Azepination‐Induced Frontier Molecular Orbital Delocalization of Multiple Resonance Emitters: Constructing Highly Efficient Narrowband Electroluminescent Materials DOI
Tingting Huang, Yincai Xu,

Yupei Qu

et al.

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

Published: April 3, 2025

Developing diversified construction strategies for high-color-purity and efficient multiple resonance thermally activated delayed fluorescence (MR-TADF) materials is a major strategic demand to meet the requirements of ultra-high-definition organic light-emitting diode (OLED) displays, posing significant challenge design synthesis emitters at molecular level. Herein, strategy proposed azepination-induced frontier orbital (FMO) delocalization MR emitters, that is, embedding azepine into prototype molecule BNCz can effectively improve π-conjugation degree extend FMO delocalization, thereby constructing series long-wavelength MR-TADF with narrowband emission. Through an intramolecular Scholl reaction, these target molecules azepine-embedded core are afforded by one-fold heptagonal cyclization phenyl ring attached (aromatic amine-substituted) aryl precursor. They all exhibit green emission around 520 nm narrow full-widths half-maximum (FWHMs) ≤ 37 in toluene. OLEDs employing show excellent electroluminescence (EL) performances, among which m-PAz-BNCz-based OLED exhibits optimal EL performances peak 528 nm, FWHM Commission Internationale de L'Eclairage (CIE) coordinates (0.26, 0.70), maximum external quantum efficiency (EQE) 36.2%.

Language: Английский

Nonalternant B,N‐Embedded Helical Nanographenes Containing Azepines: Programmable Synthesis, Responsive Chiroptical Properties and Spontaneous Resolution into a Single‐Handed Helix DOI Creative Commons

Weiwen Zhuang,

Faan‐Fung Hung, Chi‐Ming Che

et al.

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

Published: July 19, 2024

Abstract Heteroatom‐embedded helical nanographenes (NGs) constitute an important and appealing class of intrinsically chiral materials. In this work, a series B,N‐embedded NGs (BN‐HNGs) bearing azepines was synthesized via stepwise regioselective cyclodehydrogenation. First, the phenyl‐ or nitrogen‐bridged dimers were efficiently clipped into highly congested model compounds 1 2 . Later, controllable Scholl reactions tetraphenyl‐tethered precursor generated 1, 7 8 new C−C bonds, thereby establishing robust method for preparation nonalternant BN‐HNGs with up to 31 fused rings. The bilayer nature unambiguously verified by X‐ray diffraction analysis. chirality transferred stereogenic boron centers upon fluoride coordination, concave‐concave structure comply skeleton. Notably, largest BN‐HNG ( 6 ) spontaneously resolved homochiral 4 helix as molecular spiral staircase during crystallization conglomerate formation at single‐crystal scale. large twisted C ‐symmetric π‐surface dynamic skeleton induced curved might have synergistic effects on self‐recognition enantiomers achieve intriguing spontaneous resolution behavior. chiroptical properties enantiomer further investigated, revealing that had strong response in visible range (400–700 nm).

Language: Английский

Citations

3
Highly Efficient Blue/Deep‐blue Circularly Polarized Electroluminescence with Small Efficiency Roll‐Offs DOI
Yan Yan,

Zhuang Cheng,

Yangze Xu

et al.

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: 34(48)

Published: July 25, 2024

Abstract Developing efficient blue/deep‐blue circularly polarized organic light‐emitting diodes (CP‐OLEDs) with small efficiency roll‐off remains a great challenge for wide color gamut and high contrast 3D displays. Here, two pairs of chiral stable enantiomers, ( R / S )‐PPI‐OBN‐CN )‐PyI‐OBN‐CN, composed imidazole derivatives phenanthroimidazole (PPI) pyrenoimidazole (PyI) donors, group )‐octahydro‐binaphthol (OBN‐CN) acceptor are designed. These new molecular architectures exhibit excellent thermal electrochemical stabilities, hybrid local charge transfer (HLCT) excited state, clear CPL characteristics dissymmetry factors (|g PL |) 1.57 × 10 −3 /2.49 in the neat films. Moreover, CP‐OLEDs based on )‐PyI‐OBN‐CN deep‐blue/pure‐blue emission CIE coordinates (0.15, 0.08) 0.14), maximum external quantum efficiencies (EQEs) 7.25% 8.11% very roll‐offs 17.6% 1.8% at luminescence 1000 cd m −2 , respectively. Even when brightness is increased to 10000 )‐PyI‐OBN‐CN‐based device could still maintain as 6.68%. Obvious electroluminescence (CPEL) activities EL g ) +1.54 /−1.63 +1.95 /−1.72 also recorded. first highly “hot exciton” enantiomers.

Language: Английский

Citations

3
Helically chiral multiresonant thermally activated delayed fluorescent emitters and their use in hyperfluorescent organic light-emitting diodes DOI Creative Commons
Jingxiang Wang, Dongyang Chen, Juan Manuel Moreno-Naranjo

et al.

Chemical Science, Journal Year: 2024, Volume and Issue: 15(41), P. 16917 - 16927

Published: Jan. 1, 2024

Helically chiral MR-TADF compounds tBuPh-BN and DPA-tBuPh-BN show narrowband circularly polarized luminescence that translates into high-performance hyperfluorescent organic light-emitting diodes.

Language: Английский

Citations

3
Aggregation‐induced circularly polarized luminescence and delayed fluorescence enabled by activating high‐level reverse intersystem crossing DOI Creative Commons

Ke Wang,

Xinwen Ou,

Xiaofei Niu

et al.

Aggregate, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 25, 2024

Abstract Circularly polarized luminescence (CPL) materials with delayed fluorescence have attracted much attention due to their ability efficiently trap triplet state excitons, thereby improving the photoluminescence quantum yields of CPL materials. However, effort has been normally focused on utilization T 1 excitons but seldom higher excited n ( > 1) excitons. Rational manipulation and suppression Kasha's rule remains a major challenge. Herein, two gold complex enantiomers (( R / S )‐BPAuBC) based axially chiral binaphthyls 3,6‐Di‐tert‐butylcarbazole groups are synthesized systematically investigated. These exhibit aggregation‐induced circularly fluorescence. was found be enabled by activating high‐level reverse intersystem crossing (hRISC). The anti‐Kasha phosphorescence at 77 K proves that exciton large population in high‐lying 2 , which allows effective hRISC process cross back singlet emit In addition, “on–off” switching is further achieved nanoparticles acid–base stimulus, showing its potential as an responsive material.

Language: Английский

Citations

3
Azepination‐Induced Frontier Molecular Orbital Delocalization of Multiple Resonance Emitters: Constructing Highly Efficient Narrowband Electroluminescent Materials DOI
Tingting Huang, Yincai Xu,

Yupei Qu

et al.

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

Published: April 3, 2025

Developing diversified construction strategies for high-color-purity and efficient multiple resonance thermally activated delayed fluorescence (MR-TADF) materials is a major strategic demand to meet the requirements of ultra-high-definition organic light-emitting diode (OLED) displays, posing significant challenge design synthesis emitters at molecular level. Herein, strategy proposed azepination-induced frontier orbital (FMO) delocalization MR emitters, that is, embedding azepine into prototype molecule BNCz can effectively improve π-conjugation degree extend FMO delocalization, thereby constructing series long-wavelength MR-TADF with narrowband emission. Through an intramolecular Scholl reaction, these target molecules azepine-embedded core are afforded by one-fold heptagonal cyclization phenyl ring attached (aromatic amine-substituted) aryl precursor. They all exhibit green emission around 520 nm narrow full-widths half-maximum (FWHMs) ≤ 37 in toluene. OLEDs employing show excellent electroluminescence (EL) performances, among which m-PAz-BNCz-based OLED exhibits optimal EL performances peak 528 nm, FWHM Commission Internationale de L'Eclairage (CIE) coordinates (0.26, 0.70), maximum external quantum efficiency (EQE) 36.2%.

Language: Английский

Citations

0