660956 DOI: 10.1038/s41467-023-43405-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 11/07/2023] [Indexed: 11/22/2023] Open
Abstract
The forthcoming generation of materials, including artificial muscles, recyclable and healable systems, photochromic heterogeneous catalysts, or tailorable supercapacitors, relies on the fundamental concept of rapid switching between two or more discrete forms in the solid state. Herein, we report a breakthrough in the "speed limit" of photochromic molecules on the example of sterically-demanding spiropyran derivatives through their integration within solvent-free confined space, allowing for engineering of the photoresponsive moiety environment and tailoring their photoisomerization rates. The presented conceptual approach realized through construction of the spiropyran environment results in ~1000 times switching enhancement even in the solid state compared to its behavior in solution, setting a record in the field of photochromic compounds. Moreover, integration of two distinct photochromic moieties in the same framework provided access to a dynamic range of rates as well as complementary switching in the material's optical profile, uncovering a previously inaccessible pathway for interstate rapid photoisomerization.
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Affiliation(s)
- Grace C Thaggard
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, 29208, USA
| | - Kyoung Chul Park
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, 29208, USA
| | - Jaewoong Lim
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, 29208, USA
| | | | - Johanna Haimerl
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, 29208, USA
- Chair of Inorganic and Metal-Organic Chemistry, Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85748, Garching, Germany
| | - Gina R Wilson
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, 29208, USA
| | - Margaret K McBride
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, 29208, USA
| | - Kelly L Forrester
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, 29208, USA
| | - Esther R Adelson
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, 29208, USA
| | - Virginia S Arnold
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, 29208, USA
| | - Shehani T Wetthasinghe
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, 29208, USA
| | - Vitaly A Rassolov
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, 29208, USA
| | - Mark D Smith
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, 29208, USA
| | - Daniil Sosnin
- Department of Chemistry, Dartmouth College, Hanover, NH, 03755, USA
| | - Ivan Aprahamian
- Department of Chemistry, Dartmouth College, Hanover, NH, 03755, USA
| | - Manisha Karmakar
- Department of Chemistry, Jadavpur University, 700032, Kolkata, India
| | - Sayan Kumar Bag
- Department of Chemistry, Jadavpur University, 700032, Kolkata, India
| | - Arunabha Thakur
- Department of Chemistry, Jadavpur University, 700032, Kolkata, India
| | - Minjie Zhang
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, and Guangdong-Hong Kong-Macau Joint Laboratory of Optoelectronic and Magnetic Functional Materials, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, 999077, China
| | - Ben Zhong Tang
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, and Guangdong-Hong Kong-Macau Joint Laboratory of Optoelectronic and Magnetic Functional Materials, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, 999077, China
- School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong Shenzhen, Guangdong, 518172, China
- Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou, 510640, China
- AIE Institute, Guangzhou Development District, Huangpu, Guangzhou, 510530, China
| | - Jorge A Castaño
- Departamento de Química, Universidad del Valle, AA 25360, Cali, Colombia
| | - Manuel N Chaur
- Departamento de Química, Universidad del Valle, AA 25360, Cali, Colombia
- Centro de Excelencia en Neuvos Materiales (CENM), Universidad del Valle, AA 25360, Cali, Colombia
| | - Michael M Lerch
- Stratingh Institute for Chemistry, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - Roland A Fischer
- Chair of Inorganic and Metal-Organic Chemistry, Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85748, Garching, Germany
| | - Joanna Aizenberg
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA
| | - Rainer Herges
- Otto Diels Institute of Organic Chemistry, University of Kiel, 24118, Kiel, Germany
| | - Jean-Marie Lehn
- Laboratoire de Chimie Supramoléculaire, Institut de Science et d'Ingénierie Supramoléculaires (ISIS), Université de Strasbourg, 67000, Strasbourg, France
| | - Natalia B Shustova
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, 29208, USA.
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6
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Brahms A, Pravdivtsev AN, Thorns L, Sönnichsen FD, Hövener JB, Herges R. Exceptionally Mild and High-Yielding Synthesis of Vinyl Esters of Alpha-Ketocarboxylic Acids, Including Vinyl Pyruvate, for Parahydrogen-Enhanced Metabolic Spectroscopy and Imaging. J Org Chem 2023; 88:15018-15028. [PMID: 37824795 DOI: 10.1021/acs.joc.3c01461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
Metabolic changes often occur long before pathologies manifest and treatment becomes challenging. As key elements of energy metabolism, α-ketocarboxylic acids (α-KCA) are particularly interesting, e.g., as the upregulation of pyruvate to lactate conversion is a hallmark of cancer (Warburg effect). Magnetic resonance imaging with hyperpolarized metabolites has enabled imaging of this effect non-invasively and in vivo, allowing the early detection of cancerous tissue and its treatment. Hyperpolarization by means of dynamic nuclear polarization, however, is complex, slow, and expensive, while available precursors often limit parahydrogen-based alternatives. Here, we report the synthesis for novel 13C, deuterated ketocarboxylic acids, and a much-improved synthesis of 1-13C-vinyl pruvate-d6, arguably the most promising tracer for hyperpolarizing pyruvate using parahydrogen-induced hyperpolarization by side arm hydrogenation. The new synthesis is scalable and provides a high yield of 52%. We elucidated the mechanism of our Pd-catalyzed trans-vinylation reaction. Hydrogenation with parahydrogen allowed us to monitor the addition, which was found to depend on the electron demand of the vinyl ester. Electron-poor α-keto vinyl esters react slower than "normal" alkyl vinyl esters. This synthesis of 13C, deuterated α-ketocarboxylic acids opens up an entirely new class of biomolecules for fast and cost-efficient hyperpolarization with parahydrogen and their use for metabolic imaging.
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Affiliation(s)
- Arne Brahms
- Diels Institute for Organic Chemistry, Kiel University, Otto-Hahn Platz 4, 24098 Kiel, Germany
| | - Andrey N Pravdivtsev
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24114 Kiel, Germany
| | - Lynn Thorns
- Diels Institute for Organic Chemistry, Kiel University, Otto-Hahn Platz 4, 24098 Kiel, Germany
| | - Frank D Sönnichsen
- Diels Institute for Organic Chemistry, Kiel University, Otto-Hahn Platz 4, 24098 Kiel, Germany
| | - Jan-Bernd Hövener
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24114 Kiel, Germany
| | - Rainer Herges
- Diels Institute for Organic Chemistry, Kiel University, Otto-Hahn Platz 4, 24098 Kiel, Germany
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7
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Isokuortti J, Griebenow T, von Glasenapp JS, Raeker T, Filatov MA, Laaksonen T, Herges R, Durandin NA. Triplet sensitization enables bidirectional isomerization of diazocine with 130 nm redshift in excitation wavelengths. Chem Sci 2023; 14:9161-9166. [PMID: 37655019 PMCID: PMC10466275 DOI: 10.1039/d3sc02681g] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 08/04/2023] [Indexed: 09/02/2023] Open
Abstract
Diazocines are bridged azobenzenes with phenyl rings connected by a CH2-CH2 group. Despite this rather small structural difference, diazocine exhibits improved properties over azobenzene as a photoswitch and most importantly, its Z configuration is more stable than the E isomer. Herein, we reveal yet another unique feature of this emerging class of photoswitches. In striking contrast to azobenzenes and other photochromes, diazocine can be selectively switched in E → Z direction and most intriguingly from its thermodynamically stable Z to metastable E isomer upon successive excitation of two different triplet sensitizers present in solution at the same time. This approach leads to extraordinary large redshift of excitation wavelengths to perform isomerization i.e. from 400 nm blue to 530 nm green light (Z → E) and from 530 nm green to 740 nm far-red one (E → Z), which falls in the near-infrared window in biological tissue. Therefore, this work opens up of potential avenues for utilizing diazocines for example in photopharmacology, smart materials, light energy harvesting/storage devices, and out-of-equilibrium systems.
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Affiliation(s)
- Jussi Isokuortti
- Faculty of Engineering and Natural Sciences, Tampere University FI-33101 Tampere Finland
| | - Thomas Griebenow
- Otto-Diels-Institute of Organic Chemistry, Christian-Albrechts-University of Kiel 24098 Kiel Germany
| | - Jan-Simon von Glasenapp
- Otto-Diels-Institute of Organic Chemistry, Christian-Albrechts-University of Kiel 24098 Kiel Germany
| | - Tim Raeker
- Institute for Physical Chemistry, Department for Theoretical Chemistry, Christian-Albrechts-University of Kiel 24098 Kiel Germany
| | - Mikhail A Filatov
- School of Chemical and Pharmaceutical Sciences, Technological University Dublin, City Campus Grangegorman Dublin 7 Ireland
| | - Timo Laaksonen
- Faculty of Engineering and Natural Sciences, Tampere University FI-33101 Tampere Finland
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki Finland
| | - Rainer Herges
- Otto-Diels-Institute of Organic Chemistry, Christian-Albrechts-University of Kiel 24098 Kiel Germany
| | - Nikita A Durandin
- Faculty of Engineering and Natural Sciences, Tampere University FI-33101 Tampere Finland
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8
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Peters JP, Brahms A, Janicaud V, Anikeeva M, Peschke E, Ellermann F, Ferrari A, Hellmold D, Held-Feindt J, Kim NM, Meiser J, Aden K, Herges R, Hövener JB, Pravdivtsev AN. Nitrogen-15 dynamic nuclear polarization of nicotinamide derivatives in biocompatible solutions. Sci Adv 2023; 9:eadd3643. [PMID: 37611105 PMCID: PMC10446501 DOI: 10.1126/sciadv.add3643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 07/21/2023] [Indexed: 08/25/2023]
Abstract
Dissolution dynamic nuclear polarization (dDNP) increases the sensitivity of magnetic resonance imaging by more than 10,000 times, enabling in vivo metabolic imaging to be performed noninvasively in real time. Here, we are developing a group of dDNP polarized tracers based on nicotinamide (NAM). We synthesized 1-15N-NAM and 1-15N nicotinic acid and hyperpolarized them with dDNP, reaching (13.0 ± 1.9)% 15N polarization. We found that the lifetime of hyperpolarized 1-15N-NAM is strongly field- and pH-dependent, with T1 being as long as 41 s at a pH of 12 and 1 T while as short as a few seconds at neutral pH and fields below 1 T. The remarkably short 1-15N lifetime at low magnetic fields and neutral pH drove us to establish a unique pH neutralization procedure. Using 15N dDNP and an inexpensive rodent imaging probe designed in-house, we acquired a 15N MRI of 1-15N-NAM (previously hyperpolarized for more than an hour) in less than 1 s.
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Affiliation(s)
- Josh P. Peters
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118 Kiel, Germany
| | - Arne Brahms
- Otto Diels Institute for Organic Chemistry, Kiel University, Otto-Hahn Platz 4, 24098 Kiel, Germany
| | - Vivian Janicaud
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118 Kiel, Germany
| | - Maria Anikeeva
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118 Kiel, Germany
| | - Eva Peschke
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118 Kiel, Germany
| | - Frowin Ellermann
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118 Kiel, Germany
| | - Arianna Ferrari
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118 Kiel, Germany
| | - Dana Hellmold
- Department of Neurosurgery, University Medical Center Kiel, Arnold-Heller-Str. 3, House D, 24105 Kiel, Germany
| | - Janka Held-Feindt
- Department of Neurosurgery, University Medical Center Kiel, Arnold-Heller-Str. 3, House D, 24105 Kiel, Germany
| | - Na-mi Kim
- Institute of Clinical Molecular Biology, Kiel University, Rosalind-Franklin-Straße 12, 24105 Kiel, Germany
| | - Johannes Meiser
- Cancer Metabolism Group, Department of Cancer Research, Luxembourg Institute of Health, 6A Rue Nicolas-Ernest Barblé, 1210 Luxembourg, Luxembourg
| | - Konrad Aden
- Institute of Clinical Molecular Biology, Kiel University, Rosalind-Franklin-Straße 12, 24105 Kiel, Germany
- Department of Internal Medicine I, University Medical Center Kiel, Kiel, Germany
| | - Rainer Herges
- Otto Diels Institute for Organic Chemistry, Kiel University, Otto-Hahn Platz 4, 24098 Kiel, Germany
| | - Jan-Bernd Hövener
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118 Kiel, Germany
| | - Andrey N. Pravdivtsev
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118 Kiel, Germany
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9
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Ellermann F, Sirbu A, Brahms A, Assaf C, Herges R, Hövener JB, Pravdivtsev AN. Spying on parahydrogen-induced polarization transfer using a half-tesla benchtop MRI and hyperpolarized imaging enabled by automation. Nat Commun 2023; 14:4774. [PMID: 37553405 PMCID: PMC10409769 DOI: 10.1038/s41467-023-40539-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 07/31/2023] [Indexed: 08/10/2023] Open
Abstract
Nuclear spin hyperpolarization is a quantum effect that enhances the nuclear magnetic resonance signal by several orders of magnitude and has enabled real-time metabolic imaging in humans. However, the translation of hyperpolarization technology into routine use in laboratories and medical centers is hampered by the lack of portable, cost-effective polarizers that are not commercially available. Here, we present a portable, automated polarizer based on parahydrogen-induced hyperpolarization (PHIP) at an intermediate magnetic field of 0.5 T (achieved by permanent magnets). With a footprint of 1 m2, we demonstrate semi-continuous, fully automated 1H hyperpolarization of ethyl acetate-d6 and ethyl pyruvate-d6 to P = 14.4% and 16.2%, respectively, and a 13C polarization of 1-13C-ethyl pyruvate-d6 of P = 7%. The duty cycle for preparing a dose is no more than 1 min. To reveal the full potential of 1H hyperpolarization in an inhomogeneous magnetic field, we convert the anti-phase PHIP signals into in-phase peaks, thereby increasing the SNR by a factor of 5. Using a spin-echo approach allowed us to observe the evolution of spin order distribution in real time while conserving the expensive reagents for reaction monitoring, imaging and potential in vivo usage. This compact polarizer will allow us to pursue the translation of hyperpolarized MRI towards in vivo applications further.
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Affiliation(s)
- Frowin Ellermann
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118, Kiel, Germany
| | - Aidan Sirbu
- Western University, 1151 Richmond St, London, ON, N6A 3K7, Canada
| | - Arne Brahms
- Otto Diels Institute for Organic Chemistry, Kiel University, Otto- Hahn Platz 4, 24118, Kiel, Germany
| | - Charbel Assaf
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118, Kiel, Germany
| | - Rainer Herges
- Otto Diels Institute for Organic Chemistry, Kiel University, Otto- Hahn Platz 4, 24118, Kiel, Germany
| | - Jan-Bernd Hövener
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118, Kiel, Germany
| | - Andrey N Pravdivtsev
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118, Kiel, Germany.
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10
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Glotz G, Knaipp K, Maier MS, Hüll K, Novak A, Kelterer AM, Griebenow T, Herges R, Trauner D, Gescheidt G. To Isomerize or not to Isomerize? E /Z Isomers of Cyclic Azobenzene Derivatives and their Reactivity upon One-Electron Reduction. Chemistry 2023:e202300146. [PMID: 37040130 DOI: 10.1002/chem.202300146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 04/04/2023] [Accepted: 04/06/2023] [Indexed: 04/12/2023]
Abstract
Azo compounds are efficient electron acceptors. Upon one-electron reduction they generally isomerize forming the thermodynamically most stable radical anion. Here we show that the size of the central ring in 1,2-diazocines and diazonines has a ruling influence on the configuration of the one-electron reduced species. Markedly, diazonines, which bear a central nine membered heterocycle, show light induced E/Z isomerization, but retain the configuration of the diazene N=N moiety upon one-electron reduction. Accordingly, E/Z isomerization is not induced by reduction.
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Affiliation(s)
- Gabriel Glotz
- TU Graz: Technische Universitat Graz, Institute of Physical and Theoretical Chemistry, AUSTRIA
| | - Konstantin Knaipp
- TU Graz: Technische Universitat Graz, Institite of Physical and Theoretical Chemistry, AUSTRIA
| | - Martin S Maier
- New York University, Department of Chemistry, UNITED STATES
| | - Katharina Hüll
- New York University, Department of Chemistry, UNITED STATES
| | | | - Anne-Marie Kelterer
- TU Graz: Technische Universitat Graz, Institut für Physikalische und Theoretische Chemie, AUSTRIA
| | - Thomas Griebenow
- Christian-Albrechts-Universität zu Kiel: Christian-Albrechts-Universitat zu Kiel, Otto-Diels Institut für Organische Chemie, GERMANY
| | - Rainer Herges
- Christian-Albrechts-Universität zu Kiel: Christian-Albrechts-Universitat zu Kiel, Otto-Diels Institut für Organische Chemie, GERMANY
| | - Dirk Trauner
- University of Pennsylvania Department of Chemistry, Department of Chemistry, UNITED STATES
| | - Georg Gescheidt
- Graz University of Technology, Institute of Physical and Theoretical Ch, Stremayrgasse 9/1, A-8010, Graz, AUSTRIA
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11
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Hugenbusch D, Lehr M, von Glasenapp JS, McConnell AJ, Herges R. Light-Controlled Destruction and Assembly: Switching between Two Differently Composed Cage-Type Complexes. Angew Chem Int Ed Engl 2023; 62:e202212571. [PMID: 36215411 PMCID: PMC10099457 DOI: 10.1002/anie.202212571] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Indexed: 12/30/2022]
Abstract
We report on two regioisomeric, diazocine ligands 1 and 2 that can both be photoswitched between the E- and Z-configurations with violet and green light. The self-assembly of the four species (1-Z, 1-E, 2-Z, 2-E) with CoII ions was investigated upon changing the coordination vectors as a function of the ligand configuration (E vs Z) and regioisomer (1 vs 2). With 1-Z, Co2 (1-Z)3 was self-assembled, while a mixture of ill-defined species (oligomers) was observed with 2-Z. Upon photoswitching with 385 nm to the E configurations, the opposite was observed with 1-E forming oligomers and 2-E forming Co2 (2-E)3 . Light-controlled dis/assembly was demonstrated in a ligand competition experiment with sub-stoichiometric amounts of CoII ions; alternating irradiation with violet and green light resulted in the reversible transformation between Co2 (1-Z)3 and Co2 (2-E)3 over multiple cycles without significant fatigue by photoswitching.
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Affiliation(s)
- Daniel Hugenbusch
- Otto-Diels-Institute of Organic Chemistry, Christian-Albrechts-Universität zu Kiel, Otto-Hahn-Platz 4, 24118, Kiel, Germany
| | - Marc Lehr
- Otto-Diels-Institute of Organic Chemistry, Christian-Albrechts-Universität zu Kiel, Otto-Hahn-Platz 4, 24118, Kiel, Germany
| | - Jan-Simon von Glasenapp
- Otto-Diels-Institute of Organic Chemistry, Christian-Albrechts-Universität zu Kiel, Otto-Hahn-Platz 4, 24118, Kiel, Germany
| | - Anna J McConnell
- Otto-Diels-Institute of Organic Chemistry, Christian-Albrechts-Universität zu Kiel, Otto-Hahn-Platz 4, 24118, Kiel, Germany
| | - Rainer Herges
- Otto-Diels-Institute of Organic Chemistry, Christian-Albrechts-Universität zu Kiel, Otto-Hahn-Platz 4, 24118, Kiel, Germany
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12
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Meng X, Möller J, Mansouri M, Sánchez-Portal D, Garcia-Lekue A, Weismann A, Li C, Herges R, Berndt R. Controlling the Spin States of FeTBrPP on Au(111). ACS Nano 2022; 17:1268-1274. [PMID: 36440841 DOI: 10.1021/acsnano.2c09310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Spin-flip excitations of iron porphyrin molecules on Au(111) are investigated with a low-temperature scanning tunneling microscope. The molecules adopt two distinct adsorption configurations on the surface that exhibit different magnetic anisotropy energies. Density functional theory calculations show that the different structures and excitation energies reflect unlike occupations of the Fe 3d levels. We demonstrate that the magnetic anisotropy energy can be controlled by changing the adsorption site, the orientation, or the tip-molecule distance.
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Affiliation(s)
- Xiangzhi Meng
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098Kiel, Germany
| | - Jenny Möller
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität, 24098Kiel, Germany
| | - Masoud Mansouri
- Donostia International Physics Center (DIPC), 20018Donostia-San Sebastián, Spain
- Centro de Física de Materiales CSIC-UPV/EHU, 20018Donostia-San Sebastián, Spain
| | - Daniel Sánchez-Portal
- Donostia International Physics Center (DIPC), 20018Donostia-San Sebastián, Spain
- Centro de Física de Materiales CSIC-UPV/EHU, 20018Donostia-San Sebastián, Spain
| | - Aran Garcia-Lekue
- Donostia International Physics Center (DIPC), 20018Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48013Bilbao, Spain
| | - Alexander Weismann
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098Kiel, Germany
| | - Chao Li
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098Kiel, Germany
| | - Rainer Herges
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität, 24098Kiel, Germany
| | - Richard Berndt
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098Kiel, Germany
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13
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Pravdivtsev AN, Brahms A, Ellermann F, Stamp T, Herges R, Hövener JB. Parahydrogen-induced polarization and spin order transfer in ethyl pyruvate at high magnetic fields. Sci Rep 2022; 12:19361. [PMID: 36371512 DOI: 10.21203/rs.3.rs-1807976/v1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 10/13/2022] [Indexed: 05/21/2023] Open
Abstract
Nuclear magnetic resonance has experienced great advances in developing and translating hyperpolarization methods into procedures for fundamental and clinical studies. Here, we propose the use of a wide-bore NMR for large-scale (volume- and concentration-wise) production of hyperpolarized media using parahydrogen-induced polarization. We discuss the benefits of radio frequency-induced parahydrogen spin order transfer, we show that 100% polarization is theoretically expected for homogeneous B0 and B1 magnetic fields for a three-spin system. Moreover, we estimated that the efficiency of spin order transfer is not significantly reduced when the B1 inhomogeneity is below ± 5%; recommendations for the sample size and RF coils are also given. With the latest breakthrough in the high-yield synthesis of 1-13C-vinyl pyruvate and its deuterated isotopologues, the high-field PHIP-SAH will gain increased attention. Some remaining challenges will be addressed shortly.
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Affiliation(s)
- Andrey N Pravdivtsev
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118, Kiel, Germany.
| | - Arne Brahms
- Otto Diels Institute for Organic Chemistry, Kiel University, Otto- Hahn Platz 4, 24118, Kiel, Germany
| | - Frowin Ellermann
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118, Kiel, Germany
| | - Tim Stamp
- Otto Diels Institute for Organic Chemistry, Kiel University, Otto- Hahn Platz 4, 24118, Kiel, Germany
| | - Rainer Herges
- Otto Diels Institute for Organic Chemistry, Kiel University, Otto- Hahn Platz 4, 24118, Kiel, Germany
| | - Jan-Bernd Hövener
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118, Kiel, Germany.
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14
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Hugenbusch D, Lehr M, von Glasenapp JS, McConnell AJ, Herges R. Light‐Controlled Destruction and Assembly: Switching between Two Differently Composed Cage‐Type Complexes. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202212571] [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] [Indexed: 11/11/2022]
Affiliation(s)
- Daniel Hugenbusch
- Kiel University: Christian-Albrechts-Universitat zu Kiel Institute for Organic Chemistry GERMANY
| | - Marc Lehr
- Kiel University: Christian-Albrechts-Universitat zu Kiel Institute for Organic Chemistry GERMANY
| | - Jan-Simon von Glasenapp
- Kiel University: Christian-Albrechts-Universitat zu Kiel Institute for Organic Chemistry GERMANY
| | - Anna J. McConnell
- Kiel University: Christian-Albrechts-Universitat zu Kiel Institute for Organic Chemistry GERMANY
| | - Rainer Herges
- Universitaet Kiel Institut fuer Organische Chemie Otto-Hahn-Platz 4 24118 Kiel GERMANY
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15
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Brahms A, Pravdivtsev AN, Stamp T, Ellermann F, Sönnichsen FD, Hövener J, Herges R. Synthesis of 13 C and 2 H Labeled Vinyl Pyruvate and Hyperpolarization of Pyruvate. Chemistry 2022; 28:e202201210. [PMID: 35905033 PMCID: PMC9804285 DOI: 10.1002/chem.202201210] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Indexed: 01/05/2023]
Abstract
The hyperpolarization of nuclear spins has enabled unique applications in chemistry, biophysics, and particularly metabolic imaging. Parahydrogen-induced polarization (PHIP) offers a fast and cost-efficient way of hyperpolarization. Nevertheless, PHIP lags behind dynamic nuclear polarization (DNP), which is already being evaluated in clinical studies. This shortcoming is mainly due to problems in the synthesis of the corresponding PHIP precursor molecules. The most widely used DNP tracer in clinical studies, particularly for the detection of prostate cancer, is 1-13 C-pyruvate. The ideal derivative for PHIP is the deuterated vinyl ester because the spin physics allows for 100 % polarization. Unfortunately, there is no efficient synthesis for vinyl esters of β-ketocarboxylic acids in general and pyruvate in particular. Here, we present an efficient new method for the preparation of vinyl esters, including 13 C labeled, fully deuterated vinyl pyruvate using a palladium-catalyzed procedure. Using 50 % enriched parahydrogen and mild reaction conditions, a 13 C polarization of 12 % was readily achieved; 36 % are expected with 100 % pH2 . Higher polarization values can be potentially achieved with optimized reaction conditions.
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Affiliation(s)
- Arne Brahms
- Otto Diels Institute for Organic ChemistryKiel UniversityOtto-Hahn-Platz 424118KielGermany
| | - Andrey N. Pravdivtsev
- Section Biomedical ImagingMolecular Imaging North Competence Center (MOIN CC)Department of Radiology and NeuroradiologyUniversity Medical Center KielKiel UniversityAm Botanischen Garten 1424118KielGermany
| | - Tim Stamp
- Otto Diels Institute for Organic ChemistryKiel UniversityOtto-Hahn-Platz 424118KielGermany
| | - Frowin Ellermann
- Section Biomedical ImagingMolecular Imaging North Competence Center (MOIN CC)Department of Radiology and NeuroradiologyUniversity Medical Center KielKiel UniversityAm Botanischen Garten 1424118KielGermany
| | - Frank D. Sönnichsen
- Otto Diels Institute for Organic ChemistryKiel UniversityOtto-Hahn-Platz 424118KielGermany
| | - Jan‐Bernd Hövener
- Section Biomedical ImagingMolecular Imaging North Competence Center (MOIN CC)Department of Radiology and NeuroradiologyUniversity Medical Center KielKiel UniversityAm Botanischen Garten 1424118KielGermany
| | - Rainer Herges
- Otto Diels Institute for Organic ChemistryKiel UniversityOtto-Hahn-Platz 424118KielGermany
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16
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Ewert J, Heintze L, Jordà-Redondo M, von Glasenapp JS, Nonell S, Bucher G, Peifer C, Herges R. Photoswitchable Diazocine-Based Estrogen Receptor Agonists: Stabilization of the Active Form inside the Receptor. J Am Chem Soc 2022; 144:15059-15071. [PMID: 35952371 DOI: 10.1021/jacs.2c03649] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photopharmacology is an emerging approach in drug design and pharmacological therapy. Light is used to switch a pharmacophore between a biologically inactive and an active isomer with high spatiotemporal resolution at the site of illness, thus potentially avoiding side effects in neighboring healthy tissue. The most frequently used strategy to design a photoswitchable drug is to replace a suitable functional group in a known bioactive molecule with azobenzene. Our strategy is different in that the photoswitch moiety is closer to the drug's scaffold. Docking studies reveal a very high structural similarity of natural 17β-estradiol and the E isomers of dihydroxy diazocines, but not their Z isomers, respectively. Seven dihydroxy diazocines were synthesized and subjected to a biological estrogen reporter gene assay. Four derivatives exhibit distinct estrogenic activity after irradiation with violet light, which can be shut off with green light. Most remarkably, the photogenerated, active E form of one of the active compounds isomerizes back to the inactive Z form with a half-life of merely several milliseconds in water, but nevertheless is active for more than 3 h in the presence of the estrogen receptor. The results suggest a significant local impact of the ligand-receptor complex toward back-isomerization. Thus, drugs that are active when bound but lose their activity immediately after leaving the receptor could be of great pharmacological value because they strongly increase target specificity. Moreover, the drugs are released into the environment in their inactive form. The latter argument is particularly important for drugs that act as endocrine disruptors.
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Affiliation(s)
- Julia Ewert
- Otto-Diels-Institute of Organic Chemistry, Christian-Albrechts-University of Kiel, 24098 Kiel, Germany
| | - Linda Heintze
- Institute of Pharmacy, Christian-Albrechts-University of Kiel, 24118 Kiel, Germany
| | | | - Jan-Simon von Glasenapp
- Otto-Diels-Institute of Organic Chemistry, Christian-Albrechts-University of Kiel, 24098 Kiel, Germany
| | - Santi Nonell
- Institut Químic de Sarrià, Universitat Ramon Llull, 08017 Barcelona, Spain
| | - Götz Bucher
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, U. K
| | - Christian Peifer
- Institute of Pharmacy, Christian-Albrechts-University of Kiel, 24118 Kiel, Germany
| | - Rainer Herges
- Otto-Diels-Institute of Organic Chemistry, Christian-Albrechts-University of Kiel, 24098 Kiel, Germany
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17
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Leitner TD, von Glasenapp JS, Herges R, Mena‐Osteritz E, Bäuerle P. Highly Crowded Twisted Thienylene-Phenylene Structures: Evidence for Through-Space Orbital Coupling in a [4]Catenated Topology. Adv Sci (Weinh) 2022; 9:e2105785. [PMID: 35132810 PMCID: PMC9259713 DOI: 10.1002/advs.202105785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/15/2022] [Indexed: 06/14/2023]
Abstract
Sterically highly crowded and twisted thienylene-phenylenes are synthesized and structurally characterized. Single-crystal X-ray structure analyses and theoretical studies give evidence of through-space delocalization of π-electrons of peripheral (hetero)aromatic rings in toroidal and catenated topology.
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Affiliation(s)
- Tanja Desirée Leitner
- Institute of Organic Chemistry II and Advanced MaterialsUniversity of UlmAlbert‐Einstein‐Allee 11Ulm89081Germany
- PPG Industries Lackfabrik GmbHErlenbrunnenstraße 22Bodelshausen72411Germany
| | - Jan Simon von Glasenapp
- Otto Diels‐Institute of Organic ChemistryChristian‐Albrechts University KielOtto‐Hahn‐Platz 4Kiel24098Germany
| | - Rainer Herges
- Otto Diels‐Institute of Organic ChemistryChristian‐Albrechts University KielOtto‐Hahn‐Platz 4Kiel24098Germany
| | - Elena Mena‐Osteritz
- Institute of Organic Chemistry II and Advanced MaterialsUniversity of UlmAlbert‐Einstein‐Allee 11Ulm89081Germany
| | - Peter Bäuerle
- Institute of Organic Chemistry II and Advanced MaterialsUniversity of UlmAlbert‐Einstein‐Allee 11Ulm89081Germany
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18
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Abstract
![]()
Stimuli-responsive
coordination cages allow reversible control
over guest binding and release, relevant for adaptive receptors, carriers,
catalysts, and complex systems. Light serves as an advantageous stimulus,
as it can be applied with precise spatial and temporal resolution
without producing chemical waste products. We report the first Pd-mediated
coordination cage based on ligands embedding a diazocine photoswitch.
While the thermodynamically more stable cis-photoisomer
sloppily assembles to a mixture of species with general formula [Pdncis-L2n], the less stable trans-isomer yields a defined [Pd2trans-L4] cage that reversibly converts
back to the cis-system by irradiation at 530 nm or
thermal relaxation. The [Pdncis-L2n]
species do not bind a given guest; however, [Pd2trans-L4] is able to
encapsulate a bis-sulfonate as long as it is kept assembled, requiring
continuous irradiation at 385 nm. In the absence of UV light, thermal
relaxation results in back-switching and guest release. Assembly and
properties of the system were characterized by a combination of NMR,
ion mobility ESI-MS, single-crystal X-ray diffraction, and UV–vis
absorption studies.
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Affiliation(s)
- Haeri Lee
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto Hahn Straße 6, 44227 Dortmund, Germany.,Department of Chemistry, Hannam University, 1646, Yuseong-daero, Yuseong-gu, Daejeon, 34054, Republic of Korea
| | - Jacopo Tessarolo
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto Hahn Straße 6, 44227 Dortmund, Germany
| | - Daniel Langbehn
- Otto Diels Institute of Organic Chemistry, Christian-Albrechts University, Otto Hahn Platz 4, 24118 Kiel, Germany
| | - Ananya Baksi
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto Hahn Straße 6, 44227 Dortmund, Germany
| | - Rainer Herges
- Otto Diels Institute of Organic Chemistry, Christian-Albrechts University, Otto Hahn Platz 4, 24118 Kiel, Germany
| | - Guido H Clever
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto Hahn Straße 6, 44227 Dortmund, Germany
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19
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Li C, Meng X, Weismann A, von Glasenapp JS, Hamer S, Xiang F, Pignedoli CA, Herges R, Berndt R. Effect of an axial ligand on the self-assembly of molecular platforms. Phys Chem Chem Phys 2022; 24:28864-28869. [DOI: 10.1039/d2cp04760h] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Sub-monolayer amounts of trioxatriangulenium (TOTA) molecules functionalized with biphenyl on Ag(111) were investigated with scanning tunnelling microscopy.
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Affiliation(s)
- Chao Li
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - Xiangzhi Meng
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - Alexander Weismann
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - Jan-Simon von Glasenapp
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - Sebastian Hamer
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - Feifei Xiang
- nanotech@surfaces Laboratory, EMPA, Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland
| | - Carlo A. Pignedoli
- nanotech@surfaces Laboratory, EMPA, Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland
| | - Rainer Herges
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - Richard Berndt
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
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20
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Wages F, Lentes P, Griebenow T, Herges R, Peifer C, Maser E. Reduction of photoswitched, nitrogen bridged N-acetyl diazocines limits inhibition of 17βHSD3 activity in transfected human embryonic kidney 293 cells. Chem Biol Interact 2022; 354:109822. [DOI: 10.1016/j.cbi.2022.109822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 01/11/2022] [Accepted: 01/18/2022] [Indexed: 11/03/2022]
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21
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Hamer S, von Glasenapp JS, Röhricht F, Li C, Berndt R, Herges R. Azimuthal Dipolar Rotor Arrays on Surfaces. Chemistry 2021; 27:17452-17458. [PMID: 34664752 PMCID: PMC9298050 DOI: 10.1002/chem.202103237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Indexed: 11/18/2022]
Abstract
A set of dipolar molecular rotor compounds was designed, synthesized and adsorbed as self‐assembled 2D arrays on Ag(111) surfaces. The title molecules are constructed from three building blocks: (a) 4,8,12‐trioxatriangulene (TOTA) platforms that are known to physisorb on metal surfaces such as Au(111) and Ag(111), (b) phenyl groups attached to the central carbon atom that function as pivot joints to reduce the barrier to rotation, (c) pyridine and pyridazine units as small dipolar units on top. Theoretical calculations and scanning tunneling microscopy (STM) investigations hint at the fact that the dipoles of neighboring rotors interact through space through pairs of energetically favorable head‐to‐tail arrangements.
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Affiliation(s)
- Sebastian Hamer
- Otto-Diels-Institut für Organische Chemie, Kiel University, Otto-Hahn-Platz 4, 24098, Kiel, Germany
| | - Jan-Simon von Glasenapp
- Otto-Diels-Institut für Organische Chemie, Kiel University, Otto-Hahn-Platz 4, 24098, Kiel, Germany
| | - Fynn Röhricht
- Otto-Diels-Institut für Organische Chemie, Kiel University, Otto-Hahn-Platz 4, 24098, Kiel, Germany
| | - Chao Li
- Institut für Experimentelle und Angewandte Physik, Kiel University, Leibnizstrasse 19, 24098, Kiel, Germany
| | - Richard Berndt
- Institut für Experimentelle und Angewandte Physik, Kiel University, Leibnizstrasse 19, 24098, Kiel, Germany
| | - Rainer Herges
- Otto-Diels-Institut für Organische Chemie, Kiel University, Otto-Hahn-Platz 4, 24098, Kiel, Germany
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22
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Schmidt AB, Brahms A, Ellermann F, Knecht S, Berner S, Hennig J, von Elverfeldt D, Herges R, Hövener JB, Pravdivtsev AN. Selective excitation of hydrogen doubles the yield and improves the robustness of parahydrogen-induced polarization of low-γ nuclei. Phys Chem Chem Phys 2021; 23:26645-26652. [PMID: 34846056 DOI: 10.1039/d1cp04153c] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We describe a new method for pulsed spin order transfer of parahydrogen-induced polarization (PHIP) that enables high polarization in incompletely 2H-labeled molecules by exciting only the desired protons in a frequency-selective manner. This way, the effect of selected J-couplings is suspended. Experimentally 1.25% 13C polarization were obtained for 1-13C-ethyl pyruvate and 50% pH2 at 9.4 Tesla.
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Affiliation(s)
- Andreas B Schmidt
- Department of Radiology, Medical Physics, Medical Center, University of Freiburg, Faculty of Medicine, University of Freiburg, Killianstr. 5a, Freiburg 79106, Germany. .,German Cancer Consortium (DKTK), Partner Site Freiburg and German Cancer Research Center (DKFZ), Im Neuen-heimer Feld 280, Heidelberg 69120, Germany.,Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118, Kiel, Germany
| | - Arne Brahms
- Otto Diels Institute for Organic Chemistry, Kiel University, Otto-Hahn-Platz 5, 24118, Kiel, Germany
| | - Frowin Ellermann
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118, Kiel, Germany
| | | | - Stephan Berner
- Department of Radiology, Medical Physics, Medical Center, University of Freiburg, Faculty of Medicine, University of Freiburg, Killianstr. 5a, Freiburg 79106, Germany.
| | - Jürgen Hennig
- Department of Radiology, Medical Physics, Medical Center, University of Freiburg, Faculty of Medicine, University of Freiburg, Killianstr. 5a, Freiburg 79106, Germany.
| | - Dominik von Elverfeldt
- Department of Radiology, Medical Physics, Medical Center, University of Freiburg, Faculty of Medicine, University of Freiburg, Killianstr. 5a, Freiburg 79106, Germany.
| | - Rainer Herges
- Otto Diels Institute for Organic Chemistry, Kiel University, Otto-Hahn-Platz 5, 24118, Kiel, Germany
| | - Jan-Bernd Hövener
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118, Kiel, Germany
| | - Andrey N Pravdivtsev
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Kiel, Kiel University, Am Botanischen Garten 14, 24118, Kiel, Germany
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23
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Them K, Ellermann F, Pravdivtsev AN, Salnikov OG, Skovpin IV, Koptyug IV, Herges R, Hövener JB. Parahydrogen-Induced Polarization Relayed via Proton Exchange. J Am Chem Soc 2021; 143:13694-13700. [PMID: 34406748 DOI: 10.1021/jacs.1c05254] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The hyperpolarization of nuclear spins is a game-changing technology that enables hitherto inaccessible applications for magnetic resonance in chemistry and biomedicine. Despite significant advances and discoveries in the past, however, the quest to establish efficient and effective hyperpolarization methods continues. Here, we describe a new method that combines the advantages of direct parahydrogenation, high polarization (P), fast reaction, and low cost with the broad applicability of polarization transfer via proton exchange. We identified the system propargyl alcohol + pH2 → allyl alcohol to yield 1H polarization in excess of P ≈ 13% by using only 50% enriched pH2 at a pressure of ≈1 bar. The polarization was then successfully relayed via proton exchange from allyl alcohol to various target molecules. The polarizations of water and alcohols (as target molecules) approached P ≈ 1% even at high molar concentrations of 100 mM. Lactate, glucose, and pyruvic acid were also polarized, but to a lesser extent. Several potential improvements of the methodology are discussed. Thus, the parahydrogen-induced hyperpolarization relayed via proton exchange (PHIP-X) is a promising approach to polarize numerous molecules which participate in proton exchange and support new applications for magnetic resonance.
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Affiliation(s)
- Kolja Them
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein and Kiel University, Am Botanischen Garten 14, 24118 Kiel, Germany
| | - Frowin Ellermann
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein and Kiel University, Am Botanischen Garten 14, 24118 Kiel, Germany
| | - Andrey N Pravdivtsev
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein and Kiel University, Am Botanischen Garten 14, 24118 Kiel, Germany
| | - Oleg G Salnikov
- International Tomography Center, SB RAS, 3A Institutskaya st., Novosibirsk 630090, Russia.,Novosibirsk State University, 2 Pirogova st., Novosibirsk 630090, Russia.,Boreskov Institute of Catalysis SB RAS, 4 Acad. Lavrentiev pr., Novosibirsk 630090, Russia
| | - Ivan V Skovpin
- International Tomography Center, SB RAS, 3A Institutskaya st., Novosibirsk 630090, Russia.,Novosibirsk State University, 2 Pirogova st., Novosibirsk 630090, Russia
| | - Igor V Koptyug
- International Tomography Center, SB RAS, 3A Institutskaya st., Novosibirsk 630090, Russia.,Novosibirsk State University, 2 Pirogova st., Novosibirsk 630090, Russia
| | - Rainer Herges
- Otto-Diels-Institute for Organic Chemistry, Christian-Albrechts-University, 24118 Kiel, Germany
| | - Jan-Bernd Hövener
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein and Kiel University, Am Botanischen Garten 14, 24118 Kiel, Germany
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24
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Abstract
Novel nitrogen-bridged diazocines (triazocines) were synthesized that carry a formyl or an acetyl group at the CH2NR-bridge and bromo- or iodo-substituents at the distant phenyl ring. The photophysical properties were investigated in acetonitrile and water. As compared to previous approaches the yields of the intramolecular azo cyclizations were increased (from ≈40 to 60%) using an oxidative approach starting from the corresponding aniline precursors. The Z→E photoconversion yields in acetonitrile are 80-85% and the thermal half-lives of the metastable E configurations are 31-74 min. Particularly, the high photoconversion yields (≈70%) of the water-soluble diazocines are noteworthy, which makes them promising candidates for applications in photopharmacology. The halogen substituents allow further functionalization via cross-coupling reactions.
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Affiliation(s)
- Pascal Lentes
- Otto Diels-Institute of Organic Chemistry, Christian Albrechts University Kiel, Otto-Hahn-Platz 4, 24118 Kiel, Germany
| | - Jeremy Rudtke
- Otto Diels-Institute of Organic Chemistry, Christian Albrechts University Kiel, Otto-Hahn-Platz 4, 24118 Kiel, Germany
| | - Thomas Griebenow
- Otto Diels-Institute of Organic Chemistry, Christian Albrechts University Kiel, Otto-Hahn-Platz 4, 24118 Kiel, Germany
| | - Rainer Herges
- Otto Diels-Institute of Organic Chemistry, Christian Albrechts University Kiel, Otto-Hahn-Platz 4, 24118 Kiel, Germany
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25
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Wellm V, Näther C, Herges R. Molecular Spin State Switching and Photochromism in the Red and Near Infrared with Ni(II) Chlorin and Ni(II) Bacteriochlorin. J Org Chem 2021; 86:9503-9514. [PMID: 34181424 DOI: 10.1021/acs.joc.1c00806] [Citation(s) in RCA: 3] [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: 11/29/2022]
Abstract
Molecules or ions are either paramagnetic (unpaired electrons) or diamagnetic (all electrons are paired). Switching between the two states under ambient conditions was considered a typical solid state phenomenon and has been termed spin crossover. The first single-molecule spin state switches operated with light in solution were developed a decade ago and offer a number of technical applications that are not accessible to solid state systems. Magnetic switching in biological environments, however, requires water solubility, and for in vivo applications, switching wavelengths within the bio-optical window (650-950 nm) are needed. We now present molecular spin state switches that are water-soluble and switchable in the far-red and near-infrared region. At the same time, they are photochromic compounds with excellent photophysical properties. trans-cis isomerization is induced with 505 nm radiation, and cis-trans conversion with 620 or 720 nm radiation. The metastable cis isomers are stable at room temperature for at least several weeks. The detailed mechanism of this surprising and unprecedented long wavelength photoisomerization of azobenzenes is still under investigation.
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Affiliation(s)
- Vanessa Wellm
- Otto Diels-Institute of Organic Chemistry, University of Kiel, Otto-Hahn-Platz 4, Kiel D-24118, Germany
| | - Christian Näther
- Institute of Inorganic Chemistry, University of Kiel, Max-Eyth-Straße 2, Kiel D-24118, Germany
| | - Rainer Herges
- Otto Diels-Institute of Organic Chemistry, University of Kiel, Otto-Hahn-Platz 4, Kiel D-24118, Germany
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26
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Wellm V, Groebner J, Heitmann G, Sönnichsen FD, Herges R. Towards Photoswitchable Contrast Agents for Absolute 3D Temperature MR Imaging. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202015851] [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] [Indexed: 11/10/2022]
Affiliation(s)
- Vanessa Wellm
- Otto Diels Institute of Organic Chemistry Christian Albrechts University Otto Hahn Platz 4 24118 Kiel Germany
| | - Jens Groebner
- Department of Electrical Engineering and Information Technology South Westphalian University of Applied Sciences Bahnhofsallee 5 58507 Luedenscheid Germany
| | - Gernot Heitmann
- IWS Innovations- und Wissenstrategien GmbH Aviares Research Network Deichstraße 25 20459 Hamburg Germany
| | - Frank D. Sönnichsen
- Otto Diels Institute of Organic Chemistry Christian Albrechts University Otto Hahn Platz 4 24118 Kiel Germany
| | - Rainer Herges
- Otto Diels Institute of Organic Chemistry Christian Albrechts University Otto Hahn Platz 4 24118 Kiel Germany
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27
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Wellm V, Groebner J, Heitmann G, Sönnichsen FD, Herges R. Towards Photoswitchable Contrast Agents for Absolute 3D Temperature MR Imaging. Angew Chem Int Ed Engl 2021; 60:8220-8226. [PMID: 33606332 PMCID: PMC8048480 DOI: 10.1002/anie.202015851] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Indexed: 12/27/2022]
Abstract
Temperature can be used as clinical marker for tissue metabolism and the detection of inflammations or tumors. The use of magnetic resonance imaging (MRI) for monitoring physiological parameters like the temperature noninvasively is steadily increasing. In this study, we present a proof-of-principle study of MRI contrast agents (CA) for absolute and concentration independent temperature imaging. These CAs are based on azoimidazole substituted NiII porphyrins, which can undergo Light-Driven Coordination-Induced Spin State Switching (LD-CISSS) in solution. Monitoring the fast first order kinetic of back isomerisation (cis to trans) with standard clinical MR imaging sequences allows the determination of half-lives, that can be directly translated into absolute temperatures. Different temperature responsive CAs were successfully tested as prototypes in methanol-based gels and created temperature maps of gradient phantoms with high spatial resolution (0.13×0.13×1.1 mm) and low temperature errors (<0.22 °C). The method is sufficiently fast to record the temperature flow from a heat source as a film.
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Affiliation(s)
- Vanessa Wellm
- Otto Diels Institute of Organic ChemistryChristian Albrechts UniversityOtto Hahn Platz 424118KielGermany
| | - Jens Groebner
- Department of Electrical Engineering and Information TechnologySouth Westphalian University of Applied SciencesBahnhofsallee 558507LuedenscheidGermany
| | - Gernot Heitmann
- IWS Innovations- und Wissenstrategien GmbHAviares Research NetworkDeichstraße 2520459HamburgGermany
| | - Frank D. Sönnichsen
- Otto Diels Institute of Organic ChemistryChristian Albrechts UniversityOtto Hahn Platz 424118KielGermany
| | - Rainer Herges
- Otto Diels Institute of Organic ChemistryChristian Albrechts UniversityOtto Hahn Platz 424118KielGermany
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28
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Affiliation(s)
- Pascal Lentes
- Otto Diels-Institute of Organic Chemistry, Christian-Albrechts University Kiel, Otto Hahn Platz 4, 24118 Kiel, Germany
| | - Philipp Frühwirt
- Institute of Physical and Theoretical Chemistry, NAWI Graz, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Hilde Freißmuth
- Institute of Physical and Theoretical Chemistry, NAWI Graz, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Widukind Moormann
- Otto Diels-Institute of Organic Chemistry, Christian-Albrechts University Kiel, Otto Hahn Platz 4, 24118 Kiel, Germany
| | - Fabian Kruse
- Otto Diels-Institute of Organic Chemistry, Christian-Albrechts University Kiel, Otto Hahn Platz 4, 24118 Kiel, Germany
| | - Georg Gescheidt
- Institute of Physical and Theoretical Chemistry, NAWI Graz, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Rainer Herges
- Otto Diels-Institute of Organic Chemistry, Christian-Albrechts University Kiel, Otto Hahn Platz 4, 24118 Kiel, Germany
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29
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Pravdivtsev AN, Brahms A, Kienitz S, Sönnichsen FD, Hövener J, Herges R. Catalytic Hydrogenation of Trivinyl Orthoacetate: Mechanisms Elucidated by Parahydrogen Induced Polarization. Chemphyschem 2021; 22:370-377. [PMID: 33319391 PMCID: PMC7986815 DOI: 10.1002/cphc.202000957] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/12/2020] [Indexed: 12/24/2022]
Abstract
Parahydrogen (pH2 ) induced polarization (PHIP) is a unique method that is used in analytical chemistry to elucidate catalytic hydrogenation pathways and to increase the signal of small metabolites in MRI and NMR. PHIP is based on adding or exchanging at least one pH2 molecule with a target molecule. Thus, the spin order available for hyperpolarization is often limited to that of one pH2 molecule. To break this limit, we investigated the addition of multiple pH2 molecules to one precursor. We studied the feasibility of the simultaneous hydrogenation of three arms of trivinyl orthoacetate (TVOA) intending to obtain hyperpolarized acetate. It was found that semihydrogenated TVOA underwent a fast decomposition accompanied by several minor reactions including an exchange of geminal methylene protons of a vinyl ester with pH2 . The study shows that multiple vinyl ester groups are not suitable for a fast and clean (without any side products) hydrogenation and hyperpolarization that is desired in biochemical applications.
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Affiliation(s)
- Andrey N. Pravdivtsev
- Section Biomedical ImagingMolecular Imaging North Competence Center (MOIN CC)Department of Radiology and NeuroradiologyUniversity Medical Center KielKiel UniversityAm Botanischen Garten 1424114KielGermany
| | - Arne Brahms
- Otto Diels Institute for Organic ChemistryKiel UniversityOtto Hahn Platz 524098KielGermany
| | - Stephan Kienitz
- Otto Diels Institute for Organic ChemistryKiel UniversityOtto Hahn Platz 524098KielGermany
| | - Frank D. Sönnichsen
- Otto Diels Institute for Organic ChemistryKiel UniversityOtto Hahn Platz 524098KielGermany
| | - Jan‐Bernd Hövener
- Section Biomedical ImagingMolecular Imaging North Competence Center (MOIN CC)Department of Radiology and NeuroradiologyUniversity Medical Center KielKiel UniversityAm Botanischen Garten 1424114KielGermany
| | - Rainer Herges
- Otto Diels Institute for Organic ChemistryKiel UniversityOtto Hahn Platz 524098KielGermany
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30
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Ludwig J, Moje T, Röhricht F, Herges R. Synthesis of 4-substituted azopyridine-functionalized Ni(II)-porphyrins as molecular spin switches. Beilstein J Org Chem 2020; 16:2589-2597. [PMID: 33133290 PMCID: PMC7590622 DOI: 10.3762/bjoc.16.210] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 10/12/2020] [Indexed: 11/23/2022] Open
Abstract
We present the synthesis and the spin switching efficiencies of Ni(II)-porphyrins substituted with azopyridines as covalently attached photoswitchable ligands. The molecules are designed in such a way that the azopyridines coordinate to the Ni ion if the azo unit is in cis configuration. For steric reasons no intramolecular coordination is possible if the azopyridine unit adopts the trans configuration. Photoisomerization of the azo unit between cis and trans is achieved upon irradiation with 505 nm (trans→cis) and 435 nm (cis→trans). Concurrently with the isomerization and coordination/decoordination, the spin state of the Ni ion switches between singlet (low-spin) and triplet (high-spin). Previous studies have shown that the spin switching efficiency is strongly dependent on the solvent and on the substituent at the 4-position of the pyridine unit. We now introduced thiol, disulfide, thioethers, nitrile and carboxylic acid groups and investigated their spin switching efficiency.
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Affiliation(s)
- Jannis Ludwig
- Otto Diels Institute of Organic Chemistry, University of Kiel, Otto-Hahn-Platz 3-4, 24098 Kiel, Germany
| | - Tobias Moje
- Otto Diels Institute of Organic Chemistry, University of Kiel, Otto-Hahn-Platz 3-4, 24098 Kiel, Germany
| | - Fynn Röhricht
- Otto Diels Institute of Organic Chemistry, University of Kiel, Otto-Hahn-Platz 3-4, 24098 Kiel, Germany
| | - Rainer Herges
- Otto Diels Institute of Organic Chemistry, University of Kiel, Otto-Hahn-Platz 3-4, 24098 Kiel, Germany
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31
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Rusch TR, Schlimm A, Krekiehn NR, Tellkamp T, Budzák Š, Jacquemin D, Tuczek F, Herges R, Magnussen OM. Observation of Collective Photoswitching in Free-Standing TATA-Based Azobenzenes on Au(111). Angew Chem Int Ed Engl 2020; 59:17192-17196. [PMID: 32524693 PMCID: PMC7540444 DOI: 10.1002/anie.202003797] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 05/04/2020] [Indexed: 11/29/2022]
Abstract
Light-induced transitions between the trans and cis isomer of triazatriangulenium-based azobenzene derivatives on Au(111) surfaces were observed directly by scanning tunneling microscopy, allowing atomic-scale studies of the photoisomerization kinetics. Although the azobenzene units in these adlayers are free-standing and spaced at uniform distances of 1.26 nm, their photoswitching depends on the isomeric state of the surrounding molecules and, specifically, is accelerated by neighboring cis isomers. These collective effects are supported by ab initio calculations indicating that the electronic excitation preferably localizes on the n-π* state of trans isomers with neighboring cis azobenzenes.
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Affiliation(s)
- Talina R. Rusch
- Institute of Experimental and Applied PhysicsChristian Albrechts UniversityKielGermany
| | - Alexander Schlimm
- Institute of Inorganic ChemistryChristian Albrechts UniversityKielGermany
| | - Nicolai R. Krekiehn
- Institute of Experimental and Applied PhysicsChristian Albrechts UniversityKielGermany
| | - Tobias Tellkamp
- Otto Diels Institute of Organic ChemistryChristian Albrechts UniversityKielGermany
| | - Šimon Budzák
- Department of ChemistryFaculty of Natural SciencesMatej Bel UniversityBanska BystricaSlovakia
| | | | - Felix Tuczek
- Institute of Inorganic ChemistryChristian Albrechts UniversityKielGermany
| | - Rainer Herges
- Otto Diels Institute of Organic ChemistryChristian Albrechts UniversityKielGermany
| | - Olaf M. Magnussen
- Institute of Experimental and Applied PhysicsChristian Albrechts UniversityKielGermany
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32
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Rusch TR, Schlimm A, Krekiehn NR, Tellkamp T, Budzák Š, Jacquemin D, Tuczek F, Herges R, Magnussen OM. Observation of Collective Photoswitching in Free‐Standing TATA‐Based Azobenzenes on Au(111). Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202003797] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Talina R. Rusch
- Institute of Experimental and Applied Physics Christian Albrechts University Kiel Germany
| | - Alexander Schlimm
- Institute of Inorganic Chemistry Christian Albrechts University Kiel Germany
| | - Nicolai R. Krekiehn
- Institute of Experimental and Applied Physics Christian Albrechts University Kiel Germany
| | - Tobias Tellkamp
- Otto Diels Institute of Organic Chemistry Christian Albrechts University Kiel Germany
| | - Šimon Budzák
- Department of Chemistry Faculty of Natural Sciences Matej Bel University Banska Bystrica Slovakia
| | - Denis Jacquemin
- CEISAM Lab—UMR 6230— CNRS/University of Nantes Nantes France
| | - Felix Tuczek
- Institute of Inorganic Chemistry Christian Albrechts University Kiel Germany
| | - Rainer Herges
- Otto Diels Institute of Organic Chemistry Christian Albrechts University Kiel Germany
| | - Olaf M. Magnussen
- Institute of Experimental and Applied Physics Christian Albrechts University Kiel Germany
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33
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Ludwig J, Helberg J, Zipse H, Herges R. Azo-dimethylaminopyridine-functionalized Ni(II)-porphyrin as a photoswitchable nucleophilic catalyst. Beilstein J Org Chem 2020; 16:2119-2126. [PMID: 32952728 PMCID: PMC7476594 DOI: 10.3762/bjoc.16.179] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 08/21/2020] [Indexed: 12/24/2022] Open
Abstract
We present the synthesis and the photochemical and catalytic switching properties of an azopyridine as a photoswitchable ligand, covalently attached to a Ni(II)-porphyrin. Upon irradiation with 530 nm (green light), the azopyridine switches to the cis configuration and coordinates with the Ni2+ ion. Light of 435 nm (violet) isomerizes the ligand back to the trans configuration, which decoordinates for steric reasons. This so-called record player design has been used previously to switch the spin state of Ni2+ between singlet and triplet. We now use the coordination/decoordination process to switch the catalytic activity of the dimethylaminopyridine (DMAP) unit. DMAP is a known catalyst in the nitroaldol (Henry) reaction. Upon coordination to the Ni2+ ion, the basicity of the pyridine lone pair is attenuated and hence the catalytic activity is reduced. Decoordination restores the catalytic activity. The rate constants in the two switching states differ by a factor of 2.2, and the catalytic switching is reversible.
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Affiliation(s)
- Jannis Ludwig
- Otto Diels Institute of Organic Chemistry, University of Kiel, Otto-Hahn-Platz 3-4, Kiel D-24098, Germany
| | - Julian Helberg
- Department of Chemistry, Ludwig-Maximilians-Universitaet Muenchen, Butenandtstrasse 5–13, 81377 Muenchen, Germany
| | - Hendrik Zipse
- Department of Chemistry, Ludwig-Maximilians-Universitaet Muenchen, Butenandtstrasse 5–13, 81377 Muenchen, Germany
| | - Rainer Herges
- Otto Diels Institute of Organic Chemistry, University of Kiel, Otto-Hahn-Platz 3-4, Kiel D-24098, Germany
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34
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Moormann W, Tellkamp T, Stadler E, Röhricht F, Näther C, Puttreddy R, Rissanen K, Gescheidt G, Herges R. Efficient Conversion of Light to Chemical Energy: Directional, Chiral Photoswitches with Very High Quantum Yields. Angew Chem Int Ed Engl 2020; 59:15081-15086. [PMID: 32348617 PMCID: PMC7496762 DOI: 10.1002/anie.202005361] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Indexed: 12/14/2022]
Abstract
Photochromic systems have been used to achieve a number of engineering functions such as light energy conversion, molecular motors, pumps, actuators, and sensors. Key to practical applications is a high efficiency in the conversion of light to chemical energy, a rigid structure for the transmission of force to the environment, and directed motion during isomerization. We present a novel type of photochromic system (diindane diazocines) that converts visible light with an efficiency of 18 % to chemical energy. Quantum yields are exceptionally high with >70 % for the cis-trans isomerization and 90 % for the back-reaction and thus higher than the biochemical system rhodopsin (64 %). Two diastereomers (meso and racemate) were obtained in only two steps in high yields. Both isomers are directional switches with high conversion rates (76-99 %). No fatigue was observed after several thousands of switching cycles in both systems.
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Affiliation(s)
- Widukind Moormann
- Otto-Diels-Institut für Organische ChemieChristian-Albrechts-Universität zu KielOtto-Hahn-Platz 424118KielGermany
| | - Tobias Tellkamp
- Otto-Diels-Institut für Organische ChemieChristian-Albrechts-Universität zu KielOtto-Hahn-Platz 424118KielGermany
| | - Eduard Stadler
- Institute of Physical and Theoretical ChemistryGraz University of TechnologyStremayrgasse 98010GrazAustria
| | - Fynn Röhricht
- Otto-Diels-Institut für Organische ChemieChristian-Albrechts-Universität zu KielOtto-Hahn-Platz 424118KielGermany
| | - Christian Näther
- Institut für Anorganische ChemieChristian-Albrechts-Universität zu KielMax-Eyth-Str. 224118KielGermany
| | - Rakesh Puttreddy
- University of JyvaskylaDepartment of ChemistryP.O. Box 3540014JyväskyläFinland
- Smart Photonic MaterialsFaculty of Engineering and Natural SciencesTampere UniversityP. O. Box 54133101TampereFinland
| | - Kari Rissanen
- University of JyvaskylaDepartment of ChemistryP.O. Box 3540014JyväskyläFinland
| | - Georg Gescheidt
- Institute of Physical and Theoretical ChemistryGraz University of TechnologyStremayrgasse 98010GrazAustria
| | - Rainer Herges
- Otto-Diels-Institut für Organische ChemieChristian-Albrechts-Universität zu KielOtto-Hahn-Platz 424118KielGermany
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35
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Abstract
Molecular assemblers were proposed by K. Eric Drexler in 1986, based on the ideas of R. Feynman. In his (quite lurid) book "Engines of Creation: The Coming Era of Nanotechnology" and follow-up publications Drexler proposes molecular machines capable of positioning reactive molecules with atomic precision and to build larger, more sophisticated structures via mechanosynthesis. These imaginative visions started a hot controversy. The debate culminated in a cover story of Chemical & Engineering News in 2003 (ref. 1) with the key question: "Are molecular assemblers - devices capable of positioning atoms and molecules for precisely defined reactions - possible?" with Drexler as the proponent and Nobelist Richard E. Smalley being the opponent. Smalley raised two major objections: the "fat fingers" and the "sticky fingers" problem. To grab and guide each individual atom the assembler must have many nano-fingers. Smalley argued that there is just not enough room in the nanometer-sized reaction region to accommodate all the fingers of all the manipulators necessary to have complete control of the chemistry. The sticky finger issue arises from the problem that …"the atoms of the manipulator hands will adhere to the atom that is being moved. So it will often be impossible to release the building block in precisely the right spot." Smalley concludes that the fat and the sticky finger problems are fundamental and cannot be avoided. While some of the statements of E. Drexler are bold and probably not very realistic, his ideas are inspiring and might be a good starting point to assess on how far laboratory chemistry has advanced towards real "molecular assemblers" within the last two decades.
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Affiliation(s)
- Rainer Herges
- Otto-Diels-Institute of Organic Chemistry, Kiel University 24118 Kiel Germany
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36
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Moormann W, Tellkamp T, Stadler E, Röhricht F, Näther C, Puttreddy R, Rissanen K, Gescheidt G, Herges R. Effiziente Umwandlung von Licht in chemische Energie: Gerichtete, chirale Photoschalter mit sehr hohen Quantenausbeuten. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202005361] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Widukind Moormann
- Otto-Diels-Institut für Organische Chemie Christian-Albrechts-Universität zu Kiel Otto-Hahn-Platz 4 24118 Kiel Deutschland
| | - Tobias Tellkamp
- Otto-Diels-Institut für Organische Chemie Christian-Albrechts-Universität zu Kiel Otto-Hahn-Platz 4 24118 Kiel Deutschland
| | - Eduard Stadler
- Institute of Physical and Theoretical Chemistry Graz University of Technology Stremayrgasse 9 8010 Graz Österreich
| | - Fynn Röhricht
- Otto-Diels-Institut für Organische Chemie Christian-Albrechts-Universität zu Kiel Otto-Hahn-Platz 4 24118 Kiel Deutschland
| | - Christian Näther
- Institut für Anorganische Chemie Christian-Albrechts-Universität zu Kiel Max-Eyth-Str. 2 24118 Kiel Deutschland
| | - Rakesh Puttreddy
- University of Jyvaskyla Department of Chemistry P.O. Box 35 40014 Jyväskylä Finnland
- Smart Photonic Materials Faculty of Engineering and Natural Sciences Tampere University P. O. Box 541 33101 Tampere Finnland
| | - Kari Rissanen
- University of Jyvaskyla Department of Chemistry P.O. Box 35 40014 Jyväskylä Finnland
| | - Georg Gescheidt
- Institute of Physical and Theoretical Chemistry Graz University of Technology Stremayrgasse 9 8010 Graz Österreich
| | - Rainer Herges
- Otto-Diels-Institut für Organische Chemie Christian-Albrechts-Universität zu Kiel Otto-Hahn-Platz 4 24118 Kiel Deutschland
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37
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Jasper-Toennies T, Gruber M, Johannsen S, Frederiksen T, Garcia-Lekue A, Jäkel T, Roehricht F, Herges R, Berndt R. Rotation of Ethoxy and Ethyl Moieties on a Molecular Platform on Au(111). ACS Nano 2020; 14:3907-3916. [PMID: 32073820 DOI: 10.1021/acsnano.0c00029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Molecular rotors have attracted considerable interest for their prospects in nanotechnology. However, their adsorption on supporting substrates, where they may be addressed individually, usually modifies their properties. Here, we investigate the switching of two closely related three-state rotors mounted on platforms on Au(111) using low-temperature scanning tunneling microscopy and density functional theory calculations. Being physisorbed, the platforms retain important gas-phase properties of the rotor. This simplifies a detailed analysis and permits, for instance, the identification of the vibrational modes involved in the rotation process. The symmetry provided by the platform enables active control of the rotation direction through electrostatic interactions with the tip and charged neighboring adsorbates. The present investigation of two model systems may turn out useful for designing platforms that provide directional rotation and for transferring more sophisticated molecular machines from the gas phase to surfaces.
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Affiliation(s)
- Torben Jasper-Toennies
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098 Kiel, Germany
| | - Manuel Gruber
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098 Kiel, Germany
| | - Sven Johannsen
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098 Kiel, Germany
| | - Thomas Frederiksen
- Donostia International Physics Center, DIPC, Paseo Manuel de Lardizabal 4, E-20018 Donostia-San Sebastián, Spain
- IKERBASQUE, Basque Foundation for Science, E-48013 Bilbao, Spain
| | - Aran Garcia-Lekue
- Donostia International Physics Center, DIPC, Paseo Manuel de Lardizabal 4, E-20018 Donostia-San Sebastián, Spain
- IKERBASQUE, Basque Foundation for Science, E-48013 Bilbao, Spain
| | - Torben Jäkel
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität, 24098 Kiel, Germany
| | - Fynn Roehricht
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität, 24098 Kiel, Germany
| | - Rainer Herges
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität, 24098 Kiel, Germany
| | - Richard Berndt
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098 Kiel, Germany
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38
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Jasper‐Tönnies T, Gruber M, Ulrich S, Herges R, Berndt R. Frontispiece: Coverage‐Controlled Superstructures of
C
3
‐Symmetric Molecules: Honeycomb versus Hexagonal Tiling. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/anie.202081861] [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] [Indexed: 11/07/2022]
Affiliation(s)
- Torben Jasper‐Tönnies
- Institut für Experimentelle und Angewandte Physik Christian-Albrechts-Universität 24098 Kiel Germany
| | - Manuel Gruber
- Institut für Experimentelle und Angewandte Physik Christian-Albrechts-Universität 24098 Kiel Germany
| | - Sandra Ulrich
- Otto-Diels-Institut für Organische Chemie Christian-Albrechts-Universität 24098 Kiel Germany
| | - Rainer Herges
- Otto-Diels-Institut für Organische Chemie Christian-Albrechts-Universität 24098 Kiel Germany
| | - Richard Berndt
- Institut für Experimentelle und Angewandte Physik Christian-Albrechts-Universität 24098 Kiel Germany
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39
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Jasper-Tönnies T, Gruber M, Ulrich S, Herges R, Berndt R. Coverage-Controlled Superstructures of C 3 -Symmetric Molecules: Honeycomb versus Hexagonal Tiling. Angew Chem Int Ed Engl 2020; 59:7008-7017. [PMID: 32106353 PMCID: PMC7216838 DOI: 10.1002/anie.202001383] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Indexed: 11/06/2022]
Abstract
The competition between honeycomb and hexagonal tiling of molecular units can lead to large honeycomb superstructures on surfaces. Such superstructures exhibit pores that may be used as 2D templates for functional guest molecules. Honeycomb superstructures of molecules that comprise a C3 symmetric platform on Au(111) and Ag(111) surfaces are presented. The superstructures cover nearly mesoscopic areas with unit cells containing up to 3000 molecules, more than an order of magnitude larger than previously reported. The unit cell size may be controlled by the coverage. A fairly general model was developed to describe the energetics of honeycomb superstructures built from C3 symmetric units. Based on three parameters that characterize two competing bonding arrangements, the model is consistent with the present experimental data and also reproduces various published results. The model identifies the relevant driving force, mostly related to geometric aspects, of the pattern formation.
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Affiliation(s)
- Torben Jasper-Tönnies
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098, Kiel, Germany
| | - Manuel Gruber
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098, Kiel, Germany
| | - Sandra Ulrich
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität, 24098, Kiel, Germany
| | - Rainer Herges
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität, 24098, Kiel, Germany
| | - Richard Berndt
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098, Kiel, Germany
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40
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Jasper‐Tönnies T, Gruber M, Ulrich S, Herges R, Berndt R. Frontispiz: Coverage‐Controlled Superstructures of
C
3
‐Symmetric Molecules: Honeycomb versus Hexagonal Tiling. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202081861] [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] [Indexed: 11/11/2022]
Affiliation(s)
- Torben Jasper‐Tönnies
- Institut für Experimentelle und Angewandte Physik Christian-Albrechts-Universität 24098 Kiel Germany
| | - Manuel Gruber
- Institut für Experimentelle und Angewandte Physik Christian-Albrechts-Universität 24098 Kiel Germany
| | - Sandra Ulrich
- Otto-Diels-Institut für Organische Chemie Christian-Albrechts-Universität 24098 Kiel Germany
| | - Rainer Herges
- Otto-Diels-Institut für Organische Chemie Christian-Albrechts-Universität 24098 Kiel Germany
| | - Richard Berndt
- Institut für Experimentelle und Angewandte Physik Christian-Albrechts-Universität 24098 Kiel Germany
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41
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Preußke N, Moormann W, Bamberg K, Lipfert M, Herges R, Sönnichsen FD. Visible-light-driven photocontrol of the Trp-cage protein fold by a diazocine cross-linker. Org Biomol Chem 2020; 18:2650-2660. [PMID: 32207764 DOI: 10.1039/c9ob02442e] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Diazocines are characterized by extraordinary photochemical properties rendering them of particular interest for switching the conformation of biomolecules with visible light. Current developments afford synthetic access to unprecedented diazocine derivatives promising particular opportunities in photocontrol of proteins and biological systems. In this work, the well-established approach of photocontrolling the secondary structure of α-helices was exploited using a diazocine to reversibly fold and unfold the tertiary structure of a small protein. The protein of choice was the globulary folded Trp-cage, a widely used model system for the elucidation of protein folding pathways. A specifically designed, short and rigid dicarboxy-functionalized diazocine-based cross-linker was attached to two solvent-exposed side chains at the α-helix of the miniprotein through the use of a primary amine-selective active ester. This cross-linking strategy is orthogonal to the common cysteine-based chemistry. The cross-linked Trp-cage was successfully photoisomerized and exhibited a strong correlation between protein fold and diazocine isomeric state. As determined by NMR spectroscopy, the cis-isomer stabilized the fold, while the trans-isomer led to complete protein unfolding. The successful switching of the protein fold in principle demonstrates the ability to control protein function, as the activity depends on their structural integrity.
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Affiliation(s)
- Nils Preußke
- Otto-Diels-Institute for Organic Chemistry, Christian-Albrechts-University of Kiel, Otto-Hahn-Platz 4, 24118 Kiel, Germany.
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42
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Jasper‐Tönnies T, Gruber M, Ulrich S, Herges R, Berndt R. Coverage‐Controlled Superstructures of
C
3
‐Symmetric Molecules: Honeycomb versus Hexagonal Tiling. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202001383] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Torben Jasper‐Tönnies
- Institut für Experimentelle und Angewandte Physik Christian-Albrechts-Universität 24098 Kiel Germany
| | - Manuel Gruber
- Institut für Experimentelle und Angewandte Physik Christian-Albrechts-Universität 24098 Kiel Germany
| | - Sandra Ulrich
- Otto-Diels-Institut für Organische Chemie Christian-Albrechts-Universität 24098 Kiel Germany
| | - Rainer Herges
- Otto-Diels-Institut für Organische Chemie Christian-Albrechts-Universität 24098 Kiel Germany
| | - Richard Berndt
- Institut für Experimentelle und Angewandte Physik Christian-Albrechts-Universität 24098 Kiel Germany
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43
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Burk MH, Schröder S, Moormann W, Langbehn D, Strunskus T, Rehders S, Herges R, Faupel F. Fabrication of Diazocine-Based Photochromic Organic Thin Films via Initiated Chemical Vapor Deposition. Macromolecules 2020. [DOI: 10.1021/acs.macromol.9b02443] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Maximilian H. Burk
- Institute for Materials Science, Christian-Albrechts-University, Kaiserstr. 2, 24143 Kiel, Germany
| | - Stefan Schröder
- Institute for Materials Science, Christian-Albrechts-University, Kaiserstr. 2, 24143 Kiel, Germany
| | - Widukind Moormann
- Otto-Diels-Institute for Organic Chemistry, Christian-Albrechts-University, Otto-Hahn-Platz 4, 24118 Kiel, Germany
| | - Daniel Langbehn
- Otto-Diels-Institute for Organic Chemistry, Christian-Albrechts-University, Otto-Hahn-Platz 4, 24118 Kiel, Germany
| | - Thomas Strunskus
- Institute for Materials Science, Christian-Albrechts-University, Kaiserstr. 2, 24143 Kiel, Germany
| | - Stefan Rehders
- Institute for Materials Science, Christian-Albrechts-University, Kaiserstr. 2, 24143 Kiel, Germany
| | - Rainer Herges
- Otto-Diels-Institute for Organic Chemistry, Christian-Albrechts-University, Otto-Hahn-Platz 4, 24118 Kiel, Germany
| | - Franz Faupel
- Institute for Materials Science, Christian-Albrechts-University, Kaiserstr. 2, 24143 Kiel, Germany
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44
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Leitner TD, Gmeinder Y, Röhricht F, Herges R, Mena-Osteritz E, Bäuerle P. Front Cover: Twisted Thienylene-Phenylene Structures: Through-Space Orbital Coupling in Toroidal and Catenated Topologies (Eur. J. Org. Chem. 3/2020). European J Org Chem 2020. [DOI: 10.1002/ejoc.202000037] [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] [Indexed: 11/07/2022]
Affiliation(s)
- Tanja D. Leitner
- Institute of Organic Chemistry II and Advanced Materials; University of Ulm; Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Yannick Gmeinder
- Institute of Organic Chemistry II and Advanced Materials; University of Ulm; Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Fynn Röhricht
- Otto Diels-Institute of Organic Chemistry; Christian-Albrechts University Kiel; Otto-Hahn-Platz 4 24098 Kiel Germany
| | - Rainer Herges
- Otto Diels-Institute of Organic Chemistry; Christian-Albrechts University Kiel; Otto-Hahn-Platz 4 24098 Kiel Germany
| | - Elena Mena-Osteritz
- Institute of Organic Chemistry II and Advanced Materials; University of Ulm; Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Peter Bäuerle
- Institute of Organic Chemistry II and Advanced Materials; University of Ulm; Albert-Einstein-Allee 11 89081 Ulm Germany
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45
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Ludwig J, Gröbner J, Dommaschk M, Huber LM, Peters MK, Hövener JB, Herges R. Ni(II)porphyrins as pH dependent light-driven coordination-induced spin-state switches (LD-CISSS) in aqueous solution. J PORPHYR PHTHALOCYA 2020. [DOI: 10.1142/s1088424619501803] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A water-soluble Ni(II)-porphyrin substituted with a covalently attached azopyridine ligand was synthesized. Upon irradiation with violet and green light, the azo unit performs a reversible cis–trans isomerization. This geometry change triggers a coordination/de-coordination of the pyridine nitrogen at the central nickel(II) ion. The concomitant change in coordination number at the Ni ion in turn switches the spin state between high and low spin, a process we coined a “light-driven coordination-induced spin state switch (LD-CISSS). To increase the coordination power of the pyridine, particularly in aqueous environments, we introduced an electron donating OH group in 4-position. With increasing pH, the hydroxyl group is deprotonated, further enforcing coordination. We report on the properties of this pH-dependent spin switch, particularly the magnetic properties.
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Affiliation(s)
- Jannis Ludwig
- Otto Diels Institute of Organic Chemistry, University of Kiel, Otto-Hahn-Platz 3-4, Kiel D-24098, Germany
| | - Jens Gröbner
- Otto Diels Institute of Organic Chemistry, University of Kiel, Otto-Hahn-Platz 3-4, Kiel D-24098, Germany
| | - Marcel Dommaschk
- Otto Diels Institute of Organic Chemistry, University of Kiel, Otto-Hahn-Platz 3-4, Kiel D-24098, Germany
| | - Lukas M. Huber
- Molecular Imaging North Competence Center, University of Kiel, Am Botanischen Garten 14, Kiel D-24098, Germany
| | - Morten K. Peters
- Otto Diels Institute of Organic Chemistry, University of Kiel, Otto-Hahn-Platz 3-4, Kiel D-24098, Germany
| | - Jan-Bernd Hövener
- Molecular Imaging North Competence Center, University of Kiel, Am Botanischen Garten 14, Kiel D-24098, Germany
| | - Rainer Herges
- Otto Diels Institute of Organic Chemistry, University of Kiel, Otto-Hahn-Platz 3-4, Kiel D-24098, Germany
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46
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Köbke A, Gutzeit F, Röhricht F, Schlimm A, Grunwald J, Tuczek F, Studniarek M, Longo D, Choueikani F, Otero E, Ohresser P, Rohlf S, Johannsen S, Diekmann F, Rossnagel K, Weismann A, Jasper-Toennies T, Näther C, Herges R, Berndt R, Gruber M. Reversible coordination-induced spin-state switching in complexes on metal surfaces. Nat Nanotechnol 2020; 15:18-21. [PMID: 31873288 DOI: 10.1038/s41565-019-0594-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 11/14/2019] [Indexed: 06/10/2023]
Abstract
Molecular spin switches are attractive candidates for controlling the spin polarization developing at the interface between molecules and magnetic metal surfaces1,2, which is relevant for molecular spintronics devices3-5. However, so far, intrinsic spin switches such as spin-crossover complexes have suffered from fragmentation or loss of functionality following adsorption on metal surfaces, with rare exceptions6-9. Robust metal-organic platforms, on the other hand, rely on external axial ligands to induce spin switching10-14. Here we integrate a spin switching functionality into robust complexes, relying on the mechanical movement of an axial ligand strapped to the porphyrin ring. Reversible interlocked switching of spin and coordination, induced by electron injection, is demonstrated on Ag(111) for this class of compounds. The stability of the two spin and coordination states of the molecules exceeds days at 4 K. The potential applications of this switching concept go beyond the spin functionality, and may turn out to be useful for controlling the catalytic activity of surfaces15.
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Affiliation(s)
- Alexander Köbke
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Florian Gutzeit
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Fynn Röhricht
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Alexander Schlimm
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Jan Grunwald
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Felix Tuczek
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | | | - Danilo Longo
- Synchrotron SOLEIL, L'Orme des Merisiers, Gif-sur-Yvette, France
| | - Fadi Choueikani
- Synchrotron SOLEIL, L'Orme des Merisiers, Gif-sur-Yvette, France
| | - Edwige Otero
- Synchrotron SOLEIL, L'Orme des Merisiers, Gif-sur-Yvette, France
| | | | - Sebastian Rohlf
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
- Ruprecht-Haensel-Labor, Christian-Albrechts-Universität zu Kiel und Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - Sven Johannsen
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Florian Diekmann
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
- Ruprecht-Haensel-Labor, Christian-Albrechts-Universität zu Kiel und Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - Kai Rossnagel
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
- Ruprecht-Haensel-Labor, Christian-Albrechts-Universität zu Kiel und Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - Alexander Weismann
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Torben Jasper-Toennies
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Christian Näther
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Rainer Herges
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.
| | - Richard Berndt
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Manuel Gruber
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.
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47
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Leitner TD, Gmeinder Y, Röhricht F, Herges R, Mena‐Osteritz E, Bäuerle P. Twisted Thienylene–Phenylene Structures: Through‐Space Orbital Coupling in Toroidal and Catenated Topologies. European J Org Chem 2019. [DOI: 10.1002/ejoc.201901637] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Tanja D. Leitner
- Institute of Organic Chemistry II and Advanced Materials University of Ulm Albert‐Einstein‐Allee 11 89081 Ulm Germany
| | - Yannick Gmeinder
- Institute of Organic Chemistry II and Advanced Materials University of Ulm Albert‐Einstein‐Allee 11 89081 Ulm Germany
| | - Fynn Röhricht
- Otto Diels‐Institute of Organic Chemistry Christian‐Albrechts University Kiel Otto‐Hahn‐Platz 4 24098 Kiel Germany
| | - Rainer Herges
- Otto Diels‐Institute of Organic Chemistry Christian‐Albrechts University Kiel Otto‐Hahn‐Platz 4 24098 Kiel Germany
| | - Elena Mena‐Osteritz
- Institute of Organic Chemistry II and Advanced Materials University of Ulm Albert‐Einstein‐Allee 11 89081 Ulm Germany
| | - Peter Bäuerle
- Institute of Organic Chemistry II and Advanced Materials University of Ulm Albert‐Einstein‐Allee 11 89081 Ulm Germany
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48
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Dommaschk M, Gröbner J, Wellm V, Hövener JB, Riedel C, Herges R. Dendronised Ni(ii) porphyrins as photoswitchable contrast agents for MRI. Phys Chem Chem Phys 2019; 21:24296-24299. [PMID: 31686082 DOI: 10.1039/c9cp04156g] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Light-responsive contrast agents for magnetic resonance imaging (MRI) based on Ni(ii) porphyrin molecular spin switches have recently been introduced. We present their implementation in water and methanol based gels leading to the first soft materials that are rewritable with light and readable with MRI. Light of two different wavelengths as non-invasive stimuli can be applied to switch MRI contrast on and off, with a high spatiotemporal resolution and without fatigue.
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Affiliation(s)
- Marcel Dommaschk
- Otto-Diels-Institute of Organic Chemistry, Christian Albrechts University Kiel, Otto Hahn Platz 4, 24118 Kiel, Germany.
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Gutzeit F, Neumann T, Näther C, Herges R. Crystal structure of (15,20-bis-(2,3,4,5,6-penta-fluoro-phen-yl)-5,10-{(4-methyl-pyridine-3,5-di-yl)bis-[(sulfanediyl-methyl-ene)[1,1'-biphen-yl]-4',2-di-yl]}porphyrinato)nickel(II) di-chloro-methane x-solvate ( x > 1/2). Acta Crystallogr E Crystallogr Commun 2019; 75:1558-1563. [PMID: 31636994 PMCID: PMC6775725 DOI: 10.1107/s2056989019012453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 09/06/2019] [Indexed: 11/10/2022]
Abstract
The title compound, [Ni(C64H33F10N5S2)]·xCH2Cl2, consists of discrete NiII porphyrin complexes, in which the five-coordinate NiII cations are in a distorted square-pyramidal coordination geometry. The four porphyrin nitro-gen atoms are located in the basal plane of the pyramid, whereas the pyridine N atom is in the apical position. The porphyrin plane is strongly distorted and the NiII cation is located above this plane by 0.241 (3) Å and shifted in the direction of the coordinating pyridine nitro-gen atom. The pyridine ring is not perpendicular to the N4 plane of the porphyrin moiety, as observed for related compounds. In the crystal, the complexes are linked via weak C-H⋯F hydrogen bonds into zigzag chains propagating in the [001] direction. Within this arrangement cavities are formed, in which highly disordered di-chloro-methane solvate mol-ecules are located. No reasonable structural model could be found to describe this disorder and therefore the contribution of the solvent to the electron density was removed using the SQUEEZE option in PLATON [Spek (2015 ▸). Acta Cryst. C71, 9-18].
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Affiliation(s)
- Florian Gutzeit
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität Kiel, Otto-Hahn-Platz 4, D-24098 Kiel, Germany
| | - Tjorge Neumann
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität Kiel, Otto-Hahn-Platz 4, D-24098 Kiel, Germany
| | - Christian Näther
- Institut für Anorganische Chemie, Christian-Albrechts-Universität Kiel, Max-Eyth Str. 2, D-24118 Kiel, Germany
| | - Rainer Herges
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität Kiel, Otto-Hahn-Platz 4, D-24098 Kiel, Germany
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Löw R, Rusch T, Moje T, Röhricht F, Magnussen OM, Herges R. Norbornadiene-functionalized triazatriangulenium and trioxatriangulenium platforms. Beilstein J Org Chem 2019; 15:1815-1821. [PMID: 31467601 PMCID: PMC6693376 DOI: 10.3762/bjoc.15.175] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 07/17/2019] [Indexed: 11/23/2022] Open
Abstract
Triazatriangulenium (TATA) and trioxatriangulenium (TOTA) ions are particularly suited systems to mount functional molecules onto atomically flat surfaces such as Au(111). The TATA and TOTA units serve as platforms that absorb onto the surface and form ordered monolayers, while the functional groups are protruding upright and freestanding from the central carbon atoms. Azobenzene derivatized TATA’s are known to exhibit extremely fast cis→trans isomerization on metal surfaces, via a peculiar non-adiabatic singlet→triplet→singlet mechanism. We now prepared norbornadienes (NBD) and quadricyclanes (QC) attached to TATA and TOTA platforms which can be used to check if these accelerated rates and the spin change mechanism also apply to [2 + 2] cycloreversions (QC→NBD).
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Affiliation(s)
- Roland Löw
- Otto Diels Institute for Organic Chemistry, University of Kiel, Otto-Hahn-Platz 4, 24118 Kiel, Germany
| | - Talina Rusch
- Institute for Experimental and Applied Physics, University of Kiel, Leibnizstraße 19, 24098 Kiel, Germany
| | - Tobias Moje
- Otto Diels Institute for Organic Chemistry, University of Kiel, Otto-Hahn-Platz 4, 24118 Kiel, Germany
| | - Fynn Röhricht
- Otto Diels Institute for Organic Chemistry, University of Kiel, Otto-Hahn-Platz 4, 24118 Kiel, Germany
| | - Olaf M Magnussen
- Institute for Experimental and Applied Physics, University of Kiel, Leibnizstraße 19, 24098 Kiel, Germany
| | - Rainer Herges
- Otto Diels Institute for Organic Chemistry, University of Kiel, Otto-Hahn-Platz 4, 24118 Kiel, Germany
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