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Incorporating sulfur into redox-active reagents and materials. Tetrahedron 2023. [DOI: 10.1016/j.tet.2023.133262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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2
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Nayak MK, Sarkar P, Elvers BJ, Mehta S, Zhang F, Chrysochos N, Krummenacher I, Vijayakanth T, Narayanan RS, Dolai R, Roy B, Malik V, Rawat H, Mondal A, Boomishankar R, Pati SK, Braunschweig H, Schulzke C, Ravat P, Jana A. A bis-NHC-CAAC dimer derived dicationic diradical. Chem Sci 2022; 13:12533-12539. [PMID: 36382295 PMCID: PMC9629079 DOI: 10.1039/d2sc03937k] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 09/21/2022] [Indexed: 08/11/2023] Open
Abstract
The isolation of carbon-centered diradicals is always challenging due to synthetic difficulties and their limited stability. Herein we report the synthesis of a trans-1,4-cyclohexylene bridged bis-NHC-CAAC dimer derived thermally stable dicationic diradical. The diradical character of this compound was confirmed by EPR spectroscopy. The variable temperature EPR study suggests the singlet state to be marginally more stable than the triplet state (2J = -5.5 cm-1 (ΔE ST = 0.065 kJ mol-1)). The presence of the trans-1,4-cyclohexylene bridge is instrumental for the successful isolation of this dicationic diradical. Notably, in the case of ethylene or propylene bridged bis-NHC-CAAC dimers, the corresponding dicationic diradicals are transient and rearrange to hydrogen abstracted products.
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Affiliation(s)
| | - Pallavi Sarkar
- Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research Bangalore-560064 India
| | - Benedict J Elvers
- Institut für Biochemie, Universität Greifswald Felix-Hausdorff-Straße 4 D-17489, Greifswald Germany
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science Bangalore 560012 India
| | - Fangyuan Zhang
- Institute of Organic Chemistry, University of Würzburg Am Hubland 97074 Würzburg Germany
| | - Nicolas Chrysochos
- Tata Institute of Fundamental Research Hyderabad Gopanpally Hyderabad-500107 India
| | - Ivo Krummenacher
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Thangavel Vijayakanth
- Department of Chemistry, Indian Institute of Science Education and Research Pune Dr Homi Bhabha Road Pune 411008 India
| | | | - Ramapada Dolai
- Tata Institute of Fundamental Research Hyderabad Gopanpally Hyderabad-500107 India
| | - Biswarup Roy
- Tata Institute of Fundamental Research Hyderabad Gopanpally Hyderabad-500107 India
| | - Vishal Malik
- Tata Institute of Fundamental Research Hyderabad Gopanpally Hyderabad-500107 India
| | - Hemant Rawat
- Tata Institute of Fundamental Research Hyderabad Gopanpally Hyderabad-500107 India
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science Bangalore 560012 India
| | - Ramamoorthy Boomishankar
- Department of Chemistry, Indian Institute of Science Education and Research Pune Dr Homi Bhabha Road Pune 411008 India
| | - Swapan K Pati
- Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research Bangalore-560064 India
| | - Holger Braunschweig
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Carola Schulzke
- Institut für Biochemie, Universität Greifswald Felix-Hausdorff-Straße 4 D-17489, Greifswald Germany
| | - Prince Ravat
- Institute of Organic Chemistry, University of Würzburg Am Hubland 97074 Würzburg Germany
| | - Anukul Jana
- Tata Institute of Fundamental Research Hyderabad Gopanpally Hyderabad-500107 India
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Yarahmadi M, Shamlouei HR. Design of Novel Molecular Switches Using the C20 Fullerene: A DFT Study. J CLUST SCI 2022. [DOI: 10.1007/s10876-022-02310-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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4
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Song G, Kim KM, Lee S, Jeong KS. Subtle Modification of Imine-linked Helical Receptors to Significantly Alter their Binding Affinities and Selectivities for Chiral Guests. Chem Asian J 2021; 16:2958-2966. [PMID: 34378325 DOI: 10.1002/asia.202100768] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/04/2021] [Indexed: 11/07/2022]
Abstract
Aromatic helical receptors P-1 and P-2 were slightly modified by aerobic oxidation to afford new receptors P-7 and P-8 with right-handed helical cavities. This subtle modification induced significant changes in the binding properties for chiral guests. Specifically, P-1 was reported to bind d-tartaric acid (Ka =35500 M-1 ), used as a template, much strongly than l-tartaric acid (326 M-1 ). In contrast, its modified receptor P-7 exhibited significantly reduced affinities for d-tartaric acid (3600 M-1 ) and l-tartaric acid (125 M-1 ). More dramatic changes in the affinities and selectivities were observed for P-2 and P-8 upon binding of polyol guests. P-2 was determined to selectively bind d-sorbitol (52000 M-1 ) over analogous guests, but P-8 showed no binding selectivity: d-sorbitol (1890 M-1 ), l-sorbitol (3330 M-1 ), d-arabitol (959 M-1 ), l-arabitol (4970 M-1 ) and xylitol (4960 M-1 ) in 5% (v/v) DMSO/CH2 Cl2 at 25±1 °C. These results clearly demonstrate that even subtle post-modifications of synthetic receptors may significantly alter their binding affinities and selectivities, in particular for guests of long and flexible chains.
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Affiliation(s)
- Geunmoo Song
- Department of Chemistry, Yonsei University, Seoul, 03722, Republic of Korea
| | - Kyung Mog Kim
- Department of Chemistry, Yonsei University, Seoul, 03722, Republic of Korea
| | - Seungwon Lee
- Department of Chemistry, Yonsei University, Seoul, 03722, Republic of Korea
| | - Kyu-Sung Jeong
- Department of Chemistry, Yonsei University, Seoul, 03722, Republic of Korea
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Broløs L, Klaue K, Bendix J, Grubert L, Hecht S, Nielsen MB. Stabilizing Indigo
Z
‐Isomer through Intramolecular Associations of Redox‐Active Appendages. European J Org Chem 2021. [DOI: 10.1002/ejoc.202100781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Line Broløs
- Department of Chemistry University of Copenhagen Universitetsparken 5 DK-2100 Copenhagen Ø Denmark
| | - Kristin Klaue
- Department of Chemistry & IRIS Adlershof Humboldt-Universität zu Berlin Brook-Taylor-Str. 2 12489 Berlin Germany
| | - Jesper Bendix
- Department of Chemistry University of Copenhagen Universitetsparken 5 DK-2100 Copenhagen Ø Denmark
| | - Lutz Grubert
- Department of Chemistry & IRIS Adlershof Humboldt-Universität zu Berlin Brook-Taylor-Str. 2 12489 Berlin Germany
| | - Stefan Hecht
- Department of Chemistry & IRIS Adlershof Humboldt-Universität zu Berlin Brook-Taylor-Str. 2 12489 Berlin Germany
- DWI – Leibniz Institute for Interactive Materials Forckenbeckstr. 50 52074 Aachen Germany
- Institute of Technical and Macromolecular Chemistry RWTH Aachen University Worringer Weg 2 52074 Aachen Germany
| | - Mogens Brøndsted Nielsen
- Department of Chemistry University of Copenhagen Universitetsparken 5 DK-2100 Copenhagen Ø Denmark
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Broløs L, Kilde MD, Brock‐Nannestad T, Nielsen MB. Dimeric Indenofluorene‐Extended Tetrathiafulvalene Motif for Enhanced Intramolecular Complexation. European J Org Chem 2021. [DOI: 10.1002/ejoc.202100514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Line Broløs
- Department of Chemistry University of Copenhagen Universitetsparken 5 DK-2100 Copenhagen Ø Denmark
| | - Martin Drøhse Kilde
- Department of Chemistry University of Copenhagen Universitetsparken 5 DK-2100 Copenhagen Ø Denmark
| | - Theis Brock‐Nannestad
- Department of Chemistry University of Copenhagen Universitetsparken 5 DK-2100 Copenhagen Ø Denmark
| | - Mogens Brøndsted Nielsen
- Department of Chemistry University of Copenhagen Universitetsparken 5 DK-2100 Copenhagen Ø Denmark
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Cai K, Zhang L, Astumian RD, Stoddart JF. Radical-pairing-induced molecular assembly and motion. Nat Rev Chem 2021; 5:447-465. [PMID: 37118435 DOI: 10.1038/s41570-021-00283-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/16/2021] [Indexed: 12/25/2022]
Abstract
Radical-pairing interactions between conjugated organic π-radicals are relative newcomers to the inventory of molecular recognition motifs explored in supramolecular chemistry. The unique electronic, magnetic, optical and redox-responsive properties of the conjugated π-radicals render molecules designed with radical-pairing interactions useful for applications in various areas of chemistry and materials science. In particular, the ability to control formation of radical cationic or anionic species, by redox stimulation, provides a flexible trigger for directed assembly and controlled molecular motions, as well as a convenient means of inputting energy to fuel non-equilibrium processes. In this Review, we provide an overview of different examples of radical-pairing-based recognition processes and of their emerging use in (1) supramolecular assembly, (2) templation of mechanically interlocked molecules, (3) stimuli-controlled molecular switches and, by incorporation of kinetic asymmetry in the design, (4) the creation of unidirectional molecular transporters based on pumping cassettes powered by fuelled switching of radical-pairing interactions. We conclude the discussion with an outlook on future directions for the field.
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Plajer AJ, Rizzuto FJ, von Krbek LKS, Gisbert Y, Martínez-Agramunt V, Nitschke JR. Oxidation triggers guest dissociation during reorganization of an Fe II 4L 6 twisted parallelogram. Chem Sci 2020; 11:10399-10404. [PMID: 34123180 PMCID: PMC8162311 DOI: 10.1039/d0sc04352d] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 09/09/2020] [Indexed: 12/12/2022] Open
Abstract
A three-dimensional FeII 4L6 parallelogram was prepared from ferrocene-containing ditopic ligands. The steric preference of the bulky ferrocene cores towards meridional vertex coordination brought about this new structure type, in which the ferrocene units adopt three distinct conformations. The structure possesses two distinct, bowl-like cavities that host anionic guests. Oxidation of the ferrocene FeII to ferrocenium FeIII causes rotation of the ferrocene hinges, converting the structure to an FeII 1L1 + species with release of anionic guests, even though the average charge per iron increases in a way that would ordinarily increase guest binding strength. The degrees of freedom exhibited by these new structures - derived from the different configurations of the three ligands surrounding a meridional FeII center and the rotation of ferrocene cores - thus underpin their ability to reconfigure and eject guests upon oxidation.
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Affiliation(s)
- Alex J Plajer
- Department of Chemistry, University of Cambridge Lensfield Rd Cambridge CB2 1EW UK
| | - Felix J Rizzuto
- Department of Chemistry, University of Cambridge Lensfield Rd Cambridge CB2 1EW UK
| | | | - Yohan Gisbert
- Department of Chemistry, University of Cambridge Lensfield Rd Cambridge CB2 1EW UK
| | | | - Jonathan R Nitschke
- Department of Chemistry, University of Cambridge Lensfield Rd Cambridge CB2 1EW UK
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Gamm P, Sheridan MV, Van Wyck SJ, Meindl A, Senge MO, Geiger WE. Ethynylphenyl-Derivatized Free Base Porphyrins: Anodic Oxidation Processes and Covalent Grafting onto Glassy Carbon Electrodes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:96-108. [PMID: 31847520 DOI: 10.1021/acs.langmuir.9b03452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In six of seven cases, direct anodic oxidation of the ethynyl group of an ethynylphenyl-derivatized free-base porphyrin gave modified glassy carbon electrodes in which the porphyrin was strongly surface-bound, most likely in a perpendicular geometry through covalent attachment of the ethynyl group to a surface carbon atom. The porphyrins each contained an ethynylphenyl group in one meso position and varied in the groups present in the other three meso positions. Electrografted 5,10,15,20-tetrakis(ethynylphenyl)porphyrin, H21, which has ethynyl moieties in all four meso positions, has well-defined surface voltammetry and grows to multilayer levels upon repeated cyclic voltammetry (CV) deposition scans. Multilayering was not observed to the same degree for monoethynylphenyl-substituted porphyrins and became progressively less for porphyrins having groups in the 15-meso position that were more protective against ethynyl radical attack. Clean molecular monolayer-level coverage was observed for 5-ethynylphenyl-10,20-bis(3-methoxyphenyl)-15-hexylporphyrin, H25. Owing to the fact that the ethynyl oxidation potential (1.1 to 1.5 V vs ferrocene) is more positive than that of the second macrocycle oxidation, the longevities and follow-up reactions of the porphyrin dications were also studied by CV, chemical oxidation, and optical spectroscopy in homogeneous solution. The primary follow-up products of the doubly oxidized porphyrins, whether surface-bound or in solution, were pyrrole-protonated species that were easily reduced back to the neutral porphyrin.
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Affiliation(s)
- Paul Gamm
- Department of Chemistry , University of Vermont , Burlington , Vermont 05405 , United States
| | - Matthew V Sheridan
- Department of Chemistry , University of Vermont , Burlington , Vermont 05405 , United States
| | - Stephen J Van Wyck
- Department of Chemistry , University of Vermont , Burlington , Vermont 05405 , United States
| | - Alima Meindl
- School of Chemistry, Trinity College Dublin , University of Dublin , Dublin 2 , Ireland
| | - Mathias O Senge
- School of Chemistry, Trinity College Dublin , University of Dublin , Dublin 2 , Ireland
| | - William E Geiger
- Department of Chemistry , University of Vermont , Burlington , Vermont 05405 , United States
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