Helical Ladder Oligomers Exhibit Amplified Circularly Polarized Emission

Advanced Optical Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 30, 2025

Abstract Establishing design principles to engineer molecules that exhibit strong circularly polarized luminescence (CPL)‐brightness across the UV, visible and NIR spectral range remains an unsolved challenge. To achieve a large CPL‐brightness, main difficulty is optimize dissymmetry factor g lum . Herein described discovery multi‐helicene system based on series of annulated [6]helicenes perylenediimides, exhibits larger‐than‐linear amplification with helicene length. Large enhanced fluorescent quantum yields extinction coefficients are also observed for this length series. Consequently, oligomers exceptional CPL brightness (B ) above 1 × 10 3 mol −1 cm Using computational methods density functional theory (DFT), experimental trend shows increase glum due progressive alignment magnetic (|m|) electric transition (|µ|) dipole moment vectors, as helical backbone grows longer.

Language: Английский

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Synthesis and Chiroptical Properties of a Saddle-Shaped Quadruple Helicene with a Cyclooctatetrapyrrole Core

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

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Chiral nanographenes exhibiting circularly polarized luminescence

Chemical Society Reviews, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Chiral nanographenes: molecular architecture, key constituents, and their circularly polarized luminescence.

Language: Английский

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Double [8]Helicene Featuring a Dibenzo[g,p]chrysene Core: Synthesis and Chiroptical Response

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

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Pyrene bridged double[7]helicene embedded with a heptagonal ring

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(15), P. 3714 - 3725

Published: Jan. 1, 2023

The article explores the intricate relationship between chiroptical properties and molecular symmetry of pyrene-conjugated single double [7]helicene.

Language: Английский

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