1
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Misselwitz E, Spengler J, Rominger F, Kivala M. Indenoannulated Tridecacyclene: An All-Carbon Seven-Stage Redox-Amphoter. Chemistry 2024:e202400696. [PMID: 38563636 DOI: 10.1002/chem.202400696] [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: 03/18/2024] [Accepted: 04/01/2024] [Indexed: 04/04/2024]
Abstract
We disclose an indenoannulated tridecacyclene comprising a central cyclooctatetraene moiety with multiple adjacent pentagonal rings which is accessible in a concise synthetic sequence. The saddle-shaped geometry of the non-benzenoid polycyclic scaffold and its unique packing behavior in the solid state were characterized by X-ray crystallography. In electrochemical studies, the compound undergoes seven reversible redox events comprising five reductions and two oxidations. The dicationic and dianionic species obtained by chemical oxidation and reduction, respectively, were characterized spectroscopically in solution. Density functional theory calculations were applied to provide insights into aromaticity evolution in the respective charged species, highlighting the beneficial effect of the non-benzenoid moieties on charge stabilization.
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Affiliation(s)
- Erik Misselwitz
- Organisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Jonas Spengler
- Organisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Frank Rominger
- Organisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Milan Kivala
- Organisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
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2
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Konishi A, Imai S, Satake S, Chiba K, Yasuda M. Synthesis and Characterization of Hexafluorocyclopentane-Bridged Bisbutatrienes as Models for Longer Cumulenes: Various Transformations for the Constructions of π-Conjugated Frameworks. Chemistry 2023:e202301255. [PMID: 37166184 DOI: 10.1002/chem.202301255] [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: 04/20/2023] [Revised: 05/11/2023] [Accepted: 05/11/2023] [Indexed: 05/12/2023]
Abstract
Cumulenes have attracted considerable attention due to their unique structural and electronic properties. Despite their high potential for constructing condensed π-conjugated molecules, the synthetic utility of longer cumulenes remains to be established owing to their inherently high reactivity. We focused on conjugated bisbutatrienes having two cumulene moieties linked by a spacer as a mimic of a longer cumulene. Here, we describe the synthesis and characterization of hexafluorocyclopentane-bridged bisbutatrienes. These bisbutatrienes underwent various cyclizations, to construct the unique π-extended frameworks inaccessible by other methodologies. Our bisbutatrienes were converted into fulvenes, pentalene, germacycle, and benzocyclobutene under various conditions. Furthermore, cyclooctatetraene derivative was synthesized via a one-step dimerization of the bisbutatriene.
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Affiliation(s)
| | - Shizuka Imai
- Osaka University, Department of Applied Chemistry, JAPAN
| | - Shoya Satake
- Osaka University, Department of Applied Chemistry, JAPAN
| | - Kouji Chiba
- MOLSIS Inc., Material Science Division, JAPAN
| | - Makoto Yasuda
- Osaka University, Department of Applied Chemistry, Graduate School of Engineering, 2-1 Yamadaoka, Suita, 565-0871, Osaka, JAPAN
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3
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Martin MI, Pati AK, Abeywickrama CS, Bar S, Kilic Z, Altman RB, Blanchard SC. Leveraging Baird aromaticity for advancement of bioimaging applications. J PHYS ORG CHEM 2023; 36:e4449. [PMID: 36590885 PMCID: PMC9799245 DOI: 10.1002/poc.4449] [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] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 10/03/2022] [Accepted: 10/04/2022] [Indexed: 02/01/2023]
Abstract
In this perspective, we highlight the recent progress in utilizing Baird aromatic species to improve fluorophore performance in microscopy and imaging applications. We specifically focus on the origins of the use of Baird aromaticity in fluorescence applications, the development of “self‐healing” fluorophores leveraging cyclooctatetraene’ Baird aromaticity, and where developments need to occur to optimize this technology.
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Affiliation(s)
- Maxwell I. Martin
- Department of Structural BiologySt. Jude Children's Research HospitalMemphisTNUSA
- Department of Chemical Biology & TherapeuticsSt. Jude Children's Research HospitalMemphisTNUSA
| | - Avik K. Pati
- Department of Structural BiologySt. Jude Children's Research HospitalMemphisTNUSA
| | - Chathura S. Abeywickrama
- Department of Structural BiologySt. Jude Children's Research HospitalMemphisTNUSA
- Department of Chemical Biology & TherapeuticsSt. Jude Children's Research HospitalMemphisTNUSA
| | - Sukanta Bar
- Department of Structural BiologySt. Jude Children's Research HospitalMemphisTNUSA
- Department of Chemical Biology & TherapeuticsSt. Jude Children's Research HospitalMemphisTNUSA
| | - Zeliha Kilic
- Department of Structural BiologySt. Jude Children's Research HospitalMemphisTNUSA
| | - Roger B. Altman
- Department of Structural BiologySt. Jude Children's Research HospitalMemphisTNUSA
- Department of Chemical Biology & TherapeuticsSt. Jude Children's Research HospitalMemphisTNUSA
| | - Scott C. Blanchard
- Department of Structural BiologySt. Jude Children's Research HospitalMemphisTNUSA
- Department of Chemical Biology & TherapeuticsSt. Jude Children's Research HospitalMemphisTNUSA
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4
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Ejlli B, Nußbaum P, Rominger F, Freudenberg J, Bunz UHF, Müllen K. Benzo-fused Tri[8]annulenes as Molecular Models of Cubic Graphite. Angew Chem Int Ed Engl 2021; 60:20220-20224. [PMID: 34156743 PMCID: PMC8457115 DOI: 10.1002/anie.202106233] [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] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 06/11/2021] [Indexed: 12/18/2022]
Abstract
Cyclotrimerization of 9,10‐dibromo‐9,10‐dihydrodibenzo[3,4:7,8]cycloocta[1,2‐l]phenanthrene with potassium tert‐butoxide in the presence of a transition‐metal catalyst afforded two polycyclic aromatic hydrocarbon stereoisomers consisting of three cyclooctatetraene (COT) moieties connected via a central benzene ring. Both isomeric tri[8]annulenes were obtained selectively through the choice of the catalyst: The α,α,α‐form (Ru catalyst) displayed a threefold symmetrywith the COT subunits forming the side walls of a (chiral) molecular cup. In the thermodynamically more stable α,α,β‐isomer (Pd catalyst), one of the three boat‐shaped COTs was flipped over and faced the opposite molecular hemisphere with respect to the central benzene ring as evidenced by crystal structure analysis. Both title compounds are small segments of “cubic graphite”, an elusive carbon allotrope.
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Affiliation(s)
- Barbara Ejlli
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.,InnovationLab, Speyerer Str. 4, 69115, Heidelberg, Germany.,Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Pascal Nußbaum
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Frank Rominger
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Jan Freudenberg
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.,InnovationLab, Speyerer Str. 4, 69115, Heidelberg, Germany
| | - Uwe H F Bunz
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Klaus Müllen
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
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5
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Casadio DS, Aikonen S, Lenarda A, Nieger M, Hu T, Taubert S, Sundholm D, Muuronen M, Wirtanen T, Helaja J. Divergent Carbocatalytic Routes in Oxidative Coupling of Benzofused Heteroaryl Dimers: A Mechanistic Update. Chemistry 2021; 27:5283-5291. [PMID: 33427343 PMCID: PMC8048508 DOI: 10.1002/chem.202005433] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 12/21/2020] [Indexed: 12/27/2022]
Abstract
Mildly thermal air or HNO3 oxidized activated carbons catalyse oxidative dehydrogenative couplings of benzo[b]fused heteroaryl 2,2'-dimers, e.g., 2-(benzofuran-2-yl)-1H-indole, to chiral 3,3'-coupled cyclooctatetraenes or carbazole-type migrative products under O2 atmosphere. DFT calculations show that the radical cation and the Scholl-type arenium cation mechanisms lead to different products with 2-(benzofuran-2-yl)-1H-indole, being in accord with experimental product distributions.
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Affiliation(s)
- David S. Casadio
- Department of ChemistryUniversity of HelsinkiA. I. Virtasen aukio 1, P.O. Box 5500014HelsinkiFinland
| | - Santeri Aikonen
- Department of ChemistryUniversity of HelsinkiA. I. Virtasen aukio 1, P.O. Box 5500014HelsinkiFinland
| | - Anna Lenarda
- Department of ChemistryUniversity of HelsinkiA. I. Virtasen aukio 1, P.O. Box 5500014HelsinkiFinland
| | - Martin Nieger
- Department of ChemistryUniversity of HelsinkiA. I. Virtasen aukio 1, P.O. Box 5500014HelsinkiFinland
| | - Tao Hu
- Research Unit of Sustainable ChemistryFaculty of TechnologyUniversity of Oulu90014OuluFinland
| | - Stefan Taubert
- Department of ChemistryUniversity of HelsinkiA. I. Virtasen aukio 1, P.O. Box 5500014HelsinkiFinland
| | - Dage Sundholm
- Department of ChemistryUniversity of HelsinkiA. I. Virtasen aukio 1, P.O. Box 5500014HelsinkiFinland
| | - Mikko Muuronen
- Department of ChemistryUniversity of HelsinkiA. I. Virtasen aukio 1, P.O. Box 5500014HelsinkiFinland
| | - Tom Wirtanen
- Department of ChemistryUniversity of HelsinkiA. I. Virtasen aukio 1, P.O. Box 5500014HelsinkiFinland
| | - Juho Helaja
- Department of ChemistryUniversity of HelsinkiA. I. Virtasen aukio 1, P.O. Box 5500014HelsinkiFinland
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6
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Desmaizieres G, Speer ME, Thiede I, Gaiser P, Perner V, Kolek M, Bieker P, Winter M, Esser B. Dibenzo[a,e] Cyclooctatetraene-Functionalized Polymers as Potential Battery Electrode Materials. Macromol Rapid Commun 2021; 42:e2000725. [PMID: 33660343 DOI: 10.1002/marc.202000725] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/15/2021] [Indexed: 12/29/2022]
Abstract
Organic redox polymers are attractive electrode materials for more sustainable rechargeable batteries. To obtain full-organic cells with high operating voltages, redox polymers with low potentials (<2 V versus Li|Li+ ) are required for the negative electrode. Dibenzo[a,e]cyclooctatetraene (DBCOT) is a promising redox-active group in this respect, since it can be reversibly reduced in a two-electron process at potentials below 1 V versus Li|Li+ . Upon reduction, its conformation changes from tub-shaped to planar, rendering DBCOT-based polymers also of interest to molecular actuators. Here, the syntheses of three aliphatic DBCOT-polymers and their electrochemical properties are presented. For this, a viable three-step synthetic route to 2-bromo-functionalized DBCOT as polymer precursor is developed. Cyclic voltammetry (CV) measurements in solution and of thin films of the DBCOT-polymers demonstrate their potential as battery electrode materials. Half-cell measurements in batteries show pseudo capacitive behavior with Faradaic contributions, which demonstrate that electrode composition and fabrication will play an important role in the future to release the full redox activity of the DBCOT polymers.
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Affiliation(s)
- Gauthier Desmaizieres
- Institute for Organic Chemistry, University of Freiburg, Albertstraße 21, Freiburg, 79104, Germany
| | - Martin E Speer
- Institute for Organic Chemistry, University of Freiburg, Albertstraße 21, Freiburg, 79104, Germany.,Freiburg Materials Research Center (FMF), University of Freiburg, Stefan-Meier-Str. 21, Freiburg, 79104, Germany
| | - Inna Thiede
- Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Str. 1, Bonn, 53121, Germany
| | - Philipp Gaiser
- Institute for Organic Chemistry, University of Freiburg, Albertstraße 21, Freiburg, 79104, Germany
| | - Verena Perner
- MEET Battery Research Center, Institute of Physical Chemistry, University of Münster, Corrensstraße 46, Münster, 48149, Germany
| | - Martin Kolek
- MEET Battery Research Center, Institute of Physical Chemistry, University of Münster, Corrensstraße 46, Münster, 48149, Germany
| | - Peter Bieker
- MEET Battery Research Center, Institute of Physical Chemistry, University of Münster, Corrensstraße 46, Münster, 48149, Germany.,Helmholtz Institute Münster (HI MS), IEK-12, Forschungszentrum Jülich GmbH, Corrensstraße 46, Münster, 48149, Germany
| | - Martin Winter
- MEET Battery Research Center, Institute of Physical Chemistry, University of Münster, Corrensstraße 46, Münster, 48149, Germany.,Helmholtz Institute Münster (HI MS), IEK-12, Forschungszentrum Jülich GmbH, Corrensstraße 46, Münster, 48149, Germany
| | - Birgit Esser
- Institute for Organic Chemistry, University of Freiburg, Albertstraße 21, Freiburg, 79104, Germany.,Freiburg Materials Research Center (FMF), University of Freiburg, Stefan-Meier-Str. 21, Freiburg, 79104, Germany.,Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), University of Freiburg, Georges-Köhler-Allee 105, Freiburg, 79110, Germany
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7
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Chen X, Liu Y, Furukawa N, Jin DY, Savage GP, Stafford DW, Suhara Y, Williams CM, Tie JK. A novel vitamin K derived anticoagulant tolerant to genetic variations of vitamin K epoxide reductase. J Thromb Haemost 2021; 19:689-700. [PMID: 33314621 PMCID: PMC7925372 DOI: 10.1111/jth.15209] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 10/20/2020] [Accepted: 11/02/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND Vitamin K antagonists (VKAs), such as warfarin, have remained the cornerstone of oral anticoagulation therapy in the prevention and treatment of thromboembolism for more than half a century. They function by impairing the biosynthesis of vitamin K-dependent (VKD) clotting factors through the inhibition of vitamin K epoxide reductase (VKOR). The challenge of VKAs therapy is their narrow therapeutic index and highly variable dosing requirements, which are partially the result of genetic variations of VKOR. OBJECTIVES The goal of this study was to search for an improved VKA that is tolerant to the genetic variations of its target enzyme. METHODS A series of vitamin K derivatives with benzyl and related side-chain substitutions at the 3-position of 1,4-naphthoquinone were synthesized. The role of these compounds in VKD carboxylation was evaluated by mammalian cell-based assays and conventional in vitro activity assays. RESULTS Our results showed that replacing the phytyl side-chain with a methylene cyclooctatetraene (COT) moiety at the 3-position of vitamin K1 converted it from a substrate to an inhibitor for VKD carboxylation. Strikingly, this COT-vitamin K derivative displayed a similar inhibition potency in warfarin-resistant VKOR mutations whose warfarin resistance varied more than 400-fold. Further characterization of COT-vitamin K for the inhibition of VKD carboxylation suggested that this compound targets multiple enzymes in the vitamin K redox cycle. Importantly, the anticoagulation effect of COT-vitamin K can be rescued with high doses of vitamin K1 . CONCLUSION We discovered a vitamin K analogue that functions as a VKA and is tolerant to genetic variations in the target enzyme.
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Affiliation(s)
- Xuejie Chen
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Yizhou Liu
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane 4072, Queensland, Australia
| | - Natsuko Furukawa
- Laboratory of Organic Synthesis and Medicinal Chemistry, Department of Bioscience and Engineering, College of Systems Engineering and Science, Shibaura Institute of Technology, 307 Fukasaku, Minuma-ku, Saitama 337-8570, Japan
| | - Da-Yun Jin
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - G. Paul Savage
- CSIRO Manufacturing, Ian Wark Laboratory, Melbourne 3168, Victoria, Australia
| | - Darrel W. Stafford
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Yoshitomo Suhara
- Laboratory of Organic Synthesis and Medicinal Chemistry, Department of Bioscience and Engineering, College of Systems Engineering and Science, Shibaura Institute of Technology, 307 Fukasaku, Minuma-ku, Saitama 337-8570, Japan
| | - Craig M. Williams
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane 4072, Queensland, Australia
| | - Jian-Ke Tie
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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8
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Pati AK, El Bakouri O, Jockusch S, Zhou Z, Altman RB, Fitzgerald GA, Asher WB, Terry DS, Borgia A, Holsey MD, Batchelder JE, Abeywickrama C, Huddle B, Rufa D, Javitch JA, Ottosson H, Blanchard SC. Tuning the Baird aromatic triplet-state energy of cyclooctatetraene to maximize the self-healing mechanism in organic fluorophores. Proc Natl Acad Sci U S A 2020; 117:24305-15. [PMID: 32913060 DOI: 10.1073/pnas.2006517117] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Bright, photostable, and nontoxic fluorescent contrast agents are critical for biological imaging. "Self-healing" dyes, in which triplet states are intramolecularly quenched, enable fluorescence imaging by increasing fluorophore brightness and longevity, while simultaneously reducing the generation of reactive oxygen species that promote phototoxicity. Here, we systematically examine the self-healing mechanism in cyanine-class organic fluorophores spanning the visible spectrum. We show that the Baird aromatic triplet-state energy of cyclooctatetraene can be physically altered to achieve order of magnitude enhancements in fluorophore brightness and signal-to-noise ratio in both the presence and absence of oxygen. We leverage these advances to achieve direct measurements of large-scale conformational dynamics within single molecules at submillisecond resolution using wide-field illumination and camera-based detection methods. These findings demonstrate the capacity to image functionally relevant conformational processes in biological systems in the kilohertz regime at physiological oxygen concentrations and shed important light on the multivariate parameters critical to self-healing organic fluorophore design.
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9
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Matsuo Y, Tanaka T, Osuka A. Highly Stable Radical Cations of N,N'-Diarylated Tetrabenzotetraaza[8]circulene. Chemistry 2020; 26:8144-8152. [PMID: 32342540 DOI: 10.1002/chem.202001934] [Citation(s) in RCA: 16] [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: 04/21/2020] [Revised: 04/24/2020] [Indexed: 01/09/2023]
Abstract
N,N'-Diarylated tetrabenzotetraaza[8]circulenes 3 a and 3 b were synthesized in good yields by a reaction sequence involving oxidation of tetrabenzodiazadithia[8]circulene 5-Oct and SN Ar reaction with aniline derivatives. The obtained aza[8]circulenes 3 a and 3 b were easily oxidized to give their radical cations 3 a+ and 3 b+ , which are highly stable under ambient conditions. X-ray diffraction analysis of radical cation 3 a+ showed a face-to-face dimer arrangement with an interplanar separation of 3.320 Å. The spin density of 3 a+ was calculated to be delocalized over the whole circulene π-systems with spin-spin exchange integral (J=-144 cm-1 ) in the dimeric part. These radical cations displayed far red-shifted absorption bands reaching to 2000 nm. Thus this study has proved the hetero[8]circulene scaffold to be a new entry of promising electronics and spin materials.
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Affiliation(s)
- Yusuke Matsuo
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Takayuki Tanaka
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Atsuhiro Osuka
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
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10
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Abstract
A contorted polycyclic aromatic hydrocarbon (PAH) in the shape of a monkey saddle has been synthesized in three steps from a readily available truxene precursor. The monkey saddle PAH is consisting of three five-, seven six-, and three eight-membered rings and has been unambiguously characterized by single-crystal X-ray diffraction. Owing to the three biaryl axes the monkey saddle PAH is inherently chiral. The inversion of the two enantiomeric structures into each other preferably occurs through a twisting of peripheral rings rather than by a fully planar intermediate, as has been calculated by DFT methods. Enantiomers were separated by chiral HPLC and inversion barriers determined by variable temperature circular dichroism spectroscopy, supporting the twisting mechanism.
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Affiliation(s)
- Tobias Kirschbaum
- Organisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Frank Rominger
- Organisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Michael Mastalerz
- Organisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
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11
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Ishikawa T, Kawamura A, Sugawa T, Moridaira R, Yamamoto K, Murahashi T. Exceeding Metal Capacity in Sandwich Complexes: Ligand-Unsupported Docking of Extra Metal Moieties at Edges of a Metal Sheet Sandwich Complex. Angew Chem Int Ed Engl 2019; 58:15318-15323. [PMID: 31415115 DOI: 10.1002/anie.201908850] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [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: 07/16/2019] [Revised: 08/12/2019] [Indexed: 11/08/2022]
Abstract
The ligand-unsupported accommodation of extra metal moieties in a sandwich complex is reported. Although it has been considered that the metal-capacity of a metal sheet sandwich complex is strictly limited by the size of cyclic unsaturated hydrocarbon ligands, the M-M edge bonds in a metal sheet sandwich complex provide a ligand-unsupported docking site for extra metal moieties, allowing expansion of metal-capacity in sandwich complexes. The metal sheet sandwich complex [Pd4 (μ4 -C8 H8 )(μ4 -C9 H9 )]+ , in which the ligand-based metal capacity is full in terms of the usage of all C=C moieties of the smaller carbocyclic ligand C8 H8 in coordination, can accommodate extra M0 {P(OPh)3 }2 (M=Pd, Pt) moieties without coordinative assistance by either the C9 H9 or the C8 H8 ligand.
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Affiliation(s)
- Tomoko Ishikawa
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo, 152-8552, Japan
| | - Akino Kawamura
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo, 152-8552, Japan
| | - Tsuyoshi Sugawa
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo, 152-8552, Japan
| | - Risako Moridaira
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo, 152-8552, Japan
| | - Koji Yamamoto
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo, 152-8552, Japan
| | - Tetsuro Murahashi
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo, 152-8552, Japan
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12
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Oh S, Crommie MF, Cohen ML. Simulating the Nanomechanical Response of Cyclooctatetraene Molecules on a Graphene Device. ACS Nano 2019; 13:1713-1718. [PMID: 30702863 DOI: 10.1021/acsnano.8b07781] [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: 06/09/2023]
Abstract
We investigate the atomic and electronic structures of cyclooctatetraene (COT) molecules on graphene and analyze their dependence on external gate voltage using first-principles calculations. The external gate voltage is simulated by adding or removing electrons using density functional theory calculations. This allows us to investigate how changes in carrier density modify the molecular shape, orientation, adsorption site, diffusion barrier, and diffusion path. For increased hole doping, COT molecules gradually change their shape to a more flattened conformation and the distance between the molecules and graphene increases while the diffusion barrier drastically decreases. For increased electron doping, an abrupt transition to a planar conformation at a carrier density of -8 × 1013 e/cm2 is observed. These calculations imply that the shape and mobility of adsorbed COT molecules can be controlled by externally gating graphene devices.
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Affiliation(s)
- Sehoon Oh
- Department of Physics , University of California at Berkeley , Berkeley , California 94720 , United States
- Materials Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Michael F Crommie
- Department of Physics , University of California at Berkeley , Berkeley , California 94720 , United States
- Materials Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
- Kavli Energy Nano Sciences Institute at the University of California Berkeley and the Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Marvin L Cohen
- Department of Physics , University of California at Berkeley , Berkeley , California 94720 , United States
- Materials Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
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13
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Yamakado T, Takahashi S, Watanabe K, Matsumoto Y, Osuka A, Saito S. Conformational Planarization versus Singlet Fission: Distinct Excited-State Dynamics of Cyclooctatetraene-Fused Acene Dimers. Angew Chem Int Ed Engl 2018. [PMID: 29516597 DOI: 10.1002/anie.201802185] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A set of flapping acene dimers fused with an 8π cyclooctatetraene (COT) ring showed distinct excited-state dynamics in solution. While the anthracene dimer showed a fast V-shaped-to-planar conformational change within 10 ps in the lowest excited singlet state, reminding us of extended Baird aromaticity, the tetracene dimer and the pentacene dimer underwent intramolecular singlet fission (SF) in different manners: A fast and reversible SF with a characteristic delayed fluorescence (FL), and a fast and quantitative SF, respectively. Conformational flexibility of the fused COT linkage plays an important role in these ultrafast dynamics, demonstrating the utility of the flapping molecular series as a versatile platform for designing photofunctional systems.
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Affiliation(s)
- Takuya Yamakado
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Shota Takahashi
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Kazuya Watanabe
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Yoshiyasu Matsumoto
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Atsuhiro Osuka
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Shohei Saito
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.,JST-PRESTO, FRONTIER, Japan
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14
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Abstract
An unconventional cis-cis-cis-trans or (Z,Z,Z,E) structure B of cyclooctatetraene (COT) is calculated to lie only 23 kcal/mol above the well-known tub-shaped (Z,Z,Z,Z) isomer A; one example of this type of structure is known. The barrier for B returning to A is small, 3 kcal/mol. However, by suitable choice of substituents, the (Z,Z,Z,E) isomer can be made to lie in energy below the tub-shaped structure. Steric, clamping, and electronic strategies are proposed for achieving this. In the steric strategy, the C8H4(CH3)2(C( t Bu)3)2 structure B is predicted to lie 21 kcal/mol below structure A, which is separated from form B only by a small barrier. A simple clamping strategy, effective for COT planarization, does not influence the A/B isomerization much. But, if the clamping group is aromatic (a fused benzene, pyrrole, thiophene, furan), the subtle interplay of potential aromaticity with clamping can be used to confer persistence if not stability on the (Z,Z,Z,E) isomer. An electronic strategy of a different kind, push-pull substitution on the COT ring, was not very effective in stabilizing the B form. However, it led us to vicinal amine-borane-substituted normal COTs that proved to be quite good at activating H2 in a frustrated Lewis pair scenario.
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Ruiz C, Monge Á, Gutiérrez-Puebla E, Alkorta I, Elguero J, Navarrete JTL, Ruiz Delgado MC, Gómez-Lor B. Saddle-Shaped Cyclic Indole Tetramers: 3D Electroactive Molecules. Chemistry 2016; 22:10651-60. [PMID: 27320301 DOI: 10.1002/chem.201600932] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [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: 02/26/2016] [Indexed: 11/09/2022]
Abstract
We present a joint theoretical and experimental study of a series of cyclic indole tetramers aimed at understanding the fundamental electronic properties of this 3D platform and evaluating its potential in the construction of new semiconductors. To this end, we combined absorption and Raman spectroscopy, cyclic voltammetry, and spectroelectrochemistry with DFT calculations. Our results suggest that this platform can be easily and reversibly oxidized. Additionally, it has a HOMO that matches very well with the workfunction of gold, therefore charge injection from a gold electrode is expected to occur without significant barriers. Interestingly, the cyclic tetraindoles allow for good electron delocalization in spite of their saddle-shaped structures. The steric constraints introduced by N-substitution significantly inhibits ring inversion of the central cyclooctatetraene unit, whereas it only barely affects the optical and electrochemical properties (a slightly higher oxidation potential and a blueshifted absorption upon alkylation are observed).
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Affiliation(s)
- Constanza Ruiz
- Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049, Madrid, Spain
| | - Ángeles Monge
- Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049, Madrid, Spain
| | | | - Ibon Alkorta
- Instituto de Química Médica, CSIC, Juan de la Cierva 3, 28006, Madrid, Spain
| | - José Elguero
- Instituto de Química Médica, CSIC, Juan de la Cierva 3, 28006, Madrid, Spain
| | | | | | - Berta Gómez-Lor
- Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049, Madrid, Spain.
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16
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Abstract
Tetrabenzotetraaza[8]circulene (1) has been synthesized in good yield by a "fold-in" oxidative fusion reaction of a 1,2-phenylene-bridged cyclic tetrapyrrole. X-ray diffraction analysis of 1 has revealed a planar square structure with a central cyclooctatetraene (COT) core that shows little alternation of the bond lengths. Despite these structural features, 1 shows aromatic-like character, such as sharp absorption bands, high fluorescence quantum yields (Φ(F)=0.55 in THF), and a single exponential fluorescence decay with τ(F)=3.8 ns. These observations indicate a dominant contribution of an [8]radialene-like π conjugation and hence aromatic character of the local aromatic segments in 1.
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Affiliation(s)
- Fengkun Chen
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)
| | - Yong Seok Hong
- Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 120-749 (Korea)
| | - Soji Shimizu
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, Fukuoka 819-0395 (Japan)
| | - Dongho Kim
- Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 120-749 (Korea).
| | - Takayuki Tanaka
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan).
| | - Atsuhiro Osuka
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan).
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