Highly efficient thermally activated delayed fluorescence (TADF) molecules are in urgent demand for solid‐state lighting and full‐color displays. Here, the design and synthesis of three ...triarylamine‐pyridine‐carbonitrile‐based TADF compounds, TPAPPC, TPAmPPC, and tTPAmPPC, are shown. They exhibit excellent photoluminescence quantum yields of 79−100% with small ΔEST values, fast reverse intersystem crossing (RISC), and high horizontal dipole ratios (Θ// = 86−88%) in the thin films leading to the enhancement of device light outcoupling. Consequently, a green organic light‐emitting diode (OLED) based on TPAmPPC shows a high average external quantum efficiency of 38.8 ± 0.6%, a current efficiency of 130.1 ± 2.1 cd A–1, and a power efficiency of 136.3 ± 2.2 lm W–1. The highest device efficiency of 39.8% appears to be record‐breaking among TADF‐based OLEDs to date. In addition, the TPAmPPC‐based device shows superior operation lifetime and high‐temperature resistance. It is worth noting that the TPA‐PPC‐based materials have excellent optical properties and the potential for making them strong candidates for TADF practical application.
Three 2,6‐diphenylpyridine‐3,5‐dicarbonitrile‐based compounds with excellent photoluminescent quantum yields (79–100%) and high horizontal dipole ratios (86−88%) in the thin films are demonstrated. With two methyl groups on the triarylamines, the spin−orbit coupling is enhanced due to the elevated locally excited triplet states (3LE), leading to a fast reverse intersystem crossing. Green thermally activated delayed fluorescence (TADF) organic light‐emitting diodes based on them exhibit a record‐high external quantum efficiency of 39.8% without any optical extraction technique.
Converting solar energy into hydrogen energy using conjugated polymers (CP) is a promising solution to the energy crisis. Improving water solubility plays one of the critical factors in enhancing the ...hydrogen evolution rate (HER) of CP photocatalysts. In this study, a novel concept of incorporating hydrophilic side chains to connect the backbones of CPs to improve their HER is proposed. This concept is realized through the polymerization of carbazole units bridged with octane, ethylene glycol, and penta‐(ethylene glycol) to form three new side‐chain‐braided (SCB) CPs: PCz2S‐OCt, PCz2S‐EG, and PCz2S‐PEG. Verified through transient absorption spectra, the enhanced capability of PCz2S‐PEG for ultrafast electron transfer and reduced recombination effects has been demonstrated. Small‐ and wide‐angle X‐ray scattering (SAXS/WAXS) analyses reveal that these three SCB‐CPs form cross‐linking networks with different mass fractal dimensions (f) in aqueous solution. With the lowest f value of 2.64 and improved water/polymer interfaces, PCz2S‐PEG demonstrates the best HER, reaching up to 126.9 µmol h−1 in pure water‐based photocatalytic solution. Moreover, PCz2S‐PEG exhibits comparable performance in seawater‐based photocatalytic solution under natural sunlight. In situ SAXS analysis further reveals nucleation‐dominated generation of hydrogen nanoclusters with a size of ≈1.5 nm in the HER of PCz2S‐PEG under light illumination.
Pioneer examples of side‐chain‐bridged polymer photocatalysts, of tunable hydrophilicity of the side chains are presented. These polymers are capable of generating hydrogen using natural sunlight in seawater‐based photocatalytic solution. The distinctive structural characteristics and impressive HER performance of the side‐chain‐bridged conjugated polymers suggest a potential avenue in the development of photocatalytic conjugated polymers.
Owing to the high technology maturity of thermally activated delayed fluorescence (TADF) emitter design with a specific molecular shape, extremely high-performance organic light-emitting diodes ...(OLEDs) have recently been achieved
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various doping techniques. Recently, undoped OLEDs have drawn immense attention because of their manufacturing cost reduction and procedure simplification. However, capable materials as host emitters are rare and precious because general fluorophores in high-concentration states suffer from serious aggregation-caused quenching (ACQ) and undergo exciton quenching. In this work, a series of diboron materials, CzDBA, iCzDBA, and
t
BuCzDBA, is introduced to realize the effect of steric hindrance and the molecular aspect ratio
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experimental and theoretical studies. We computed transition electric dipole moment (TEDM) and molecular dynamics (MD) simulations as a proof-of-concept model to investigate the molecular stacking in neat films. It is worth noting that the pure
t
BuCzDBA film with a high horizontal ratio of 92% is employed to achieve a nondoped OLED with an excellent external quantum efficiency of 26.9%. In addition, we demonstrated the first ultrathin emitting layer (1 nm) TADF device, which exhibited outstanding power efficiency. This molecular design and high-performance devices show the potential of power-saving and economical fabrication for advanced OLEDs.
A strategy of substituent engineering of DBA-based molecules is investigated
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experimental and theoretical methods. A 1 nm-thick emitting layer OLED has been developed.
Reliable biotransfer factor (BTF) data are critical for animal-feed studies in human risk assessment. A wide range of BTF values have been reported (0.0015-0.83 d/kg), expressed as the ratio of total ...arsenic (tAs) concentration (µg/kg) in chicken to daily intake rate (µg/d) of tAs in feed (tAs/tAs). Data on inorganic As (iAs) for chicken meat and tAs concentrations for feed were obtained from our related study. Using the linear regression technique developed in this study, we estimated the BTF as 0.016 d/kg, as iAs/tAs (R
2
> 0.7702) and 0.55 d/kg as tAs/tAs (R
2
= 0.9743) for whole chicken meat. From a mass-balance perspective, we suggest that tAs be used as the denominator for the BTF unit. To illustrate our feed-risk assessment method, we analyzed commercial feeds for tAs concentration (n = 79). Consumption data for the general population (n = 2479) were obtained from a Taiwanese total diet study. Bivariate Monte Carlo simulations (n = 10,000) showed that the 95
th
percentile (P95) of estimated daily intake (EDI) was 0.002 µg/kg body weight (bw)/d as iAs (< the benchmark dose lower limit of 3.0 µg/kg bw/d). Our results thus show that the commercial chicken feeds assessed in this study are of low health concern for the general Taiwanese population. We discuss the factors that may have affected the assessment, such as the type of animals investigated, type of feeds, feed tested, type of chemical species used for BTF estimation and statistical approach.
Tacrolimus (TAC) is the backbone of an immunosuppressive drug used in most solid organ transplant recipients. A single nucleotide polymorphism (SNP) at position 6986G>A in CYP3A5 has been notably ...involved in the pharmacokinetic variability of TAC. It is hypothesized that CYP3A5 genotyping in patients may provide a guideline for TAC therapeutic regimen. To further evaluate the impact of CYP3A5 variants in donors and recipients, ABCB1 and ACE SNPs in recipients on TAC disposition, clinical and laboratory data were retrospectively reviewed from 90 pediatric patients with liver transplantation and their corresponding donors after 1 year of transplantation. The recipients with CYP3A5 *1/*1 or *1/*3 required more time to achieve TAC therapeutic range during the induction phase, and needed more upward dose during the late induction and the maintained phases, with lower C/D ratio, compared with those with CYP3A5 *3/*3. And donor CYP3A5 genotypes were found to impact on TAC trough concentrations after liver transplantation. No association between ABCB1 or ACE genotypes and TAC disposition post-transplantation was found. These results strongly suggest that CYP3A5 genotyping both in recipient and donor, not ABCB1 or ACE is necessary for establishing a personalized TAC dosage regimen in pediatric liver transplant patients.
A complete infectious focus survey relies on a thorough physical examination as well as a pelvic examination. Tubo-ovarian abscess, though less likely to occur in senior women, may become a ...life-threatening disease requiring emergent surgery. Hence, clinical awareness and aggressive management are warranted to avoid delayed diagnosis and subsequent complications.
We report a post-menopausal woman presented with sepsis of unknown origin, which turned out to be a huge tubo-ovarian abscess. Although tubo-ovarian abscess mostly occurs in women of fertile age, it is likely that the immune status of our post-menopausal patient was compromised because of old age and uremia. Moreover, due to underlying dementia, she could not express her discomfort in the early stage. Her sepsis resolved after a unilateral salpingo-oophorectomy surgery and antibiotic treatment. It is crucial to exclude pelvic inflammatory disease (PID) if no specific source of infection can be identified.
Rupture of the tubo-ovarian abscess is a condition of high mortality rate. Although tubo-ovarian abscess is more likely to develop in patients aged 15-25 years old, the tubo-ovarian abscess should be listed as a differential diagnosis in all post-menopausal women, especially those who are immunocompromised or with a palpable pelvic mass, to enable timely management and better prognosis.
Multiple resonance thermally activated delayed fluorescence (MR-TADF) emitters hold promise for efficient organic light-emitting diodes (OLEDs) and wide gamut displays. An azepine donor is introduced ...into the boron–nitrogen system for the first time. The highly twisted conformation of a seven-ring embedded new molecule, TAzBN, increases the intermolecular distances, suppressing self-aggregation emission quenching. Meanwhile, the azepine donor is crucial to achieve a narrow singlet-triplet gap (0.03 eV) as well as boost the reverse intersystem crossing (RISC) rate to 8.50 × 10 5 s −1 . It is noteworthy that TAzBN demonstrates an impressive photoluminescence quantum yield of 94%. In addition, its nonsensitized OLED displayed a remarkable external quantum efficiency (EQE max ) with values peaking at 27.3%, and an EQE of 21.4% at 500 cd m −2 . This finding shows that when TAzBN is used at a high concentration of 10 wt%, its device maintains efficiency even at higher brightness levels, highlighting TAzBN's resistance to aggregation quenching. Furthermore, TAzBN enantiomers showed circularly polarized photoluminescence characteristics with dissymmetry factors | g PL | of up to 1.07 × 10 −3 in doped films. The curved heptagonal geometry opens an avenue to design the MR-TADF emitters with fast spin-flip and chiroptical properties.
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•Donor–acceptor systems based on conjugated microporous polymers incorporating thiazolo5,4-dthiazole linkages was designed.•The integration of electron-rich pyrene and ...electron-deficient ThTh units in Py-ThTh-CMP provided a H2 evolution rate of 1873 µmol g–1h−1.•A new approach for preparing highly efficient photocatalysts in the quest for the practical development of cost-effective H2 evolution.
In this paper, we describe efficient, inexpensive, and donor–acceptor (D–A) systems based on conjugated microporous polymers incorporating thiazolo5,4-dthiazole (ThTh) linkages for the extraction of H2 from H2O under visible light in the presence of ascorbic acid (AA) as a sacrificial electron donor without additional noble metals as co-catalyst. The integration of electron-rich pyrene (Py) and electron-deficient ThTh units in Py-ThTh-CMP resulted in a D–A system that provided an H2 evolution rate (HER) of 1874 µmol g–1h−1; this value was greater than those of the other tested CMPs prepared with and without the ThTh acceptor moiety. Notably, Py-ThTh-CMP also exceeded the HERs of many other reported materials for photocatalytic H2O reduction, including co-catalysts based on covalent organic frameworks, CMPs, and graphitic carbon nitride. The DFT and TD-DFT suggested the incorporation of ThTh moiety in the CMPs backbone to enhance the charge transfer via S1 ↔ T1 and contribute to the H2 formation. This study presents a new approach for preparing highly efficient photocatalysts for the practical development of cost-effective H2 evolution.
The strategy of acceptor modification is a powerful technique for tuning the emission color of thermally activated delayed fluorescence (TADF) emitters. In this study, we have successfully designed ...and synthesized three TADF emitters with donor–acceptor (D–A) structures using a 4-(diphenylamino)-2,6-dimethylphenyl (TPAm) donor and various pyridine-3,5-dicarbonitrile (PC) acceptor units. As a result, three compounds named TPAmbPPC, TPAm2NPC, and TPAmCPPC exhibited greenish-yellow to orange-red emissions with high photoluminescent quantum yields (76–100%) in thin films. Remarkably, a greenish-yellow device based on TPAmbPPC and TPAm2NPC showed a high maximum external quantum efficiency (EQEmax) of 39.1 and 39.0%, respectively. Furthermore, benefiting from the suitable steric hindrance between the acceptor and donor, the nondoped organic light-emitting diodes (OLEDs) based on TPAmbPPC demonstrated an exceptional EQEmax of 21.6%, indicating its promising potential as an efficient emitter for the application of OLED applications. Furthermore, orange-red OLED devices based on TPAmCPPC exhibited a high EQEmax of 26.2%, a CE of 50.1 cd A–1, and a PE of 52.4 lm W–1.
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