Red Emissive Double Aza[7]helicenes with Antiaromaticity / Aromaticity Switching via the Redox‐Induced Radical Cation and Dication Species

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(18)

Published: March 6, 2023

We herein present the synthetic approach to a new antiaromatic double aza[7]helicene C that features NN-embedded polycyclic aromatic hydrocarbons (PAHs). This heteroatom-doped helicene showed rarely obtained long-wavelength emission and far-red circularly polarized luminescence (CPL) in solid state. These optical chiroptical properties could be ascribed both NN-PAH core structure further extension through angular ring fusions. Such unique electronic also culminated facile chemical oxidations of neutral positively charged chiral radical (C⋅+ ) dication species (C2+ ). Interestingly, DFT computations revealed pyridazine central an antiaromaticity-to-aromaticity switching, contrast inversed transition for helical periphery cationic states. The reported approaches are anticipated lead development redox-active systems potential applications chiroptoelectronics, spintronics as well fluorescent bioimaging.

Language: Английский

---

Aqueous Circularly Polarized Luminescence Induced by Homopolypeptide Self-Assembly

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(50), P. 27282 - 27294

Published: Dec. 8, 2023

Remarkable advances have been achieved in solution self-assembly of polypeptides from the perspective nanostructures, mechanisms, and applications. Despite intrinsic chirality polypeptides, promising generation aqueous circularly polarized luminescence (CPL) based on their has rarely reported due to weak fluorescence most indeterminate mechanism. Here, we propose a facile strategy for achieving CPL simple homopolypeptides modified with terminal group featuring both twisted intramolecular charge transfer aggregation-induced emission properties. A morphology-dependent can be observed under different conditions by altering solvents. nanotoroid-dispersed detectable obtained using tetrahydrofuran as good solvent self-assembly, which is attributed involvement chiral environment formed homopolypeptide chains. However, such packing mode cannot realized nanorods self-assembled dioxane, resulting an inactive phenomenon. Furthermore, signals greatly amplified co-assembly achiral small molecule derived group. This work not only provides pathway construct CPL-active nanomaterials but also reveals potential mechanism production, transfer, amplification polypeptide-based nanostructures.

Language: Английский

---

Enantioselective synthesis of a two-fold inherently chiral molecular nanographene

Nature Synthesis, Journal Year: 2024, Volume and Issue: 3(4), P. 545 - 553

Published: Feb. 22, 2024

Abstract The introduction and precise control of stereogenic elements in chemical structures is typically a challenging task. Most asymmetric methods require the presence heteroatom starting substrates acting as an anchor point for successful transfer chiral information. For this reason, compounds comprising only carbon atoms, such optically active molecular nanographenes, are usually obtained racemates, isolated by chromatographic separation. Here, we report enantioselective strategy that uses three stereocontrolled synthetic steps to introduce extend different types elements, namely central, axial helicoidal chirality, into polycyclic aromatic structure. Thus, two nanographene layers covalently connected through triindane core. final graphitization Scholl reaction affords formation units with remarkable enantiomeric excesses, high stereochemical stability good chiroptical properties.

Language: Английский

---

Synthesis of Aza[n]helicenes up to n = 19: Hydrogen-Bond-Assisted Solubility and Benzannulation Strategy

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(25), P. 17428 - 17437

Published: June 12, 2024

Synthetic challenges toward anomalous structures and electronic states often involve handling problems such as insolubility in common organic solvents oxidative degradation under aerobic conditions. We designed benzo-annulated aza[n]helicenes, which benefit from both the suppressed elevation of highest occupied molecular orbital (HOMO) energies high solubility due to hydrogen bonding with solvent molecules overcome these challenges. This strategy enabled synthesis six new aza[n]helicenes ([n]AHs) different lengths (n = 9–19) acyclic precursors via one-pot intramolecular fusion reactions. The all synthesized were determined by X-ray diffraction (XRD) analysis, their electrochemical potentials measured cyclic voltammetry. Among [17]AH [19]AH are first heterohelicenes a triple-layered helix. noncovalent interaction (NCI) plots confirm existence an effective π–π between layers. absorption fluorescence spectra red-shifted helical increased, without any distinct saturation points. optical resolutions N-butylated [9]AH, [11]AH, [13]AH, [15]AH accomplished, circular dichroism (CD) circularly polarized luminescence (CPL) measured. Thus, structural, (chir)optical, properties comprehensively analyzed.

Language: Английский

---

Circularly Polarized Luminescent π‐Conjugated Chiral Nanorings and Nanobelts

Advanced Optical Materials, Journal Year: 2024, Volume and Issue: 12(18)

Published: May 20, 2024

Abstract Molecular chirality plays a pivotal role across the disciplines of chemical and physical sciences, as well holding significant implications in realms medicine technology. Chiral macrocycles have attracted recent interests synthetic chemistry, material science, supramolecular chemistry. Due to cyclic arrangements stereogenic elements or special orientations confined rigid structures, π‐conjugated chiral are expected be highly luminescent, configurationally stable, thus serve develop high‐performance chiroptical materials. Given rapid progress achieved this new area years, it is highlight concepts breakthroughs. This minireview will offer overview wide range from traditional molecules which include axially, helically, planar skeletons nanobelts with focus on structure‐function relationship between unique properties.

Language: Английский

---

Chiral light–matter interactions in solution-processable semiconductors

Nature Reviews Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 17, 2025

Language: Английский

---

Boosting quantum yields and circularly polarized luminescence of penta- and hexahelicenes by doping with two BN-groups

Chemical Science, Journal Year: 2023, Volume and Issue: 15(2), P. 466 - 476

Published: Oct. 25, 2023

The presented penta- and hexahelicenes with two boron–nitrogen groups resemble their all-carbon analogs structurally but show considerably improved (chir)optical properties like absorptivities, quantum yields luminescence dissymmetries.

Language: Английский

---

A Multiple Circularly Polarized Luminescence Regulation Platform Driven by Acid, Base, and Primary Amines

Advanced Optical Materials, Journal Year: 2024, Volume and Issue: 12(19)

Published: April 30, 2024

Abstract Functional materials that exhibit circularly polarized luminescence (CPL) have shown immense potential in applications such as 3D optical displays and advanced information encryption. However, facile efficient regulation of the multiple emission properties chiral systems has remained a challenge due to scarcity suitable complexity systems. Herein, CPL platform is fabricated by helical co‐assembly an aldehyde‐functionalized fluorane dye (Rhodol‐CHO, 6′‐(diethylamino)‐3′‐hydroxy‐3‐oxo‐3H‐spiro[isobenzofuran‐1,9′‐xanthene]‐4′‐carbaldehyde) liquid crystals, which can efficiently combine stimuli‐responsive characteristics high activity. By introducing acid, base, compounds containing primary amino (─NH 2 ) groups, property system be easily modified. The obtained apparent asymmetry, with g lum values reaching 0.54–0.75). Further, these modules are successfully applied multi‐mode encryption, highlighting their practical utility. Therefore, this study presents novel strategy for developing diverse behaviors based on simple‐designed platform, advancing further materials.

Language: Английский

---

Benzo-Extended Heli(aminoborane)s: Inner Rim BN-Doped Helical Molecular Carbons with Remarkable Chiroptical Properties

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(32), P. 22600 - 22611

Published: Aug. 5, 2024

Atomically precise synthesis of three-dimensional boron-nitrogen (BN)-based helical structures constitutes an undeveloped field with challenges in synthetic chemistry. Herein, we synthesized and comprehensively characterized a new class molecular carbons, named benzo-extended [n]heli(aminoborane)s (

Language: Английский

---

Helicene‐type β‐isoindigo‐based boron‐dipyrromethene analogs with strong near‐infrared chiroptical activity

Aggregate, Journal Year: 2024, Volume and Issue: 5(3)

Published: Jan. 5, 2024

Abstract Near‐infrared (NIR) chiroptical response has been less explored because it is challenging to achieve both chirality and NIR absorption/emission. Herein, we describe the design of heterohelicene‐type β‐isoindigo‐based boron‐dipyrromethene (BODIPY) analogs (β‐IBs), which shift absorption peak 800 nm produce significant Cotton effects (127.8 M −1 cm ) absorbance dissymmetry factors (| g abs | = 3.5 × 10 −3 ). The luminescence factor ( lum circularly polarized (CPL) brightness B CPL up 1.24 1.78 were realized beyond nm. These β‐IBs are first examples helicene‐type compounds with highest in region Theoretical calculations demonstrate that strong activities triggered by their large transition magnetic dipole moments. This study not only provides a new approach synthesis larger variety unprecedented BODIPY but also demonstrates excellent properties.

Language: Английский

---