Chemistry methods : new approaches to solving problems in chemistry最新文献

Phenomena occurring in the electrolyte as well as the interfaces with the electrodes, such as Li⁺ solvation/desolvation and solid–electrolyte interphase formation, govern the performance and safety of Li-ion batteries. In this article, a dedicated, spring-loaded operando attenuated-total-reflectance Fourier-transform infrared cell is presented, enabling quantitative, time-resolved probing of the electrode–electrolyte processes under electrochemical examination. The optical design is based on a 45^∘ incidence diamond waveguide, while the electrochemical setup comprises a gas-tight stainless steel body. The procedure for preparing the self-supported electrode and the acquisition protocol are also presented, together with a reproducible analysis workflow for tracking solvated versus free electrolyte solvent species without baseline subtraction. Representative measurements on composite tin electrodes validate the ability of the setup to resolve band shifts and intensity changes linked to Li⁺ coordination and electrolyte reduction. The methodology generalizes to diverse negative-electrode chemistries and provides molecular-level insight into battery phenomena under electrochemical operating conditions.

Zeolites are widely studied as promising catalysts for the chemical recycling of plastics due to their inherent microporosity and shape-selective properties. The accessibility of polymer chains to internal acid sites is limited, and initial reactions are supposed to occur near the external surface. A deeper understanding of the role of external acid sites is required to optimize the structure and morphology of the zeolites. In this study, a novel ZSM-5 zeolite catalyst with Brønsted acid sites selectively localized only on the external surface (ZSM-5-SA) is synthesized via selective ion exchange using bulky tetrapropylammonium ions, followed by calcination. Catalytic testing of low- and high-density polyethylene revealed that the initial degradation is mainly triggered at Brønsted acid sites located on the external surface and near-surface internal regions. Once protonated, the polymer chains undergo β-scission, leading to similar product distributions regardless of the acid site density. These findings highlight that a small number of spatially accessible acid sites can effectively initiate and propagate the cracking reaction. These findings establish a direct link between the acid site location and reaction pathway and offer a rational design principle for advanced zeolite catalysts tailored for polymer cracking and chemical upcycling.

Metal–organic frameworks (MOFs) are promising materials for photocatalytic hydrogen production. However, their efficiency is often limited by the optical properties of conventional organic linkers, such as terephthalic acid (TA). In this work, the synthesis of two novel triphenylamine-based organic dyes (L0-TA and L1-TA) featuring a donor–π–acceptor (D–π–A) structure is reported. These dyes are functionalized with a terminal moiety analogous to aminoterephthalic acid, which serves as visible-light-absorbing linkers. These dyes retain the coordination ability required for MOF assembly while enhancing light-harvesting properties. Crystallographic simulations confirm the structural compatibility of these colinkers in hybrid MOFs, providing a viable strategy to maintain MOF crystallinity while improving photocatalytic performance.

The Cover Feature illustrates the vapour-phase metalation of ML-(NH₄)₂V₇O₁₆ squares by atomic layer deposition (ALD) using diethylzinc (DEZ) as precursor, transforming them into zinc vanadate. The image reflects angstrom-scale precision, morphological preservation, and solvent-free sustainability. Directional motifs and layered textures evoke chemisorption, structural metamorphosis, and a rocket-like ascent toward magnetic and functional properties. More information can be found in the Research Article by M. A. Moreno and co-workers (DOI: 10.1002/cmtd.202500066).

The Front Cover shows fluorescence probes that report on subcellular polarity; they are exquisitely tailored by combining environment-sensitive dyes with organelle-targeting groups: the “keys” for specific delivery. Such probes have allowed polarity scales within organelles to be established—from the most hydrophobic regions in lipid droplets and membranes to the most polar cellular structures like mitochondria—thus providing invaluable tools for studying polarity changes related to physiological processes and disease. More information can be found in the Review by M. C. Gonzalez-Garcia, A. Orte and co-workers (DOI: 10.1002/cmtd.202500072). Artwork by Letpub Accdon Ltd.

Fluorine-18 is an attractive positron-emitter for positron emission tomography (PET) because of its half-life (t_1/2 = 109.8 min) and availability as [¹⁸F]fluoride ion in high activity from biomedical cyclotrons. For ¹⁸F-labeled tracers intended to image low-density protein targets (e.g., receptors, transporters and enzymes), the molar activity (A_m) must be high (usually > 37 GBq μmol⁻¹) to comply with the tracer principle, avoid attenuation of specific signal, and minimize pharmacological effects. Typically, A_m is determined by measuring radioactivity with an ionization chamber and total tracer isotopologue mass with high-performance liquid chromatography with ultraviolet absorbance detection. Molar activities often vary widely across day-to-day tracer productions and between PET radiochemistry laboratories. The terminal radiometric methods provide little insight into sources of carrier. Here, we describe accurate and simple nonradiometric methods for measuring A_m for [¹⁸F]fluoride through highly sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) on two rapidly derived surrogates, [¹⁸F]fallypride and [¹⁸F]4-(pyrrolidine-1-carbonyl)benzenesulfonyl fluoride. These methods can serve as forensic tools for investigating the sources of carrier in tracer syntheses and for A_m determinations during routine tracer productions. Moreover, the LC-MS/MS technique can be applied to radiotracers lacking a strong UV chromophore, as with [¹⁸F]2-fluoro-2-deoxy-D-glucose tetraacetate, an intermediate in the synthesis of the most widely used PET tracer, [¹⁸F]2-fluoro-2-deoxy-D-glucose.

Polyphenolic flame-retardant (FR) systems have attracted growing attention as promising candidates that can simultaneously address environmental sustainability and fire safety requirements. This review comprehensively analyzes their operating mechanisms and application performance through a comparative assessment of the literature. Representative polyphenolic materials—including lignin, polydopamine, tannic acid, flavonoids, and related phenolics—are examined with respect to char formation, radical scavenging, metal-ion coordination, surface protection mechanisms, and synergistic effects with inorganic or organic coadditives. Their FR efficacy, durability, and stability are compared across diverse substrates, including polymers, wood, fibers, and coatings, with emphasis on biodegradability, renewability, and environmental safety. Furthermore, life cycle assessment (LCA) and safe-and-sustainable-by-design (SSbD) frameworks are applied to evaluate their alignment with circular economy principles. Collectively, this review clarifies the opportunities and limitations of polyphenolic FR systems and highlights their potential as sustainable candidates for next-generation fire mitigation technologies.

Automated pipetting is a valuable tool for the preparation of high-throughput experimentation screens; however, automation in postreaction processing (work-up) steps is often overlooked. Opentrons has created an affordable commercial pipetting robot that unlocks automated liquid dispensing and transferring for even the early-career researcher. This article demonstrates the utility of this affordable automated pipetting solution for postreaction processing through four case studies, selectively sampling biphasic mixtures when applicable. Work-up procedures appropriate for high-throughput screening of academic and industrially relevant reactions, including Suzuki–Miyaura coupling, Buchwald–Hartwig coupling and Miyaura borylation, are described. An additional protocol is designed for determining the appropriate aqueous wash to reduce protodeboronation for both an aryl boronic acid and aryl boronic pinacol ester.

Mesoporous materials have many technologically important applications and are often impregnated with a solution during functionalization and/or operation. However, our understanding of the liquid-filled and dried states at the level of individual pores remains limited. Cryogenic electron tomography (cryo-ET) enables local 3D imaging of liquid-impregnated mesoporous materials with nanometer resolution, but it is rarely applied due to complex sample preparation, imaging, and analysis. Here, a “dry” cryo-ET approach is presented, enabling the 3D imaging of water- and metal-salt solution-impregnated disordered mesoporous γ-Al₂O₃ supports. The results show that empty and liquid-filled pores are clearly distinguishable and that mesoscale variations in pore volume and specific surface exist. Pore structure, pore size, and pore surface corrugation remain unaffected by water- or metal-salt solutions. As solution molarity increases, reduced contrast between the solution and γ-Al₂O₃ support prevents quantitative analysis. After freeze-drying, deposits accumulate at the perimeter of the imaged particle, while a uniform deposition is observed within the center of the pore network. Metal-salt deposition reduces pore node distance and average size, while surface curvature decreases and corrugation increases. Our “dry” cryo-ET workflow enables the first time 3D analysis and quantification of liquid-impregnated and freeze-dried disordered mesoporous materials.

Tall oil fatty acid (TOFA) represents an important byproduct obtained from processing of lignocellulosic biomass, mainly in the pulp and paper industry. In this work, TOFA is first transformed into its soap form under optimized alkaline conditions. TOFA-based soap is then employed as feedstock for the production of long-chain alkenes through photocatalysis, using a photoreactor equipped with a ultraviolet a-light emitting diode source. The photocatalytic efficiency of TiO₂ is improved by surface modification with NH₄⁺ species. A response surface methodology (RSM) approach is applied to examine the influence of reaction duration (135, 180, and 225 min), photocatalyst loading (80, 110, and 140 mg), and the amount of TOFA-based soap (50, 100, and 150 mg). The maximum yield of C_n−1 long-chain alkenes (77.7 mg) is achieved at nearly 1:1 ratio of TOFA-based soap to NH₄-TiO₂ after 180 min irradiation at 365 nm. Under these optimized conditions, approximately 55% of the TOFA-based soap could be converted into long-chain alkenes. Hydration of these alkenes with sulfuric acid yields corresponding long-chain alcohols, which may act as precursors for bio-based extended surfactants and related applications. This study emphasizes the potential of TOFA, a byproduct of lignocellulosic waste streams, as a renewable feedstock for generating high-value chemicals.