Dynamic Extension−Contraction Motion in Supramolecular Springs

Kim, Ho-Joong; Lee, Eunji; Park, Hye-Seo; Lee, Myongsoo

doi:10.1021/ja073554b

Cited by 132 publications

(53 citation statements)

References 18 publications

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“…[2] In addition, chirality-amplified macromolecular systems have attracted considerable attention since Lee and co-workers reported the temperature-dependent conformational changes in the single helical springs of coordination polymers. [3] As small discrete systems, [4] Th IV -assisted quadruple-stranded bis-bidentate helicates were found by Xu and Raymond [5] and self-organized Cu I -bridged double helices were developed by Nitschke and co-workers using nitrogen-containing aromatic ligands. [6] In many cases the chirality in metal-ligand clusters can be controlled by auxiliaries such as the chiral substituents of ligand molecules.…”

Section: Introductionmentioning

confidence: 99%

Formation of Metal‐Assisted Stable Double Helices in Dimers of Cyclic Bis‐Tetrapyrroles that Exhibit Spring‐Like Motion

Hashimoto

Nishimura

Lim

et al. 2010

Chemistry A European J

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Bidipyrrin-bridged macrocycles, prepared from Ni(II)-bridged dipyrrin-based nanorings by intramolecular oxidative biaryl coupling reactions, yielded [2+4]-type Zn(II)-assisted stable twisted-ring dimers comprising two double helices. These [2+4]-type metal complexes can be optically resolved by chiral HPLC and exhibit tunable electronic and optical properties as a result of spring-like motions. The double helices behave as glue to connect two macrocycles and as the screws of hinges to form thermally responsive synchronized spring systems.

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Section: Introductionmentioning

confidence: 99%

Formation of Metal‐Assisted Stable Double Helices in Dimers of Cyclic Bis‐Tetrapyrroles that Exhibit Spring‐Like Motion

Hashimoto

Nishimura

Lim

et al. 2010

Chemistry A European J

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“…4 Considering the geometries of π-conjugated systems, linear metalcoordination ligand molecules, in contrast with planar molecules such as porphyrins, seem preferable for the fabrication of such helical structures with fascinating chiral properties.…”

mentioning

confidence: 99%

“…1 For example, helical metal complexes of π-conjugated molecules are potential molecular systems that exhibit attractive chiral electronic and optical properties, 2 asymmetric catalytic properties, 3 and macromolecular chiral amplification. 4 Considering the geometries of π-conjugated systems, linear metalcoordination ligand molecules, in contrast with planar molecules such as porphyrins, seem preferable for the fabrication of such helical structures with fascinating chiral properties. 5 As a candidate for linear building subunits involved in helical π-conjugated systems, bidipyrrin (1, Figure 1 Therefore, the introduction of appropriate terminal end units to bidipyrrins would enable the formation of helical metal complexes in various modes.…”

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confidence: 99%

Helical π-Systems of Bidipyrrin–Metal Complexes

et al. 2014

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Various metal-bridged single and double helical complexes of π-conjugated ligand molecules, bidipyrrins, were prepared. The introduction of terminal end units enabled the formation of chiral single and double helices; their spectroscopic properties and temperature-dependent behaviors were examined.Coordination programming is a new concept for the fabrication of a variety of metal complexes with potential application as functional materials and in devices.1 For example, helical metal complexes of π-conjugated molecules are potential molecular systems that exhibit attractive chiral electronic and optical properties, 2 asymmetric catalytic properties, 3 and macromolecular chiral amplification. 4 Considering the geometries of π-conjugated systems, linear metalcoordination ligand molecules, in contrast with planar molecules such as porphyrins, seem preferable for the fabrication of such helical structures with fascinating chiral properties.5 As a candidate for linear building subunits involved in helical π-conjugated systems, bidipyrrin (1, Figure 1), which is a directly linked linear tetrapyrrolic dipyrrin dimer, 6 can form various complexing modes according to the metal cations involved: bidipyrrins form [1 + 1]-type fairly planar complexes with cations such as Ni II and Cu II , 7 whereas they provide [2 + 2]-type double helical complexes with cations such as Zn II . 8,9 Therefore, the introduction of appropriate terminal end units to bidipyrrins would enable the formation of helical metal complexes in various modes.α-Phenyl-substituted bidipyrrin 2 (Figure 1) was prepared in 16% yield through the acid-catalyzed condensation of 5,5¤-bis(hydroxyphenylmethyl)bipyrrole 10 and 2-phenylpyrrole and subsequent oxidation by p-chloranil. The synthetic procedure differs from that for 1, for which intramolecular oxidation coupling of the corresponding dipyrrinNi II complex and subsequent demetallation were conducted. The UVvis absorption maxima ( max ) of 2 in CHCl 3 were observed at 455 and 667 nm, which were red-shifted relative to those of 1 at 412 and 587 nm.

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“…Similarly, a left-handed helix of poly(phenylacetylene) at lower temperatures could reversibly transform into a right-handed helix at higher temperatures. 23 Kim et al 24 later described a reversible extension-contraction motion of polymer backbones in response to temperature changes, which resulted in fluorescent switching between enhancement and complete quenching.…”

Section: External Stimuli-mediated Transformation Of Chiral Conformatmentioning

confidence: 99%

The transformation of chiral signals into macroscopic properties of materials using chirality-responsive polymers

Qing

Sun

2012

NPG Asia Mater

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The ability to transform the chiral signals of molecules into the macroscopic properties of a material will offer significant advantages in the development of chiral functional devices and chirality-related applications. Chirality-responsive polymers provide an excellent platform to realize this objective, which often involves two basic strategies. The first strategy is to utilize various external stimuli to directly mediate the chiral conformations of a polymer, through which the energy input is transformed into a macroscopic change in the properties of a material. The second strategy is to utilize the enantioselective interaction between polymers and guest chiral molecules to trigger a stepwise conformational change in smart polymers, which then results in transformation of the macroscopic properties. This review summarizes recent progress in generating chirality-responsive polymers based on these strategies and discusses advances in their applications as chiral sensors, liquid crystals, optical and electrical devices, nanomachines and so on. We then introduce the emerging field of chiral bio-interface materials, in which chiral signals are transformed into changes in the macroscopic behavior of cells and biomacromolecules based on the stereospecific interactions between biological systems and artificial materials.

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Dynamic Extension−Contraction Motion in Supramolecular Springs

Cited by 132 publications

References 18 publications

Formation of Metal‐Assisted Stable Double Helices in Dimers of Cyclic Bis‐Tetrapyrroles that Exhibit Spring‐Like Motion

Formation of Metal‐Assisted Stable Double Helices in Dimers of Cyclic Bis‐Tetrapyrroles that Exhibit Spring‐Like Motion

Helical π-Systems of Bidipyrrin–Metal Complexes

The transformation of chiral signals into macroscopic properties of materials using chirality-responsive polymers

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