Synthetic Process Research Articles

Bubbling Chemical Vapors in Molten Metal toward XIV-Group Nanosheets.

Two-dimensional (2D) XIV-group nanosheets (germanene, silicene, and stannene) possess unique physical and chemical features promising in fields of electronics, energy storage, and conversions. However, preparing these nanosheets is challenging owing to their non van der Waals structure with strong chemical bonds inside. Herein, a bubbling chemical-vapor growth method is proposed to synthesize these XIV-group nanosheets by bubbling XIV-group-element chlorides in molten sodium. During the synthetic process, XIV-group materials are formed by the reaction of XIV-group element chlorides with strong reducing sodium, then nucleated, and finally isolated to 2D nanosheets in the gas-liquid interface. With the collapse of vapor bubbles and subsequent injection, 2D nanosheets are continuously produced. The nanosheets (Ge) possess a thickness of ∼3.8 nm and a lateral size of ∼2.0 μm. Combining with graphene, the hybrid and flexible films are obtained, delivering a volumetric specific capacity of 4785 mAh cm-3 and superior cycling stability (over 4000 cycles) in lithium-ion batteries.

Development of a multigram synthetic process to clinical candidate TMP195, a class IIa histone deacetylase selective inhibitor

Development of a multigram synthetic process to clinical candidate TMP195, a class IIa histone deacetylase selective inhibitor

Looking at the Modern to Better Understand the Ancient: Is It Possible to Differentiate Mars Pigments from Archaeological Ochres?

This article offers a discussion of the possibility of distinguishing ochres from Mars pigments. The discussion addresses technological, archaeological, and artistic aspects. Natural earth pigments such as ochres, siennas, and umbers have been widely used from the Paleolithic to the present day and still find wide application despite the development of synthetic iron oxide pigment synthesis processes, called Mars pigments. The potential ability of today’s analytical techniques to distinguish between two classes of pigments of the same color with very similar chemical composition—but perhaps sufficient for reliable recognition—is also discussed. The paper begins by addressing the proper use of the terms “ochres” and “Mars pigments” and their accurate identification in artworks. It reviews the literature on the chemical–mineralogical characterization of yellow and red iron pigments and analyzes pigment catalogs to understand how companies distinguish ochres from Mars pigments. An experimental analysis using External Reflection Infrared Spectroscopy (FTIR-ER) compared painting samples made with natural ochres and Mars pigments, confirming the literature findings and suggesting future research directions. Key differences such as hematite in yellow ochres and specific spectral peaks in red ochres support the potential of FTIR-ER spectroscopy as a noninvasive tool for distinguishing pigments, especially for fragile artifacts and archaeological applications.

Optimal carbofuran degradation via CWPO in NOM-doped water by a framework Cu-doped aluminate perovskite catalyst derived from aluminum saline slags

This study is the first to propose the synthesis of LayAl1–xCuxO3–δ perovskite catalysts using Al recovered from acid leaching of saline slags. The effect of parameters such as the La/Al molar ratio was explored during the synthetic process. A suite of characterization techniques—including XRF, XRD, N2 adsorption, H2-TPR, FTIR, TGA-DTA, TEM, SEM, EDX, and XPS—confirmed the successful synthesis of high-purity (up to 90 %) perovskites with La and O vacancies, and a high concentration of Cu(I) active sites dispersed within the perovskite lattice. The best catalyst was used to optimize the degradation of carbofuran (CBF) in water doped with synthetic dissolved natural organic matter (NOM) using the Fenton-like catalytic wet peroxide oxidation (CWPO) approach. The effects of catalyst concentration, H2O2 dose, and pH on catalytic performance were investigated. Degradation, mineralization (COD removal), and H2O2 consumption were maximized, while Cu leaching was minimized using a statistical desirability function for multiple responses. Optimal conditions were found to be a catalyst concentration (mg Cu/mg H2O2) of 0.234 (2.0 g L–1), an H2O2 dose of 73.3 % (0.73 times the stoichiometric dose for full COD mineralization), and a remarkable circumneutral pH of 6.2. Under these conditions, degradation reached 94.1 %, and COD mineralization was 51 % under room temperature. Notably, the perovskite catalyst exhibited remarkable stability during reuse in up to three cycles, as demonstrated by the low Cu leaching (<1.30 mg L–1).

Absolute instability of power law liquid jets

Non-Newtonian fluid threads are common in many natural and synthetic processes. An appreciation of how such threads break into droplets has been a subject of study for a long time. In this paper, we investigate the absolute instability of a cylindrical thread, modeled as a power law fluid, falling under gravity surrounded by an inviscid medium. Particular attention is paid to investigating the effects of the gas-to-liquid density ratio and the Reynolds number as well as the influence of the flow index number on critical Weber numbers (which mark the transition between convective and absolute instability). Our results determine the convective to absolute instability boundary for a number of different parameter values.

Synthetic thermal image generation and processing for close proximity operations

The new scenarios foreseen in forthcoming space missions have increased interest towards optical-based relative navigation techniques, which have demonstrated efficacy in a variety of operational conditions. Although object detection methods have predominantly been used within the visible spectrum, optical payloads struggle in weak lighting conditions and are susceptible to overexposure. Consequently, thermal imaging systems are being investigated as a potential solution, as their integration into the current systems would greatly extend future mission capabilities. This study seeks to fill the gap in literature by assessing the performance of state-of-the-art object detection algorithms with images captured in the thermal spectrum. Given the scarcity of readily available thermal infrared (TIR) images captured in orbit, a novel rendering pipeline is implemented to generate physically accurate thermal images relevant to close-proximity scenarios. These synthetic representations feature a simplified target spacecraft against Earth and deep space backgrounds, including variations in illumination conditions, material properties, relative state, and scale. To ensure realistic outputs, the radiative field of the Earth is modelled based on satellite measurements collected in the cloud and Earth radiant energy system (CERES) database. To enrich the fidelity of the outputs, a thermal sensor model and the corresponding noise levels are introduced in the pipeline. The generated images are then used to test the performance of traditional object detection algorithms in discerning the region of interest (ROI) under different orbital scenarios. The results demonstrate the effectiveness of the selected methodologies in mitigating the influence of the Earth in the ROI extraction process, while also revealing a performance degradation due to the presence of multi-material targets.

The Chemistry of Levulinic Acid: Its Potential in the Production of Biomass‐based Chemicals

Biomass has been identified as the ultimate sustainable resource for all carbon‐based consumer products of the chemical industries in the future. Its catalytic conversion leads to the formation of various platform chemicals that could partially or even fully replace the fossil‐based building blocks that have been currently used in synthetic chemical processes. Among these compounds, levulinic acid (LA) has been recognized as a member of the "Top Value Added Chemicals from Biomass" and has attracted significant attention since the seminal paper reported by Werpy and Petersen in 2004. This review summarizes the properties, recent advances, and developments in the chemistry of levulinic acid. The production of LA from both plant and animal‐based carbohydrate feedstocks via 5‐hydroxymethylfurfural or furfuryl alcohol is discussed from a mechanistic perspective, highlighting intrinsic molecular‐level limitations to LA formation. The efficiencies of recently developed catalytic systems are also summarized and compared. Furthermore, the conversion of LA into high‐value‐added downstream chemicals, including its role in the synthesis of complex molecular structures, is overviewed. This section discussed the reactions of LA in the points of view of its various transformations on carbonyl‐, carboxy‐, methyl‐, and methylene functional groups. The reactions of these functionalities with C‐ ,N‐, O‐, and S‐nucleophiles, alcohols, amines, organometallic reagents, oxygen etc. were thematically summarized. Our review also outlooks to highlight the challenges and opportunities associated with the extensive research area of organic chemistry of levulinic acid.

Green and Mild Fabrication of Magnetic Poly(trithiocyanuric acid) Polymers for Rapid and Selective Separation of Mercury(II) Ions in Aqueous Samples

The removal and detection of highly toxic mercury(II) ions (Hg2+) in water used daily is essential for human health and monitoring environmental pollution. Efficient porous organic polymers (POPs) can provide a strong adsorption capacity toward heavy metal ions, although the complex synthetic process and inconvenient phase separation steps limit their application. Hence, a combination of POPs and magnetic nanomaterials was proposed and a new magnetic porous organic polymer adsorbent was fabricated by a green and mild redox reaction in the aqueous phase with trithiocyanuric acid (TA) and its sodium salts acting as reductive monomers and iodine acting as an oxidant. In the preparation steps, no additional harmful organic solvent is required and the byproducts of sodium iodine are generally considered to be non-toxic. The resulting magnetic poly(trithiocyanuric acid) polymers (MPTAPs) are highly porous, have large surface areas, are rich in sulfhydryl groups and show easy magnetic separation ability. The experimental results show that MPTAPs exhibit good adsorption affinity toward Hg2+ with high selectivity, rapid adsorption kinetics (10 min), a large adsorption capacity (211 mg g−1) and wide adsorption applicability under various pH environments (pH 2~8). Additionally, MPTAPs can be reused for up to 10 cycles, and the magnetic separation step of MPTAPs is fast and convenient, reducing energy consumption compared to centrifugation and filtration steps required for non-magnetic adsorbents. These results demonstrate the promising capability of MPTAPs as superior adsorbents for effective adsorption and separation of Hg2+. Based on this, the prepared MPTAPs were adopted as magnetic solid-phase extraction (MSPE) materials for isolation of trace Hg2+ from aqueous samples. Under optimized conditions, the extraction and quantification of trace Hg2+ in water samples were accomplished using inductively coupled plasma mass spectrometry (ICP-MS) detection after MSPE procedures. The proposed MPTAPs-based MSPE-ICP-MS method is efficient, rapid, sensitive and selective for the determination of trace Hg2+, and was successfully employed for the accurate analysis of trace Hg2+ in tap water, wastewater, lake water and river water samples.

Synthesis and Characterization of Zirconia-Based Ceramics: A Comprehensive Exploration of Film Formation and Mixed Metal Oxide Nanoparticle Synthesis

Due to its strong ionic conductivity and superior mechanical qualities, zirconia-based ceramics are frequently used in electrochemical devices. Today, zirconium oxychloride octahydrate and ethanol have been developed for the purpose of reducing zirconium thin films on glass, single-crystal silicon p-type, substrates. The phase composition and properties of the films, as well as the physicochemical processes involved in film formation, have all been investigated. Zirconia mixed metal oxide nanoparticles with various physicochemical properties can be created using a variety of synthetic processes in conjunction with additional variables like concentration, PH, type of precursor utilized, etc. In order to create zirconia mixed metal oxide nanoparticles, many synthetic techniques, including sol-gel, hydrothermal, and coprecipitation methods are discussed in this article.

Comparative Study of Catalysis Strategies: Friedel-Crafts Alkylation Vs. Michael's Addition of Indoles to Nitroalkenes

Indoles are critical in natural amalgamation for their flexible jobs in drugs, regular items, and material science, exhibiting huge pharmacological and compound reactivity. Due to their versatility and high reactivity, nitroalkenes are essential electrophilic partners in organic synthesis. While indoles and nitroalkenes are used in both Michael addition and Friedel-Crafts alkylation for producing carbon-carbon bonds, the catalyst types and reactions involved are different. Michael addition employs conjugate addition, whereas Friedel-Crafts alkylation employs electrophilic aromatic substitution. Each technique has a different level of selectivity and distinct synthetic applications. This review examines the advancements and persistent challenges in catalysis, focusing on the comparative methodologies of Friedel-Crafts alkylation and Michael addition involving indoles and nitroalkenes. Emphasizing green chemistry principles, it discusses the potential for sustainable and efficient synthetic processes through the use of innovative catalysts, including photocatalysis and biocatalysis. The integration of computational studies and interdisciplinary collaboration is essential for developing economically viable and environmentally responsible chemical synthesis, ultimately contributing to the creation of advanced materials and pharmaceuticals.

Noninvasive Deep Learning Analysis for Smith–Magenis Syndrome Classification

Smith–Magenis syndrome (SMS) is a rare, underdiagnosed condition due to limited public awareness of genetic testing and a lengthy diagnostic process. Voice analysis can be a noninvasive tool for monitoring and detecting SMS. In this paper, the cepstral peak prominence and mel-frequency cepstral coefficients are used as disease monitoring and detection metrics. In addition, an efficient neural network, incorporating synthetic data processes, was used to detect SMS in a cohort of individuals with the disease. Three study cases were conducted with a set of 19 SMS patients and 292 controls. The three study cases employed various oversampling and undersampling techniques, including SMOTE, random oversampling, NearMiss, random undersampling, and 16 additional methods, resulting in balanced accuracies ranging from 69% to 92%. This is the first study using a neural network model to focus on a rare genetic syndrome using phonation analysis data. By using synthetic data (oversampling and undersampling) and a CNN, it was possible to detect SMS with high levels of accuracy. Voice analysis and deep learning techniques have proven to be a useful and noninvasive method. This is a finding that may help in the complex identification of this syndrome as well as other rare diseases.

Direct cleavage of C=O double bond in CO2 by the subnano MoOx surface on Mo2N

Compared to H2-assisted activation mode, the direct dissociation of CO2 into carbonyl (*CO) with a simplified reaction route is advantageous for CO2-related synthetic processes and catalyst upgrading, while the stable C = O double bond makes it very challenging. Herein, we construct a subnano MoO3 layer on the surface of Mo2N, which provides a dynamically changing surface of MoO3↔MoOx (x < 3) for catalyzing CO2 hydrogenation. Rich oxygen vacancies on the subnano MoOx surface with a high electron donating capacity served as a scissor to directly shear the C = O double bond of CO2 to form CO at a high rate. The O atoms leached in CO2 dissociation are removed timely by H2 to regenerate active oxygen vacancies. Owing to the greatly enhanced dissociative activation of CO2, this MoOx/Mo2N catalyst without any supported active metals shows excellent performance for catalyzing CO2 hydrogenation to CO. The construction of highly disordered defective surface on heterostructures paves a new pathway for molecule activation.

High‐Performance Na‐Storage and Sodiation Behavior Identification in Cellulose‐Derived Hard Carbon by High‐Resolution Element Mapping Microscopy

Nowadays, hard carbon is one of the most promising anode materials for sodium‐ion batteries. However, the Na‐storage performance of hard carbon varies for different precursors and synthetic processes due to disparities in the dopant content, dimensions, and categories of defects, graphitic domains, which lead to controversial explanations for the energy storage mechanism. Herein, self‐freestanding membrane of cellulose‐derived carbon fibers is presented, delivering a reversible Na‐storage capacity of 330 mAh g−1 at 50 mA g−1 due to abundant ordered graphitic zones with enlarged interlayer spacings around 0.39 ± 0.03 nm. Benefiting from a robust solid electrolyte interphase layer rich in NaF nanocrystals, the membrane also holds a superior rate capability of 100 mAh g−1 at 2 A g−1 and long‐term cycling stability with capacity retention of 82.6% at 1.5 A g−1 for 4000 cycles. A clear sodiation behavior of Na+ intercalation into enlarged carbon graphitic layers at the slope step above 0.10 V and Na cluster evolution in the micropores at the plateau step around 0.01–0.10 V is disclosed by high‐resolution element mapping microscopy, different from the accepted mechanism of Na+ intercalation into graphitic layers at the plateau step.

Comparative Study on Catalysis Strategies: Friedel-Crafts Alkylation vs. Michael Addition of Indoles to Nitroalkenes

Indoles are critical in natural amalgamation for their flexible jobs in drugs, regular items, and material science, exhibiting huge pharmacological and compound reactivity. Due to their versatility and high reactivity, nitroalkenes are essential electrophilic partners in organic synthesis. While indoles and nitroalkenes are used in both Michael addition and Friedel-Crafts alkylation for producing carbon-carbon bonds, the catalyst types and reactions involved are different. Michael addition employs conjugate addition, whereas Friedel-Crafts alkylation employs electrophilic aromatic substitution. Each technique has a different level of selectivity and distinct synthetic applications. This review aims to examine the advancements and persistent challenges in catalysis, focusing on the comparative methodologies of Friedel-Crafts alkylation and Michael addition involving indoles and nitroalkenes. Emphasizing green chemistry principles, it discusses the potential for sustainable and efficient synthetic processes through the use of innovative catalysts, including photocatalysis and biocatalysis. The integration of computational studies and interdisciplinary collaboration is essential for developing economically viable and environmentally responsible chemical synthesis, ultimately contributing to the creation of advanced materials and pharmaceuticals.

Efficient Simulation of Viral Transduction and Propagation for Biomanufacturing.

The design of biomanufacturing platforms based on viral transduction and/or propagation poses significant challenges at the intersection between synthetic biology and process engineering. This paper introduces vitraPro, a software toolkit composed of a multiscale model and an efficient numeric technique that can be leveraged for determining genetic and process designs that optimize transduction-based biomanufacturing platforms and viral amplification processes. Viral infection and propagation for up to two viruses simultaneously can be simulated through the model, considering viruses in either the lytic or lysogenic stage, during batch, perfusion, or continuous operation. The model estimates the distribution of the viral genome(s) copy number in the cell population, which is an indicator of transduction efficiency and viral genome stability. The infection age distribution of the infected cells is also calculated, indicating how many cells are in an infection stage compatible with recombinant product expression or viral amplification. The model can also consider the presence of defective interfering particles in the system, which can severely compromise the productivity of biomanufacturing processes. Model benchmarking and validation are demonstrated for case studies of the baculovirus expression vector system and influenza A propagation in suspension cultures.

Atomic-level design of biomimetic iron-sulfur clusters for biocatalysis.

Designing biomimetic materials with high activity and customized biological functions by mimicking the central structure of biomolecules has become an important avenue for the development of medical materials. As an essential electron carrier, the iron-sulfur (Fe-S) clusters have the advantages of simple structure and high electron transport capacity. To rationally design and accurately construct functional materials, it is crucial to clarify the electronic structure and conformational relationships of Fe-S clusters. However, due to the complex catalytic mechanism and synthetic process in vitro, it is hard to reveal the structure-activity relationship of Fe-S clusters accurately. This review introduces the main structural types of Fe-S clusters and their catalytic mechanisms first. Then, several typical structural design strategies of biomimetic Fe-S clusters are systematically introduced. Furthermore, the development of Fe-S clusters in the biocatalytic field is enumerated, including tumor treatment, antibacterial, virus inhibition and plant photoprotection. Finally, the problems and development directions of Fe-S clusters are summarized. This review aims to guide people to accurately understand and regulate the electronic structure of Fe-S at the atomic level, which is of great significance for designing biomimetic materials with specific functions and expanding their applications in biocatalysis.

Maneuvering Trajectory Synthetic Aperture Radar Processing Based on the Decomposition of Transfer Functions in the Frequency Domain Using Average Blurred Edge Width Assessment

With the rapid development of synthetic aperture radar (SAR), delivery platforms are gradually becoming diversified and miniaturized. The SAR flight process is susceptible to external influences, resulting in unsatisfactory imaging results, so it is necessary to optimize imaging processing in combination with the SAR imaging quality assessment (IQA) index. Based on the principle of SAR imaging, this paper analyzes the impact of defocusing on imaging results caused by mismatched filters and draws on the assessment algorithm of motion blur, proposing a SAR IQA index based on average blurred edge width (ABEW) in the salient area. In addition, the idea of decomposing the transfer function in the frequency domain and fitting the matched filter with a polynomial is also proposed. The estimation of the flight trajectory is changed to a correction of the matched filter, avoiding the precise estimation of Doppler parameters and complex calculations during the time–frequency conversion process. The effectiveness of ABEW was verified by using SAR images of real scenes, and the results were highly consistent with the actual image quality. The imaging processing was tested using the echo signals generated by the errors introduced during the flight process, and more satisfactory imaging results were obtained by using ABEW with the filter for correction. The imaging process was tested using the echo signal generated by introducing errors during the flight, and the filter was corrected using ABEW as an index, obtaining a comparatively ideal imaging result.

Facile One-Pot Synthesis of Fe3O4 Nanoparticles Composited with Reduced Graphene Oxide as Fast-Chargeable Anode Material for Lithium-Ion Batteries.

To address the rapidly growing demand for high performance of lithium-ion batteries (LIBs), the development of high-capacity anode materials should focus on the practical perspective of a facile synthetic process. In this work, iron oxide nanoparticles (Fe3O4 NPs) in situ grown on the surface of reduced graphene oxide (rGO), denoted as Fe3O4 NPs@rGO, were prepared through a facile one-pot synthesis under the wet-colloidal conditions. The synthesized Fe3O4 NPs showed that uniform Fe3O4 NPs, with a size of around 9 nm, were distributed on the rGO surfaces. When applied as an anode material for LIBs, the Fe3O4 NPs@rGO anode revealed a high reversible capacity of 1191 mAh g-1 at 1.0 A g-1 after 200 cycles. It also exhibited excellent rate performance, achieving 608 mAh g-1 at a current density of 5.0 A g-1 over 500 cycles, with improved electronic and ionic conductivities due to the rGO template. This suggested that practically available anode materials can be developed through our one-pot synthesis by in situ growing the Fe3O4 NPs.

Photoinduced Transformations with Diverse Maleimide Scaffolds

Maleimides serve as crucial components in various synthetic processes and are of significant interest to researchers in bioorganic chemistry and biotechnology. Although thermal reactions involving maleimides have been studied extensively, light-mediated reactions with maleimides remain relatively underutilized. This review focuses on understanding the behavior of maleimides in their excited state, particularly their role as synthetic scaffolds for excited-state reactions. Specific emphasis is placed on the diverse photoreactions involving maleimides and photophysical evaluation from our research group.

Reductive Photocatalytic Proton-Coupled Electron Transfer by a Zirconium-based Molecular Platform.

Reductive proton-coupled electron transfer (PCET) has important energetic implications in numerous synthetic and natural redox processes. The development of catalytic systems that can mediate such transformations has become an attractive target, especially when light is used to generate the reactive species towards solar-to-chemicals conversion. However, such approach becomes challenged by kinetic competition with H2 evolution. Here we describe the excited state reactivity of a molecular Zr-based platform under visible light irradiation for the efficient reduction of multiple bonds. Mechanistic investigations shine light on a charge separation process that colocalizes an excited electron and an acidic proton to promote selective PCET. We further leveraged this reactivity for the photocatalytic reduction of a variety of organic substrates. Our results demonstrate the promise of this molecular platform to design strong photocatalytic PCET mediators for reductive transformations. More broadly, we also show the potential relevance of PCET mechanisms in the (photo)redox chemistry of Zr-based molecular materials.