Search

A cascade reaction of Pd(II)/dppben-catalyzed [3 + 2] cycloaddition of N -aryl nitrones with allenoates and sequential reduction has been developed for the synthesis of functionalized benzazepines bearing three contiguous carbon stereocenters in moderate to good yields ranging from 15 to 82% and high diastereoselectivity. The obtained benzazepines could be converted into various benzazepine scaffolds, and an estrone-derived benzazepine scaffold was prepared over four steps from estrone. More importantly, chiral benzazepine bearing three contiguous carbon stereocenters could be obtained in 88% ee value with chiral auxiliary.

We present the first approach to controlled metal chelation of peptide backbones, where the anchoring site is an aza-amino acid nitrogen and the directionality of chelation events is dictated by the acidity of neighboring NHs. Selective backbone chelation precludes the need for metal-binding side chains and/or free N - or C -termini in peptides. We show that the presence and location of an aza-amino acid impact complex formation and report the first X-ray crystal structures of azapeptides bound to palladium and nickel. Evidence of atropisomerism in metallo-azapeptides is also presented.

Blue perovskite light-emitting diodes (LEDs) lag behind green and red LEDs, which have made considerable strides in efficiency and stability. The main disadvantage is its unmodulated phase domains and low energy transfer efficiency, which impede the efficiency, optical purity, and operational stability of the devices. Herein, we show that using biomolecule-derived plasmonic nanostructures can significantly promote defect passivation, van der Waals gap reduction, and cascade energy transfer through synergistic small-molecule interactions and localized surface plasmonic contributions, thereby improving the electroluminescence (EL) properties and operational stability. The designed blue quasi-2D perovskite LED benefits from the synergistic effect with a higher external quantum efficiency (EQE = 3.51%), EL spectral stability, and superior long-term operational stability. These results validate the optimization of structural and energy cascades of quasi-2D perovskites through a simple and environmentally friendly biomolecular tailorable plasmonic nanostructure approach, paving the way for the development of sustainable electronics.

The development of membrane-bound protocells, which process cascade biochemical reactions in distinct microcompartments, marks a significant advancement in soft systems. However, many synthesized protocells with cell membrane-like structures are prone to rupturing in biological environments and are challenging to functionalize, limiting their biomedical applications. In this study, we explore the liquid-liquid phase separation of tannic acid (TA) and polyethylene glycol (PEG) to form coacervate droplets. Upon introducing polyvinylpyrrolidone (PVP) molecules, a dense hydrogen bonding network spontaneously forms at the surfaces of the coacervate droplets, resulting in robust fluidic membrane-bound protocells (FMPs). These protocells can be flexibly postfunctionalized to incorporate functional nanomaterials via electrostatic attraction, enabling the design of cascade reactions for biomedical applications. To demonstrate this, nanozymes (Pt/CeO 2 ) are assembled onto Fe 3+ /FMPs, resulting in functional FMPs (Pt/CeO 2 @Fe 3+ /FMPs) capable of catalyzing the degradation of uric acid and its harmful byproduct, H 2 O 2 , offering potential treatments for gout.

Herein, we report a novel strategy of hypervalent iodine(III) compound-mediated selective C sp -C sp 2 bond cleavage of alkynes and C═N/N-O bond cleavage of nitrones and recombination of C-C/C-O/C-N multiple bonds to access various functionalized [1,4]oxazinones bearing a vicinal carbon stereocenter in good yields and high diastereoselectivity. Mechanistic studies revealed that the reaction undergoes a domino [4 + 3] cycloaddition, 1,3-rearrangement of N-O bond, intramolecular cyclization, dearomatization, and rearomatization over four steps in a single flask. The present method features good functional group tolerance, broad substrate scope, and C-C/C═N/N-O multiple bonds cleavage and recombination.

We fabricated three-dimensional (3D)-printed polycaprolactone (PCL) and PCL/graphene oxide (GO) (PGO) scaffolds for bone tissue engineering. An anti-inflammatory and pro-osteogenesis drug dexamethasone (DEX) was adsorbed onto GO and a 3D-printed PGO/DEX (PGOD) scaffold successfully improved drug delivery with a sustained release of DEX from the scaffold up to 1 month. The physicochemical properties of the PCL, PGO, and PGOD scaffolds were characterized by various analytical techniques. The biological response of these scaffolds was studied for adherence, proliferation, and osteogenic differentiation of seeded rabbit adipose-derived stem cells (ASCs) from DNA assays, alkaline phosphatase (ALP) production, calcium quantification, osteogenic gene expression, and immunofluorescence staining of osteogenic marker proteins. The PGOD scaffold was demonstrated to be the best scaffold for maintaining cell viability, cell proliferation, and osteogenic differentiation of ASCs in vitro. In vivo biocompatibility of PGOD was confirmed from subcutaneous implantation in nude mice where ASC-seeded PGOD can form ectopic bones, demonstrated by microcomputed tomography (micro-CT) analysis and immunofluorescence staining. Furthermore, implantation of PGOD/ASCs constructs into critical-sized cranial bone defects in rabbits form tissue-engineered bones at the defect site, observed using micro-CT and histological analysis.

Organic photodetector (OPD) studies have undergone a revolutionary transformation by introducing nonfullerene acceptors (NFAs), which provide substantial benefits such as tunable band gaps and enhanced absorption in the visible spectrum. Vacuum-processed small-molecule-based OPD devices are presented in this study by utilizing a blend of boron subphthalocyanine (SubPc) and chlorinated subphthalocyanine (Cl 6 SubPc) as the active layer. Four different active layer thicknesses are further investigated to understand the intrinsic phenomena, unveiling the suppression of dark current density while maintaining photoexcitation and charge separation efficiency. Experimental results reveal that, at an applied bias of -3 V, the 50-nm-thick active layer achieves a remarkably low dark current density of 1.002 nA cm -2 alongside a high external quantum efficiency (EQE) of 52.932% and a responsivity of 0.226 A W -1 . These impressive performance metrics lead to a specific detectivity of 1.263 × 10 13 Jones. Furthermore, the findings offer new insights into intrinsic phenomena within the bulk heterojunction (BHJ), such as thermally generated current and exciton quenching. This integration is potentially well-heeled to revolutionize display technology by combining high-sensitivity photodetection, offering new possibilities for novel display panels with sensing applications.

Traditional screen printing is an easy approach commonly used for conductive pattern fabrication of electronics but lacks high resolution. Photolithography offers better resolution but is complex. Photosensitive silver pastes (PSP) combine the benefits of both but suffer from undercut issues, causing uneven etching, decreased interfacial adhesion, and thus poor resolutions. In this study, we explore the use of molecular precursors (i.e., silver oxalate) to replace metallic silver particles and enhance the depth of light penetration. Our findings demonstrate a successful solution to the undercut issue, achieving an undercut index of 1.0, indicating an undercut-free scenario and enabling higher resolutions in line and pattern formation. Additionally, our research confirms the feasibility of multilayer stacking of photosensitive pastes, achieving unprecedented aspect ratios in line patterns. By replacing 25% of micrometer silver powder with silver oxalate (PSP-25), we achieved optimal line widths as fine as 10 μm. The three-layer stack of PSP-25 reached a substantial aspect ratio with a height of 29.4 μm and an optimal fringe pattern resolution of 10 μm line width with a 15 μm aisle width. Utilization of silver oxalate was observed to slightly expand the line width, likely due to light scattering by the fine silver nanoparticles (∼40 nm) formed during the photodecomposition of silver oxalate.

Selective inhibition of the RGD (Arg-Gly-Asp) integrin αvβ1 has been recently identified as an attractive therapeutic approach for the treatment of liver fibrosis given its function, target expression, and safety profile. Our identification of a non-RGD small molecule lead followed by focused, systematic changes to the core structure utilizing a crystal structure, in silico modeling, and a tractable synthetic approach resulted in the identification of a potent small molecule exhibiting a remarkable affinity for αvβ1 relative to several other integrin isoforms measured. Azabenzimidazolone 25 demonstrated antifibrotic efficacy in an in vivo rat liver fibrosis model and represents a tool compound capable of further exploring the biological consequences of selective αvβ1 inhibition.

The pursuit of high-performance electronic devices has driven the research focus toward 2D semiconductors with high electron mobility and suitable band gaps. Previous studies have demonstrated that quasi-2D Bi 2 O 2 Se (BOSe) has remarkable physical properties and is a promising candidate for further exploration. Building upon this foundation, the present work introduces a novel concept for achieving nonvolatile and reversible control of BOSe's electronic properties. The approach involves the epitaxial integration of a ferroelectric PbZr 0.2 Ti 0.8 O 3 (PZT) layer to modify BOSe's band alignment. Within the BOSe/PZT heteroepitaxy, through two opposite ferroelectric polarization states of the PZT layer, we can tune the Fermi level in the BOSe layer. Consequently, this controlled modulation of the electronic structure provides a pathway to manipulate the electrical properties of the BOSe layer and the corresponding devices.

We described an iron(III) and BF 3 ·OEt 2 -promoted oxygen transfer reaction of N -aryl-α,β-unsaturated nitrones to prepare various N , O -difluoroboron β-ketoiminates in good yields ranging from 24% to 87%. Control experiments revealed that the enaminone was the vital intermediate for the formation of N , O -difluoroboron β-ketoiminates, and iron(III) combined with BF 3 ·OEt 2 played as cocatalyst to promote the oxygen transfer reaction through intramolecular cyclization and N-O bond cleavage. More importantly, an estrone-derived N , O -difluoroboron β-ketoiminate was easily prepared in 40% yield from estrone in four steps.

Hydrogen bonding networks are ubiquitous in biological systems and play a key role in controlling the conformational dynamics and allosteric interactions of enzymes. Yet in small organometallic catalysts, hydrogen bonding rarely controls ligand binding to the metal center. In this work, a hydrogen bonding network within a well-defined organometallic catalyst works in concert with cation-dipole interactions to gate substrate access to the active site. An ammine ligand acts as one cofactor, templating a hydrogen bonding network within a pendent crown ether and preventing the binding of strong donor ligands, such as nitriles, to the nickel center. Sodium ions are the second cofactor, disrupting hydrogen bonding to enable switchable ligand substitution reactions. Thermodynamic analyses provide insight into the energetic requirements of the different supramolecular interactions that enable substrate gating. The dual cofactor approach enables switchable catalytic hydroamination of crotononitrile. Systematic comparisons of catalysts with varying structural features provide support for the critical role of the dual cofactors in achieving on/off catalysis with substrates containing strongly donating functional groups that might otherwise interfere with switchable catalysts.

Bright, scalable, and deterministic single-photon emission (SPE) is essential for quantum optics, nanophotonics, and optical information systems. Recently, SPE from hexagonal boron nitride (h-BN) has attracted intense interest because it is optically active and stable at room temperature. Here, we demonstrate a tunable quantum emitter array in h-BN at room temperature by integrating a wafer-scale plasmonic array. The transient voltage electrophoretic deposition (EPD) reaction is developed to effectively enhance the filling of single-crystal nanometals in the designed patterns without aggregation, which ensures the fabricated array for tunable performances of these single-photon emitters. An enhancement of ∼500% of the SPE intensity of the h-BN emitter array is observed with a radiative quantum efficiency of up to 20% and a saturated count rate of more than 4.5 × 10 6 counts/s. These results suggest the integrated h-BN-plasmonic array as a promising platform for scalable and controllable SPE photonics at room temperature.

ZnGa 2 O 4 sensing films were prepared using an RF magnetron sputtering system and connected to a commercial metal oxide semiconductor field-effect transistor (MOSFET) as the extended-gate field-effect transistor (EGFET) to detect pH values. Experimental parameters were adjusted by varying the oxygen flow rate in the process chamber to produce ZnGa 2 O 4 sensing films with different oxygen ratios. These films were then treated in a furnace tube at an annealing temperature of 700 °C. The sensitivity and linearity of the constant current mode and the constant voltage mode were measured and analyzed in the pH range of 2-12. Under the deposition conditions with an oxygen ratio of 6%, the sensitivity reached 23.14 mV/pH and 33.49 μA/pH, with corresponding linearity values of 92.1 and 96.15%, respectively. Finally, the sensing performance of the ZnGa 2 O 4 EGFET pH sensor with and without annealing processes was analyzed and compared., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

The performance of blue perovskite light-emitting diodes (PeLEDs) lags behind the green and red counterparts owing to high trap density and undesirable red shift of the electroluminescence spectrum under operation conditions. Organic molecular additives were employed as passivators in previous reports. However, most commonly have limited functions, making it challenging to effectively address both efficiency and stability issues simultaneously. Herein, we reported an innovatively dynamic in situ hydrolysis strategy to modulate quasi-2D sky-blue perovskites by the multifunctional passivator phenyl dichlorophosphate that not only passivated the defects but also underwent in situ hydrolysis reaction to stabilize the emission. Moreover, hydrolysis products were beneficial for low-dimensional phase manipulation. Eventually, we obtained high-performance sky-blue PeLEDs with a maximum external quantum efficiency (EQE) of 16.32% and an exceptional luminance of 5740 cd m -2 . More importantly, the emission peak of devices located at 485 nm remained stable under different biases. Our work signified the significant advancement toward realizing future applications of PeLEDs.

Novel N -ethy-2-pyrrolidinone-substituted flavonols, myricetin alkaloids A-C ( 1 - 3 ), quercetin alkaloids A-C ( 4a , 4b , and 5 ), and kaempferol alkaloids A and B ( 6 and 7 ), were prepared from thermal reaction products of myricetin, quercetin, kaempferol─l-theanine, respectively. We used HPLC-ESI-HRMS/MS to detect 1 - 7 in 14 cultivars of green tea and found that they were all present in "Shuchazao," "Longjing 43", "Fudingdabai", and "Zhongcha 108" green teas. The structures of 1 - 4 and 6 were determined by extensive 1D and 2D NMR spectroscopies. These flavonol alkaloids along with their skeletal flavonols were assessed for anti-Alzheimer's disease effect based on molecular docking, acetylcholinesterase inhibition, and the transgenic Caenorhabditis elegans CL4176 model. Compound 7 strongly binds to the protein amyloid β (Aβ 1-42 ) through hydrogen bonds (BE: -9.5 kcal/mol, K i : 114.3 nM). Compound 3 (100 μM) is the strongest one in significantly extending the mean lifespan (13.4 ± 0.5 d, 43.0% promotion), delaying the Aβ 1-42 -induced paralysis (PT 50 : 40.7 ± 1.9 h, 17.1% promotion), enhancing the locomotion (140.0% promotion at 48 h), and alleviating glutamic acid (Glu)-induced neurotoxicity (153.5% promotion at 48 h) of CL4176 worms ( p < 0.0001).

Cobalt polypyridyl complexes stand out as efficient catalysts for electrochemical proton reduction, but investigations into their operating mechanisms, with broad-reaching implications in catalyst design, have been limited. Herein, we investigate the catalytic activity of a cobalt(II) polypyridyl complex bearing a pendant pyridyl base with a series of organic acids spanning 20 p K a units in acetonitrile. Structural analysis, as well as electrochemical studies, reveals that the Co(III) hydride intermediate is formed through reduction of the Co(II) catalyst followed by direct metal protonation in the initial EC step despite the presence of the pendant base, which is commonly thought of as a more kinetically accessible protonation site. Protonation of the pendant base occurs after the Co(III) hydride intermediate is further reduced in the overall ECEC pathway. Additionally, when the acid used is sufficiently strong, the Co(II) catalyst can be protonated, and the Co(III) hydride can react directly with acid to release H 2 . With thorough mechanistic understanding, the appropriate electroanalytical methods were identified to extract rate constants for the elementary steps over a range of conditions. Thermodynamic square schemes relating catalytic intermediates proposed in the three electrocatalytic HER mechanisms were constructed. These findings reveal a full description of the HER electrocatalysis mediated by this molecular system and provide insights into strategies to improve synthetic fuel-forming catalysts operative through metal hydride intermediates.

Single-cell multiplexed phenotypic analysis expands the biomarkers for diagnosis, heralding a new era of precision medicine. Cell secretions are the primary measures of immune function, but single-cell screening remains challenging. Here, a novel cell membrane-based assay was developed using cholesterol-linked antibodies (CLAbs), integrating immunosorbent assays and droplet microfluidics to develop a flexible high-throughput single-cell secretion assay for multiplexed phenotyping. CLAb-grafted single cells were encapsulated in water-in-oil droplets to capture their own secretions. Subsequently, the cells were extracted from droplets for fluorescence labeling and screening. Multiple secretions and surface proteins were simultaneously measured from single cells by flow cytometry. To validate the approach, THP-1 cells, THP-1-derived M1 macrophages, and dendritic cells were assayed, indicating the differentiation efficiency of THP-1 cells under different chemical stimulations. Moreover, peripheral blood mononuclear cells from healthy donors under various stimuli showed varied active immune cell populations (6.62-47.14%). The peripheral blood mononuclear cells (PBMCs) of nasopharyngeal carcinoma patients were analyzed to identify a higher percentage of actively cytokine-secreted single cells in the basal state (2.82 ± 1.48%), compared with that in the health donors (0.70 ± 0.29%).

Graphene possesses an exotic band structure that spans a wide range of important technological wavelength regimes for photodetection, all within a single material. Conventional methods aimed at enhancing detection efficiency often suffer from an extended response time when the light is switched off. The task of achieving ultrafast broad-band photodetection with a high gain remains challenging. Here, we propose a devised architecture that combines graphene with a photosensitizer composed of an alternating strip superstructure of WS 2 -WSe 2 . Upon illumination, n + -WS 2 and p + -WSe 2 strips create alternating electron- and hole-conduction channels in graphene, effectively overcoming the tradeoff between the responsivity and switch time. This configuration allows for achieving a responsivity of 1.7 × 10 7 mA/W, with an extrinsic response time of 3-4 μs. The inclusion of the superstructure booster enables photodetection across a wide range from the near-ultraviolet to mid-infrared regime and offers a distinctive photogating route for high responsivity and fast temporal response in the pursuit of broad-band detection.

The [4 + 2] annulation of β-formyl ketones with an indole has been developed for the regioselective synthesis of diphenyl-substituted carbazoles in the presence of a catalytic amount of iodine. The 1,4-dicarbonyl compound containing a phenyl group at the α-position of an aldehyde group reacts more readily with indoles to form carbazole derivatives. Using this method, a variety of carbazole derivatives can be readily accessed under mild reaction conditions.

A variety of spirooxindole-1,2-oxazinan-5-one derivatives were prepared in moderate to excellent yields through 2,2,2-trifluoroethanol (TFE)-promoted [3 + 3] cycloaddition of N -vinyl oxindole nitrones with oxyallyl cations generated from α-tosyloxy ketones under mild reaction conditions. Mechanistic studies revealed that [3 + 3] cycloaddition might involve two possible reaction pathways, including direct [3 + 3] cycloaddition of N -vinyl oxindole ntirones with oxyallyl cations, or the addition of TFE to N -vinyl oxindole nitrones, sequential addition to oxyallyl cations, elimination, and cyclization. The present method features mild reaction conditions, broad substrate scope, good functional group tolerance, easy gram scalable preparation, and new applications of TFE.

A strategy for the synthesis of dibenz[ a , j ]anthracenes (DBAs) from cyclohexa-2,5-diene-1-carboxylic acids is presented. Our approach involves sequential C-H olefination, cycloaddition, and decarboxylative aromatization. In the key step for DBA skeleton construction, the bis-C-H olefination products, 1,3-dienes, are utilized as substrates for [4 + 2] cycloaddition with benzyne. This concise synthetic route allows for regioselective ring formation and functional group introduction. The structural features and photophysical properties of the resulting DBA molecules are discussed.

In this study, we synthesized a series of four large-band gap small molecule acceptors with side-chain engineering of the dithieno-pyrrolo-fused pentacyclic benzotriazole (BZTTP or Y1 core) or the fused-ring dithienothiophene-pyrrolobenzothiadiazole (TPBT or Y6 core) with difluoro-indene-dione (IO2F) or dichloro-indene-dione (IO2Cl) end groups to form Y1-IO2F, Y1-IO2Cl, Y6-IO2F, and Y6-IO2Cl acceptors, respectively, for blending with poly(3-hexyl thiophene) (P3HT) for bulk heterojunction organic photovoltaics. The complementary UV-vis absorption spectra of these small molecules and P3HT along with their offset energy bands allow broad absorption and effective electron transfer. Through synchrotron wide-angle X-ray scattering (WAXS) analyses and contact angle measurements, we found that the blend of the small molecule Y6-IO2F (having a TPBT core) and P3HT achieves an optimum morphology that balances their crystallinity and miscibility, among those of these four blends, leading to a substantial enhancement in the short-circuit current density and thus power conversion efficiency (PCE) in their devices. For example, the P3HT:Y6-IO2F (w/w: 1/1.2) device exhibited a champion PCE of 10.5% with a short current density ( J sc ) value of 15.9 mA/cm 2 as compared to the P3HT:Y1-IO2F device having a PCE of 2.2% with a J sc value of 5.7 mA/cm 2 because of the higher Y6-IO2F (with TPBT core) molecular packing that facilitated carrier transport in the devices. The enhanced thermal stability exhibited by the devices incorporating Y6-IO2F and Y6-IO2Cl, as compared to that of Y1-IO2F and Y1-IO2Cl devices, is also due to the more planar TPBT core structure, while the photostability of devices incorporating Y6-IO2Cl and Y1-IO2Cl is better than that of devices incorporating Y6-IO2F and Y1-IO2F, owing to more photostable chemical structures. These results present an outstanding performance for P3HT-based organic solar cells. Moreover, these small molecule blends are processed with an environmentally friendly solvent tetrahydrofuran, demonstrating both the sustainability and commercial viability of these types of organic photovoltaics.

Selective autophagy is a defense mechanism by which foreign pathogens and abnormal substances are processed to maintain cellular homeostasis. Sequestosome 1 (SQSTM1)/p62, a vital selective autophagy receptor, recruits ubiquitinated cargo to form autophagosomes for lysosomal degradation. Nab-PTX is an albumin-bound paclitaxel nanoparticle used in clinical cancer therapy. However, the role of SQSTM1 in regulating the delivery and efficacy of nanodrugs remains unclear. Here we showed that SQSTM1 plays a crucial role in Nab-PTX drug delivery and efficacy in human lung and colorectal cancers. Nab-PTX induces SQSTM1 phosphorylation at Ser403, which facilitates its incorporation into the selective autophagy of nanoparticles, known as nanoparticulophagy. Nab-PTX increased LC3-II protein expression, which triggered autophagosome formation. SQSTM1 enhanced Nab-PTX recognition to form autophagosomes, which were delivered to lysosomes for albumin degradation, thereby releasing PTX to induce mitotic catastrophe and apoptosis. Knockout of SQSTM1 downregulated Nab-PTX-induced mitotic catastrophe, apoptosis, and tumor inhibition in vitro and in vivo and inhibited Nab-PTX-induced caspase 3 activation via a p53-independent pathway. Ectopic expression of SQSTM1 by transfection of an SQSTM1-GFP vector restored the drug efficacy of Nab-PTX. Importantly, SQSTM1 is highly expressed in advanced lung and colorectal tumors and is associated with poor overall survival in clinical patients. Targeting SQSTM1 may provide an important strategy to improve nanodrug efficacy in clinical cancer therapy. This study demonstrates the enhanced efficacy of Nab-PTX for human lung and colorectal cancers via SQSTM1-mediated nanodrug delivery.

Bis(2-phenylpyridine)(acetylacetonate)iridium, Ir(ppy) 2 (acac), is a benchmark green emitter for phosphorescent organic light-emitting diodes (PhOLEDs). In this work, we reported three positional isomeric cyano-substituted Ir(ppy) 2 (acac) complexes, i.e., Ir(3-CN), Ir(4-CN), and Ir(10-CN), with the emission in the yellow to red region (544-625 nm). Through theoretical investigation and single-crystal analysis, it was found that the introduction of cyano substitution at various positions of the ppy ligand allows for tuning the electron distribution and coordination bond length of Ir complexes. Therefore, the charge transfer property of Ir complexes is enhanced such that the energy gap of the cyano-substituted Ir(ppy) 2 (acac) complexes was reduced. In addition, Ir(3-CN), Ir(4-CN), and Ir(10-CN) exhibited high PLQYs of 83, 54, and 75%, respectively, with the phosphorescence lifetime in the range of 0.79-2.08 μs. Notably, the device utilizing Ir(3-CN) as the emitter exhibited a maximum external quantum efficiency (EQE) of 25.4%, current efficiency of 56.9 cd A -1 , power efficiency of 68.7 lm W -1 , and brightness of 61,340 cd m -2 at 8 V. The EQE of this device remained 24.3 and 19.9% at luminances of 1,000 and 10,000 cd m -2 , corresponding to the efficiency roll-off of 4.3 and 21.7%, respectively. Comparing to the Ir complexes using the ligand with an extended conjugated structure, our results demonstrated a simple molecular design strategy for phosphorescence emitters with reduced molecular weight for efficient PhOLEDs in the yellow to red color region.

Deep-blue thermally activated delayed fluorescence (TADF) molecules present promising potential in organic light-emitting diodes (OLEDs), especially for display applications. Here, an efficient molecular engineering approach to modifying the donor or acceptor features of the D-π-A-configured TADF molecules for deep-blue emission is reported. By introducing oxygen and sulfone as a bridge unit onto the macrocyclic donor, two emitters, c-ON-MeTRZ and c-NS-MeTRZ , are synthesized and characterized, respectively. The reduced donor strength of c-ON-MeTRZ and c-NS-MeTRZ as compared to that of the model molecule c-NN-MeTRZ leads to blue-shifted emissions with high photoluminescence quantum yields (PLQYs) and retains TADF characters, while the new emitter c-NN-MePym with the most blue-shifted emission only exhibits a pure fluorescent nature because of the electron-accepting feature of pyrimidine that is insufficient for inducing the TADF property. In the presence of macrocyclic donors, these new emitters show high horizontal dipole ratios (Θ // = 85-89%), which are beneficial for improving the light out-coupling efficiency. Deep-blue TADF OLEDs incorporating c-ON-MeTRZ as an emitter doped in the mCPCN host achieves a high maximum external quantum efficiency (EQE max ) of 30.2% together with 1931 Commission Internationale de I'Eclairage (CIE) coordinates of (0.14, 0.13), while the counter device employing c-NS-MeTRZ as a dopant gives EQE max of 15.4% and CIE coordinates of (0.14, 0.09). The EQE max of c-ON-MeTRZ- and c-NS-MeTRZ -based devices can be significantly improved to 34.4 and 29.3%, respectively, with a polar host DPEPO, which stabilizes the charge transfer (CT) S 1 state to give lower Δ E ST for improving the reverse intersystem crossing process. The efficient TADF character, high PLQYs, and high anisotropic emission dipole ratios work together to render the superior electroluminescence (EL) efficiencies. Based on the detailed characterizations of physical properties, theoretical analyses, and comprehensive study on the corresponding devices, a clear structure-property-performance relationship has been successfully established to verify the effective molecular design strategy of modulating the macrocyclic donor characters for efficient deep-blue TADF emitters.

Crystal structure prediction (CSP) is an invaluable tool in the pharmaceutical industry because it allows to predict all the possible crystalline solid forms of small-molecule active pharmaceutical ingredients. We have used a CSP-based cocrystal prediction method to rank ten potential cocrystal coformers by the energy of the cocrystallization reaction with an antiviral drug candidate, MK-8876, and a triol process intermediate, 2-ethynylglyclerol. For MK-8876, the CSP-based cocrystal prediction was performed retrospectively and successfully predicted the maleic acid cocrystal as the most likely cocrystal to be observed. The triol is known to form two different cocrystals with 1,4-diazabicyclo[2.2.2]octane (DABCO), but a larger solid form landscape was desired. CSP-based cocrystal screening predicted the triol-DABCO cocrystal as rank one, while a triol-l-proline cocrystal was predicted as rank two. Computational finite-temperature corrections enabled determination of relative crystallization propensities of the triol-DABCO cocrystals with different stoichiometries and prediction of the triol-l-proline polymorphs in the free-energy landscape. The triol-l-proline cocrystal was obtained during subsequent targeted cocrystallization experiments and was found to exhibit an improved melting point and deliquescence behavior over the triol-free acid, which could be considered as an alternative solid form in the synthesis of islatravir.

A novel series of non-amidine-based C1s inhibitors have been explored. Starting from high-throughput screening hit 3 , isoquinoline was replaced with 1-aminophthalazine to enhance C1s inhibitory activity while exhibiting good selectivity against other serine proteases. We first disclose a crystal structure of a complex of C1s and a small-molecule inhibitor ( 4e ), which guided structure-based optimization around the S2 and S3 sites to further enhance C1s inhibitory activity by over 300-fold. Improvement of membrane permeability by incorporation of fluorine at the 8-position of 1-aminophthalazine led to identification of ( R )-8 as a potent, selective, orally available, and brain-penetrable C1s inhibitor. ( R )-8 significantly inhibited membrane attack complex formation induced by human serum in a dose-dependent manner in an in vitro assay system, proving that selective C1s inhibition blocked the classical complement pathway effectively. As a result, ( R )-8 emerged as a valuable tool compound for both in vitro and in vivo assessment.

A metal-to-ligand charge transfer with mixed intraligand character is observed for the rhenium hexakisarylisocyanide complex [Re(CNAr) 6 ]PF 6 (CNAr = 2,6-dimethylphenylisocyanide, λ max = 300 nm). Upon oxidation to [Re(CNAr) 6 ](PF 6 ) 2 , the dominant low energy optical transition is a ligand-to-metal charge transfer (LMCT) mixed with intraligand transitions (λ max = 650 nm). TD-DFT was used to identify the participating ligand-based orbitals in the LMCT transition, revealing that the majority of the donor orbital is based on the aryl ring (85%) as opposed to the CN bond (14%). For both [Re(CNAr) 6 ] + and [Re(CNAr) 6 ] 2+ , structural characterization by X-ray diffraction reveals deviations from O h geometry at the central Re ion, with larger reduction in symmetry observed for Re(II). For [Re(CNAr) 6 ] + , these structural changes lead to a broadening of the strong ν(C≡N) stretch (2065 cm -1 ), as the degeneracy of the T 1u IR-active mode is broken. Furthermore, a shoulder is observed for this ν(C≡N) stretch, resulting from deviation of the C-N-Ar bond from linearity. By contrast, [Re(CNAr) 6 ] 2+ has two weak bands in the ν(C≡N) region (2065 and 2121 cm -1 ). DFT calculations indicate that reduction of symmetry at the central rhenium ion manifests in the decrease in intensity and the observed split of the ν(C≡N) band. Stability of both complexes are limited by light-induced decomposition where Re(I) dissociates a isocyanide ligand upon irradiation and Re(II) absorbance decays under ambient light. These data provide new insights to the electronic structure of [Re(CNAr) 6 ] 2+ , enhancing our understanding of LMCT excited states and the versatility of isocyanide ligands.

The development of orally bioavailable, furanopyrimidine-based double-mutant (L858R/T790M) EGFR inhibitors is described. First, selectivity for mutant EGFR was accomplished by replacing the ( S )-2-phenylglycinol moiety of 12 with either an ethanol or an alkyl substituent. Then, the cellular potency and physicochemical properties were optimized through insights from molecular modeling studies by implanting various solubilizing groups in phenyl rings A and B. Optimized lead 52 shows 8-fold selective inhibition of H1975 (EGFR L858R/T790M overexpressing) cancer cells over A431 (EGFR WT overexpressing) cancer cells; western blot analysis further confirmed EGFR mutant-selective target modulation inside the cancer cells by 52 . Notably, 52 displayed in vivo antitumor effects in two different mouse xenograft models (BaF3 transfected with mutant EGFR and H1975 tumors) with TGI = 74.9 and 97.5% after oral administration ( F = 27%), respectively. With an extraordinary kinome selectivity ( S (10) score of 0.017), 52 undergoes detailed preclinical development.

Traditional methods for synthesizing complex oligosaccharides currently developed are not efficient, requiring a new glycosylation methodology. Herein, using phosphotungstic acid (PTA) as a catalyst has demonstrated to be a simple possibility for carbohydrate synthesis. The methodology is engineered into a PTA-catalyzed thioglycoside preparation under microwave conditions and de- O -acetylation of carbohydrates. These easier operations and convenient protocols display a wide substrate scope. Moreover, both methods can be developed into a one-pot reaction for the efficient synthesis of carbohydrate analogues., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Contact doping is considered crucial for reducing the contact resistance of two-dimensional (2D) transistors. However, a process for achieving robust contact doping for 2D electronics is lacking. Here, we developed a two-step doping method for effectively doping 2D materials through a defect-repairing process. The method achieves strong and hysteresis-free doping and is suitable for use with the most widely used transition-metal dichalcogenides. Through our method, we achieved a record-high sheet conductance (0.16 mS·sq -1 without gating) of monolayer MoS 2 and a high mobility and carrier concentration (4.1 × 10 13 cm -2 ). We employed our robust method for the successful contact doping of a monolayer MoS 2 Au-contact device, obtaining a contact resistance as low as 1.2 kΩ·μm. Our method represents an effective means of fabricating high-performance 2D transistors.

Scalable production of electrocatalysts capable of performing high-current water splitting is crucial to support green energy utilization. We adopted acidic redox-assisted deposition (ARD) to realize the continuous roll-to-roll fabrication of a strongly adherent cobalt manganese oxyhydroxide (CMOH) film on Ni foam under ambient conditions in water. The as-fabricated products show uniform CMOH coverage and oxygen evolution activities with dimensions as large as 5 m length by 0.25 m width. Also, we converted CMOH into a metallic form (denoted as CM) with the preserved high adhesion to serve as a high-current hydrogen evolution electrocatalyst. Our results reveal that the insufficient adhesion of powder forms electrocatalysts (i.e., Pt and RuO 2 as benchmarks), even with the binder, at high-current electrolysis (>1000 mA) can be solved using the fabricated CM||CMOH cell. With an active area of 1 cm × 1 cm assembly in anion exchange membrane (AEM) electrolyzers, we observed the remarkable record of alkaline electrolysis stably at 5000 mA. This result established a new benchmark record on the high-current water splitting research.

Oxidative addition is an essential elementary reaction in organometallic chemistry and catalysis. While a diverse array of oxidative addition reactions has been reported to date, examples of P-O bond activation are surprisingly rare. Herein, we report the ligand-templated oxidative addition of a phosphinite P-O bond in the diphosphinito aniline compound HN(2-OP i Pr 2 -3,5- t Bu-C 6 H 2 ) 2 [H(P 2 ONO)] at Ni 0 to form (PONO)Ni(HP i Pr 2 ) after proton rearrangement. Notably, the P-O cleavage occurs selectively over an amine N-H bond activation. Additionally, the ligand cannibalization is reversible, as addition of XPR 2 (X = Cl, Br; R = i Pr, Cy) to (PONO)Ni(HP i Pr 2 ) readily produces either symmetric or unsymmetric (P 2 ONO)NiX species and free HP i Pr 2 . Finally, the mechanisms of both the initial P-O bond cleavage and its subsequent reconstruction are investigated to provide further insight into how to target P-O bond activation.

Four emitters based on the naphthyridine acceptor moiety and various donor units exhibiting thermally activated delayed fluorescence (TADF) were designed and synthesized. The emitters exhibited excellent TADF properties with a small Δ E ST and a high photoluminescence quantum yield. A green TADF organic light-emitting diode based on 10-(4-(1,8-naphthyridin-2-yl)phenyl)-10 H -phenothiazine exhibited a maximum external quantum efficiency of 16.4% with Commission Internationale de L'éclairage coordinates of (0.368, 0.569) as well as a high current and power efficiency of 58.6 cd/A and 57.1 lm/W, respectively. The supreme power efficiency is a record-high value among the reported values of devices with naphthyridine-based emitters. This results from its high photoluminescence quantum yield, efficient TADF, and horizontal molecular orientation. The molecular orientations of the films of the host and the host doped with the naphthyridine emitter were explored by angle-dependent photoluminescence and grazing-incidence small-angle X-ray scattering (GIWAXS). The orientation order parameters (Θ ADPL ) were found to be 0.37, 0.45, 0.62, and 0.74 for the naphthyridine dopants with dimethylacridan, carbazole, phenoxazine, and phenothiazine donor moieties, respectively. These results were also proven by GIWAXS measurement. The derivative of naphthyridine and phenothiazine was shown to be more flexible to align with the host and to show the favorable horizontal molecular orientation and crystalline domain size, benefiting the outcoupling efficiency and contributing to the device efficiency., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Nanodiamonds (NDs) are emerging with great potential in biomedical applications like biomarking through fluorescence and magnetic resonance imaging (MRI), targeted drug delivery, and cancer therapy. The magnetic and optical properties of NDs could be tuned by selective doping. Therefore, we report multifunctional manganese-incorporated NDs (Mn-NDs) fabricated by Mn ion implantation. The fluorescent properties of Mn-NDs were tuned by inducing the defects by ion implantation and enhancing the residual nitrogen vacancy density achieved by a two-step annealing process. The cytotoxicity of Mn-NDs was investigated using NCTC clone 929 cells, and the results revealed no cytotoxicity effect. Mn-NDs have demonstrated dual mode contrast enhancement for both T 1 - and T 2 -weighted in vitro MR imaging. Furthermore, Mn-NDs have illustrated a significant increase in longitudinal relaxivity (fivefold) and transversal relaxivity (17-fold) compared to the as-received NDs. Mn-NDs are employed to investigate their ability for in vivo MR imaging by intraperitoneal (ip) injection of Mn-NDs into mice with liver tumors. After 2.5 h of ip injection, the enhancement of contrast in T 1 - and T 2 -weighted images has been observed via the accumulation of Mn-NDs in liver tumors of mice. Therefore, Mn-NDs have great potential for in vivo imaging by MR imaging in cancer therapy., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Continued efforts are made on the development of earth-abundant metal catalysts for dehydrogenation/hydrolysis of amine boranes. In this study, complex [K-18-crown-6-ether][(NO) 2 Fe(μ- Me Pyr)(μ-CO)Fe(NO) 2 ] ( 3-K-crown , Me Pyr = 3-methylpyrazolate) was explored as a pre-catalyst for the dehydrogenation of dimethylamine borane (DMAB). Upon evolution of H 2(g) from DMAB triggered by 3-K-crown , parallel conversion of 3-K-crown into [(NO) 2 Fe( N , N '- Me PyrBH 2 NMe 2 )] - ( 5 ) and an iron-hydride intermediate [(NO) 2 (CO)Fe(μ-H)Fe(CO)(NO) 2 ] - ( A ) was evidenced by X-ray diffraction/nuclear magnetic resonance/infrared/nuclear resonance vibrational spectroscopy experiments and supported by density functional theory calculations. Subsequent transformation of A into complex [(NO) 2 Fe(μ-CO) 2 Fe(NO) 2 ] - ( 6 ) is synchronized with the deactivated generation of H 2(g) . Through reaction of complex [Na-18-crown-6-ether][(NO) 2 Fe(η 2 -BH 4 )] ( 4-Na-crown ) with CO (g) as an alternative synthetic route, isolated intermediate [Na-18-crown-6-ether][(NO) 2 (CO)Fe(μ-H)Fe(CO)(NO) 2 ] ( A-Na-crown ) featuring catalytic reactivity toward dehydrogenation of DMAB supports a substrate-gated transformation of a pre-catalyst [(NO) 2 Fe(μ- Me Pyr)(μ-CO)Fe(NO) 2 ] - ( 3 ) into the iron-hydride species A as an intermediate during the generation of H 2(g) .

In this work, a low-power memristor based on vertically stacked two-dimensional (2D) layered materials, achieved by plasma-assisted vapor reaction, as the switching material, with which the copper and gold metals as electrodes featured by reversible polymorphous phase changes from a conducting 1T-phase to a semiconducting 2H-one once copper cations interacted between vertical lamellar layers and vice versa, was demonstrated. Here, molybdenum diselenide was chosen as the switching material, and the reversible polymorphous phase changes activated by the intercalation of Cu cations were confirmed by pseudo-operando Raman scattering, transmission electron microscopy, and scanning photoelectron microscopy under high and low resistance states, respectively. The switching can be activated at about ±1 V with critical currents less than 10 μA with an on/off ratio approaching 100 after 100 cycles and low power consumption of ∼0.1 microwatt as well as linear weight updates controlled by the amount of intercalation. The work provides alternative feasibility of reversible and all-solid-state metal interactions, which benefits monolithic integrations of 2D materials into operative electronic circuits.

Robust antimicrobial coatings featuring high transparency, strong bactericidal activity, and an easy application procedure on generic surfaces can be widely accepted by the public to prevent pandemics. In this work, we demonstrated the hand-sprayer-based approach to deposit complex oxide coatings composed of Co-Mn-Cu-Zn-Ag on screen protectors of smartphones through acidic redox-assisted deposition (ARD). The as-obtained coatings possess high transparency (99.74% transmittance at 550 nm) and long-lasting durability against swiping (for 135 days of average use) or wet cleaning (for a routine of 3 times/day for 33 days). The spray coating enabling 3.14% Escherichia coli viability can further be reduced to 0.21% through a consistent elemental composition achieved via the immersion method. The high intake of Cu 2+ in the coating is majorly responsible for the bactericidal activity, and the presence of Ag + and Zn 2+ is necessary to achieve almost complete eradication. The success of extending the bactericidal coatings on other typical hand-touched surfaces (e.g., stainless steel railings, rubber handrails, and plastic switches) in public areas has been demonstrated.