Corannulene‐based Quintuple [6]/[7]helicenes: Well‐preserved Bowl Core, Inhibited Bowl Inversion and Supramolecular Assembly with Fullerenes DOI Open Access

Kaixin Zhang,

Zuo‐Chang Chen, Yin‐Fu Wu

et al.

Angewandte Chemie, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 31, 2024

Abstract Herein, corannulene‐based quintuple [6]helicenes ( Q[6]H‐1 and Q[6]H‐2 ) [7]helicene Q[7]H were synthesized via penta‐fold Heck Mallory reaction. Notably, represents the highest reported helicene based on corannulene. X‐ray crystallography reveals that adopts a propeller‐shaped conformation with well‐preserved corannulene core, while exhibit quasi‐propeller‐shaped conformations. Upon heating, conformer undergoes conversion to thermodynamically more stable , whereas remains unchanged due larger steric congestion. Racemization of enantiomer conformational observed simultaneously at elevated temperature, DFT studies indicating racemization barrier 32.06 kcal ⋅ mol −1 . In contrast, for was calculated be 45.46 exceptional chiral stability. Surprisingly, bowl inversions conformers are somewhat inhibited by helical blades, this not other possible Q[6]H These results first demonstrated subtle variations can lead significant changes in stability multiple helicenes. Due electron complementarity, recognize fullerenes both solution solid state, which is rare instance co‐crystallization assembly between helicenes fullerenes.

Language: Английский

Recent development of azahelicenes showing circularly polarized luminescence DOI Creative Commons
Chihiro Maeda, Tadashi Ema

Chemical Communications, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

This feature article summarizes the recent developments of azahelicenes showing circularly polarized luminescence.

Language: Английский

Citations

0
Synthesis and Chiroptical Properties of a Saddle-Shaped Quadruple Helicene with a Cyclooctatetrapyrrole Core DOI
Xu‐Lang Chen,

Si-Qian Yu,

Ziming Cheng

et al.

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: March 28, 2025

A quadruple helicene with a cyclooctatetrapyrrole core was synthesized via simple Ullmann reaction. Its single-crystal structure exhibits saddle shape. The compound shows fluorescence emission λem = 575 nm and good chiroptical properties, including dissymmetric absorption factor (|gabs|) of 5.84 × 10–3 (|glum|) 1.21 10–2.

Language: Английский

Citations

0
Double [8]Helicene Featuring a Dibenzo[g,p]chrysene Core: Synthesis and Chiroptical Response DOI
Xu‐Lang Chen, Ziming Cheng, Zhaoliang Zheng

et al.

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: May 2, 2025

Double [8]helicene 1, featuring a dibenzo[g,p]chrysene core, was synthesized via the Scholl reaction, and its structure unambiguously confirmed by single-crystal X-ray diffraction analysis of dicationic salt [1-Cl]2+·(SbCl6-)2. The compound exhibits red fluorescence with an emission maximum at 618 nm (λem) quantum yield 16.2%, highlighting potential in optoelectronic applications. Furthermore, circular dichroism (CD) circularly polarized luminescence (CPL) measurements reveal notable chiroptical activity, absorption dissymmetry factors |gabs| = 5.11 × 10-3 |glum| 7.1 10-4, respectively.

Language: Английский

Citations

0
Corannulene‐based Quintuple [6]/[7]helicenes: Well‐preserved Bowl Core, Inhibited Bowl Inversion and Supramolecular Assembly with Fullerenes DOI

Kaixin Zhang,

Zuo‐Chang Chen, Yin‐Fu Wu

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 31, 2024

Herein, corannulene-based quintuple [6]helicenes (Q[6]H-1 and Q[6]H-2) [7]helicene (Q[7]H) were synthesized via penta-fold Heck Mallory reaction. Notably, Q[7]H represents the highest reported helicene based on corannulene. X-ray crystallography reveals that Q[6]H-2 adopts a propeller-shaped conformation with well-preserved corannulene core, while Q[6]H-1 exhibit quasi-propeller-shaped conformations. Upon heating, conformer undergoes conversion to thermodynamically more stable Q[6]H-2, whereas remains unchanged due larger steric congestion. Racemization of enantiomer conformational observed simultaneously at elevated temperature, DFT studies indicating racemization barrier 32.06 kcal ⋅ mol

Language: Английский

Citations

3
Helicenes with Four Helical Turns: Dimerization of [13]Helicenes to [27]Helicenoids DOI Creative Commons

Matea Sršen,

Stephan K. Pedersen, Tomislav Rožić

et al.

Angewandte Chemie International Edition, Journal Year: 2025, Volume and Issue: unknown

Published: May 27, 2025

Abstract The promise of enhanced circularly polarized luminescence (CPL) from organic molecules has inspired synthetic efforts to prepare elongated multi‐layer helicenes. It proven particularly challenging synthesize and isolate enantiomerically pure multi‐turn helicenes, consequently, clear guidelines for the molecular design helicenes achieve large CPL output remain elusive. We explore oxidative dimerization a 2‐naphthol‐annulated hetero[13]helicene, observe formation two types structurally distinct hetero[27]helicenes, both with four helical turns, form. With Cu II Cl(OH)‐TMEDA as oxidant, symmetric dimer ( bi[13] ) formed, joining same helicity in their keto tautomeric forms. Using (OTf)₂ oxidant led an unsymmetrical [27]helicenoid composed by M )‐ P )‐enantiomer [13]helicene through unusual coupling between 1‐ 3‐positions 2‐naphthol units. Structural characterization was achieved NMR spectroscopy single‐crystal (X‐ray or electron) diffraction analysis. enantiomers this were analyzed electronic circular dichroism (ECD) measurements. spectroscopic data corroborated DFT calculations, intense is preserved despite presence ‐helicene molecule. These [27]helicenoids are first isolated structures that feature π‐systems turns.

Language: Английский

Citations

0
Helicenes with Four Helical Turns: Dimerization of [13]Helicenes to [27]Helicenoids DOI Creative Commons

Matea Sršen,

Stephan K. Pedersen, Tomislav Rožić

et al.

Angewandte Chemie, Journal Year: 2025, Volume and Issue: unknown

Published: May 27, 2025

Abstract The promise of enhanced circularly polarized luminescence (CPL) from organic molecules has inspired synthetic efforts to prepare elongated multi‐layer helicenes. It proven particularly challenging synthesize and isolate enantiomerically pure multi‐turn helicenes, consequently, clear guidelines for the molecular design helicenes achieve large CPL output remain elusive. We explore oxidative dimerization a 2‐naphthol‐annulated hetero[13]helicene, observe formation two types structurally distinct hetero[27]helicenes, both with four helical turns, form. With Cu II Cl(OH)‐TMEDA as oxidant, symmetric dimer ( bi[13] ) formed, joining same helicity in their keto tautomeric forms. Using (OTf)₂ oxidant led an unsymmetrical [27]helicenoid composed by M )‐ P )‐enantiomer [13]helicene through unusual coupling between 1‐ 3‐positions 2‐naphthol units. Structural characterization was achieved NMR spectroscopy single‐crystal (X‐ray or electron) diffraction analysis. enantiomers this were analyzed electronic circular dichroism (ECD) measurements. spectroscopic data corroborated DFT calculations, intense is preserved despite presence ‐helicene molecule. These [27]helicenoids are first isolated structures that feature π‐systems turns.

Language: Английский

Citations

0
A Carbazole‐Centered Expanded Helicene Stabilized with Hexabenzocoronene (HBC) Units DOI
Xinyue Wang,

Jinku Bai,

Yun‐Jia Shen

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 18, 2024

The synthesis and stabilization of heteroatom-doped nanocarbon molecules, such as carbazole-containing (super)helicenes, present significant challenges due to the complexities involved in maintaining structural integrity electronic functionality. In this study, we successfully synthesized a carbazole-centered expanded tris-hexabenzo[7]helicene (1) via facile FeCl

Language: Английский

Citations

1
Hexabenzoperylene‐Cored Double Thiahelicenes with Strong Luminescence DOI
Yuying Ma, Long Zhou, Jingyun Tan

et al.

Advanced Optical Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 16, 2024

Abstract Thiahelicenes, an important subclass of helicenes, are renowned for their pronounced chiroptical properties, particularly circular dichroism. However, the exploration circularly polarized luminescence (CPL) has been hindered due to inherently weak fluorescence, leaving a critical gap in development thiahelicenes as efficient CPL emitters. To address this limitation, novel strategy enhancing by integrating thiophene‐containing units with highly emissive hexabenzoperylene (HBP) core is presented. Two isomeric HBP‐cored double synthesized, which serve proof concept. These molecules exhibit exceptionally high fluorescence quantum yields ( Φ F = 83% and 91%), surpassing all previously reported thiahelicenes. Furthermore, dissymmetry factors show four‐fold enhancement compared parent HBP, resulting remarkable brightness up 84.9 M −1 cm . findings not only limitation but also establish new pathway developing high‐performance materials.

Language: Английский

Citations

1
Impacts of Heteroatom Substitution on Excited State Dynamics of π-Extended Helicenes DOI Creative Commons

Yuto Kondo,

Yusuke Tsutsui,

Yusuke Matsuo

et al.

Nanoscale Advances, Journal Year: 2024, Volume and Issue: 6(18), P. 4567 - 4571

Published: Jan. 1, 2024

The excited state dynamics of heterohelicenes [9]TH and [9]AH were spectroscopically studied. showed enhanced fluorescence, while phosphorescence occurred in due to its spin–orbit coupling swift intersystem crossing.

Language: Английский

Citations

0
Synthesis of Terminus-Decorated Aza[9]helicenes: Control of Interlayer Interaction DOI Creative Commons

Yusuke Matsuo,

Shu Seki, Takayuki Tanaka

et al.

Chemistry Letters, Journal Year: 2024, Volume and Issue: 53(8)

Published: July 31, 2024

Abstract Azahelicenes are intriguing luminescent materials with a planar chirality. The properties of aza[9]helicene can be perturbed by attaching substituent at the termini. impact terminal decoration has been investigated in view structural and electronic aspects, leading to control interlayer interaction.

Language: Английский

Citations

0