A Photo‐ and Thermo‐Driven Azoarene‐Based Circularly Polarized Luminescence Molecular Switch in a Liquid Crystal Host

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(48)

Опубликована: Авг. 31, 2023

The development of chiral optical active materials with switchable circularly polarized luminescence (CPL) signals remains a challenge. Here an azoarene-based molecular switch, (S, R, S)-switch 1 and (R, R)-switch 2, are designed prepared (R)-binaphthyl azo group as photosensitive moiety two (S)- or fluorescent molecules opposite the same handedness moieties. Both switches exhibit reversible trans/cis isomerization when irradiated by 365 nm UV light 520 green in solvent liquid crystal (LC) media. In contrast control switch is doped into nematic LCs, polarization inversion switching-off CPL achieved resultant helical superstructure upon irradiation light, respectively. Meanwhile, fluorescence intensity system basically unchanged during this switching process. particular, these variations could be recovered after heating, realizing true sense switching. Taking advantage unique switching, proof-of-concept for "a dual-optical information encryption system" based on above material demonstrated.

Язык: Английский

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Induced CPL‐Active Materials Based on Chiral Supramolecular Co‐Assemblies

Chemistry - A European Journal, Год журнала: 2023, Номер 29(22)

Опубликована: Янв. 24, 2023

Abstract Circularly polarized luminescence (CPL) has attracted much interest due to its potential applications on chiral photonic techniques and optoelectronic materials science. As known, dissymmetry factor ( g em ) of CPL is one essential for evaluating the features CPL‐active materials. Much attention focused how increase value, which most important issues practical applications. Recently, more works have demonstrated that supramolecular could provide significant strategy improve value through orderly helical superstructure building blocks. Normally, this kind assembly process can be accompanied by chirality transfer induction mechanism, promote amplification effect induced achiral dyes. In review, we fully summarized recent advances co‐assemblies, their in circularly organic light‐emitting diodes (CP‐OLEDs) current challenges.

Язык: Английский

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Chiral Liquid Crystalline Metal–Organic Framework Thin Films for Highly Circularly Polarized Luminescence

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(23), С. 16213 - 16221

Опубликована: Май 30, 2024

Combining metal–organic frameworks (MOFs) with liquid crystals to construct crystalline MOFs (LCMOF) offers the advantage of endowing and enhancing their functionality, yet it remains a challenging task. Herein, we report chiral MOF (CLCMOF) thin films by cross-linking (CLC) realize highly circular polarization luminescence (CPL) performance photo thermal switching. By layer stilbene-containing CLC stilbene-based (CLC/MOF) film, CLCMOF were successfully obtained after UV irradiation due abundant [2 + 2] photocycloaddition. The resulted have strong chirality, obvious photochromic fluorescent, CPL (the asymmetry factor reaches 0.4). Furthermore, fluorescent thermotropic CLC, can be reversed red-shifted heating treatment, showing photo- Such MOF-based photo/thermal switching prepared patterns codes for demonstration potential application in advanced information anticounterfeit encryption. This study not only opens strategy developing combining but also new route achieve optical applications.

Язык: Английский

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Light‐Driven Sign Inversion of Circularly Polarized Luminescence Enabled by Dichroism Modulation in Cholesteric Liquid Crystals

Advanced Materials, Год журнала: 2024, Номер 36(16)

Опубликована: Янв. 12, 2024

Stimuli-responsive circularly polarized luminescence (CPL) materials show great promise in applying information encryption and anticounterfeiting. Herein, light-driven CPL sign inversion is achieved by combining a photoresponsive achiral negative dichroic dye (KG) static positive (NR) as dopants at the 0.5:0.5 weight ratio into cholesteric liquid crystal (CLC) host. The side chains of KG undergo trans/cis isomerization after 365 nm UV light irradiation, leading to dichroism (S

Язык: Английский

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A Halogen‐Bonded Fluorescent Molecular Photoswitch: Transition from 3D Cubic Lattice to 1D Helical Superstructure for Polarization Inversion of Circularly Polarized Luminescence

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(36)

Опубликована: Июнь 10, 2024

The fabrication of materials that can switch between circularly polarized luminescence (CPL) signals is both essential and challenging. Here, two new halogen-bonded fluorescent molecular photoswitches, namely, HB-switch 1 2, containing α-cyano-substituted diarylethene compounds with different end groups were developed. Upon exposure to specific UV or visible light wavelengths, they exhibited controllable reversible Z/E photoisomerization. When these switches integrated into blue-phase liquid crystals (BPLCs), the temperature range BP significantly expanded. Notably, system incorporating exclusively achieved polarization inversion CPL under irradiation UV/Visible during cooling/heating. photo/thermal dual-response behavior be attributed phase transition from a high-symmetry 3D Icubic lattice low-symmetry 1D helical superstructure induced by photoisomerization changes. This study underscores significance employing halogen-bond assembly strategies design switchable signals, opening possibilities for CPL-active systems.

Язык: Английский

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Regulation and application of supramolecular gel with circularly polarized luminescence

Science China Chemistry, Год журнала: 2024, Номер 67(6), С. 1865 - 1880

Опубликована: Апрель 12, 2024

Язык: Английский

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Achiral Dichroic Dyes‐mediated Circularly Polarized Emission Regulated by Orientational Order Parameter through Cholesteric Liquid Crystals

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(46)

Опубликована: Сен. 30, 2023

It is noteworthy that cholesteric liquid crystal (CLC) platforms have been witnessed in high-performance circularly polarized luminescence (CPL) behaviors through the highly organized chiral co-assembled arrangement of achiral dyes. However, most CPL-active design strategies are closely relative to helix co-assembly structure CLC rather than Herein, we developed an intriguing regulation strategy for materials. They were regulated using orientational order parameter (SF ) dichroic dyes as incisive probe degree media. The I-shaped phenothiazine derivative PHECN dye =0.30) emitted a strong CPL signal (|glum |=0.47). In contrast, T-shaped (PHEBen) =0.09) showed weak circular polarization level |=0.07) at similar textures. Most interestingly, this kind with higher SF could greatly improve contrast ratio (Δglum =0.47) and emission intensity (ΔFL=46.0 %) direct-current electric field compared PHEBen =0.07 ΔFL=1.0 CLC. This work demonstrates induced can be mediated dye, which will open new avenue developing excellent display

Язык: Английский

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Induced Red Circularly Polarized Luminescence Emission Promoted by Intermolecular Förster Resonance Energy Transfer through a Cholesteric Liquid Crystal Medium

ACS Applied Materials & Interfaces, Год журнала: 2023, Номер 15(21), С. 25783 - 25790

Опубликована: Май 18, 2023

In this paper, planar chiral helicenes based on [2.2]paracyclophane PCPH5 acted as both inducers and energy donors to construct the circularly polarized luminescence (CPL)-active ternary cholesteric liquid crystals (T-N*-LCs) in a commercial nematic crystal (SLC1717, N-LCs) medium. Induced red CPL emission acceptor of achiral polymer DTBTF8 could be successfully promoted by intermolecular Förster resonance transfer mechanism. The resulting T-N*-LCs can generate intensive signals with glum up +0.70/–0.67. Interestingly, kind "on–off" switching manipulated applied direct current electric field.

Язык: Английский

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Boost the Circularly Polarized Phosphorescence of Chiral Organometallic Platinum Complexes by Hierarchical Assembly into Fibrillar Networks

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(25)

Опубликована: Апрель 10, 2024

Abstract Circularly polarized luminescence (CPL)‐active molecular materials have drawn increasing attention due to their promising applications for next‐generation display and optoelectronic technologies. Currently, it is challenging obtain CPL with both large dissymmetry factor ( g lum ) high quantum yield Φ ). A pair of enantiomeric N C‐type Pt(II) complexes L/D )‐ 1 modified chiral Leucine methyl ester are presented herein. Though the solutions these CPL‐inactive, spin‐coated thin films exhibit giantly‐amplified circularly phosphorescences | 0.53 at 560 nm air ~50 %, as well appealing circular dichroism (CD) signals maximum absorption abs 0.37–0.43 480 nm. This superior performance benefits from hierarchical formation crystalline fibrillar networks upon spin coating. Comparative studies another 2 a symmetric C coordination mode suggest that asymmetric favorable efficient exciton delocalization amplify performance. Optical in CPL‐contrast imaging inducing CP light generation achiral emitters common light‐emitting diode lamps been successfully realized.

Язык: Английский

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Three‐Level Chirality Transfer and Amplification in Liquid Crystal Supramolecular Assembly for Achieving Full‐Color and White Circularly Polarized Luminescence

Advanced Materials, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 2, 2024

Chiral liquid crystal supramolecular assembly provides an ideal strategy for constructing excellent circularly polarized luminescence (CPL) materials. However, the chirality transfer in chiral crystals normally occurs at two levels from configurational to phase chirality. The more precise and of transmission are fascinating but remain challenging. present work reports first success three-level amplification configurationally point small molecules conformationally helical polymers finally cholesteric composed nonfluorescent (P46) nematic crystals. Noticeably, twisting power P46 is five-fold larger than its monomer. Full-color white CPL with maximum dissymmetry factor up 1.54 photoluminescence quantum yield 63.8% realized utilizing combined selective reflection mechanism. Also significantly, electrically stimuli-responsive switching device as well anti-counterfeiting security, information encryption, logic gate applications developed. This study deepens understanding across different hierarchical levels.

Язык: Английский

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