Communications Chemistry最新文献

Multi-resonance (MR) materials hold an intriguing feature of narrow emission spectra and have attracted considerable attention in the manufacture of high-definition organic light-emitting diodes (OLEDs). However, the majority of MR materials are composed by a boron-nitrogen skeleton, which is unfavorable for expanding the scope of luminescent materials with narrow emission spectra to meet various application demands. In this work, we wish to report a new carbonyl-nitrogen (C = O/N) skeleton of 5,12-dihydroquinolino[2,3-b]acridine-7,14-dione (QA), and three tailored C = O/N MR molecules are synthesized and fully characterized by crystallography, thermal measurement, cyclic voltammetry, steady-state and transient spectroscopy and theoretical calculation. They show efficient green emissions with narrow full width at half maximum (FWHM) of about 27 nm and high photoluminescence quantum yields of up to 93% in doped films. Efficient hyperfluorescence OLEDs are fabricated using these materials as emitters, providing pure green lights with electroluminescence peaks at 526‒538 nm, narrow FWHMs of 29‒33 nm, excellent external quantum efficiencies of up to 29.48% and small efficiency roll-offs. These results reveal that QA could be a potential skeleton for exploring efficient C = O/N MR molecules.

RNA methyltransferases (MTases) have recently become increasingly important in drug discovery. Yet, most frequently utilized RNA MTase assays are limited in their throughput and hamper this rapidly evolving field of medicinal chemistry. This study developed a microscale thermophoresis (MST)-based split aptamer assay for enzymatic MTase investigations, improving current methodologies by offering a non-proprietary, cost-effective, and highly sensitive approach. Our findings demonstrate the assay's effectiveness across different RNA MTases, including inhibitor characterization of METTL3/14, DNMT2, NSUN2, and S. aureus TrmD, enabling future drug discovery efforts. Using this concept, a pilot screening on the cancer drug target DNMT2 discovered several hit compounds with micromolar potency.

The nine human NR3 nuclear receptors translate steroid hormone signals in transcriptomic responses and operate multiple highly important processes ranging from development over reproductive tissue function to inflammatory and metabolic homeostasis. Although several NR3 ligands such as glucocorticoids are invaluable drugs, this family is only partially explored, for example, in autoimmune diseases and neurodegeneration, but may hold therapeutic potential in new areas. Here we report a chemogenomics (CG) library to reveal elusive effects of NR3 receptor modulation in phenotypic settings. 34 highly annotated and chemically diverse ligands covering all NR3 receptors were selected considering complementary modes of action and activity, selectivity and lack of toxicity. Endoplasmic reticulum stress resolving effects of N3 CG subsets in proof-of-concept application validate suitability of the set to connect phenotypic outcomes with targets and to explore NR3 receptors from a translational perspective.

Electrochemical synthesis routes powered by renewable electricity can provide sustainable chemical commodities by replacing conventional fossil-based processes. Increasing research focuses on value-added chemicals like the indispensable fertilizer urea, which also constitutes a study case for electrochemical CN-coupling. To guide the identification of highly selective catalysts, we aim to provide new insight by analysing existing experimental data on the selectivity of transition metal catalysts towards electrochemically synthesized urea. Firstly, we project high dimensional experimental data using principal component analysis (PCA) to lower dimensions, and thereby confirm that urea selectivity is correlated with the selectivity towards CO and NH₃. Furthermore, we identified the most suitable two-dimensional descriptors for selectivity prediction out of various adsorption energies calculated using density functional theory (DFT). We suggest that the adsorption energies of *H and *O on transition metal slabs predict the selectivity towards urea in the co-reduction of CO₂ and nitrite ( ${\mathrm{NO}}_2^{-}$ ).

Lithium metal as a negative electrode material offers ten times the specific capacity of graphitic electrodes, but its rechargeable operation poses challenges like excessive and continuous interphase formation, high surface area lithium deposits and safety issues. Improving the lithium | electrolyte interface and interphase requires powerful surface analysis techniques, such as ToF-SIMS sputter depth profiling.This study investigates lithium metal sections with an SEI layer by ToF-SIMS using different sputter ions. An optimal sputter ion is chosen based on the measured ToF-SIMS sputter depth profiles and SEM analysis of the surface damage. Further, this method is adapted to lithium metal foil with an intermetallic coating. ToF-SIMS sputter depth profiles in both polarities provide comprehensive insights into the coating structure. Both investigations highlight the value of ToF-SIMS sputter depth profiling in lithium metal battery research and offer guidance for future studies.

The knowledge of phase relations of constitutive minerals is essential to investigate the structure, dynamics and evolution of the Earth and planetary interiors. This paper reviews the phase relations of bridgmanite, the most abundant mineral in the Earth's lower mantle, with an ideal composition of MgSiO₃. Bridgmanite has an orthorhombic structure with larger dodecahedral A and smaller octahedral B cation sites. The A-sites can incorporate Mg²⁺, Fe²⁺, Fe³⁺, and Al³⁺, while the B-sites accommodate Si⁴⁺, Al³⁺ and Fe³⁺. The incorporation of hydrogen and large cations like Ca is likely limited, although these issues are still debated. Al³⁺ and Fe³⁺, respectively, can form the charge-coupled components, AlAlO₃ and Fe³⁺Fe³⁺O₃ occupying both A- and B-sites. When both Al³⁺ and Fe³⁺ are present, Al³⁺ occupies B-sites, and Fe³⁺ occupies A-sites, forming Fe³⁺AlO₃. In systems with excess MgO, Al and Fe³⁺ also form the oxygen vacancy components MgAl³⁺O_2.5□_0.5 and MgFe³⁺O_2.5□_0.5. The phase relationships of bridgmanite with coexisting phases are discussed as a function of pressure, temperature, and oxygen fugacity from the simple MgSiO₃ system to the complex MgO-Fe²⁺O-Fe³⁺₂O₃-Al₂O₃-SiO₂ system.

Alkaline exchange membrane fuel cells (AEMFCs) offer a promising alternative to the traditional fossil fuel due to their ability to use inexpensive platinum group metal (PGM)-free catalysts, which could potentially replace Platinum-based catalysts. Iron coordinated in nitrogen-doped carbon (Fe-N-C) single atom electrocatalysts offer the best Pt-free ORR activities. However, most research focuses on material development in alkaline conditions, with limited attention on catalyst layer fabrication. Here, we demonstrate how the oxygen reduction reaction (ORR) performance of a porous Fe-N-C catalyst is affected by the choice of three different commercial ionomers and the ionomer-to-catalyst ratio (I/C). A Mg-templated Fe-N-C is employed as a catalyst owing to the electrochemical accessibility of the Fe sites, and the impact of ionomer properties and coverage were studied and correlated with the electrochemical performance in a gas-diffusion electrode (GDE). The catalyst layer with Nafion at I/C = 2.8 displayed the best activity at high current densities (0.737 ± 0.01 V_{RHE iR-free} at 1 A cm⁻²) owing to a more homogeneous catalyst layer, while Sustainion displayed a higher performance in the kinetic region at the same I/C. These findings provide insights into the impact of catalyst layer optimization to achieve optimal performance in Fe-N-C based AEMFCs.

The thiol-ene reaction between an alkene and a thiol can be exploited for selective labelling of cysteine residues in protein profiling applications. Here, we explore thiol-ene activation in systems from chemical models to complex cellular milieus, using UV, visible wavelength and redox initiators. Initial studies in chemical models required an oxygen-free environment for efficient coupling and showed very poor activation when using a redox initiator. When thiol-ene activation was performed in protein and cell lysate models, all three initiation methods were successful. Faster thiol-ene reaction was observed as the cysteine and alkene were brought into proximity by a binding event prior to activation, leading to quicker adduct formation in the protein model system than the chemical models. Furthermore, in the protein-protein coupling, none of the activators required an oxygen-free environment. Taken together, these observations demonstrate the broad potential for thiol-ene coupling to be used in protein profiling.

Generative models have revolutionized de novo drug design, allowing to produce molecules on-demand with desired physicochemical and pharmacological properties. String based molecular representations, such as SMILES (Simplified Molecular Input Line Entry System) and SELFIES (Self-Referencing Embedded Strings), have played a pivotal role in the success of generative approaches, thanks to their capacity to encode atom- and bond- information and ease-of-generation. However, such 'atom-level' string representations could have certain limitations, in terms of capturing information on chirality, and synthetic accessibility of the corresponding designs.In this paper, we present fragSMILES, a novel fragment-based molecular representation in the form of string. fragSMILES encode fragments in a 'chemically-meaningful' way via a novel graph-reduction approach, allowing to obtain an efficient, interpretable, and expressive molecular representation, which also avoids fragment redundancy. fragSMILES contributes to the field of fragment-based representation, by reporting fragments and their 'breaking' bonds independently. Moreover, fragSMILES also embeds information of molecular chirality, thereby overcoming known limitations of existing string notations. When compared with SMILES, SELFIES and t-SMILES for de novo design, the fragSMILES notation showed its promise in generating molecules with desirable biochemical and scaffolds properties.