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  1. Article ; Online: Multistate Structural Switching of [3]Catenanes with Cyclic Porphyrin Dimers by Complexation with Amine Ligands.

    Oka, Yuki / Masai, Hiroshi / Terao, Jun

    Angewandte Chemie (International ed. in English)

    2023  Volume 62, Issue 14, Page(s) e202217002

    Abstract: Catenanes with multistate switchable properties are promising components for next-generation molecular machines and supramolecular materials. Herein, we report a ligand-controlled switching method, a novel method for the multistate switching of catenanes ...

    Abstract Catenanes with multistate switchable properties are promising components for next-generation molecular machines and supramolecular materials. Herein, we report a ligand-controlled switching method, a novel method for the multistate switching of catenanes controlled by complexation with added amine ligands. To verify this method, a [3]catenane comprising cyclic porphyrin dimers with a rigid π-system has been synthesized. Owing to the rigidity, the relative positions among the cyclic components of the [3]catenane can be precisely controlled by complexation with various amine ligands. Moreover, ligand-controlled multistate switching affects the optical properties of the [3]catenanes: the emission intensity can be tuned by modulating the sizes and coordination numbers of integrated amine ligands. This work shows the utility of using organic ligands for the structural switching of catenanes, and will contribute to the further development of multistate switchable mechanically interlocked molecules.
    Language English
    Publishing date 2023-01-26
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 2011836-3
    ISSN 1521-3773 ; 1433-7851
    ISSN (online) 1521-3773
    ISSN 1433-7851
    DOI 10.1002/anie.202217002
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  2. Article: Precision synthesis of linear oligorotaxanes and polyrotaxanes achieving well-defined positions and numbers of cyclic components on the axle

    Masai, Hiroshi / Oka, Yuki / Terao, Jun

    Chemical communications. 2022 Feb. 3, v. 58, no. 11

    2022  

    Abstract: Interest in macromolecules has increased because of their functional properties, which can be tuned using precise organic synthetic methods. For example, desired functions have been imparted by controlling the nanoscale structures of such macromolecules. ...

    Abstract Interest in macromolecules has increased because of their functional properties, which can be tuned using precise organic synthetic methods. For example, desired functions have been imparted by controlling the nanoscale structures of such macromolecules. In particular, compounds with interlocked structures, including rotaxanes, have attracted attention because of their unique supramolecular structures. In such supramolecular structures, the mobility and freedom of the macrocycles are restricted by an axle and dependent on those of other macrocycles, which imparts unique functions to these threaded structures. Recently, methods for the ultrafine engineering and synthesis, as well as functions, of “defined” rotaxane structures that are not statistically dispersed on the axle (i.e., control over the number and position of cyclic molecules) have been reported. Various synthetic strategies allow access to such well-defined linear oligo- and polyrotaxanes, including [1]rotaxanes and [n]rotaxanes (mostly n > 3). These state-of-the-art synthetic methods have resulted in unique functions of these oligo-and polyrotaxane materials. Herein, we review the effective synthetic protocols and functions of precisely constructed one-dimensional oligomers and polymers bearing defined threaded structures, and discuss the latest reports and trends.
    Keywords axles ; chemical communication ; engineers ; functional properties ; nanomaterials ; polymers ; rotaxanes
    Language English
    Dates of publication 2022-0203
    Size p. 1644-1660.
    Publishing place The Royal Society of Chemistry
    Document type Article
    ZDB-ID 1472881-3
    ISSN 1364-548X ; 1359-7345 ; 0009-241X
    ISSN (online) 1364-548X
    ISSN 1359-7345 ; 0009-241X
    DOI 10.1039/d1cc03507j
    Database NAL-Catalogue (AGRICOLA)

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  3. Article ; Online: Effects of Alkyl Ester Chain Length on the Toughness of PolyAcrylate-Based Network Materials.

    Kawano, Yutaro / Masai, Hiroshi / Nakagawa, Shintaro / Yoshie, Naoko / Terao, Jun

    Polymers

    2023  Volume 15, Issue 10

    Abstract: Polyacrylate-based network materials are widely used in various products owing to their facile synthesis via radical polymerization reactions. In this study, the effects of alkyl ester chains on the toughness of polyacrylate-based network materials were ... ...

    Abstract Polyacrylate-based network materials are widely used in various products owing to their facile synthesis via radical polymerization reactions. In this study, the effects of alkyl ester chains on the toughness of polyacrylate-based network materials were investigated. Polymer networks were fabricated via the radical polymerization of methyl acrylate (MA), ethyl acrylate (EA), and butyl acrylate (BA) in the presence of 1,4-butanediol diacrylate as a crosslinker. Differential scanning calorimetry and rheological measurements revealed that the toughness of MA-based networks drastically increased compared with that of EA- and BA-based networks; the fracture energy of the MA-based network was approximately 10 and 100 times greater than that of EA and BA, respectively. The high fracture energy was attributed to the glass transition temperature of the MA-based network (close to room temperature), resulting in large energy dissipation via viscosity. Our results set a new basis for expanding the applications of polyacrylate-based networks as functional materials.
    Language English
    Publishing date 2023-05-20
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2527146-5
    ISSN 2073-4360 ; 2073-4360
    ISSN (online) 2073-4360
    ISSN 2073-4360
    DOI 10.3390/polym15102389
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Luminescent Thermoresponse via Excimer/Exciplex Transition of Pyrene Derivative in Polymer Networks Containing [3]Rotaxane.

    Nakagawa, Tomoki / Ishino, Saqura / Inamori, Daiki / Masai, Hiroshi / Terao, Jun

    ACS macro letters

    2023  Volume 12, Issue 6, Page(s) 751–758

    Abstract: The modulation of molecular interaction with a [3]rotaxane structure enabled a luminescent thermoresponse with high sensitivity over a wide temperature range. Herein, a pyrene moiety was encapsulated by permethylated α-cyclodextrins and was introduced ... ...

    Abstract The modulation of molecular interaction with a [3]rotaxane structure enabled a luminescent thermoresponse with high sensitivity over a wide temperature range. Herein, a pyrene moiety was encapsulated by permethylated α-cyclodextrins and was introduced into a polymer network material of poly(vinyl alcohol) as a cross-linker. The luminescence nature associated with the pyrene moiety was continuously switched from a static pyrene-pyrene excimer emission mode at 193 K to a dynamic pyrene-dimethylaniline (DMA) exciplex emission mode at 293 K. A series of [3]rotaxane structures revealed the impact of supramolecular control of the interaction among pyrenes and DMA. Consequently, the continuously coupled two luminescent modes of pyrene (excimer and exciplex) provided a monotonical luminescence change over a wide temperature range (100 K) with high sensitivity of the wavelength variation (0.64 nm/K) as a distinguished thermoresponsive material to visualize the thermal information.
    Language English
    Publishing date 2023-05-22
    Publishing country United States
    Document type Journal Article
    ISSN 2161-1653
    ISSN (online) 2161-1653
    DOI 10.1021/acsmacrolett.3c00196
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Insulation of a coumarin derivative with [1]rotaxane to control solvation-induced effects in excited-state dynamics for enhanced luminescence.

    Russell, Go M / Masai, Hiroshi / Terao, Jun

    Physical chemistry chemical physics : PCCP

    2022  Volume 24, Issue 25, Page(s) 15195–15200

    Abstract: A coumarin derivative bearing a [1]rotaxane structure with permethylated α-cyclodextrins suppressed unwanted solvation-induced effects and increased luminescent quantum yields in medium- and high-polarity solvents. The non-radiative decay was suppressed ... ...

    Abstract A coumarin derivative bearing a [1]rotaxane structure with permethylated α-cyclodextrins suppressed unwanted solvation-induced effects and increased luminescent quantum yields in medium- and high-polarity solvents. The non-radiative decay was suppressed by the twist in the π-conjugated system and the radiative decay was enhanced by the suppression of the polarity-induced structural changes.
    MeSH term(s) Coumarins/chemistry ; Luminescence ; Rotaxanes ; Solvents/chemistry
    Chemical Substances Coumarins ; Rotaxanes ; Solvents
    Language English
    Publishing date 2022-06-29
    Publishing country England
    Document type Journal Article
    ZDB-ID 1476244-4
    ISSN 1463-9084 ; 1463-9076
    ISSN (online) 1463-9084
    ISSN 1463-9076
    DOI 10.1039/d2cp02221d
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Precision synthesis of linear oligorotaxanes and polyrotaxanes achieving well-defined positions and numbers of cyclic components on the axle.

    Masai, Hiroshi / Oka, Yuki / Terao, Jun

    Chemical communications (Cambridge, England)

    2022  Volume 58, Issue 11, Page(s) 1644–1660

    Abstract: Interest in macromolecules has increased because of their functional properties, which can be tuned using precise organic synthetic methods. For example, desired functions have been imparted by controlling the nanoscale structures of such macromolecules. ...

    Abstract Interest in macromolecules has increased because of their functional properties, which can be tuned using precise organic synthetic methods. For example, desired functions have been imparted by controlling the nanoscale structures of such macromolecules. In particular, compounds with interlocked structures, including rotaxanes, have attracted attention because of their unique supramolecular structures. In such supramolecular structures, the mobility and freedom of the macrocycles are restricted by an axle and dependent on those of other macrocycles, which imparts unique functions to these threaded structures. Recently, methods for the ultrafine engineering and synthesis, as well as functions, of "defined" rotaxane structures that are not statistically dispersed on the axle (
    Language English
    Publishing date 2022-02-03
    Publishing country England
    Document type Journal Article ; Review
    ZDB-ID 1472881-3
    ISSN 1364-548X ; 1359-7345 ; 0009-241X
    ISSN (online) 1364-548X
    ISSN 1359-7345 ; 0009-241X
    DOI 10.1039/d1cc03507j
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Systematic Synthesis of Macrocycles Bearing up to Six 2,2'-Bipyridine Moieties through Self-Assembled Double Helix Structure.

    Onda, Yudai / Masai, Hiroshi / Terao, Jun

    The Journal of organic chemistry

    2022  Volume 87, Issue 19, Page(s) 13331–13338

    Abstract: A new synthetic strategy for macrocycles bearing multiple coordination moieties was developed. A self-assembled double helix structure, composed of two linear strands bearing 2,2'-bipyridine units and Cu(I) ions, provided access to macrocycles bearing a ... ...

    Abstract A new synthetic strategy for macrocycles bearing multiple coordination moieties was developed. A self-assembled double helix structure, composed of two linear strands bearing 2,2'-bipyridine units and Cu(I) ions, provided access to macrocycles bearing a defined number of 2,2'-bipyridine moieties and a defined ring size, via an olefin-metathesis reaction between two linear strands in the helix. The double helix structure improved the selectivity of the macrocycle synthesis by bringing the reaction points in close proximity even in the case of large macrocycles.
    MeSH term(s) 2,2'-Dipyridyl ; Alkenes/chemistry
    Chemical Substances Alkenes ; 2,2'-Dipyridyl (551W113ZEP)
    Language English
    Publishing date 2022-09-29
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 123490-0
    ISSN 1520-6904 ; 0022-3263
    ISSN (online) 1520-6904
    ISSN 0022-3263
    DOI 10.1021/acs.joc.2c01194
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Linked Rotaxane Structure Restricts Local Molecular Motions in Solution to Enhance Fluorescence Properties of Tetraphenylethylene.

    Miyagishi, Hiromichi V / Masai, Hiroshi / Terao, Jun

    Chemistry (Weinheim an der Bergstrasse, Germany)

    2022  Volume 28, Issue 6, Page(s) e202103175

    Abstract: The restriction of local molecular motions is critical for improving the fluorescence quantum yields (FQYs) and the photostability of fluorescent dyes. Herein, we report a supramolecular approach to enhance the performance of fluorescent dyes by ... ...

    Abstract The restriction of local molecular motions is critical for improving the fluorescence quantum yields (FQYs) and the photostability of fluorescent dyes. Herein, we report a supramolecular approach to enhance the performance of fluorescent dyes by incorporating a linked rotaxane structure with permethylated α-cyclodextrins. Tetraphenylethylene (TPE) derivatives generally exhibit low FQYs in solution due to the molecular motions in the excited state. We show that TPE with linked rotaxane structures on two sides displays up to 15-fold higher FQYs. Detailed investigations with variable temperature
    MeSH term(s) Fluorescent Dyes ; Molecular Structure ; Motion ; Rotaxanes ; Stilbenes
    Chemical Substances Fluorescent Dyes ; Rotaxanes ; Stilbenes ; tetraphenylethylene
    Language English
    Publishing date 2022-01-03
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1478547-X
    ISSN 1521-3765 ; 0947-6539
    ISSN (online) 1521-3765
    ISSN 0947-6539
    DOI 10.1002/chem.202103175
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  9. Article ; Online: Fabrication of Photoprocessable Materials via Photopolymerization Using an Acid-Induced Photocleavable Platinum-Acetylide Crosslinker.

    Kaneko, Takashi / Russell, Go M / Kawano, Yutaro / Masai, Hiroshi / Terao, Jun

    Angewandte Chemie (International ed. in English)

    2023  Volume 62, Issue 26, Page(s) e202305374

    Abstract: Photopolymerization and photoprocessing are core technologies for molding and tuning polymer materials. However, they are incompatible with single materials owing to their contradictory photoreactivity. Herein, an acid-induced photocleavable crosslinker, ...

    Abstract Photopolymerization and photoprocessing are core technologies for molding and tuning polymer materials. However, they are incompatible with single materials owing to their contradictory photoreactivity. Herein, an acid-induced photocleavable crosslinker, a platinum-acetylide complex covered by permethylated cyclodextrins, enables the fabrication of photoprocessable materials via photopolymerization with N-(2-hydroxyethyl)acrylamide. The polymer networks are molded by 365 nm irradiation as well as softened and degraded by a cooperative reaction with HCl as an acidic additive under 365 nm UV light, or 470 nm visible light in the presence of a photosensitizer. Moreover, the crosslinker is applied to a photoadhesive triggered by 365 nm irradiation. The adhesion is detachable on-demand through acid-induced photodegradation with the same wavelength and intensity of irradiation. Thus, acid-induced photocleavage allows the integration of light-induced molding and processing under various lights of various wavelengths, opening up new strategies for polymer technologies.
    MeSH term(s) Platinum ; Polymers ; Photolysis ; Ultraviolet Rays
    Chemical Substances Platinum (49DFR088MY) ; Polymers
    Language English
    Publishing date 2023-05-16
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 2011836-3
    ISSN 1521-3773 ; 1433-7851
    ISSN (online) 1521-3773
    ISSN 1433-7851
    DOI 10.1002/anie.202305374
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  10. Article ; Online: Suppression of Undesirable Isomerization and Intermolecular Reactions of Double Bonds by a Linked Rotaxane Structure.

    Miyagishi, Hiromichi V / Masai, Hiroshi / Terao, Jun

    Chemistry, an Asian journal

    2020  Volume 15, Issue 12, Page(s) 1890–1895

    Abstract: For luminescent materials, the isomerization and intermolecular reactions of their double bonds are often undesirable because they cause a reduction in the luminescence properties of the π-system. Herein, we report a new methodology to simultaneously ... ...

    Abstract For luminescent materials, the isomerization and intermolecular reactions of their double bonds are often undesirable because they cause a reduction in the luminescence properties of the π-system. Herein, we report a new methodology to simultaneously prevent isomerization and intermolecular reactions by utilizing the steric effect of a linked rotaxane structure. The ring units are covalently linked in order to prevent any undesired shuttling effect from occurring during isomerization. In addition, the insulated structure provides robust optical properties by prevention of intermolecular reactions. Bulky linked rotaxane structures on both sides of the N=N and C=C double bonds suppress E/Z isomerization; photoluminescence quantum yield (PLQY) measurements reveal that this results in suppression of PLQY reduction caused by isomerization. Moreover, an improvement in the stability under light irradiation and air atmosphere is demonstrated.
    Language English
    Publishing date 2020-05-20
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 2233006-9
    ISSN 1861-471X ; 1861-4728
    ISSN (online) 1861-471X
    ISSN 1861-4728
    DOI 10.1002/asia.202000350
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