Achieving Multi‐Color Emissive Organic Light‐Emitting Diodes With Single‐Component Molecule Through Conformational Regulation

Aggregate, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 21, 2025

ABSTRACT Purely organic single‐component luminescent materials enabling multi‐color photoluminescence are gaining significant interest, given their tunable optical properties, environmental friendliness, and cost‐effectiveness. However, realizing electroluminescence from a emitter for application in light‐emitting diode (OLED) remains challenging, mainly due to the limitations achieving distinct excited‐state conformations amorphous or solid states. In this study, we report two novel emitters (Bppy‐PTZ Bpph‐PTZ) by incorporating benzophenone acceptor phenothiazine donor with pyridyl phenyl π‐bridging spacers. The introduction of pyridine ring Bppy‐PTZ establishes intramolecular hydrogen bonding, stabilizing quasi‐axial (QA) conformation state, thereby facilitating white‐light emissions thin‐film OLED devices. Photophysical theoretical analyses reveal emission behaviors QA quasi‐equatorial conformations, exhibiting enhanced dual‐emission mechanochromic properties. Importantly, adopting Bppy‐PTZ, fabricated OLEDs realize color‐tunable emissions, including blue, yellow, adjustable white lights, reaching maximum external quantum efficiencies up 15.5%. This work provides valuable insights development efficient affording high performances.

Language: Английский

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Dynamic Magneto‐Optical Response and Reversible Humidity‐Sensitive Luminescence Tuned by Intermolecular Interactions in Manganese Halides

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

Published: April 21, 2025

Abstract Dynamically luminescent systems have driven great progress in materials and chemistry communities due to their structural flexibility tunable photo functions. Eco‐friendly manganese (Mn)‐based hybrid halides are promising switches with high emission efficiency, low‐cost solution processibility, low toxicity. However, limited success is achieved tuning the dynamic luminescence of response multiple stimuli. Herein, an effective way manipulate (Mn‐2DMAP Mn‐4DMAP) through tailoring intermolecular interactions reported. Stronger Mn‐2DMAP induce distortion Mn─Cl bond lengths, resulting a weaker crystal field compared Mn‐4DMAP. The reduction crystal‐field strength leads blue‐shifted enhances sensitivity external magnetic field. Mn‐4DMAP uptakes water molecules form hydrated Mn‐4DMAP‐H 2 O which exhibits stronger interactions. Taking advantage exceptional crystallinity, 1D color‐tunable optical waveguide as photonic memory system under humidity heating dual‐stimuli developed. Therefore, this work not only represents first attempt tune at level, but also utilizes dynamical for application micro/nanoscale.

Language: Английский

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Core-Substituted Pyromellitic Diimides: A Versatile Molecular Scaffold for Tunable Triplet Emission

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: April 28, 2025

Arylene diimides represent a versatile class of n-type organic semiconductors, widely recognized for tunable photophysical properties, making them highly relevant across various optoelectronic applications. While their fluorescence can be finely modulated through core substitution, triplet-state emission has received comparatively little attention. This is particularly surprising given the growing field ambient-organic triplet harvesting materials, such as thermally activated delayed and phosphorescent systems, which would greatly benefit from structural modifications to π-conjugated backbone substitution arylene achieve desired properties. Realizing states within family molecules crucial advancing triplet-based materials applications in lighting, photocatalysis, beyond. In this context, we present an unprecedented study demonstrating pyromellitic diimides, smallest member diimide family, with accessible emissive state due narrow singlet-triplet energy gap. Herein, report synthesis series core-substituted (cPmDIs) using diverse synthetic strategies. Core not only induces wide spectrum colors but, notably, enables wide-range phosphorescence spanning visible spectrum, depending on substituent. article details electrochemical characterization library cPmDIs, supported by theory. Furthermore, demonstrate potential molecular design achieving ambient-orange phosphorescence, exemplified thiophenyl-cPmDI derivative, exhibits crystalline film minimizing vibrational dissipation. regard, envision that represents significant step toward predictive structure-property phosphors materials.

Language: Английский

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Coordination-Defect-Driven Construction of Responsive Pure-MOF Microspheres for Switchable Mode-Dependent Anticounterfeiting Labels

ACS Applied Materials & Interfaces, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 23, 2024

Luminescent metal–organic frameworks (MOFs) with exceptional dynamics and diverse active sites possess tremendous potential in information security anticounterfeiting applications. However, traditional MOF systems are based on broadband spectral signals spectrum overlap, which easily leads to low-resolution signal identification, compromising the overall level. Here, we report coordination-defect-induced amorphous pure-MOF microsphere switchable whispering-gallery-mode (WGM) as a mode-dependent platform. Amorphous microspheres prepared by chlorine coordination-defect-driven growth strategy aperiodic arrangement coordinate networks. The as-prepared well-defined circular morphology display typical WGM resonance dimension-dependent character, permitting creation of photonic barcodes substantial encoding capacity. Furthermore, exhibit optical mode switching behavior due reversible framework shrinkage, enables design covert labels, finally demonstrating responsive coding property enhanced security. results provide novel for exploring an MOF-based platform encryption anticounterfeiting.

Language: Английский

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Engineered Energy Transfer in Room Temperature Phosphorescent Materials for Time‐Resolved Dual‐Mode Encryption

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

Published: Dec. 12, 2024

Abstract Room temperature phosphorescence (RTP) materials are of significant attentions due to their unique optical properties and potential applications in anti‐counterfeiting information security. However, single spatial resolution decryption methods fail meet high‐level security demands. A novel dual‐mode encryption strategy based on self‐trapped exciton (STE) fluorescence is proposed. By introducing ns 2 metal ions into the zero‐dimensional organic–inorganic hybrid halide (Ph 3 S) SnCl 6 , energy transfer pathways from S 1 T n levels STEs constructed, enabling precise control performance. This material exhibited STE fluorescence‐phosphorescence with different afterglow time, which can be utilized develop high‐performance time‐resolved cryptographic systems. Femtosecond transient absorption experiments indicated that rate significantly affected characteristics long materials. The this systems demonstrated, enhancing through multi‐level providing a new avenue for advanced

Language: Английский

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