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1.
Nat Commun ; 15(1): 6909, 2024 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-39134527

RESUMEN

Late-stage specific and selective diversifications of peptides and proteins performed at target residues under ambient conditions are recognized to be the most facile route to various and abundant conjugates. Herein, we report an orthogonal modification of cysteine residues using alkyl thianthreium salts, which proceeds with excellent chemoselectivity and compatibility under mild conditions, introducing a diverse array of functional structures. Crucially, multifaceted bioconjugation is achieved through clickable handles to incorporate structurally diverse functional molecules. This "two steps, one pot" bioconjugation method is successfully applied to label bovine serum albumin. Therefore, our technique is a versatile and powerful tool for late-stage orthogonal bioconjugation.


Asunto(s)
Cisteína , Péptidos , Albúmina Sérica Bovina , Cisteína/química , Péptidos/química , Albúmina Sérica Bovina/química , Sales (Química)/química , Química Clic/métodos , Animales , Proteínas/química , Bovinos
2.
J Exp Bot ; 2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-39082682

RESUMEN

The optimal timing of the transition from vegetative growth to reproductive growth is critical for plant reproductive success, and the underlying regulatory mechanisms have been well studied in angiosperm model species, but relatively little in gymnosperms. DAL1, a MADS domain transcription factor (TF) gene that shows a conserved age-related expression profile in conifers, may be an age timer. However, how the DAL1 mediates the onset of reproductive growth remains poorly understood. Here, we have shown that the PtDAL1 directly regulates the PtDAL10 transcription by binding to its promoter region in vitro. PtDAL1, forms ternary complexes in vitro and in N. benthamiana with PtDAL10 and PtMADS11, two potential candidate regulators of the vegetative to reproductive transition in Chinese pine (Pinus tabuliformis). The PtDAL10 was progressively induced in new shoots with age and highly accumulated in male and female cones. Overexpression of PtDAL10 rescued the flowering of ft-10 and soc1-1-2 mutants in Arabidopsis. We provide insight into the molecular components associated with the PtDAL1, which integrates the vegetative to reproductive phase transition into age-mediated progressive development of the whole plant in conifers.

3.
Angew Chem Int Ed Engl ; : e202408712, 2024 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-38962896

RESUMEN

Noncovalent spatial interaction has become an intriguing and important tool for constructing optoelectronic molecules. In this study, we linearly attached three conjugated units in a multi π-stacked manner by using just one trident bridge based on indeno[2,1-b]fluorene. To achieve this structure, we improved the synthetic approach through double C-H activation, significantly simplifying the preparation process. Due to the proximity of the C10, C11, and C12 sites in indeno[2,1-b]fluorene, we derived two novel donor|acceptor|donor (D|A|D) type molecules, 2DMB and 2DMFB, which exhibited closely packed intramolecular stacking, enabling efficient through-space charge transfer. This molecular construction is particularly suitable for developing high-performance thermally activated delayed fluorescence materials. With donor(s) and acceptor(s) constrained and separated within this spatially rigid structure, elevated radiative transition rates, and high photoluminescence quantum yields were achieved. Organic light-emitting diodes incorporating 2DMB and 2DMFB demonstrated superior efficiency, achieving maximum external quantum efficiencies of 28.6 % and 16.2 %, respectively.

4.
Angew Chem Int Ed Engl ; 63(31): e202403066, 2024 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-38752880

RESUMEN

Pure aromatic hydrocarbon materials (PHCs) represent a new generation of host materials for phosphorescent OLEDs (PhOLEDs), free of heteroatoms. They reduce the molecular complexity, can be easily synthesized and are an important direction towards robust devices. As heteroatoms can be involved in bonds dissociations in operating OLEDs through exciton induced degradation processes, developing novel PHCs appear particularly relevant for the future of this technology. In the present work, we report a series of extended PHCs constructed by the assembly of three spirobifluorene fragments. The resulting positional isomers present a high triplet energy level, a wide HOMO/LUMO difference and improved thermal and morphological properties compared to previously reported PHCs. These characteristics are beneficial for the next generation of host materials for PhOLEDs and provide relevant design guidelines. When used as a host in blue-emitting PhOLEDs, which are still the weakest link of the field, a very high EQE of 24 % and low threshold voltage of 3.56 V were obtained with a low-efficiency roll-off. This high performance strengthens the position of PHC strategy as an efficient alternative for OLED technology and opens the way to a more simple electronic.

5.
Free Radic Biol Med ; 219: 153-162, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38657753

RESUMEN

The anemia of inflammation (AI) is characterized by the presence of inflammation and abnormal elevation of hepcidin. Accumulating evidence has proved that Rocaglamide (RocA) was involved in inflammation regulation. Nevertheless, the role of RocA in AI, especially in iron metabolism, has not been investigated, and its underlying mechanism remains elusive. Here, we demonstrated that RocA dramatically suppressed the elevation of hepcidin and ferritin in LPS-treated mice cell line RAW264.7 and peritoneal macrophages. In vivo study showed that RocA can restrain the depletion of serum iron (SI) and transferrin (Tf) saturation caused by LPS. Further investigation showed that RocA suppressed the upregulation of hepcidin mRNA and downregulation of Fpn1 protein expression in the spleen and liver of LPS-treated mice. Mechanistically, this effect was attributed to RocA's ability to inhibit the IL-6/STAT3 pathway, resulting in the suppression of hepcidin mRNA and subsequent increase in Fpn1 and TfR1 expression in LPS-treated macrophages. Moreover, RocA inhibited the elevation of the cellular labile iron pool (LIP) and reactive oxygen species (ROS) induced by LPS in RAW264.7 cells. These findings reveal a pivotal mechanism underlying the roles of RocA in modulating iron homeostasis and also provide a candidate natural product on alleviating AI.


Asunto(s)
Benzofuranos , Hepcidinas , Homeostasis , Interleucina-6 , Hierro , Animales , Ratones , Anemia/metabolismo , Anemia/genética , Anemia/tratamiento farmacológico , Anemia/patología , Proteínas de Transporte de Catión/genética , Proteínas de Transporte de Catión/metabolismo , Ferritinas/metabolismo , Ferritinas/genética , Regulación de la Expresión Génica/efectos de los fármacos , Hepcidinas/efectos de los fármacos , Hepcidinas/genética , Hepcidinas/metabolismo , Homeostasis/efectos de los fármacos , Inflamación/metabolismo , Inflamación/genética , Inflamación/patología , Interleucina-6/metabolismo , Interleucina-6/genética , Hierro/metabolismo , Lipopolisacáridos/farmacología , Hígado/metabolismo , Hígado/patología , Macrófagos/metabolismo , Macrófagos/efectos de los fármacos , Células RAW 264.7 , Especies Reactivas de Oxígeno/metabolismo , Receptores de Transferrina/metabolismo , Receptores de Transferrina/genética , Transducción de Señal/efectos de los fármacos , Factor de Transcripción STAT3/metabolismo , Factor de Transcripción STAT3/genética , Benzofuranos/farmacología
6.
Adv Sci (Weinh) ; 11(21): e2308491, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38466927

RESUMEN

Peptide and protein postmodification have gained significant attention due to their extensive impact on biomolecule engineering and drug discovery, of which cysteine-specific modification strategies are prominent due to their inherent nucleophilicity and low abundance. Herein, the study introduces a novel approach utilizing multifunctional 5-substituted 1,2,3-triazine derivatives to achieve multifaceted bioconjugation targeting cysteine-containing peptides and proteins. On the one hand, this represents an inaugural instance of employing 1,2,3-triazine in biomolecular-specific modification within a physiological solution. On the other hand, as a powerful combination of precision modification and biorthogonality, this strategy allows for the one-pot dual-orthogonal functionalization of biomolecules utilizing the aldehyde group generated simultaneously. 1,2,3-Triazine derivatives with diverse functional groups allow conjugation to peptides or proteins, while bi-triazines enable peptide cyclization and dimerization. The examination of the stability of bi-triazines revealed their potential for reversible peptide modification. This work establishes a comprehensive platform for identifying cysteine-selective modifications, providing new avenues for peptide-based drug development, protein bioconjugation, and chemical biology research.


Asunto(s)
Cisteína , Péptidos , Proteínas , Triazinas , Cisteína/química , Triazinas/química , Péptidos/química , Proteínas/química
7.
BMC Cardiovasc Disord ; 24(1): 77, 2024 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-38281925

RESUMEN

BACKGROUND: New-generation self-expanding valves can improve the success rate of transcatheter aortic valve replacement (TAVR) for severe pure native aortic regurgitation (PNAR). However, predictors of new-onset conduction block post-TAVR using new-generation self-expanding valves in patients with PNAR remain to be established. Therefore, this study aimed to identify predictors of new-onset conduction block post-TAVR using new-generation self-expanding valves (VitaFlow Liberty™) in patients with PNAR. METHODS: In this retrospective cohort study, patients were categorized into pacemaker and non-pacemaker groups based on their need for new postoperative permanent pacemaker implantation (PPI). Based on the postoperative presence of either new-onset complete left bundle branch block (cLBBB) or high-grade atrioventricular block (AVB), patients were further classified into conduction disorder and non-conduction disorder groups. Laboratory, echocardiographic, computed tomography, preoperative and postoperative electrocardiography, and procedural and clinical data were collected immediately after TAVR and during hospitalization and compared between the groups. Multivariate logistic regression analysis was performed incorporating the significant variables from the univariate analyses. RESULTS: This study examined 68 consecutive patients with severe PNAR who underwent TAVR. In 20 patients, a permanent pacemaker was fitted postoperatively. Multivariate logistic regression analysis revealed an association between the need for postoperative PPI and preoperative complete right bundle branch block (cRBBB) or first-degree AVB, as well as a non-tubular left ventricular outflow tract (LVOT). In addition, valve implantation depth and angle of aortic root were independent predictors of new-onset cLBBB or high-grade AVB developing post-TAVR. The predictive value of valve implantation depth and angle of aortic root was further supported by receiver operating characteristic curve analysis results. CONCLUSIONS: In patients with PNAR undergoing TAVR using self-expanding valves, preoperative cRBBB or first-degree AVB and a non-tubular LVOT were indicators of a higher likelihood of PPI requirement. Moreover, deeper valve implantation depth and greater angle of aortic root may be independent risk factors for new-onset cLBBB or high-grade AVB post-TAVR. Valve implantation depth and angle of aortic root values may be used to predict the possibility of new cLBBB or high-grade AVB post-TAVR.


Asunto(s)
Insuficiencia de la Válvula Aórtica , Estenosis de la Válvula Aórtica , Bloqueo Atrioventricular , Marcapaso Artificial , Reemplazo de la Válvula Aórtica Transcatéter , Humanos , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Insuficiencia de la Válvula Aórtica/diagnóstico por imagen , Insuficiencia de la Válvula Aórtica/etiología , Estudios Retrospectivos , Estimulación Cardíaca Artificial/efectos adversos , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/complicaciones , Resultado del Tratamiento , Bloqueo Atrioventricular/diagnóstico , Bloqueo Atrioventricular/etiología , Bloqueo Atrioventricular/terapia , Marcapaso Artificial/efectos adversos , Arritmias Cardíacas , Bloqueo de Rama/diagnóstico , Bloqueo de Rama/etiología , Bloqueo de Rama/terapia , Factores de Riesgo , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía
8.
BMC Cancer ; 23(1): 1140, 2023 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-37996813

RESUMEN

PURPOSE: We aimed to investigate the efficacy and side effects of concurrent chemoradiotherapy, with or without nimotuzumab, for the treatment of locally advanced nasopharyngeal carcinoma after neoadjuvant chemotherapy. METHODS: This study retrospectively enrolled 109 patients with NPC from our hospital from July 2019 to May 2021.All patients were treated with docetaxel, cisplatin, and fluorouracil(TPF) neoadjuvant chemotherapy for 2 cycles, and concurrent chemoradiotherapy was performed 2 weeks after chemotherapy. According to whether nimotuzumab was added in concurrent chemoradiotherapy, they were divided into the nimotuzumab group and the control group, with 52 cases in the nimotuzumab group and 57 cases in the control group.The efficacy and adverse reactions of the two groups were retrospectively analyzed. RESULTS: The objective remission and complete remission rates in the nimotuzumab and control groups were 100% vs 98.2% (p = 1.000), and 92.3% vs 78.9% (p = 0.049), respectively. The 3-year distant metastasis-free survival of the nimotuzumab and control groups was 91.6% and 77.3% (p = 0.047), respectively.The 3-year progression-free survival, locoregional relapse-free survival, and overall survival of the nimotuzumab and control groups were 87.6% vs 75.5% (p = 0.110), 90.5% vs 86.9% (p = 0.566), and 94.5% vs 87.1% (p = 0.295), respectively. In the nimotuzumab group, subgroup analysis showed that patients aged < 60 years (hazard ratio [HR] = 0.350, 95% confidence interval [CI]: 0.131-0.934, p = 0.036) and those with a neutrophil-to-lymphocyte ratio (neutrophil/lymphocyte ratio) ≤ 4 (HR = 0.365, 95% CI: 0.144-0.923, p = 0.033) achieved a better result. Additionally, multivariate analysis demonstrated that neutrophil/lymphocyte ratio was an independent risk factor for disease progression (HR = 7.485, p = 0.012) and distant metastasis (HR = 17.540, p = 0.009).No grade 4 adverse reactions were observed in either group. Grade 3 oral mucosal reactions, as well as pharyngeal and esophageal reactions were slightly higher in the nimotuzumab group than in the control group, but the difference was not statistically significant. No significant differences were observed in the incidence of adverse reactions such as leukopenia, HB reduction, thrombocytopenia between the two groups (P > 0.05). CONCLUSION: The concurrent chemoradiotherapy plus nimotuzumab after neoadjuvant chemotherapy for locally advanced nasopharyngeal carcinoma achieved a higher complete remission rate and significantly improved distant metastasis-free survival compared with concurrent chemoradiotherapy alone. Additionally, an increasing trend was observed in progression-free survival, and the incidence of side effects was similar in both groups.


Asunto(s)
Leucopenia , Neoplasias Nasofaríngeas , Humanos , Carcinoma Nasofaríngeo/tratamiento farmacológico , Carcinoma Nasofaríngeo/patología , Estudios Retrospectivos , Terapia Neoadyuvante/efectos adversos , Neoplasias Nasofaríngeas/tratamiento farmacológico , Neoplasias Nasofaríngeas/patología , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Recurrencia Local de Neoplasia/tratamiento farmacológico , Quimioradioterapia/efectos adversos , Cisplatino/efectos adversos , Leucopenia/inducido químicamente
9.
Angew Chem Int Ed Engl ; 62(40): e202310047, 2023 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-37593817

RESUMEN

The current availability of multi-resonance thermally activated delayed fluorescence (MR-TADF) materials with excellent color purity and high device efficiency in the deep-blue region is appealing. To address this issue in the emerged nitrogen/carbonyl MR-TADF system, we propose a spiro-lock strategy. By incorporating spiro functionalization into a concise molecular skeleton, a series of emitters (SFQ, SOQ, SSQ, and SSeQ) can enhance molecular rigidity, blue-shift the emission peak, narrow the emission band, increase the photoluminescence quantum yield by over 92 %, and suppress intermolecular interactions in the film state. The referent CZQ without spiro structure has a more planar skeleton, and its bluer emission in the solution state redshifts over 40 nm with serious spectrum broadening and a low PLQY in the film state. As a result, SSQ achieves an external quantum efficiency of 25.5 % with a peak at 456 nm and a small full width at half maximum of 31 nm in a simple unsensitized device, significantly outperforming CZQ. This work discloses the importance of spiro-junction in modulating deep-blue MR-TADF emitters.

10.
Org Lett ; 25(32): 6024-6028, 2023 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-37552571

RESUMEN

Red through-space charge transfer thermally activated delayed fluorescence (TSCT TADF) materials named SAF36DCPP and SAF27DCPP with sandwiched structures were synthesized. Single crystals indicated that the intramolecular C-H···π interactions play a vital role in rigidifying the sandwiched structure, which results in a fluorescence yield of 63% for SAF36DCPP compared to 40% for SAF27DCPP. Organic light-emitting diodes with SAF36DCPP as the emitter realized a maximum external quantum efficiency of 16.12%.

11.
Int Heart J ; 64(4): 543-550, 2023 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-37460321

RESUMEN

Multiple reports relate new-onset atrial fibrillation (NOAF) to poor clinical outcomes in patients with ST-elevation myocardial infarction (STEMI) who received percutaneous coronary intervention (PCI). The prognostic nutritional index (PNI) is a reliable indicator of immunonutritional-inflammatory status, and it is linked to clinical outcomes in cardiovascular disease patients. This research aims to explore the relationship between NOAF and PNI.Overall, 600 STEMI patients treated with PCI were recruited for this retrospective analysis. The patients were categorized into the NOAF group or sinus rhythm (SR) group. Logistic regression and receiver operating characteristic (ROC) curve analyses were conducted to assess PNI estimation. Lastly, the Kaplan-Meier curve was used to compare all-cause mortality between both groups.The combined NOAF incidence in PCI-treated STEMI patients was 7.7%. PNI was independently correlated with NOAF using multivariate regression analyses (odds ratio [OR], 0.824; 95% confidence interval [CI], 0.750-0.906; P < 0.001). In ROC curve analyses, the best PNI threshold value for predicting NOAF was 40.1, with sensitivity, and specificity of 76.09% and 71.30%, respectively area under the curve, 0.787; 95% CI, 0.752-0.819; P < 0.001). After a median of 41-month follow-up, the Kaplan-Meier curve revealed that the NOAF patients displayed an elevated all-cause death incidence compared with SR patients, with a log-rank of P = 0.005.This study demonstrated that PNI is an independent predictor of NOAF in STEMI patients during hospitalization after PCI, which is strongly correlated with a poor outcome upon discharge.

12.
Proc Natl Acad Sci U S A ; 120(23): e2301118120, 2023 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-37252984

RESUMEN

For organic photovoltaic (OPV) devices to achieve consistent performance and long operational lifetimes, organic semiconductors must be processed with precise control over their purity, composition, and structure. This is particularly important for high volume solar cell manufacturing where control of materials quality has a direct impact on yield and cost. Ternary-blend OPVs containing two acceptor-donor-acceptor (A-D-A)-type nonfullerene acceptors (NFAs) and a donor have proven to be an effective strategy to improve solar spectral coverage and reduce energy losses beyond that of binary-blend OPVs. Here, we show that the purity of such a ternary is compromised during blending to form a homogeneously mixed bulk heterojunction thin film. We find that the impurities originate from end-capping C=C/C=C exchange reactions of A-D-A-type NFAs, and that their presence influences both device reproducibility and long-term reliability. The end-capping exchange results in generation of up to four impurity constituents with strong dipolar character that interfere with the photoinduced charge transfer process, leading to reduced charge generation efficiency, morphological instabilities, and an increased vulnerability to photodegradation. As a consequence, the OPV efficiency falls to less than 65% of its initial value within 265 h when exposed to up to 10 suns intensity illumination. We propose potential molecular design strategies critical to enhancing the reproducibility as well as reliability of ternary OPVs by avoiding end-capping reactions.

13.
Health Informatics J ; 29(1): 14604582231164694, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36913624

RESUMEN

BACKGROUND: An unplanned readmission is a dual metric for both the cost and quality of medical care. METHODS: We employed the random forest (RF) method to build a prediction model using a large dataset from patients' electronic health records (EHRs) from a medical center in Taiwan. The discrimination abilities between the RF and regression-based models were compared using the areas under the ROC curves (AUROC). RESULTS: When compared with standardized risk prediction tools, the RF constructed using data readily available at admission had a marginally yet significantly better ability to identify high-risk readmissions within 30 and 14 days without compromising sensitivity and specificity. The most important predictor for 30-day readmissions was directly related to the representing factors of index hospitalization, whereas for 14-day readmissions the most important predictor was associated with a higher chronic illness burden. CONCLUSIONS: Identifying dominant risk factors based on index admission and different readmission time intervals is crucial for healthcare planning.


Asunto(s)
Hospitales , Readmisión del Paciente , Humanos , Estudios Retrospectivos , Factores de Riesgo , Registros Electrónicos de Salud
14.
Chemistry ; 29(5): e202202628, 2023 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-36250810

RESUMEN

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.


Asunto(s)
Aminas , Citoesqueleto , Fluorescencia , Cetonas , Vibración
15.
Molecules ; 27(13)2022 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-35807295

RESUMEN

The employment of thermally activated delayed fluorescence (TADF) emitters is one of the most promising ways to realize the external quantum efficiency (EQE) of over 25% for organic light-emitting diodes (OLEDs). In addition, the TADF emitter based on oxygen-bridged boron (BO) fragment can maintain blue emission with high color purity. Herein, we constructed two blue TADF emitters, 3TBO and 5TBO, for OLEDs application. Both emitters consist of three donors linked at the oxygen-bridged boron acceptor. OLED devices based on 3TBO and 5TBO exhibited both high excellent device efficiency and high color purity with a maximum EQE; full-width at half-maximum (FWHM); and CIE coordinates of 17.3%, 47 nm, (0.120, 0.294), and 26.2%, 57 nm, (0.125, 0.275), respectively.

16.
Angew Chem Int Ed Engl ; 61(34): e202206861, 2022 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-35689409

RESUMEN

Organic materials with multi-stimulus response (MSR) properties have demonstrated many potential and practical applications. Herein, a π-stacked thermally activated delayed fluorescence (TADF) material with multi-stimulus response (MSR) properties, named SDMAC, was designed and synthesized using distorted 9,9-dimethyl-10-phenyl-9,10-dihydroacridine as a donor. SDMAC possesses a rigid π-stacked configuration with intramolecular through-space interactions and exhibits aggregation-induced emission enhancement (AIEE), solvatochromic, piezochromic, and circularly polarized luminescence (CPL) under different external stimuli. The rigid molecular structure and efficient TADF properties of SDMAC can be used in displays and lighting. Using SDMAC as an emitter, the maximum external quantum efficiency (EQE) of the fabricated organic light-emitting diodes (OLEDs) is as high as 28.4 %, which make them the most efficient CP-TADF OLEDs based on the through-space charge transfer strategy. The CP organic light-emitting diodes (CP-OLEDs) exhibit circularly polarized electroluminescence (CPEL) signals.

17.
Angew Chem Int Ed Engl ; 61(35): e202207204, 2022 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-35729063

RESUMEN

To date, all efficient host materials reported for phosphorescent OLEDs (PhOLEDs) are constructed with heteroatoms, which have a crucial role in the device performance. However, it has been shown in recent years that the heteroatoms not only increase the design complexity but can also be involved in the instability of the PhOLED, which is nowadays the most important obstacle to overcome. Herein, we design pure aromatic hydrocarbon materials (PHC) as very efficient hosts in high-performance white and blue PhOLEDs. With EQE of 27.7 %, the PHC-based white PhOLEDs display similar efficiency as the best reported with heteroatom-based hosts. Incorporated as a host in a blue PhOLED, which are still the weakest links of the technology, a very high EQE of 25.6 % is reached, surpassing, for the first time, the barrier of 25 % for a PHC and FIrpic blue emitter. This performance shows that the PHC strategy represents an effective alternative for the future development of the OLED industry.

18.
Nat Commun ; 13(1): 3621, 2022 06 24.
Artículo en Inglés | MEDLINE | ID: mdl-35750872

RESUMEN

Photo-controlled living polymerization has received great attention in recent years. However, despite the great success therein, the report on photo-controlled living cationic polymerization has been greatly limited. We demonstrate here a novel decolorable, metal-free and visible light-controlled living cationic polymerization system by using tris(2,4-dimethoxyphenyl)methylium tetrafluoroborate as the photocatalyst and phosphate as the chain transfer agent (CTA) for polymerization of 4-methoxystyrene. This polymerization reaction under green LED light irradiation shows clear living characteristics including predictable molar mass, low molar-mass dispersity (D = 1.25), and sequential polymerization capability. In addition, the photocatalytic system exits excellent "on-off" photo switchability and shows the longest "off period" of 36 h up to now for photo-controlled cationic polymerization. Furthermore, the residual photo-catalyst is easily deactivated and decolored with addition of a base after the polymerization. The present study has extended the photo-controlled living cationic polymerization systems with new organic photocatalysts, phosphate CTA and polymerizable monomer as well as the new properties of excellent photostability and in-situ decolored capacity.


Asunto(s)
Luz , Fosfatos , Catálisis , Polimerizacion
19.
Angew Chem Int Ed Engl ; 61(22): e202201886, 2022 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-35293091

RESUMEN

A multiple resonance thermally activated delayed fluorescence (MR-TADF) molecule with a fused, planar architecture tends to aggregate at high doping ratios, resulting in broad full width at half maximum (FWHM), redshifting electroluminescence peaks, and low device efficiency. Herein, we propose a mono-substituted design strategy by introducing spiro-9,9'-bifluorene (SBF) units with different substituted sites into the MR-TADF system for the first time. As a classic steric group, SBF can hinder interchromophore interactions, leading to high device efficiency (32.2-35.9 %) and narrow-band emission (≈27 nm). Particularly, the shield-like molecule, SF1BN, seldom exhibits a broadened FWHM as the doping ratio rises, which differs from the C3-substituted isomer and unhindered parent emitter. These results manifest an effective method for constructing highly efficient MR-TADF emitters through a spiro strategy and elucidate the feasibility for steric modulation of the spiro structure in π-framework.

20.
Adv Mater ; 34(22): e2104125, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34595783

RESUMEN

Organic semiconductors can be designed and constructed in π-stacked structures instead of the conventional π-conjugated structures. Through-space interaction (TSI) occurs in π-stacked optoelectronic materials. Thus, unlike electronic coupling along the conjugated chain, the functional groups can stack closely to facilitate spatial electron communication. Using π-stacked motifs, chemists and materials scientists can find new ways for constructing materials with aggregation-induced emission (AIE), thermally activated delayed fluorescence (TADF), circularly polarized luminescence (CPL), and room-temperature phosphorescence (RTP), as well as enhanced molecular conductance. Organic optoelectronic devices based on π-stacked molecules have exhibited very promising performance, with some of them exceeding π-conjugated analogues. Recently, reports on various organic π-stacked structures have grown rapidly, prompting this review. Representative molecular scaffolds and newly developed π-stacked systems could stimulate more attention on through-space charge transfer the well-known through-bond charge transfer. Finally, the opportunities and challenges for utilizing and improving particular materials are discussed. The previous achievements and upcoming prospects may provide new insights into the theory, materials, and devices in the field of organic semiconductors.

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