Helical Synthetic Nanographenes with Atomic Precision

Accounts of Chemical Research, Год журнала: 2023, Номер 56(3), С. 363 - 373

Опубликована: Янв. 26, 2023

ConspectusUnderstanding and harnessing the properties of nanoscale molecular entities are considered as new frontiers in basic chemistry. In this regard, synthetic nanographene with atomic precision has attracted much attention recently. For instance, taking advantage marvelous bonding capability carbon, flat, curved, ribbon-type, or cone-shaped nanographenes have been prepared highly controllable elegant manner, allowing one to explore fascinating architectures intriguing optical, electrochemical, magnetic characteristics. This stands stark contrast other carbon-rich nanomaterials, such graphite oxides carbon quantum dots, which preclude thorough investigations because complicate structural defects. Undoubtedly, contributes strongly modern aromatic chemistry represents a vibrant field that may deliver transforming functional materials crucial for optoelectronics, nanotechnologies, biomedicine.Nonetheless, many cases, synthesis characterization compounds demanding. Low solubility, high strain, undesired selectivity, well incomplete excessive C-C bond formation common impediments, require formidable efforts control geometry, modulate edge structure, achieve accurate doping, push upper size boundary. These endeavors indispensable establishing structure-property relationships, lay down foundation exploring at level sophistications.In Account, we summarize our contributions by presenting series helical nanographenes, hexapole [7]helicene (H7H), nitrogen-doped H7H, [9]helicene (H9H), superhelicene, supertwistacene. kind giant reaches domain albeit precise structure. It provides unique platform study chirality nanoscale. We discuss methods point out, particular, strengths pitfalls Scholl oxidation, expected be valuable making general. addition, illustrate their exciting electrochemical photophysical performance, include, but not limited to, reversible multielectron redox chemistry, record panchromatic absorption, impressive photothermal behavior, extremely strong Cotton effect. unusual characteristics convincingly traced back three-dimensional conjugated architectures, highlighting critical roles π-electron delocalization, heteroatom-doping, substitution, symmetry determining nanographenes' functions. Lastly, put forward understanding on challenges opportunities lies ahead hope Account will inspire ever more ambitious achievements from attractive area research.

Язык: Английский

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A π‐Extended Pentadecabenzo[9]Helicene

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(15)

Опубликована: Фев. 16, 2023

A novel chiral nanographene (i.e. EP9H) with a pentadecabenzo[9]helicene core fragment has been synthesized and fully characterized. Single-crystal X-ray diffraction unambiguously confirms the helical structure. The fluorescence emission of EP9H is located in near infrared region (λem =684 nm) medium quantum yield (0.10) for helicene derivatives. Cyclic voltammetry reveals its seven quasi-reversible redox states from -2 to +5. Furthermore, enantiopure displays distinct CD signals broad spectral range 300 700 nm. Notably, compared reported small organic molecules, an outstanding |glum | value 4.50×10-2 BCPL as 304 M-1 cm-1 .

Язык: Английский

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Design and enantioselective synthesis of 3D π-extended carbohelicenes for circularly polarized luminescence

Nature Synthesis, Год журнала: 2024, Номер 3(6), С. 774 - 786

Опубликована: Апрель 19, 2024

Язык: Английский

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π‐Extended Diaza[7]helicenes with Dual Negatively Curved Heptagons: Extensive Synthesis and Spontaneous Resolution into Strippable Homochiral Lamellae with Helical Symmetry

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(11)

Опубликована: Янв. 17, 2024

Abstract We report a unique category of π‐extended diaza[7]helicenes with double negative curvatures. This is achieved by two‐fold regioselective heptagonal cyclization the oligoarylene‐carbazole precursors through either intramolecular C−H arylation or Scholl reaction. The fusion two rings in helical skeleton dramatically increases strain and forces terminal carbazole moieties to stack compressed fashion. presence deformable negatively curved endows resulting dynamic chiral skeletons, aggregation‐induced emission feature relatively low racemization barrier ca. 25.6 kcal mol −1 . Further π‐extension on subsequently leads more sophisticated C 2 ‐symmetric homochiral triple helicene. Notably, these show structure‐dependent stacking upon crystallization, switching from heterochiral packing intra‐layer stacking. Interestingly, helicene molecules spontaneously resolve into lamellar structure 3 1 helix symmetry. Upon ultrasonication nonsolvent, crystals can be readily exfoliated large‐area ultrathin nanosheets height 4.4 nm corresponding layers stacked thicker constituted even‐numbered molecular lamellae. Moreover, regular hexagonal thin platelets size larger than 30 μm fabricated flash aggregation.

Язык: Английский

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Advanced Porous Aromatic Frameworks: A Comprehensive Overview of Emerging Functional Strategies and Potential Applications

ACS Nano, Год журнала: 2025, Номер unknown

Опубликована: Фев. 18, 2025

Porous aromatic frameworks (PAFs) are a fundamental group of porous materials characterized by their distinct structural features and large surface areas. These synthesized from building units linked strong carbon–carbon bonds, which confer exceptional rigidity long-term stability. PAFs functionalities may arise directly the intrinsic chemistry or through postmodification motifs using well-defined chemical processes. Compared to other traditional such as zeolites metallic-organic frameworks, demonstrate superior stability under severe treatments due robust bonding. Even in challenging environments, ease functionalization flexibility specificity. Research on has significantly expanded accelerated over past decade, necessitating comprehensive overview key advancements this field. This review provides an in-depth analysis recent advances synthesis, functionalization, dimensionality PAFs, along with distinctive properties wide-ranging applications. explores innovative methodologies strategies for functionalizing structures, manipulation tailor specific potential Similarly, application areas, including batteries, absorption, sensors, CO2 capture, photo-/electrocatalytic usages, supercapacitors, separation, biomedical discussed detail, highlighting versatility addressing modern scientific industrial challenges.

Язык: Английский

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Synthesis of Highly Luminescent Chiral Nanographene

Angewandte Chemie International Edition, Год журнала: 2022, Номер 62(4)

Опубликована: Ноя. 26, 2022

Chiral nanographenes with both high fluorescence quantum yields (ΦF ) and large dissymmetry factors (glum are essential to the development of circularly polarized luminescence (CPL) materials. However, most studies have been focused on improvement glum , whereas how design highly emissive chiral is still unclear. In this work, we propose a new strategy achieve ΦF by helical π-extension strongly luminescent chromophores while maintaining frontier molecular orbital (FMO) distribution pattern. nanographene perylene as core two dibenzo[6]helicene fragments wings has synthesized, which exhibits record 93 % among reported excellent CPL brightness (BCPL 32 M-1 cm-1 .

Язык: Английский

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New advances in chiral nanographene chemistry

Organic Chemistry Frontiers, Год журнала: 2023, Номер 10(16), С. 4167 - 4197

Опубликована: Янв. 1, 2023

This review will highlight several recent and lesser-reviewed works related to the preparation of chiral nanographenes, specifically focusing on structures prepared by non-Scholl methods.

Язык: Английский

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Multiple Helicenes Defected by Heteroatoms and Heptagons with Narrow Emissions and Superior Photoluminescence Quantum Yields**

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(29)

Опубликована: Май 18, 2023

The incorporation of heteroatoms and/or heptagons as the defects into helicenes expands variety chiroptical materials with novel properties. However, it is still challenging to construct boron-doped heptagon-containing high photoluminescence quantum yields (PLQYs) and narrow full-width-at-half-maximum (FWHM) values. We report an efficient scalable synthesis a quadruple helicene 4Cz-NBN two nitrogen-boron-nitrogen (NBN) units double 4Cz-NBN-P1 bearing NBN-doped heptagons, latter could be formed via two-fold Scholl reaction former. exhibit excellent PLQYs up 99 % 65 FWHM 24 nm 22 nm, respectively. emission wavelengths are tunable stepwise titration experiments toward fluoride, enabling distinguished circularly polarized luminescence (CPL) from green, orange (4Cz-NBN-P1-F1) yellow (trans/cis-4Cz-NBN-P1-F2) near-unity broader circular dichroism (CD) ranges. five structures aforementioned four were confirmed by single crystal X-ray diffraction analysis. This work provides design strategy for construction non-benzenoid multiple exhibiting emissions superior PLQYs.

Язык: Английский

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Saddle-shaped aza-nanographene with multiple odd-membered rings

Chemical Science, Год журнала: 2023, Номер 14(9), С. 2353 - 2360

Опубликована: Янв. 1, 2023

A saddle-shaped aza-nanographene containing a central 1,4-dihydropyrrolo[3,2-

Язык: Английский

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Synthesis of an all-carbon conjugated polymeric segment of carbon nanotubes and its application for lithium-ion batteries

Nano Research, Год журнала: 2023, Номер 16(7), С. 10342 - 10347

Опубликована: Фев. 23, 2023

Язык: Английский

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