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Chowdhury S, Reynard-Feytis Q, Roizard C, Frath D, Chevallier F, Bucher C, Gibaud T. Light-Controlled Aggregation and Gelation of Viologen-Based Coordination Polymers. J Phys Chem B 2021; 125:12063-12071. [PMID: 34677961 DOI: 10.1021/acs.jpcb.1c06090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Ditopic bis-(triazole/pyridine)viologens are bidentate ligands that self-assemble into coordination polymers. In such photo-responsive materials, light irradiation initiates photo-induced electron transfer to generate π-radicals that can self-associate to form π-dimers. This leads to a cascade of events: processes at the supramolecular scale associated with mechanical and structural transition at the macroscopic scale. By tuning the irradiation power and duration, we evidence the formation of aggregates and gels. Using microscopy, we show that the aggregates are dense, polydisperse, micron-sized, spindle-shaped particles which grow in time. Using microscopy and time-resolved micro-rheology, we follow the gelation kinetics which leads to a gel characterized by a correlation length of a few microns and a weak elastic modulus. The analysis of the aggregates and the gel states vouch for an arrested phase separation process, a new scenario to supramolecular systems.
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Affiliation(s)
- Shagor Chowdhury
- Laboratoire de Chimie, Université de Lyon, Ens de Lyon, CNRS UMR 5182, F69342 Lyon, France
| | - Quentin Reynard-Feytis
- Laboratoire de Chimie, Université de Lyon, Ens de Lyon, CNRS UMR 5182, F69342 Lyon, France
| | - Clément Roizard
- Laboratoire de Chimie, Université de Lyon, Ens de Lyon, CNRS UMR 5182, F69342 Lyon, France
| | - Denis Frath
- Laboratoire de Chimie, Université de Lyon, Ens de Lyon, CNRS UMR 5182, F69342 Lyon, France
| | - Floris Chevallier
- Laboratoire de Chimie, Université de Lyon, Ens de Lyon, CNRS UMR 5182, F69342 Lyon, France
| | - Christophe Bucher
- Laboratoire de Chimie, Université de Lyon, Ens de Lyon, CNRS UMR 5182, F69342 Lyon, France
| | - Thomas Gibaud
- Laboratoire de Physique, Université de Lyon, Ens de Lyon, University Claude Bernard, CNRS, F69342 Lyon, France
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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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Kahlfuss C, Chowdhury S, Carreira AF, Grüber R, Dumont E, Frath D, Chevallier F, Eric-Saint-Aman, Bucher C. Electron-Triggered Metamorphism in Palladium-Driven Self-Assembled Architectures. Inorg Chem 2021; 60:3543-3555. [PMID: 33620206 DOI: 10.1021/acs.inorgchem.0c02365] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A metal-induced self-assembly strategy is used to promote the π-dimerization of viologen-based radicals at room temperature and in standard concentration ranges. Discrete box-shaped 2:2 (M:L) macrocycles or coordination polymers are formed in solution by self-assembly of a viologen-based ditopic ligand with cis-[Pd(en)(NO3)2], trans-[Pd(CH3CN)2(Cl)2], or [Pd(CH3CN)4(BF4)2]. Changing the redox state of the bipyridium units involved in the tectons, from their dicationic state to their radical cation state, results in a reversible "inflation/deflation" of the discrete 2:2 (M:L) macrocyclic assemblies associated to a large modification in the size of their inner cavity. Viologen-centered electron transfer is also used to trigger a dissociation of the coordination polymers formed with tetrakis(acetonitrile)Pd(II), the driving force of the disassembling process being the formation of discrete box-shaped 2:2 (M:L) assemblies stabilized by π-dimerization of both viologen cation radicals.
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Affiliation(s)
- Christophe Kahlfuss
- Univ Lyon, Ens de Lyon, CNRS UMR 5182, Université Claude Bernard Lyon 1, Laboratoire de Chimie, F69342 Lyon, France
| | - Shagor Chowdhury
- Univ Lyon, Ens de Lyon, CNRS UMR 5182, Université Claude Bernard Lyon 1, Laboratoire de Chimie, F69342 Lyon, France
| | - Adérito Fins Carreira
- Univ Lyon, Ens de Lyon, CNRS UMR 5182, Université Claude Bernard Lyon 1, Laboratoire de Chimie, F69342 Lyon, France
| | - Raymond Grüber
- Univ Lyon, Ens de Lyon, CNRS UMR 5182, Université Claude Bernard Lyon 1, Laboratoire de Chimie, F69342 Lyon, France
| | - Elise Dumont
- Univ Lyon, Ens de Lyon, CNRS UMR 5182, Université Claude Bernard Lyon 1, Laboratoire de Chimie, F69342 Lyon, France.,Institut Universitaire de France, 5 rue Descartes, 75005 Paris, France
| | - Denis Frath
- Univ Lyon, Ens de Lyon, CNRS UMR 5182, Université Claude Bernard Lyon 1, Laboratoire de Chimie, F69342 Lyon, France
| | - Floris Chevallier
- Univ Lyon, Ens de Lyon, CNRS UMR 5182, Université Claude Bernard Lyon 1, Laboratoire de Chimie, F69342 Lyon, France
| | - Eric-Saint-Aman
- Univ. Grenoble Alpes, CNRS, Département de Chimie Moléculaire, F38000 Grenoble, France
| | - Christophe Bucher
- Univ Lyon, Ens de Lyon, CNRS UMR 5182, Université Claude Bernard Lyon 1, Laboratoire de Chimie, F69342 Lyon, France
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Fujiwara T, Muranaka A, Nishinaga T, Aoyagi S, Kobayashi N, Uchiyama M, Otani H, Iyoda M. Preparation, Spectroscopic Characterization and Theoretical Study of a Three-Dimensional Conjugated 70 π-Electron Thiophene 6-mer Radical Cation π-Dimer. J Am Chem Soc 2020; 142:5933-5937. [PMID: 32105450 DOI: 10.1021/jacs.9b13573] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A radical cation, generated from an extended π-conjugated thiophene 6-mer composed of four ethynylene-thienylene and two vinylene-thienylene units, was observed to form a stable three-dimensional π-dimer containing 70 π-electrons. The π-dimer prepared in solution was investigated by using magnetic circular dichroism (MCD), ESR spectroscopy, and UV-vis-NIR absorption spectroscopy. Probing the individual NIR absorption bands showed that the MCD signals can be assigned to the pseudo Faraday A term, indicating that the absorption bands are comprised of nearly degenerate electronic transitions. X-ray crystallographic analysis revealed that the π-dimer has a three-dimensional face-to-face and continuous π-conjugated donutlike structure. Analysis of the UV-vis-NIR and ESR spectra of the π-dimer in the solid state confirmed that it possesses the dimer structure. The prediction made by using TD-DFT calculations that the dimer would have a 70 π-electron diatropic nature was confirmed by using solid state 1H NMR spectroscopy.
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Affiliation(s)
- Toshihiro Fujiwara
- Graduate School of Environment and Information Sciences, Yokohama National University, Hodogaya-ku, Yokohama, Kanagawa 240-8501, Japan
| | - Atsuya Muranaka
- Cluster for Pioneering Research (CPR), Advanced Elements Chemistry Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Tohru Nishinaga
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan
| | - Shinobu Aoyagi
- Department of Information and Basic Science, Nagoya City University, Nagoya 467-8501, Japan
| | - Nagao Kobayashi
- Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano 386-8567, Japan
| | - Masanobu Uchiyama
- Cluster for Pioneering Research (CPR), Advanced Elements Chemistry Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.,Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hiroyuki Otani
- Graduate School of Environment and Information Sciences, Yokohama National University, Hodogaya-ku, Yokohama, Kanagawa 240-8501, Japan
| | - Masahiko Iyoda
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan
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Photo/redox-responsive 2D-Supramolecular assembly involving Cucurbit[8]uril and a star-shaped porphyrin tecton. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2019.05.077] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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