Multiple Enol-Keto Isomerization and Excited-State Unidirectional Intramolecular Proton Transfer Generate Intense, Narrowband Red OLEDs.

A novel series of excited-state intramolecular proton transfer (ESIPT) emitters, namely, DPNA, DPNA-F, and DPNA-tBu, endowed with dual intramolecular hydrogen bonds, were designed and synthesized. In the condensed phase, DPNAs exhibit unmatched absorption and emission spectral features, where the minor 0-0 absorption peak becomes a major one in the emission. Detailed spectroscopic and dynamic approaches conclude fast ground-state equilibrium among enol-enol (EE), enol-keto (EK), and keto-keto (KK) isomers. The equilibrium ratio can be fine-tuned by varying the substitutions in DPNAs. Independent of isomers and excitation wavelength, ultrafast ESIPT takes place for all DPNAs, giving solely KK tautomer emission maximized at >650 nm. The spectral temporal evolution of ESIPT was resolved by a state-of-the-art technique, namely, the transient grating photoluminescence (TGPL), where the rate of EK* → KK* is measured to be (157 fs)-1 for DPNA-tBu, while a stepwise process is resolved for EE* → EK* → KK*, with a rate of EE* → EK* of (72 fs)-1. For all DPNAs, the KK tautomer emission shows a narrowband emission with high photoluminescence quantum yields (PLQY, ∼62% for DPNA in toluene) in the red, offering advantages to fabricate deep-red organic light-emitting diodes (OLED). The resulting OLEDs give high external quantum efficiency with a spectral full width at half-maximum (FWHM) as narrow as ∼40 nm centered at 666-670 nm for DPNAs, fully satisfying the BT. 2020 standard. The unique ESIPT properties and highly intense tautomer emission with a small fwhm thus establish a benchmark for reaching red narrowband organic electroluminescence.

Synergetic Modulation of Steric Hindrance and Excited State for Anti-Quenching and Fast Spin-Flip Multi-Resonance Thermally Activated Delayed Fluorophore.

Multi-resonance thermally activated delayed fluorescence (MR-TADF) materials hold great promise for advanced high-resolution organic light-emitting diode (OLED) displays. However, persistent challenges, such as severe aggregation-caused quenching (ACQ) and slow spin-flip, hinder their optimal performance. We propose a synergetic steric-hindrance and excited-state modulation strategy for MR-TADF emitters, which is demonstrated by two blue MR-TADF emitters, IDAD-BNCz and TIDAD-BNCz, bearing sterically demanding 8,8-diphenyl-8H-indolo[3,2,1-de]acridine (IDAD) and 3,6-di-tert-butyl-8,8-diphenyl-8H-indolo[3,2,1-de]acridine (TIDAD), respectively. These rigid and bulky IDAD/TIDAD moieties, with appropriate electron-donating capabilities, not only effectively mitigate ACQ, ensuring efficient luminescence across a broad range of dopant concentrations, but also induce high-lying charge-transfer excited states that facilitate triplet-to-singlet spin-flip without causing undesired emission redshift or spectral broadening. Consequently, implementation of a high doping level of IDAD-BNCz resulted in highly efficient narrowband electroluminescence, featuring a remarkable full-width at half-maximum of 34 nm and record-setting external quantum efficiencies of 34.3 % and 31.8 % at maximum and 100 cd m-2, respectively. The combined steric and electronic effects arising from the steric-hindered donor introduction offer a compelling molecular design strategy to overcome critical challenges in MR-TADF emitters.

Regional Functionalization Molecular Design Strategy: A Key to Enhancing the Efficiency of Multi-Resonance OLEDs.

Herein, we propose a regional functionalization molecular design strategy that enables independent control of distinct pivotal parameters through different molecule segments. Three novel multiple resonances thermally activated delayed fluorescence (MR-TADF) emitters A-BN, DA-BN, and A-DBN, have been successfully synthesized by integrating highly rigid and three-dimensional adamantane-containing spirofluorene units into the MR framework. These molecules form two distinctive functional parts: part 1 comprises a boron-nitrogen (BN)-MR framework with adjacent benzene and fluorene units forming a central luminescent core characterized by an exceptionally rigid planar geometry, allowing for narrow FWHM values; part 2 includes peripheral mesitylene, benzene, and adamantyl groups, creating a unique three-dimensional "umbrella-like" conformation to mitigate intermolecular interactions and suppress exciton annihilation. The resulting A-BN, DA-BN, and A-DBN exhibit remarkably narrow FWHM values ranging from 18 to 14 nm and near-unity photoluminescence quantum yields. Particularly, OLEDs based on DA-BN and A-DBN demonstrate outstanding efficiencies of 35.0 % and 34.3 %, with FWHM values as low as 22 nm and 25 nm, respectively, effectively accomplishing the integration of high color purity and high device performance.

Boosting External Quantum Efficiency to 12.0 % of an Ultraviolet OLED by Engineering the Horizontal Dipole Orientation of a Hot Exciton Emitter.

Currently, much research effort has been devoted to improving the exciton utilization efficiency and narrowing the emission spectra of ultraviolet (UV) fluorophores for organic light-emitting diode (OLED) applications, while almost no attention has been paid to optimizing their light out-coupling efficiency. Here, we developed a linear donor-acceptor-donor (D-A-D) triad, namely CDFDB, which possesses high-lying reverse intersystem crossing (hRISC) property. Thanks to its integrated narrowband UV photoluminescence (PL) (λPL: 397 nm; FWHM: 48 nm), moderate PL quantum yield (ϕPL: 72 %, Tol), good triplet hot exciton (HE) conversion capability, and large horizontal dipole ratio (Θ//: 92 %), the OLEDs based on CDFDB not only can emit UV electroluminescence with relatively good color purity (λEL: 398 nm; CIEx,y: 0.161, 0.040), but also show a record maximum external quantum efficiency (EQEmax) of 12.0 %. This study highlights the important role of horizontal dipole orientation engineering in the molecular design of HE UV-OLED fluorophores.

A Feasible Strategy for a Highly Efficient Thermally Activated Delayed Fluorescence Emitter Over 900 nm Based on Phenalenone Derivatives.

Near-infrared (NIR) organic light-emitting diodes (OLEDs) suffer from the low external electroluminescence (EL) quantum efficiency (EQE), which is a critical obstacle for potential applications. Herein, 1-oxo-1-phenalene-2,3-dicarbonitrile (OPDC) is employed as an electron-withdrawing aromatic ring, and by incorporating with triphenylamine (TPA) and biphenylphenylamine (BBPA) donors, two novel NIR emitters with thermally activated delayed fluorescence (TADF) characteristics, namely OPDC-DTPA and OPDC-DBBPA, are first developed and compared in parallel. Intense NIR emission peaks at 962 and 1003 nm are observed in their pure films, respectively. Contributed by the local excited (LE) characteristics in the triplet (T1 ) state in synergy with the charge transfer (CT) characteristics for the singlet (S1 ) state to activate TADF emission, the solution processable doped NIR OLEDs based on OPDC-DTPA and OPDC-DBBPA yield EL peaks at 834 and 906 nm, accompanied with maximum EQEs of 0.457 and 0.103 %, respectively, representing the state-of-the-art EL performances in the TADF emitter-based NIR-OLEDs in the similar EL emission regions so far. This work manifests a simple and effective strategy for the development of NIR TADF emitters with long wavelength and efficiency synchronously.

Enhanced Moisture Condensation on Hierarchical Structured Superhydrophobic-Hydrophilic Patterned Surfaces.

Patterned surfaces combining hydrophobic and hydrophilic properties show great promise in moisture condensation; however, a comprehensive understanding of the multiscale interfacial behavior and the further controlling method is still lacking. In this paper, we studied the moisture condensation on a hybrid superhydrophobic-hydrophilic surface with hierarchical structures from micro- to nanoscale. For the first time, we demonstrated the effects of wettability difference and microstructure size on the final condensation efficiency. By optimizing the wettability difference, sub-millimeter pattern width, and microstructure size, maximum 90% enhancement of the condensation rate was achieved as compared with the superhydrophobic surface at a subcooling of 13 K. We also demonstrated the enhanced condensation mechanism by a detailed analysis of the condensation process. Our work proposed effective and systematical methods for controlling and optimizing moisture condensation on the patterned surfaces and shed light on application integration of such promising functional surfaces.

Novel Polycyclic Fused Amide Derivatives: Properties and Applications for Sky-blue Electroluminescent Devices.

Aromatic imide derivatives play a critical role in boosting the electroluminescent (EL) performance of organic light-emitting diodes (OLEDs). However, the majority of aromatic imide-based materials are limited to long wavelength emission OLEDs rather than blue emissions due to their strong electron-withdrawing characteristics. Herein, two novel polycyclic fused amide units were reported as electron acceptor to be combined with either a tetramethylcarbazole or acridine donor via a phenyl linker to generate four conventional fluorescence blue emitters of BBI-4MeCz, BBI-DMAC, BSQ-4MeCz and BSQ-DMAC for the first time. BSQ-4MeCz and BSQ-DMAC based on a BSQ unit exhibited higher thermal stability and photoluminescence quantum yields than BBI-4MeCz and BBI-DMAC based on a BBI unit due to their more planar acceptor structure. The intermolecular interactions that exist in the BSQ series materials effectively inhibit the molecular rotation and configuration relaxation, and thus allow for blue-shifted emissions. Blue OLED devices were constructed with the developed materials as emitters, and the effects of both the structure of the polycyclic fused amide acceptor and the electron donor on the EL performance were clarified. Consequently, a sky-blue OLED device based on BSQ-DMAC was created, with a high maximum external quantum efficiency of 4.94% and a maximum luminance of 7761 cd m-2.

Single-cell RNA-sequencing reveals the existence of naive and primed pluripotency in pre-implantation rhesus monkey embryos.

Naive pluripotency exists in epiblast cells of mouse pre-implantation embryos. However, whether the naive pluripotency is transient or nonexistent in primate embryos remains unclear. Using RNA-seq in single blastomeres from 16-cell embryos through to hatched blastocysts of rhesus monkey, we constructed the lineage segregation roadmap in which the specification of trophectoderm, epiblast, and primitive endoderm is initiated simultaneously at the early blastocyst stage. Importantly, we uncovered the existence of distinct pluripotent states in monkey pre-implantation embryos. At the early- and middle-blastocyst stages, the epiblast cells have the transcriptome features of naive pluripotency, whereas they display a continuum of primed pluripotency characteristics at the late and hatched blastocyst stages. Moreover, we identified potential regulators that might play roles in the transition from naive to primed pluripotency. Thus, our study suggests the transient existence of naive pluripotency in primates and proposes an ideal time window for derivation of primate embryonic stem cells with naive pluripotency.

Highly Emissive Dinuclear Platinum(III) Complexes.

Dinuclear Pt(III) complexes were commonly reported to have short-lived lowest-lying triplet states, resulting in extremely weak or no photoluminescence. To overcome this obstacle, a new series of dinuclear Pt(III) complexes, named Pt2a-Pt2c, were strategically designed and synthesized using donor (D)-acceptor (A)-type oxadiazole-thiol chelates as bridging ligands. These dinuclear Pt(III) complexes possess a d7-d7 electronic configuration and exhibit intense phosphorescence under ambient conditions. Among them, Pt2a exhibits orange phosphorescence maximized at 618 nm in degassed dichloromethane solution (Φp ≈ 8.2%, τp ≈ 0.10 µs) and near-infrared (NIR) emission at 749 nm (Φp ≈ 10.1% τp ≈ 0.66 µs) in the crystalline powder and at 704 nm (Φp ≈ 33.1%, τp ≈ 0.34 µs) in the spin-coated neat film. An emission blue-shifted by more than 3343 cm-1 is observed under mechanically ground crystalline Pt2a, affirming intermolecular interactions in the solid states. Time-dependent density functional theory (TD-DFT) discloses the lowest-lying electronic transition of Pt2a-Pt2c complexes to be a bridging ligand-metal-metal charge transfer (LMMCT) transition. The long-lived triplet states of these dinuclear platinum(III) complexes may find potential use in lighting. Employing Pt2a as an emitter, high-performance organic light-emitting diodes (OLEDs) were fabricated with NIR emission at 716 nm (η = 5.1%), red emission at 614 nm (η = 8.7%), and white-light emission (η = 11.6%) in nondoped, doped (in mCP), and hybrid (in CzACSF) devices, respectively.

Transcriptome analyses of rhesus monkey preimplantation embryos reveal a reduced capacity for DNA double-strand break repair in primate oocytes and early embryos.

Preimplantation embryogenesis encompasses several critical events including genome reprogramming, zygotic genome activation (ZGA), and cell-fate commitment. The molecular basis of these processes remains obscure in primates in which there is a high rate of embryo wastage. Thus, understanding the factors involved in genome reprogramming and ZGA might help reproductive success during this susceptible period of early development and generate induced pluripotent stem cells with greater efficiency. Moreover, explaining the molecular basis responsible for embryo wastage in primates will greatly expand our knowledge of species evolution. By using RNA-seq in single and pooled oocytes and embryos, we defined the transcriptome throughout preimplantation development in rhesus monkey. In comparison to archival human and mouse data, we found that the transcriptome dynamics of monkey oocytes and embryos were very similar to those of human but very different from those of mouse. We identified several classes of maternal and zygotic genes, whose expression peaks were highly correlated with the time frames of genome reprogramming, ZGA, and cell-fate commitment, respectively. Importantly, comparison of the ZGA-related network modules among the three species revealed less robust surveillance of genomic instability in primate oocytes and embryos than in rodents, particularly in the pathways of DNA damage signaling and homology-directed DNA double-strand break repair. This study highlights the utility of monkey models to better understand the molecular basis for genome reprogramming, ZGA, and genomic stability surveillance in human early embryogenesis and may provide insights for improved homologous recombination-mediated gene editing in monkey.

Systemic In Silico Screening in Drug Discovery for Coronavirus Disease (COVID-19) with an Online Interactive Web Server.

The emergence of the new coronavirus (nCoV-19) has impacted human health on a global scale, while the interaction between the virus and the host is the foundation of the disease. The viral genome codes a cluster of proteins, each with a unique function in the event of host invasion or viral development. Under the current adverse situation, we employ virtual screening tools in searching for drugs and natural products which have been already deposited in DrugBank in an attempt to accelerate the drug discovery process. This study provides an initial evaluation of current drug candidates from various reports using our systemic in silico drug screening based on structures of viral proteins and human ACE2 receptor. Additionally, we have built an interactive online platform (https://shennongproject.ai/) for browsing these results with the visual display of a small molecule docked on its potential target protein, without installing any specialized structural software. With continuous maintenance and incorporation of data from laboratory work, it may serve not only as the assessment tool for the new drug discovery but also an educational web site for the public.

Dissecting yield-associated loci in super hybrid rice by resequencing recombinant inbred lines and improving parental genome sequences.

The growing world population and shrinkage of arable land demand yield improvement of rice, one of the most important staple crops. To elucidate the genetic basis of yield and uncover its associated loci in rice, we resequenced the core recombinant inbred lines of Liang-You-Pei-Jiu, the widely cultivated super hybrid rice, and constructed a high-resolution linkage map. We detected 43 yield-associated quantitative trait loci, of which 20 are unique. Based on the high-density physical map, the genome sequences of paternal variety 93-11 and maternal cultivar PA64s of Liang-You-Pei-Jiu were significantly improved. The large recombinant inbred line population combined with plentiful high-quality single nucleotide polymorphisms and insertions/deletions between parental genomes allowed us to fine-map two quantitative trait loci, qSN8 and qSPB1, and to identify days to heading8 and lax panicle1 as candidate genes, respectively. The quantitative trait locus qSN8 was further confirmed to be days to heading8 by a complementation test. Our study provided an ideal platform for molecular breeding by targeting and dissecting yield-associated loci in rice.

Translation and validation of the simplified Chinese new Knee Society Scoring System.

BACKGROUND: The NKSS has recently been translated into Dutch version. The reliability and validity were also assessed. However, there is no Simplified Chinese version of New Society Knee Scoring System (SC-NKSS) for Chinese population. METHODS: The SC-NKSS was translated from the original English version following international guidelines. All patients undergoing total knee arthroplasty (TKA) between September 2012 and September 2013 were invited to participate in this study. Finally, a total of 105 did so. Patients (preoperative and postoperative) completed the Chinese version of NKSS, Oxford Knee Score (OKS), the Medical Outcomes General Health Survey (SF-36) and Visual analog scale (VAS). Psychometric testing of reliability, construct validity, content validity were conducted. RESULTS: All the 105 participants completed the questionnaires and no floor or ceiling effects were checked. Internal consistency was excellent with Cronbach's alpha coefficient ranging from 0.71 to 0.85. Test-retest reliability was satisfactory with an intraclass correlation coefficient of 0.92 (95%confidence interval, 0.86-0.95). Construct validity was demonstrated to correlate well with the Chinese version of OKS (r = -0.78; p < 0.01), VAS (r = -0.70; p < 0.01), Physical Function (PF) (r = 0.74; p < 0.01), Body Pain (BP) (r = 0.63; p < 0.01) and General Health (GH) (r = 0.51; p < 0.01) of SF-36 domains. CONCLUSION: The SC-NKSS was well accepted and demonstrated acceptable psychometric properties in mainland China.

Development of a valid simplified Chinese version of the Oxford Hip Score in patients with hip osteoarthritis.

BACKGROUND: Although the Oxford Hip Score has been translated and validated in several languages, there is currently no Chinese version of the outcomes measurement. Our study aims to crossculturally adapt and validate the Oxford Hip Score into a simplified Chinese version. QUESTIONS/PURPOSES: We tested the (1) reliability; (2) validity; and (3) responsiveness of the Chinese version of the Oxford Hip Score. METHODS: First we translated the Oxford Hip Score into simplified Chinese, then back into English, then held a consensus meeting to achieve the final simplified Chinese version. Then we evaluated the psychometric properties of Chinese version of the Oxford Hip Score in patients undergoing total hip arthroplasty (THA). All patients undergoing THA between July and December 2012 were invited to participate in this study; a total of 108 (79% of 136 invited) did so. To assess the test-retest validity, all participants completed the Chinese version of the Oxford Hip Score again with a 2-week interval. Pearson correlation coefficient was used to evaluate the construct validity between the Chinese version of the Oxford Hip Score and visual analog scale (VAS), Harris hip score, and eight individual domains of the SF-36. Responsiveness was demonstrated by comparing the pre- and postoperative scores of the Chinese version of the Oxford Hip Score. RESULTS: The test-retest reliability with intraclass correlation coefficient (0.937) and internal consistency with Cronbach's alpha (0.91) were excellent. The Chinese version of the Oxford Hip Score correlated with the Harris hip score (0.89, p < 0.01), VAS (-0.79, p < 0.01), and Physical Functioning (0.79, p < 0.01) and Bodily Pain (0.70, p < 0.01) domains of SF-36, which suggested construct validity. No floor or ceiling effects were found. The effect size and standardized response mean values were 3.52 and 3.31, respectively, indicating good responsiveness. CONCLUSIONS: The Chinese version of the Oxford Hip Score showed good reliability, validity, and responsiveness in evaluating standard Chinese-speaking patients with hip osteoarthritis undergoing THA. It can be used by clinical surgeons as a complement to the traditional outcome measures.

Highly Horizontal Oriented Tricomponent Exciplex Host with Multiple Reverse Intersystem Crossing Channels for High-Performance Narrowband Electroluminescence and Eye-Protection White Organic Light-Emitting Diodes.

Despite multiple-resonance thermally activated delayed fluorescence (MR-TADF) emitters with small full-width at half maximum are attractive for wide color-gamut display and eye-protection lighting applications, their inefficient reverse intersystem crossing (RISC) process and long exciton lifetime induce serious efficiency roll-off, which significantly limits their development. Herein, a novel device concept of building highly efficient tricomponent exciplex with multiple RISC channels is proposed to realize reduced exciton quenching and enhanced upconversion of nonradiative triplet excitons, and subsequently used as a host for high-performance MR-TADF organic light-emitting diodes (OLEDs). Compared with traditional binary exciplex, the tricomponent exciplex exhibits obviously improved photoluminescence quantum yield, emitting dipole orientation and RISC rate constant, and a record-breaking external quantum efficiency (EQE) of 30.4% is achieved for tricomponent exciplex p-PhBCzPh: PO-T2T: DspiroAc-TRZ (50: 20: 30) based OLED. Remarkably, maximum EQEs of 36.2% and 40.3% and ultralow efficiency roll-off with EQEs of 26.1% and 30.0% at 1000 cd m-2 are respectively achieved for its sky-blue and pure-green MR-TADF doped OLEDs. Additionally, the blue emission unit hosted by tricomponent exciplex is combined with an orange-red TADF emission unit to achieve a double-emission-layer blue-hazard-free warm white OLED with an EQEmax of 30.3% and stable electroluminescence spectra over a wide brightness range.

Early failure of the Durom prosthesis in metal-on-metal hip resurfacing in Chinese patients.

Hip resurfacing (HR) is being used increasingly as an alterative to total hip arthroplasty in osteonecrosis (ON) and ankylosing spondylitis (AS) of the hip. We performed 141 consecutive HR arthroplasties in 111 patients comprising 3 etiology groups: ON, AS, and osteoarthritis (OA). After retrospective study of retrieved components, we hypothesized that the main reason for revision was femoral loosening in the ON group (4 of 46 hips; 8.7%) and femoral-neck fracture in the AS group (3 of 58 hips; 5.2%). Necrotic areas were seen on femoral heads retrieved from patients with femoral loosening, whereas femoral heads were fixed tightly to components in patients with femoral-neck fractures. Etiology may be an important risk factor for postoperative complications.

Azaacene containing iridium(III) phosphors: elaboration of the π-conjugation effect and application in highly efficient solution-processed near-infrared OLEDs.

Azaacenes have attracted wide research interest due to their tremendous potential in organic electronics. However, near-infrared (NIR) light-emitting iridium(III) phosphors bearing azaacene derivatives are rarely investigated. In this contribution, two solution-processable heteroleptic iridium(III) complexes, namely DBPzIr and PPzIr, are rationally designed and synthesized, and they contain a rigid phenanthrene- or pyrene-fused diazaacene core and two peripheral groups of 4-tert-butyl-phenyl attached at the 12,13-positions in the core, respectively. The effects of the diazaacene core and appending groups on the optoelectronic properties of both complexes are systematically investigated. A dramatically red-shifted NIR emission peak at 789 nm with a photoluminescence quantum yield (PLQY) of 14% is observed in PPzIr compared with the 746 nm emission with a PLQY of 40% in DBPzIr. Taking advantage of their photophysical properties, the solution-processed device doped with DBPzIr achieves a maximum external quantum efficiency (EQEmax) of 8.00% with a radiance of 54 866 mW Sr-1 m-2 at 716 nm and the device doped with PPzIr exhibits a significantly red-shifted emission at 772 nm with an EQEmax of 3.53%. The achieved device performance is among the best values in the reported NIR-OLEDs based on iridium(III) complexes via a solution process at the same color gamut. Our study indicates that the reasonable collocation of the rigid diazaacene chelating core and flexible peripheral groups in the iridium(III) complex is of great significance in designing highly efficient NIR emitters.

Highly Efficient Purely Organic Phosphorescence Light-Emitting Diodes Employing a Donor-Acceptor Skeleton with a Phenoxaselenine Donor.

Purely organic room-temperature phosphorescence (RTP) materials generally exhibit low phosphorescence quantum yield (ϕP ) and long phosphorescence lifetime (τP ) due to the theoretically spin-forbidden triplet state. Herein, by introducing a donor-acceptor (D-A) skeleton with a phenoxaselenine donor, three nonaromatic amine donor containing compounds with high ϕP and short τP in amorphous films are developed. Besides the enhanced spin-orbit coupling (SOC) by the heavy-atom effect of selenium, the D-A skeleton which facilitates orbital angular momentum change can further boost SOC, and severe nonradiative energy dissipation is also suppressed by the rigid molecular structure. Consequently, a record-high external quantum efficiency of 19.5% are achieved for the RTP organic light-emitting diode (OLED) based on 2-(phenoxaselenin-3-yl)-4,6-diphenyl-1,3,5-triazine (PXSeDRZ). Moreover, voltage-dependent color-tunable emission and single-molecule white emission are also realized. These results shed light on the broad prospects of purely organic phosphorescence materials as highly efficient OLED emitters especially for potential charming lighting applications.

Macrocyclic Engineering of Thermally Activated Delayed Fluorescent Emitters for High-Efficiency Organic Light-Emitting Diodes.

Several thermally activated delayed fluorescence (TADF) materials have been studied and developed to realize high-performance organic light-emitting diodes (OLEDs). However, TADF macrocycles have not been sufficiently investigated owing to the synthetic challenges, resulting in limited exploration of their luminescent properties and the corresponding highly efficient OLEDs. In this study, a series of TADF macrocycles is synthesized using a modularly tunable strategy by introducing xanthones as acceptors and phenylamine derivatives as donors. A detailed analysis of their photophysical properties combined with fragment molecules reveals characteristics of high-performance macrocycles. The results indicate that: a) the ideal structure decreases the energy loss, which in turn reduces the non-radiative transitions; b) reasonable building blocks increase the oscillator strength providing a higher radiation transition rate; c) the horizontal dipole orientation (Θ) of the extended macrocyclic emitters is increased. Owing to the high photoluminescence quantum yields of ≈100% and 92% and excellent Θ of 80 and 79% for macrocycles MC-X and MC-XT in 5 wt% doped films, the corresponding devices exhibit record-high external quantum efficiencies of 31.6% and 26.9%, respectively, in the field of TADF macrocycles.