Achieving 37.1% Green Electroluminescent Efficiency and 0.09 eV Full Width at Half Maximum Based on a Ternary Boron-Oxygen-Nitrogen Embedded Polycyclic Aromatic System

Comparative study of TDDFT and TDDFT-based STEOM-DLPNO-CCSD calculations for predicting the excited-state properties of MR-TADF

The time dependent density functional theory (TDDFT) and TDDFT/similarity transformed EOM domain-based local pair natural orbital CCSD (STEOM-DLPNO-CCSD) calculations were explored to estimate their validity in predicting the excited-state properties of multi-resonant thermally activated delayed fluorescence (MR-TADF) materials. Obviously, it was demonstrated that TDDFT calculation is inadequate to provide the quantitative prediction of the lowest singlet excited-state (S1), the lowest triplet excited-state (T1), and ΔEST. On the other hand, TDDFT/STEOM-DNLPNO-CCSD calculation reveals the superior prediction of S1, T1, and ΔEST that are in quantitative agreement with experiments. More importantly, it was found that TD-LC-⎤ * HPBE/STEOM-DLPNO-CCSD calculation provides the most accurate prediction of S1, T1, and ΔEST. Accordingly, we suggest that TD-LC-⎤ * HPBE/STEOM-DLPNO-CCSD calculation should be utilized to compute the excited-states properties of MR-TADF materials accurately.

Excited-State Engineering Enables Efficient Deep-Blue Light-Emitting Diodes Exhibiting BT.2020 Color Gamut

Organic luminescent materials that exhibit thermally activated delayed fluorescence (TADF) can convert non-emissive triplet excitons into emissive singlet states through a reverse intersystem crossing (RISC) process. Therefore, they have tremendous potential for applications in organic light-emitting diodes (OLEDs). However, with the development of ultra-high definition 4K/8K display technologies, designing efficient deep-blue TADF materials to achieve the Commission Internationale de l'Éclairage (CIE) coordinates fulfilling BT.2020 remains a significant challenge. Here, an effective approach is proposed to design deep-blue TADF molecules based on hybrid long- and short-range charge-transfer by incorporation of multiple donor moieties into organoboron multiple resonance acceptors. The resulting TADF molecule exhibits deep-blue emission at 414 nm with a full width at half maximum (FWHM) of 29 nm, together with a thousand-fold increase in RISC rate. OLEDs based on the champion material achieve a record maximum external quantum efficiency (EQE) of 22.8% with CIE coordinates of (0.163, 0.046), approaching the coordinates of the BT.2020 blue standard. Moreover, TADF-assisted fluorescence devices employing the designed material as a sensitizer exhibit an exceptional EQE of 33.1%. This work thus provides a blueprint for future development of efficient deep-blue TADF emitters, representing an important milestone towards meeting the blue color gamut standard of BT.2020.

A molecular descriptor of a shallow potential energy surface for the ground state to achieve narrowband thermally activated delayed fluorescence emission

Narrowband thermally activated delayed fluorescence (TADF) molecules have extensive applications in optoelectronics, biomedicine, and energy. The full-width at half-maximum (FWHM) holds significant importance in assessing the luminescence efficiency and color purity of TADF molecules. The goal is to achieve efficient and stable TADF emissions by regulating and optimizing the FWHM. However, a bridge from the basic physical parameters (such as geometric structure and reorganization energy) to the macroscopic properties (delayed fluorescence, efficiency, and color purity) is needed and it is highly necessary and urgent to explore the internal mechanisms that influence FWHM. Herein, first-principles calculations coupled with the thermal vibration correlation function (TVCF) theory were performed to study the energy consumption processes of the excited states for the three TADF molecules (2,3-POA, 2,3-DPA, and 2,3-CZ) with different donors; inner physical parameters affecting the FWHM were detected. By analyzing the basic geometric and electronic structures as well as the transition properties and reorganization energies, three main findings in modulating FWHM were obtained, namely a large local excitation (LE) proportion in the first singlet excited state is advantageous in reducing FWHM, a donor group with weak electron-donating ability is beneficial for achieving narrowband emission, and small reorganization energies for the ground state are favorable for reducing FWHM. Thus, wise molecular design strategies to achieve efficient narrowband TADF emission are theoretically proven and proposed. We hope that these results will promote an in-depth understanding of FWHM and accelerate the development of high color purity TADF emitters.

Organoboron-based multiple-resonance emitters: synthesis, structure-property correlations, and prospects

Boron-based multiple-resonance (MR) emitters exhibit the advantages of narrowband emission, high absolute photoluminescence quantum yield, thermally activated delayed fluorescence (TADF), and sufficient stability during the operation of organic light-emitting diodes (OLEDs). Thus, such MR emitters have been widely applied as blue emitters in triplet-triplet-annihilation-driven fluorescent devices used in smartphones and televisions. Moreover, they hold great promise as TADF or terminal emitters in TADF-assisted fluorescence or phosphor-sensitised fluorescent OLEDs. Herein we comprehensively review organoboron-based MR emitters based on their synthetic strategies, clarify structure-photophysical property correlations, and provide design guidelines and future development prospects.

Indolo[3,2-b]indole-based multi-resonance emitters for efficient narrowband pure-green organic light-emitting diodes

Organic light-emitting diodes (OLEDs) utilizing multi-resonance (MR) emitters show great potential in ultrahigh-definition display benefitting from superior merits of MR emitters such as high color purity and photoluminescence quantum yields. However, the scarcity of narrowband pure-green MR emitters with novel backbones and facile synthesis has limited their further development. Herein, two novel pure-green MR emitters (IDIDBN and tBuIDIDBN) are demonstrated via replacing the carbazole subunits in the bluish-green BCzBN skeleton with new polycyclic aromatic hydrocarbon (PAH) units, 5-phenyl-5,10-dihydroindolo[3,2-b]indole (IDID) and 5-(4-(tert-butyl)phenyl)-5,10-dihydroindolo[3,2-b]indole (tBuIDID), to simultaneously enlarge the π-conjugation and enhance the electron-donating strength. Consequently, a successful red shift from aquamarine to pure-green is realized for IDIDBN and tBuIDIDBN with photoluminescence maxima peaking at 529 and 532 nm, along with Commission Internationale de l'Eclairage (CIE) coordinates of (0.25, 0.71) and (0.28, 0.70). Furthermore, both emitters revealed narrowband emission with small full width at half-maximum (FWHM) below 28 nm. Notably, the narrowband pure-green emission was effectively preserved in corresponding devices, which afford elevated maximum external quantum efficiencies of 16.3% and 18.3% for IDIDBN and tBuIDIDBN.

Tailored Design of π-Extended Multi-Resonance Organoboron using Indolo[3,2-b]Indole as a Multi-Nitrogen Bridge

Extending the π-skeletons of multi-resonance (MR) organoboron emitters can feasibly modulate their optoelectronic properties. Here, we first adopt the indolo[3,2-b]indole (32bID) segment as a multi-nitrogen bridge and develop a high-efficiency π-extended narrowband green emitter. This moiety establishes not only a high-yield one-shot multiple Bora-Friedel-Crafts reaction towards a π-extended MR skeleton, but a compact N-ethylene-N motif for a red-shifted narrowband emission. An emission peak at 524 nm, a small full width at half maximum of 25 nm and a high photoluminescence quantum yield of 96 % are concurrently obtained in dilute toluene. The extended molecular plane also results in a large horizontal emitting dipole orientation ratio of 87 %. A maximum external quantum efficiency (EQE) of 36.6 % and a maximum power efficiency of 135.2 lm/W are thereafter recorded for the corresponding device, also allowing a low efficiency roll-off with EQEs of 34.5 % and 28.1 % at luminance of 1,000 cd/m2 and 10,000 cd/m2 , respectively.

Narrowband Fluorescent Emitters Based on BN-Doped Polycyclic Aromatic Hydrocarbons for Efficient and Stable Organic Light-Emitting Diodes

Organic light-emitting diodes (OLEDs) using conventional fluorescent emitters are currently attracting considerable interests due to outstanding stability and abundant raw materials. To construct high-performance narrowband fluorophores to satisfy requirements of ultra-high-definition displays, a strategy fusing multi-resonance BN-doped moieties to naphthalene is proposed to construct two novel narrowband fluorophores. Green Na-sBN and red Na-dBN, manifest narrow full-width at half-maxima of 31 nm, near-unity photoluminescence quantum yields and molecular horizontal dipole ratios above 90 %. Their OLEDs exhibit the state-of-the-art performances including high external quantum efficiencies (EQE), ultra-low efficiency roll-off and long operational lifetimes. The Na-sBN-based device achieves EQE as high as 28.8 % and remains 19.8 % even at luminance of 100,000 cd m-2 , and Na-dBN-based device acquires a record-high EQE of 25.2 % among all red OLEDs using pure fluorescent emitters.

B-N/B-O Contained Heterocycles as Fusion Locker in Multi-Resonance Frameworks towards Highly-efficient and Stable Ultra-Narrowband Emission

Fusing condensed aromatics into multi-resonance (MR) frameworks has been an exquisite strategy to modulate the optoelectronic properties, which, however, always sacrifices the small full width at half maxima (FWHM). Herein, we strategically embed B-N/B-O contained heterocycles as fusion locker into classical MR prototypes, which could enlarge the π-extension and alleviate the steric repulsion for an enhanced planar skeleton to suppress the high-frequency stretching/ scissoring vibrations for ultra-narrowband emissions. Sky-blue emitters with extremely small FWHMs of 17-18 nm are thereafter obtained for the targeted emitters, decreased by (1.4-1.9)-fold compared with the prototypes. Benefiting from their high photoluminescence quantum yields of >90 % and fast radiative decay rates of >108  s-1 , one of those emitters shows a high maximum external quantum efficiency of 31.9 % in sensitized devices, which remains 25.8 % at a practical luminance of 1,000 cd m-2 with a small FWHM of merely 19 nm. Notably a long operation half-lifetime of 1,278 h is also recorded for the same device, representing one of the longest lifetimes among sky-blue devices based on MR emitters.

Narrowband Organic Afterglow via Phosphorescence Förster Resonance Energy Transfer for Multifunctional Applications

Achieving multicolor organic afterglow materials with narrowband emission and high color purity is important in various optoelectronic fields but remains a great challenge. Here, an efficient strategy is presented to obtain narrowband organic afterglow materials via Förster resonance energy transfer from long-lived phosphorescence donors to narrowband fluorescence acceptors in a polyvinyl alcohol matrix. The resulting materials exhibit narrowband emission with a full width at half maximum (FWHM) as small as 23 nm and the longest lifetime of 721.22 ms. Meanwhile, by pairing the appropriate donors and acceptors, multicolor and high color purity afterglow ranging from green to red with the maximum photoluminescence quantum yield of 67.1% are achieved. Moreover, given their long luminescence lifetime, high color purity, and flexibility, the potential applications are demonstrated in high-resolution afterglow displays and dynamic and quick information identification in low-light conditions. This work provides a facile approach for developing multicolor and narrowband afterglow materials as well as expands the features of organic afterglow.

Precise modulation of multiple resonance emitters toward efficient electroluminescence with pure-red gamut for high-definition displays

Multiple resonance (MR) compounds have garnered substantial attention for their prospective utility in wide color gamut displays. Nevertheless, developing red MR emitters with both high efficiency and saturated emission color remains demanding. We herein introduce a comprehensive strategy for spectral tuning in the red region by simultaneously regulating the π-conjugation and electron-donating strengths of a double boron-embedded MR skeleton while preserving narrowband characteristics. The proof-of-concept materials manifested emissions from orange-red to deep red, with bandwidths below 0.12 eV. The pure-red device based on CzIDBNO displayed superior color purity with CIE coordinates of (0.701, 0.298), approaching the Broadcast Television 2020 standard. In concert with high photoluminescence quantum yield and strong horizontal dipole orientation, CzIDBNO also achieved a maximum external quantum efficiency of 32.5% and a current efficiency of 20.2 cd A^-1, outstripping prior reported organic light-emitting diodes (OLEDs) with CIE_x exceeding 0.68. These findings offer a roadmap for designing high-performance emitters with exceptional color purity for future OLED material research advancements.

Energy-Efficient Stable Hyperfluorescence Organic Light-Emitting Diodes with Improved Color Purities and Ultrahigh Power Efficiencies Based on Low-Polar Sensitizing Systems

Multi-resonance (MR) molecules with thermally activated delayed fluorescence (TADF) are emerging as promising candidates for high-definition displays because of their narrow emission spectra. However, the electroluminescence (EL) efficiencies and spectra of MR-TADF molecules are highly sensitive to hosts and sensitizers when applied to organic light-emitting diodes (OLEDs), and the highly polar environments in devices often lead to significantly broadened EL spectra. In this study, a proof-of-concept TADF sensitizer (BTDMAC-XT) with low polarity, high steric hindrance, and concentration-quenching free feature is constructed, which acts as a good emitter in doped and non-doped OLEDs with high external quantum efficiencies (η_ext s) of 26.7% and 29.3%, respectively. By combining BTDMAC-XT with conventional low-polarity hosts, low-polarity sensitizing systems with a small carrier injection barrier and full exciton utilization are constructed for the MR-TADF molecule BN2. Hyperfluorescence (HF) OLEDs employing the low-polar sensitizing systems successfully improve the color quality of BN2 and afford an excellent η_ext of 34.4%, a record-high power efficiency of 166.3 lm W^-1 and a long operational lifetime (LT₅₀  = 40309 h) at an initial luminance of 100 cd m^-2 . These results provide instructive guidance for the sensitizer design and device optimization for energy-efficient and stable HF-OLEDs with high-quality light.

Realizing efficient blue and deep-blue delayed fluorescence materials with record-beating electroluminescence efficiencies of 43.4

As promising luminescent materials for organic light-emitting diodes (OLEDs), thermally activated delayed fluorescence materials are booming vigorously in recent years, but robust blue ones still remain challenging. Herein, we report three highly efficient blue and deep-blue delayed fluorescence materials comprised of a weak electron acceptor chromeno[3,2-c]carbazol-8(5H)-one with a rigid polycyclic structure and a weak electron donor spiro[acridine-9,9'-xanthene]. They hold distinguished merits of excellent photoluminescence quantum yields (99%), ultrahigh horizontal transition dipole ratios (93.6%), and fast radiative transition and reverse intersystem crossing, which furnish superb blue and deep-blue electroluminescence with Commission Internationale de I'Eclairage coordinates (CIE_x,y) of (0.14, 0.18) and (0.14, 0.15) and record-beating external quantum efficiencies (η_exts) of 43.4% and 41.3%, respectively. Their efficiency roll-offs are successfully reduced by suppressing triplet-triplet and singlet-singlet annihilations. Moreover, high-performance deep-blue and green hyperfluorescence OLEDs are achieved by utilizing these materials as sensitizers for multi-resonance delayed fluorescence dopants, providing state-of-the-art η_exts of 32.5% (CIE_x,y = 0.14, 0.10) and 37.6% (CIE_x,y = 0.32, 0.64), respectively, as well as greatly advanced operational lifetimes. These splendid results can surely inspire the development of blue and deep-blue luminescent materials and devices.

Solution-Processed Pure Red TADF Organic Light-Emitting Diodes With High External Quantum Efficiency and Saturated Red Emission Color

In spite of recent research progress in red thermally activated delayed fluorescence (TADF) emitters, highly efficient solution-processable pure red TADF emitters are rarely reported. Most of the red TADF emitters reported to date are designed using a rigid acceptor unit which renders them insoluble and unsuitable for solution-processed organic light-emitting diodes (OLEDs). To resolve this issue, a novel TADF emitter, 6,7-bis(4-(bis(4-(tert-butyl)phenyl)amino)phenyl)-2,3-bis(4-(tert-butyl)phenyl)quinoxaline-5,8-dicarbonitrile (tBuTPA-CNQx) is designed and synthesized. The highly twisted donor-acceptor architecture and appropriate highest occupied molecular orbital/lowest unoccupied molecular orbital distribution lead to a very small singlet-triplet energy gap of 0.07 eV, high photoluminescence quantum yield of 92%, and short delayed fluorescence lifetime of 52.4 µs. The peripheral t-butyl phenyl decorated quinoxaline acceptor unit and t-butyl protected triphenylamine donor unit are proven to be useful building blocks to improve solubility and minimize the intermolecular interaction. The solution-processed OLED based on tBuTPA-CNQx achieves a high external quantum efficiency (EQE) of 16.7% with a pure red emission peak at 662 nm, which is one of the highest EQE values reported till date in the solution-processed pure red TADF OLEDs. Additionally, vacuum-processable OLED based on tBuTPA-CNQx exhibits a high EQE of 22.2% and negligible efficiency roll-off.

Intramolecular Cyclization: A Convenient Strategy to Realize Efficient BT.2020 Blue Multi-Resonance Emitter for Organic Light-Emitting Diodes

Rationally tuning the emission position and narrowing the full width at half-maximum (FWHM) of an emitter is of great importance for many applications. By synergistically improving rigidity, strengthening the resonant strength, inhibiting molecular bending and rocking, and destabilizing the HOMO energy level, a deep-blue emitter (CZ2CO) with a peak wavelength of 440 nm and an ultranarrow spectral FWHM of 16 nm (0.10 eV) was developed via intramolecular cyclization in a carbonyl/N resonant core (QAO). The dominant υ_0-0 transition character of CZ2CO gives a Commission Internationale de I'Éclairage coordinates (CIE) of (0.144, 0.042), nicely complying with the BT.2020 standard. Moreover, a hyper-fluorescent device based on CZ2CO shows a high maximum external quantum efficiency (EQE_max ) of 25.6 % and maintains an EQE of 22.4 % at a practical brightness of 1000 cd m^-2 .

Solution-Processable Pure-Red Multiple Resonance-induced Thermally Activated Delayed Fluorescence Emitter for Organic Light-Emitting Diode with External Quantum Efficiency over 20

Developing solution-processable red organic light-emitting diodes (OLEDs) with high color purity and efficiency based on multiple resonance thermally activated delayed fluorescence (MR-TADF) is a formidable challenge. Herein, by introducing auxiliary electron donor and acceptor moieties into the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) distributed positions of multiple resonance skeleton simultaneously, an effective strategy to obtain red MR-TADF emitters was represented. The proof-of-the-concept molecule BN-R exhibits a narrowband pure-red emission at 624 nm, with a high luminous efficiency of 94 % and a narrow bandwidth of 46 nm. Notably, the fabricated solution-processable pure-red OLED based on BN-R exhibits a state-of-the-art external quantum efficiency over 20 % with the Commission Internationale de I'Éclairage coordinates of (0.663, 0.337) and a long operational lifetime (LT₅₀ ) of 1088 hours at an initial luminance of 1000 cd m^-2 .

Carbonyl-Containing Thermally Activated Delayed Fluorescence Emitters for Narrow-Band Electroluminescence

Carbonyl-containing derivatives show enduring vitality in the field of thermally activated delayed fluorescence (TADF) materials; they can realize high device efficiency by using both singlet and triplet excitons for electroluminescence. Recently, a system based on fused ketone/amine exhibited huge potential for constructing multi-resonance TADF (MR-TADF) emitters, which exhibit higher narrow-band emission than conventional TADF emitters with twisted donor-acceptor (D-A) structure. Herein, we summarize current research progress in both traditional and MR-type ketone derivatives with TADF characteristics for introducing the molecular design strategy of maintaining high device efficiency while keeping narrow-band emission profile. We hope this review can inspire the emergence of more high-performance narrow-band materials.

Gold(I) Multi-Resonance Thermally Activated Delayed Fluorescent Emitters for Highly Efficient Ultrapure-Green Organic Light-Emitting Diodes

Acceleration of singlet-triplet intersystem crossings (ISC) is instrumental in bolstering triplet exciton harvesting of multi-resonance thermally activated delayed fluorescent (MR-TADF) emitters. This work describes a simple gold(I) coordination strategy to enhance the spin-orbit coupling of green and blue BN(O)-based MR-TADF emitters, which results in a notable increase in rate constants of the spectroscopically observed ISC process to 3×10⁹  s^-1 with nearly unitary ISC quantum yields. Accordingly, the resultant thermally-stable Au^I emitters attained large values of delayed fluorescence radiative rate constant up to 1.3×10⁵ /1.7×10⁵  s^-1 in THF/PMMA film while preserving narrowband emissions (FWHM=30-37 nm) and high emission quantum yields (ca. 0.9). The vapor-deposited ultrapure-green OLEDs fabricated with these Au^I emitters delivered high luminance of up to 2.53×10⁵  cd m^-2 as well as external quantum efficiencies of up to 30.3 % with roll-offs as low as 0.8 % and long device lifetimes (LT₆₀ ) of 1210 h at 1000 cd m^-2 .

Highly Efficient Green and Red Narrowband Emissive Organic Light-Emitting Diodes Employing Multi-Resonant Thermally Activated Delayed Fluorescence Emitters

Herein, we demonstrate how judicious selection of the donor decorating a central multi-resonant thermally activated delayed fluorescence (MR-TADF) core based on DiKTa can lead to very high-performance OLEDs. By decorating the DiKTa core with triphenylamine (TPA) and diphenylamine (DPA), 3TPA-DiKTa and 3DPA-DiKTa exhibit bright, narrowband green and red emission in doped films, respectively. The OLEDs based on these emitters showed record-high performance for this family of emitters with maximum external quantum efficiencies (EQEmax ) of 30.8 % for 3TPA-DiKTa at λEL of 551 nm and 16.7 % for 3DPA-DiKTa at λEL =613 nm. The efficiency roll-off in the OLEDs was improved significantly by using 4CzIPN as an assistant dopant in hyperfluorescence (HF) devices. The outstanding device performance has been attributed to preferential horizontal orientation of the transition dipole moments of 3TPA-DiKTa and 3DPA-DiKTa.

Constructing high-efficiency orange-red thermally activated delayed fluorescence emitters by three-dimension molecular engineering

Preparing high-efficiency solution-processable orange-red thermally activated delayed fluorescence (TADF) emitters remains challenging. Herein, we design a series of emitters consisting of trinaphtho[3,3,3]propellane (TNP) core derivatized with different TADF units. Benefiting from the unique hexagonal stacking architecture of TNPs, TADF units are thus kept in the cavities between two TNPs, which decrease concentration quenching and annihilation of long-lived triplet excitons. According to the molecular engineering of TADF and host units, the excited states can further be regulated to effectively enhance spin-orbit coupling (SOC) processes. We observe a high-efficiency orange-red emission at 604 nm in one instance with high SOC value of 0.862 cm^-1 and high photoluminescence quantum yield of 70.9%. Solution-processable organic light-emitting diodes exhibit a maximum external quantum efficiency of 24.74%. This study provides a universal strategy for designing high-performance TADF emitters through molecular packing and excited state regulation.

Selenium-Doped Polycyclic Aromatic Hydrocarbon Multiresonance Emitters with Fast Reverse Intersystem Crossing for Narrowband Blue Emission

Two kinds of boron- (B), selenium- (Se), and nitrogen-doped (N) polycyclic aromatic hydrocarbon (PAH) emitters (Cz-BSeN and DCz-BSeN) with a multiresonance effect are developed for narrowband blue emission by embedding boron as an electron-deficient atom and selenium and nitrogen as electron-donating atoms into a benzo[a]naphtho[1,2,3-hi]aceanthrylene skeleton. It is found that both emitters exhibit strong spin-orbit coupling and fast reverse intersystem crossing (rate constant of 7.5-8.8 × 106 s-1) due to the heavy-atom effect of selenium, which is 2 orders of magnitude faster than its B, N-doped PAH analogue. Meanwhile, compared to parent B, Se, N-doped PAH emitter Cz-BSeN, incorporating carbazole moieties on the para position of the boron atom in DCz-BSeN not only blueshifts the emission by 7 nm without broadening its spectra but also results in an enhanced photoluminescent quantum efficiency of 93% in the doped film. The organic light-emitting diode (OLED) employing DCz-BSeN as emitter revealed narrowband blue emission at 481 nm with a small full-width at half-maximum (fwhm) of 32 nm, as well as a maximum external quantum efficiency of 22.3%, accompanied by alleviated efficiency roll-off compared to its B, N-containing counterpart.

A Chiral Dual-Core Organoboron Structure Realizes Dual-Channel Enhanced Ultrapure Blue Emission and Highly Efficient Circularly Polarized Electroluminescence

The realization of luminescent materials with narrowband and circularly polarized luminescence (CPL) is of great significance for the development of future optical and photonic devices. Herein, through a steric-hindrance-assisted dual-core strategy, two pairs of chiral dual-core multiple resonance thermally activated delayed fluorescence (MR-TADF) materials (R/S-DOBN and R/S-DOBNT) are directly constructed by the bonding of two organoboron MR-TADF monocores (SOBN and SOBNT) with carbazole/3,6-di-tert-butyl-9H-carbazole and phenol derivative as donors, realizing obvious CPL and narrowband emissions. Furthermore, the dual-core effect in the prepared R/S-DOBN and R/S-DOBNT increases the transition oscillator strength two times more than that of a monocore structure, while maintaining the ultrapure blue emissions peaking at 453 and 459 nm with a narrower full-width at half-maximum of 21 nm through reorganization energy reduction. The circularly polarized organic light-emitting diodes based on the enantiomers exhibit ultrapure blue emission with Commission Internationale de L'Eclairage (CIE) coordinates of (0.14, 0.10) and (0.13, 0.12), high maximum external quantum efficiencies of 23.9% and 25.6%, and obvious circularly polarized electroluminescence with dissymmetry factors (|g_EL |) ≈ 10^-3 .

The COMPAS Project: A Computational Database of Polycyclic Aromatic Systems. Phase 1: cata-Condensed Polybenzenoid Hydrocarbons

Chemical databases are an essential tool for data-driven investigation of structure-property relationships and for the design of novel functional compounds. We introduce the first phase of the COMPAS Project─a COMputational database of Polycyclic Aromatic Systems. In this phase, we developed two data sets containing the optimized ground-state structures and a selection of molecular properties of ∼34k and ∼9k cata-condensed polybenzenoid hydrocarbons (at the GFN2-xTB and B3LYP-D3BJ/def2-SVP levels, respectively) and placed them in the public domain. Herein, we describe the process of the data set generation, detail the information available within the data sets, and show the fundamental features of the generated data. We analyze the correlation between the two types of computations as well as the structure-property relationships of the calculated species. The data and insights gained from them can inform rational design of novel functional aromatic molecules for use in, e.g., organic electronics, and can provide a basis for additional data-driven machine- and deep-learning studies in chemistry.