jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Marc Dolcet | Kristi Timmo | Valdek Mikli | J. Krustok | Mati Danilson | A. Suchodolskis | Cristian Radu | Aurelian Catalin Galca | Maarja Grossberg-Kuusk | Marit Kauk‐Kuusik
Source: SSRN Electronic Journal (preprint, 2025-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Effects of Cationic Substitution on the Properties of Sb1-Xbixsei (X = 0 to 1) Compounds Substitution (logic) ; Cationic polymerization ; Chemistry ; Computer science ; Organic chemistry Crystal Structures and Properties
Authors: Dominik Just | Dawid Janas
Source: ECS Meeting Abstracts (article, 2025-07-11)
Field: Materials Science — Materials Chemistry

Highly Effective Sorting and Functionalization of Single-Walled Carbon Nanotubes There is an urgent requirement to devise methods for producing pure SWCNTs in high concentrations with significantly enhanced PLQYs to support their extensive use in practical applications. Exciton engineering through the sp 3 functionalization of SWCNTs is currently the most promising strategy to achieve these materials with better optical properties [1-3]. However, diazonium chemistry, which is perhaps the most widely used approach for the chemical modification of SWCNTs, faces several drawbacks, such as the instability of the reactants and the lengthy processing times without external stimuli. Additionally, this technique for grafting SWCNTs is fundamentally restricted to aqueous environments unless the solubility of diazonium salts is enhanced using specific chemical agents [4]. Other modification methods also present significant limitations. In this study, we demonstrate how these constraints can be circumvented, allowing the accomplishment of both previously mentioned long-sought objectives. The integration of PFO-BPy as a selective extractor for SWCNTs, along with dual-function additives in a liquid environment, not only significantly increased the capacity for sorting SWCNTs but also yielded extremely concentrated and well-modified monochiral SWCNTs. The newly developed functionalization platform facilitated rapid functionalization, allowing for the attachment of various functional groups to SWCNTs, thereby fine-tuning the material's emission properties. Importantly, the method discussed proved to be universal, as it enabled the production of chemically modified pure SWCNTs within minutes in both aqueous and organic settings. The simplicity and effectiveness of the new protocol render it exceptionally useful for adjusting the luminescence of SWCNTs for specific applications [5]. [1] D. Janas, Mater. Horiz. 2020, 7, 2860-2881. [2] J. Zaumseil, Adv. Optical Mater. 2022, 10, 2101576. [3] T. Shiraki et al., Acc. Chem. Res. 2020, 53, 1846-1859. [4] F. Berger et al., ACS Nano 2019, 13, 9259-9269. [5] D. Just et al., in revision. Surface modification ; Carbon nanotube ; Sorting ; Nanotechnology ; Materials science ; Chemical engineering ; Computer science ; Engineering ; Algorithm Carbon Nanotubes in Composites ; Graphene research and applications ; Conducting polymers and applications
Authors: Bo Hu | Yan Luo
Source: International Journal of Advanced Chemistry Research (article, 2025-06-01)
Field: Chemistry — Inorganic Chemistry

Asymmetric epoxidation of olefins using chiral manganese-salen complexes The catalytic asymmetric epoxidation of unfunctionalized olefins has been a benchmark challenge in stereoselective synthesis since Jacobsen and Katsuki independently reported their chiral Mn(III)-salen systems in the early 1990s. This research describes the preparation of four new Mn(III)-salen complexes bearing electron-donating and electron-withdrawing substituents on the 3, 3′ and 5, 5′ positions of the salen ligand and evaluates their performance in the epoxidation of seven structurally varied olefins using m-chloroperoxybenzoic acid (mCPBA) and sodium hypochlorite as terminal oxidants. Complexes were synthesized by condensation of (1R, 2R)-1, 2-diaminocyclohexane with substituted salicylaldehydes followed by metalation with manganese(III) acetate. The catalysts were characterized by FT-IR, UV-Vis, ESI-MS, and elemental analysis. When applied to trans-stilbene epoxidation at 5 mol% loading with mCPBA in dichloromethane at 0 °C, the best-performing complex—bearing tert-butyl groups at the 3, 3′ positions and methoxy groups at the 5, 5′ positions—delivered 96.1% conversion and 94.7% enantiomeric excess of the (2R, 3R)-epoxide within 8 h. Substrate screening showed that cis-alkenes gave lower enantioselectivity (ee 72.6–89.3%) than their trans counterparts, in line with the established side-on approach model for olefin binding to the Mn=O intermediate. Kinetic profiling at 2, 5, and 10 mol% catalyst loadings revealed pseudo-first-order behaviour with an apparent activation energy of 42.8 kJ/mol. NaOCl proved a viable alternative oxidant, affording comparable ee values but slightly lower conversion at the same reaction time. These results show that systematic ligand modification can fine-tune enantioselectivity in Mn-salen epoxidation and identify the tert-butyl/methoxy combination as an effective catalyst for both aromatic and cyclic olefins. Catalysis ; Olefin fiber ; Dichloromethane ; Kinetic resolution ; Ligand (biochemistry) ; Stereoselectivity ; Enantioselective synthesis ; Enantiomeric excess Metal-Catalyzed Oxygenation Mechanisms ; Mesoporous Materials and Catalysis ; Organic Chemistry Cycloaddition Reactions
Authors: Azita Rezvani (8524383) | Zhuang Wang (4728315) | K. David Wegner (1775371) | Hadi Soltanmoradi (21353609) | Alexander Kichigin (20751776) | Xin Zhou (54275) | Tobias Gantenberg (21353612) | Juergen Schram (21353615) | Benjamin Apeleo Zubiri (14796154) | Erdmann Spiecker (1511563) | Johannes Walter (1464094) | Ute Resch-Genger (626347) | Doris Segets (1464091)
Source: Figshare (article, 2025-05-13)
Field: Materials Science — Materials Chemistry

Separationof Indium Phosphide/Zinc Sulfide Core–ShellQuantum Dots from Shelling Byproducts through Multistep Agglomeration Semiconductor quantum dots (QDs) possess unique electronic and optical properties, making them promising candidates for applications in light-emitting diodes, solar cells, bioimaging, and photocatalysis. Precise control over their size, shape, and chemical and electronic structure is crucial to ensure the desired functional properties and optimize device performance. However, challenges in QD synthesis and post-synthesis modification persist, especially in large-scale production. This study addresses the classification of QDs synthesized in a tubular flow reactor consisting of a mixture of the desired InP/ZnS core–shell QDs and QDs made from the shell material, i.e., here ZnS QDs formed as a byproduct during the formation step of the ZnS shell. The homogeneous nucleation of ZnS nanoparticles from the shelling material introduces a heterogeneity in size and composition and affects the optical properties of the resulting QDs. To address this issue, we developed a size-selective agglomeration (SSA) technique by incrementally introducing ethanol as a poor solvent and classified the synthesized QDs into 13 distinct fractions. These 13 fractions are sorted into three distinct groups: (i) larger InP/ZnS QDs, (ii) a combination of smaller InP/ZnS QDs and larger ZnS QDs, and (iii) predominant ZnS QDs with some very tiny InP/ZnS QDs. The comprehensive characterization of the fractions was conducted using UV–visible absorption spectroscopy, photoluminescence spectroscopy, high-resolution scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy, total reflection X-ray fluorescence, and analytical ultracentrifugation. We could demonstrate that our method effectively separated unwanted ZnS QDs from the target InP/ZnS QDs. In addition, the fractions enriched in smaller InP/ZnS QDs exhibited a higher photoluminescence quantum yield compared to the fractions with larger QDs. This demonstrates the efficacy of SSA in fine-tuning the composition of QD mixtures produced on a larger scale to improve their functional properties. This approach provides fundamental understanding toward the development of a scalable two-dimensional classification process for such ultrasmall nanoparticles by particle size and composition. Quantum dot ; Photoluminescence ; Indium ; Nanoparticle ; Zinc sulfide ; Quantum yield ; Economies of agglomeration ; Nucleation ; Cadmium sulfide ; Yield (engineering) Quantum Dots Synthesis And Properties ; Carbon and Quantum Dots Applications ; Silicon Nanostructures and Photoluminescence
Authors: Shengyi Su (12323221) | Haomiao Xie (4053265) | Bang Hou (4435735) | Xianhui Tang (5347496) | Kent O. Kirlikovali (1924915) | Zi-Ming Ye (1586923) | Nathan C. Gianneschi (1320738) | Omar K. Farha (1301625)
Source: Figshare (article, 2025-10-08)
Field: Chemistry — Inorganic Chemistry

Customizable ApertureGeometry in Metal–OrganicFrameworks for Kinetic Hydrocarbon Separation Precise control of aperture dimensions is crucial in adsorptive separations of hydrocarbons, as it directly affects key parameters such as selectivity, capacity, diffusion, and recyclability. The development of metal–organic frameworks (MOFs) has enabled the fine-tuning of local pore environments to address important hydrocarbon separations. However, customizing the aperture geometry to tune the kinetic separation performance remains challenging. Here, we deploy a mixed-linker synthesis strategy, combining long and short linkers on <b>fcu</b> net Zr-MOFs with equilateral triangular apertures to construct isoreticular multivariate MOFs, NU-415 and NU-416, with tailored isosceles triangular apertures suitable for the separation of hexane isomers. Sorption, liquid batch separation, and X-ray diffraction measurements demonstrate significantly improved selectivity, capacity, stability, and recyclability of NU-415 and NU-416 compared with Zr-muconate and MOF-801. Notably, both NU-415 and NU-416 achieve uptake capacities of 2.2 mmol g<sup>–1</sup> in 1 min with an <i>n</i>-hexane to 2,2-dimethylbutane selectivity over 200 in an equimolar ternary mixture at ambient conditions, comparable to leading reported materials. Mechanistic studies confirm that separation performance is predominantly governed by significant kinetic differences rather than by thermodynamics. The successful customization of aperture geometry not only enables superior linear to monobranched hexane selectivity in NU-415 but also demonstrates the mixed-linker synthesis strategy as a promising solution for precise and predictable pore architecture control in MOFs. Equilateral triangle ; Aperture (computer memory) ; Hexane ; Ternary operation ; Kinetic energy ; Selectivity ; Hydrocarbon Metal-Organic Frameworks: Synthesis and Applications ; Mesoporous Materials and Catalysis ; Covalent Organic Framework Applications
Authors: Yajing Mu | Jinchang Fan | Tianyi Gao | Lina Wang | Lei Zhang | Xiaoxin Zou | Weitao Zheng | Yong‐Wei Zhang | Zhi Gen Yu | Xiaoqiang Cui
Source: Angewandte Chemie (article, 2025-03-13)
Field: Chemistry — Electrochemistry

Tuning Ru–O Coordination for Switching Redox Centers in Acidic Oxygen Evolution Electrocatalysis Abstract Avoiding lattice oxygen involvement (oxygen redox) while promoting the coupling of adjacent adsorbed oxygen (metal redox) during the acidic oxygen evolution reaction (OER) is essential for gaining high activity and robust stability in RuO 2 ‐based catalysts but remains elusive. Here, we present a precise strategy to selectively activate the metal redox process while suppressing the undesired oxygen redox pathway by fine‐tuning the Ru–O coordination number in amorphous RuO x . The optimized catalyst exhibits outstanding acidic OER performance, achieving a low overpotential of 215 mV at 10 mA cm −2 and maintaining stability for 300 h with a negligible degradation rate of 100 µV h −1 . X‐ray absorption measurements and multiple operando spectra reveal that only Ru 2 –O 11 moieties can selectively activate the metal redox process, whereas Ru 2 –O 9 and Ru 2 –O 8 moieties either trigger both redox pathways or bypass them. Theoretical calculations reveal that Ru 2 –O 11 moiety reduces crystal field splitting energy at active Ru sites, disables lattice oxygen activation, and lowers the energy barrier for oxygen coupling. The strategy developed in this work offers new avenues for switching redox centers and refining OER mechanisms to enhance catalytic performance and long‐term stability. Electrocatalyst ; Redox ; Oxygen evolution ; Chemistry ; Oxygen ; Oxygen reduction ; Inorganic chemistry ; Electrochemistry ; Electrode ; Physical chemistry ; Organic chemistry Electrochemical Analysis and Applications ; Electrocatalysts for Energy Conversion ; Conducting polymers and applications
Authors: Kiran Aluri (22241964) | Hrithvik Reddy Pullagurla (22241967) | Syam Prasad Reddy Annareddy (22241970) | Bhaskar Reddy Pitta (2290879)
Source: Figshare (article, 2025-09-13)
Field: Chemistry — Organic Chemistry

Investigation of Pd Catalyst for Key Coupling Reactionin Asciminib Synthesis and Impurity Characterization Asciminib, marketed as Scemblix, is approved for treating adults with newly diagnosed Philadelphia chromosome-positive chronic myeloid leukemia (Ph+ CML) in chronic phase (CP), as well as for those previously treated with two or more tyrosine kinase inhibitors (TKIs). Existing literature on Asciminib manufacturing processes involves considerable quantities of preformed Pd complex catalysts for the key coupling reaction. We optimized the commercial production process by identifying dichlorobis[di<i>tert</i>-butyl(4-dimethylaminophenyl)phosphine]palladium(II) PdCl<sub>2</sub>(Amphos)<sub>2</sub> as the most effective catalyst for the key coupling reaction. By fine-tuning the Pd complex quantity to a 0.0035 weight ratio relative to the key starting materialapproximately one-third of the previously reported amountwe achieved complete conversion and obtained the desired coupling product in high yield. Additionally, we developed a highly effective and commercially viable method combining l-cystine and activated carbon to efficiently remove Pd metal impurities from the final product. The optimized process was successfully validated under GMP conditions at the multikilogram level and has proven to be easily scalable for larger quantities. This report also addresses the lack of detailed information on potential process and degradation impurities of Asciminib. We identified and synthesized potential process impurities (P-1 to P-5) and degradation impurities (DP-1 to DP-3), confirming their structures using <sup>1</sup>H NMR, <sup>13</sup>C NMR, mass spectrometry, and IR spectroscopy. This comprehensive impurity identification enhances the quality and safety of Asciminib and supports the development of robust analytical methods for impurity quantification and validation. Impurity ; Catalysis ; Degradation (telecommunications) ; Metal ; Process (computing) ; Characterization (materials science) ; Coupling (piping) ; Transition metal Catalytic Cross-Coupling Reactions ; Chronic Myeloid Leukemia Treatments ; Click Chemistry and Applications
Authors: Balaji R. Jagirdar | Kamla D. Netam
Source: SSRN Electronic Journal (preprint, 2025-01-01)
Field: Chemistry — Inorganic Chemistry

Steric and Electronic Influence on the Reactivity and Hydrogenation Catalytic Activity of Alkenes and Alkynes Using Ruthenium Pincer Complexes Pincer movement ; Ruthenium ; Steric effects ; Reactivity (psychology) ; Catalysis ; Chemistry ; Photochemistry ; Organic chemistry ; Medicine Asymmetric Hydrogenation and Catalysis ; Catalysis and Hydrodesulfurization Studies ; Catalysis for Biomass Conversion
Source:  (preprint, 2025-06-06)
Field: Materials Science — Biomaterials

Exploring the link between microstructure, order, and toughness in bioinspired composites Composites with intricate microstructures are ubiquitous in the natural world where they fulfil the specific functional demands imposed by the environment. For instance, nacre presents a fracture toughness 40 times higher than its main constituent, a crystalline form of calcium carbonate. This relative increase in toughness value is obtained as a crack propagating within this natural brick-and-mortar structure must interact with multiple reinforcing mechanisms, leading to a millimetre-sized process zone. The boost in performance obtained has pushed scientists for a few decades to use nacre as a blueprint to increase the toughness of synthetic ceramics and composites. Our ability to reproduce accurately the structure of nacre from the nanometre to the millimetre scale has improved with the introduction of Magnetically-Assisted Slip Casting (M.A.S.C.), a technique that combines an aqueous-based slip casting process with magnetically-directed anisotropic particle assembly. Using this technique, we can now fine tune the structural properties of nacre-inspired alumina-based composites to reach strengths up to 670 MPa, KIC up to 7 MPa.m1/2 with subsequent stable crack propagation and this even at temperature up to 1200°C. While these materials already present interesting properties for engineering applications, we fail to see the large process zone that are acting in natural nacre. This led us to work on a new composite system, using this time monodisperse silica rods that can self-assemble into bulk colloidal crystals to finally test the effect of order in the microstructure on the toughness. The presence of this regularity in the microstructure proves crucial in enabling a large process zone. We obtained a 40-fold increase in toughness compared with the polymer use as a matrix in a composite made of 80% in volume of ceramic, all of which is processed at room temperature. From these two studies, we can extract the role of the interface and grain morphology in tough bioinspired composites and what will be the next steps for these materials. Microstructure ; Composite material ; Toughness ; Link (geometry) ; Materials science ; Order (exchange) ; Mathematics ; Business Calcium Carbonate Crystallization and Inhibition ; Bone Tissue Engineering Materials ; Material Selection and Properties
Authors: V.N. Daggupati | Thulitha Abeywickrama | Yuanbing Mao
Source: ECS Meeting Abstracts (article, 2025-11-24)
Field: Materials Science — Materials Chemistry

Reactive Molten Salt Synthesis of NaCo <sub>2</sub> O <sub>4</sub> : Effects of Salt Composition, Temperature, and pH on Morphology Sodium cobaltite (NaCo 2 O 4 ) is a promising layered oxide material known for its unique electrical, thermal, and optical properties. How to tune its morphology, especially at the nanometer scale, faces many challenges. This study explores the reactive molten salt synthesis method as a highly effective approach for synthesizing NaCo 2 O 4 nanoparticles, offering precise control over its size, shape, and structural characteristics through variations in salt composition, reaction temperature, and pH. By altering the molten salt composition, we observe significant changes in ion diffusion rates, leading to variations in particle size and crystallinity. Increasing the reaction temperature enhances grain growth, resulting in larger and more well-defined particles, while lower temperatures promote finer nanostructures. Additionally, adjusting the pH of the precursor solution influences the nucleation and growth process, affecting the shape and thickness of the resulting nanoparticles. Higher pH values favor the formation of thinner, plate-like structures, whereas lower pH conditions lead to increased particle diameter and varied morphologies. This controlled synthesis approach enables the tailored design of NaCo 2 O 4 nanomaterials for phosphor applications, where optimized morphology enhances luminescence efficiency and stability. Moreover, the ability to fine-tune particle characteristics extends the potential of NaCo 2 O 4 in thermos-electrics and opto-electronic devices, demonstrating the versatility of the reactive molten salt synthesis method. Molten salt ; Nucleation ; Salt (chemistry) ; Particle size ; Morphology (biology) ; Particle (ecology) ; Diffusion ; Oxide Thermal Expansion and Ionic Conductivity ; Advancements in Battery Materials ; Luminescence Properties of Advanced Materials
Authors: Wei Huang (36889) | Gessica M. Adornato (22477187) | Maggie Horst (20513968) | Turki M. Alturaifi (13948405) | Kaipeng Hou (1589947) | Peng Liu (120506) | William F. DeGrado (276486) | Yang Yang (45629)
Source: Figshare (article, 2025-10-22)
Field: Chemistry — Organic Chemistry

<i>De Novo</i> Design, Directed Evolutionand Computational Study of Heme-Binding Helical Bundle Protein Catalystsfor Biocatalytic Enantioselective Ge–H Insertion <i>De novo</i> designed proteins offer a malleable platform for the development of stereoselective transformations not found in biochemistry. Here, we report the <i>de novo</i> design and directed evolution of helical bundle protein catalysts for enantioselective germylation through Ge–H insertion, a transformation not previously achieved by enzymatic catalysis. Comparative computational analysis revealed that, relative to Si–H insertion, the Ge–H insertion reaction proceeds through an earlier and more flexible transition state, introducing distinct challenges for stereocontrol. Using a fully <i>de novo</i> designed truncated four-helix bundle scaffold as the starting point, directed evolution afforded a quadruple mutant that catalyzes Ge–H insertion with high efficiency, enantioselectivity, and broad substrate scope. Molecular dynamics simulations indicated that beneficial mutations introduced from directed evolution enhanced active-site preorganization and modulated local backbone flexibility, contributing to improved transition-state complementarity with fine-tuned binding pocket size and more stable cofactor positioning regulated by hydrogen bonding interactions. These findings showcase the excellent potential for <i>de novo</i> proteins to achieve stereoselective transformations previously unknown to biocatalysts and underscore the importance of active-site remodeling of <i>de novo</i> protein scaffolds via directed evolution in achieving selective catalysis involving flexible transition states. Directed evolution ; Enantioselective synthesis ; Protein design ; Catalysis ; Protein engineering ; Directed Molecular Evolution ; Stereoselectivity ; Protein structure ; Hydrogen bond Cyclopropane Reaction Mechanisms ; Microbial Natural Products and Biosynthesis ; Enzyme Catalysis and Immobilization