Helical Bilayer Nanographenes: Impact of the Helicene Length on the Structural, Electrochemical, Photophysical, and Chiroptical Properties

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(21), P. 11599 - 11610

Published: May 2, 2023

Helical bilayer nanographenes (HBNGs) are chiral π-extended aromatic compounds consisting of two π-π stacked hexabenzocoronenes (HBCs) joined by a helicene, thus resembling van der Waals layered 2D materials. Herein, we compare [9]HBNG, [10]HBNG, and [11]HBNG helical bilayers endowed with [9], [10], [11]helicenes embedded in their structure, respectively. Interestingly, the helicene length defines overlapping degree between HBCs (number benzene rings involved interactions layers), being 26, 14, 10 rings, respectively, according to X-ray analysis. Unexpectedly, electrochemical study shows that lesser system [9]HBNG strongest electron donor character, part interlayer exchange resonance, more red-shifted values emission. Furthermore, also exceptional chiroptical properties biggest gabs glum (3.6 × 10-2) when compared [10]HBNG owing fine alignment configuration its electric magnetic dipole transition moments. spectroelectrochemical studies as well fluorescence spectroscopy support aforementioned experimental findings, confirming strong impact on this new family nanographenes.

Language: Английский

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Synthesis of π-Conjugated Chiral Organoborane Macrocycles with Blue to Near-Infrared Emissions and the Diradical Character of Cations

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(18), P. 10092 - 10103

Published: April 26, 2023

Highly emissive π-conjugated macrocycles with tunable circularly polarized luminescence (CPL) have sparked theoretical and synthetic interests in recent years. Herein, we report a approach to obtain new chiral organoborane (CMC1, CMC2, CMC3) that are built on the structurally [5]helicenes highly luminescent triarylborane/amine moieties embedded into cyclic systems. These rarely accessible B/N-doped main-group show unique topology dependence of optoelectronic chiroptical properties. CMC1 CMC2 higher dissymmetry factor (glum) together an enhanced CPL brightness (BCPL) as compared CMC3. Electronic effects were also tuned resulted bathochromic shifts their emission responses from blue for near-infrared (NIR) region Furthermore, chemical oxidations N donor sites gave rise stable radical cation (CMC1·+SbF6–) diradical dication species (CMC12·2+2SbF6–) serve rare example positively charged open-shell macrocycle.

Language: Английский

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Polycationic Open‐Shell Cyclophanes: Synthesis of Electron‐Rich Chiral Macrocycles, and Redox‐Dependent Electronic States

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(27)

Published: Feb. 27, 2024

π-Conjugated chiral nanorings with intriguing electronic structures and chiroptical properties have attracted considerable interests in synthetic chemistry materials science. We present the design principles to access new macrocycles (1 2) that are essentially built on key components of main-group electron-donating carbazolyl moieties or π-expanded aza[7]helicenes. Both show unique molecular conformations a (quasi) figure-of-eight topology as result conjugation patterns 2,2',7,7'-spirobifluorenyl 1 triarylamine-coupled aza[7]helicene-based building blocks 2. This nature redox-active, carbazole-rich backbones enabled these be readily oxidized chemically electrochemically, leading sequential production series positively charged polycationic open-shell cyclophanes. Their redox-dependent states resulting multispin polyradicals been characterized by VT-ESR, UV/Vis-NIR absorption spectroelectrochemical measurements. The singlet (ΔE

Language: Английский

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Design and Synthesis of New Type of Macrocyclic Architectures Used for Optoelectronic Materials and Supramolecular Chemistry

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(54)

Published: July 13, 2023

Abstract Supramolecular chemistry has received much attention for decades. Macrocyclic architectures as representative receptors play a vital role in supramolecular and are applied many fields such assembly host‐guest recognition. However, the classical macrocycles generally lack functional groups scaffolds, which limit their further applications, especially optoelectronic materials. Therefore, developing new design principle is not only essential to better understand macrocyclic behaviors, but also expand applications research fields. In recent years, doping compounds with main‐group heteroatoms (B, N, S, O, P) into carbon‐based π‐conjugated offered strategy build unique properties. particular, energy gaps redox behavior can be effectively tuned by incorporating scaffolds. this Minireview, we briefly summarize synthesis of macrocycles, discuss related materials chemistry.

Language: Английский

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Expanding new chemistry of aza-boracyclophanes with unique dipolar structures, AIE and redox-active open-shell characteristics

Chemical Science, Journal Year: 2022, Volume and Issue: 13(39), P. 11672 - 11679

Published: Jan. 1, 2022

We have achieved the synthesis of new B/N doped macrocycles by stitching oligoarylamine pentamers using arylborane acceptor segments. They exhibit open-shell radical species and AIE under ambient conditions.

Language: Английский

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Recent Progress of Chiral Conjugated Organic Triarylboron (Ar3B) Luminescent Materials

Chinese Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: 45(4), P. 1119 - 1119

Published: Jan. 1, 2025

Language: Английский

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Recent Advances of Boron‐Containing Chiral Luminescent Materials^†

Chinese Journal of Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 25, 2024

Comprehensive Summary As a class of organic dyes, boron‐containing compounds play an important role in luminescent materials. They have attracted considerable attention due to their unique photophysical properties. Chiral systems wide range practical applications biological imaging, optoelectronic devices, information storage and 3D display. Boron‐containing chiral materials can not only effectively improve the properties CPL materials, but also bring system, which enables them be used as favorable emitting for expanded applications. Here, we review research progress by detailed discuss according different skeletons, such point chirality, 1,1’‐binaphthyl, [ n ]helicenes, [2,2]paracyclophane pillar[5]arenes. We believe that this is significance development Key Scientists The studies circularly polarized luminescence (CPL) based on small molecules advanced significantly. However, gained recent years. In 2019, Zhao's group prepared binaphthalene derivative modified with triarylborane, representing molecule material exhibit characteristics responsive both solvent fluoride ions. 2020, Chen's steric effects triarylborane triphenylamine prepare planar 2021, Wang's developed new B,N‐embedded double hetero[7]helicenes strong chiroptical responses UV‐visible region. same year, He's asymmetric reactions synthesize boron‐based point‐chirality high efficiency enantioselectivity. 2023, Ravat synthesized 1,4‐B,N‐embedded helicenes exhibiting narrow‐band fluorescence CPL. During period, Matthias Wagner et al obtained (BO) 2 ‐doped tetrathia[7]helicene via efficient four‐step synthesis, Zheng reported nearly pure green electroluminescent device (CP‐OLED). 2024, hetero‐[9]helicenes offering pathway towards significantly enhanced helicene‐based CPEL.

Language: Английский

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Theoretical spectroscopy for unraveling the intensity mechanism of the optical and photoluminescent spectra of chiral Re(I) transition metal complexes

The Journal of Chemical Physics, Journal Year: 2023, Volume and Issue: 159(8)

Published: Aug. 22, 2023

In this work, we present a computational study that is able to predict the optical absorption and photoluminescent properties of chiral Re(I) family complexes [fac-ReX(CO)3L], where X either Cl or I L N-heterocyclic carbene extended with π-conjugated [5]-helicenic unit. The strategy based on carefully calibrated time dependent density functional theory calculations operates in conjunction an excited state dynamics approach treat addition (ABS) photoluminescence (PL), electronic circular dichroism (ECD), circularly polarized luminescence (CPL) spectroscopies, respectively. employed provides, addition, access computation phosphorescence rates terms radiative non-radiative relaxation processes. chosen molecules consist representative examples non-helicenic (NHC) helicenic diastereomers. agreement between theoretical experimental spectra, including (ABS, ECD) emission (PL, CPL), excellent, validating quantitative interpretation spectral features basis natural transition orbitals TheoDore analyses. It demonstrated across set studied diastereomers, process case NHC diastereomers metal ligand charge transfer nature dominated by easy-axis anisotropy emissive multiplet. On contrary, cases intra respective easy-plane This affects remarkably PL CPL band shapes, spin-vibronic coupling, times, quantum yields. Spin-vibronic coupling effects are investigated at level state-average complete active space self-consistent field quasi-degenerate second order perturbation theory. fact mechanism controls observed photophysics class complexes.

Language: Английский

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Applying the B/N Lewis Pair Approach to Access Fusion-Expanded Binaphthyl-Based Chiral Analogues

Inorganic Chemistry, Journal Year: 2022, Volume and Issue: 61(39), P. 15315 - 15319

Published: Sept. 22, 2022

We herein describe the synthesis of two axially chiral systems (HBN and BBN) by incorporation B centers into binaphthyl derivatives (HPy BPy). Heteroatom-doped polycyclic aromatic hydrocarbons were thus formed fusion azaboroles to binaphthyls with formation B-N dative bonds. The resulting Lewis pairs that serve as attractive fluorophores enabled modulation chiroptical properties both in solution solid state.

Language: Английский

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Polycationic Open‐Shell Cyclophanes: Synthesis of Electron‐Rich Chiral Macrocycles, and Redox‐Dependent Electronic States

Angewandte Chemie, Journal Year: 2024, Volume and Issue: 136(27)

Published: Feb. 27, 2024

Abstract π‐Conjugated chiral nanorings with intriguing electronic structures and chiroptical properties have attracted considerable interests in synthetic chemistry materials science. We present the design principles to access new macrocycles ( 1 2 ) that are essentially built on key components of main‐group electron‐donating carbazolyl moieties or π‐expanded aza[7]helicenes. Both show unique molecular conformations a quasi figure‐of‐eight topology as result conjugation patterns 2,2’,7,7’‐spirobifluorenyl triarylamine‐coupled aza[7]helicene‐based building blocks . This nature redox‐active, carbazole‐rich backbones enabled these be readily oxidized chemically electrochemically, leading sequential production series positively charged polycationic open‐shell cyclophanes. Their redox‐dependent states resulting multispin polyradicals been characterized by VT‐ESR, UV/Vis‐NIR absorption spectroelectrochemical measurements. The singlet (Δ E S‐T =−1.29 kcal mol −1 nearly degenerate singlet‐triplet ground state S−T(calcd) =−0.15 Δ S−T(exp) =0.01 were proved for diradical dications 2+2 ⋅ ⋅, respectively. Our work provides an experimental proof construction nanorings, more importantly highly potential applications chirospintronics organic conductors.

Language: Английский

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