Solid-State Characterization and Photoinduced Intramolecular Electron Transfer in a Nanoconfined Octacationic Homo[2]Catenane

Barnes, Jonathan C.; Frasconi, Marco; Young, Ryan M.; Khdary, Nezar H.; Liu, Wei Guang; Dyar, Scott M.; McGonigal, Paul R.; Gibbs-Hall, Ian C.; Diercks, Christian S.; Sarjeant, Amy A.; Stern, Charlotte L.; Goddard, William A.; Wasielewski, Michael R.

doi:10.1021/ja505093d

Cited by 33 publications

(14 citation statements)

References 39 publications

(21 reference statements)

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“…Reduction of the viologen units wasa chieved in situ upon submitting the sample to light irradiation in the presence of as acrificiale lectron donor (TEOA = triethanolamine). Consistent with the literature, we found that viologen cation radicals can be photogenerated in situ, either by directi rradiation of the viologen moieties (300 < l < 400 nm) [50][51][52][53][54][55] or by excitation of as uitable photosensitizer such as tris(bipyridine)ruthenium(II) chloride (RuBPy; l ex % 450 nm) introduced in catalytic amount. [56][57][58][59] In our experimental conditions (thin-layer cell,i n situ measurements, concentrated sample),p hoto-production was found to be most effectiveu sing al ed lamp X-Cite 120LEDBoost equipped with al ong-pass filter (l > 360 nm) enabling to excite the viologen moieties.…”

Section: Rheological Studiessupporting

confidence: 89%

Redox‐Induced Molecular Metamorphism Promoting a Sol/Gel Phase Transition in a Viologen‐Based Coordination Polymer

Kahlfuss

Gibaud

Denis‐Quanquin

et al. 2018

Chemistry A European J

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We have developed a strategy enabling control over the organization of ditopic molecular tectons within a palladium-based self-assembled system. The key electron-responsive sub-unit is a viologen-based mechanical hinge that can toggle under electric stimulation between a folded and a stretched position, the driving force of the folding motion being the π-dimerisation of the electrogenerated viologen cation radicals. The title ditopic tecton features two planar, N2-type, triazole/pyridine-based bidentate binding units, providing the tecton with the ability to chelate two palladium ions both in its folded and in its elongated conformations. Association of this ditopic redox-responsive tecton with palladium to form 1D self-assembled architectures undergoing large scale reorganizations in solution under electric stimulation, has been established on the ground of spectroscopic, electrochemical, spectro-electrochemical and rheological data. Our result reveal that addition of metal leads to a significant stabilization of the π-dimer species in solution and that the redox-triggered reorganisation of the tectons comes along in suitable conditions with a macroscopic sol/gel-type phase transition.

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Section: Rheological Studiessupporting

confidence: 89%

Redox‐Induced Molecular Metamorphism Promoting a Sol/Gel Phase Transition in a Viologen‐Based Coordination Polymer

Kahlfuss

Gibaud

Denis‐Quanquin

et al. 2018

Chemistry A European J

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“…The formed complexes showed a strong NIR absorption band peaked at ≈1000 nm . Moreover, the stability of these radicals can be greatly improved by mechanically confining the viologen radical cations into the cavity of CBPQT 2(·+) , either by the formation of rotaxanes or by the fabrication of catenanes, showing high stability within days or even weeks. More recently, they reported that the folding of oligoviologens with different repeating units could also lead to a red‐shift of the absorption towards the NIR region (as far as 1320 nm), which is due to the formation of radical dimers or trimers involving two or three viologen radical cations …”

Section: Fabrication Of Supramolecularly Stabilized Organic Radicalsmentioning

confidence: 99%

Tuning the Energy Gap by Supramolecular Approaches: Towards Near‐Infrared Organic Assemblies and Materials

Song

Jiao

Wang

et al. 2015

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Near-infrared (NIR) organic materials are of great importance for both fundamental research and practical applications. While much effort has been taken to covalently design and synthesize NIR organic materials with a low energy gap, there are supramolecular approaches for tuning the energy gap to noncovalently fabricate NIR organic assemblies and materials. In this concept article, we summarize and discuss several supramolecular approaches, including the fabrication of charge transfer supramolecular complexes, the fabrication of supramolecular J-aggregates, and the fabrication of supramolecularly stabilized organic radicals. The nature of noncovalent interactions in supramolecular approaches can provide NIR organic assemblies and materials with unique properties such as reversibility, stimuli-responsiveness, recyclability, and adaptive abilities.

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“…The viologen unit (47) at the center of the half-dumbbell 1 2+ was chosen as a recognition site to promote complexation with CBPQT 4+ by virtue of radical templation (46)(47)(48)(49)(50)(51)(52)(53)(54). A bulky 3,5-di-tert-butylphenyl stopper situated at the other end of the viologen unit ensures that the semirotaxanes become mechanically interlocked once the benzoic acid group is capped by the Zr cluster.…”

Section: +mentioning

confidence: 99%

“…It is only in their radical cation redox states that favorable interactions (47)(48)(49)(50)(51)(52)(53)(54)(55)(56) between the electrons of the viologen centers bring the components together to form (Fig. 4B) the trisradical semirotaxane 1…”

Section: (•+)mentioning

confidence: 99%

Electrochemically addressable trisradical rotaxanes organized within a metal–organic framework

McGonigal

Deria

Hod

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

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The organization of trisradical rotaxanes within the channels of a Zr 6 -based metal-organic framework (NU-1000) has been achieved postsynthetically by solvent-assisted ligand incorporation. Robust Zr IV -carboxylate bonds are forged between the Zr clusters of NU-1000 and carboxylic acid groups of rotaxane precursors (semirotaxanes) as part of this building block replacement strategy. Ultravioletvisible-near-infrared (UV-Vis-NIR), electron paramagnetic resonance (EPR), and 1 H nuclear magnetic resonance (NMR) spectroscopies all confirm the capture of redox-active rotaxanes within the mesoscale hexagonal channels of NU-1000. Cyclic voltammetry measurements performed on electroactive thin films of the resulting material indicate that redox-active viologen subunits located on the rotaxane components can be accessed electrochemically in the solid state. In contradistinction to previous methods, this strategy for the incorporation of mechanically interlocked molecules within porous materials circumvents the need for de novo synthesis of a metal-organic framework, making it a particularly convenient approach for the design and creation of solid-state molecular switches and machines. The results presented here provide proof-of-concept for the application of postsynthetic transformations in the integration of dynamic molecular machines with robust porous frameworks.mechanically interlocked molecules | metal-organic framework | molecular switches | rotaxanes | radicals T he predictability and reliability with which metal-organic frameworks (MOFs) are assembled (1-11) has accelerated the rate at which porous materials can be developed for applications as diverse as gas storage and separation (7), sensing (8), catalysis (9), and light harvesting (10, 11). Metal oxide joints and organic struts are arranged regularly within MOFs, giving rise to hybrid materials with permanent porosities. It has been proposed (12, 13) that integrating the rigidity and periodicity of MOFs with the addressability and workings of molecular switches and machines, such as bistable mechanically interlocked molecules (MIMs) (14-16), stands a good chance of giving rise to a new class of functional materials that are simultaneously both robust and dynamic. Most switchable MIMs that have been developed operate in solution where they are stochastically oriented and the net movement of a population of switches averages to zero. By integrating such rudimentary molecular switches within highly ordered MOFs, however, they can be organized periodically and precisely in 3D space, allowing their otherwise incoherent motions to be rectified. Although steady progress has been made (17-26) toward this goal in recent years, it still remains a considerable challenge to design such systems that can be addressed by stimuli in the solid state. Electrochemical potential and light would be particularly appealing stimuli on account of their ease of interfacing with current technologies. The avenues of investigation that have been explored up to this point have entailed t...

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Solid-State Characterization and Photoinduced Intramolecular Electron Transfer in a Nanoconfined Octacationic Homo[2]Catenane

Abstract: Synthesis, crystallographic data, and theoretical calculations of HC•8SbF 6 as well as photoinduced IET data. This material is available free of charge via the Internet at http://pubs.acs.org.

Cited by 33 publications

References 39 publications

Redox‐Induced Molecular Metamorphism Promoting a Sol/Gel Phase Transition in a Viologen‐Based Coordination Polymer

Redox‐Induced Molecular Metamorphism Promoting a Sol/Gel Phase Transition in a Viologen‐Based Coordination Polymer

Tuning the Energy Gap by Supramolecular Approaches: Towards Near‐Infrared Organic Assemblies and Materials

Electrochemically addressable trisradical rotaxanes organized within a metal–organic framework

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