jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Nicolas Nyssen | Abdullah Abudayyeh | Fedor E. Zhurkin | Pamela Aoun | Aleksandar Višnjevac | Benoît Colasson | Ivan Jabin | Olivia Reinaud
Source: European Journal of Inorganic Chemistry (article, 2024-05-17)
Field: Chemistry — Physical and Theoretical Chemistry

TMPA‐based Cavitary Cobalt (II) Funnel Complexes Abstract The synthesis of a series of mononuclear, dicationic Co II funnel complexes is reported herein. Three ligands Calix‐TMPA X present a calix[6]arene cone closed at its small rim by a tris (2‐pyridylmethyl)amine (TMPA) unit and differ by the nature of three cavity walls, anisole, phenol or quinone. The X‐ray diffraction structure of [Co II (MeCN) Calix‐TMPA OMe ](ClO 4 ) 2 displays a trigonal bipyramidal geometry, with Co bound to all 4 nitrogen atoms of the TMPA cap, and to one MeCN guest molecule buried inside the calixarene cavity. All complexes were fully characterized in solution as high spin 5‐coordinate species using various techniques, including 1 H NMR spectroscopy. For comparison purpose, an analogous Co II complex based on the TMPA CH2OH ligand, devoid of a calixarene core, was synthetized. Its X‐ray structure shows a dicationic 7‐coordinate cobalt(II) center in the N 4 O 3 environment provided by the ligand, leaving no space for exogenous ligand binding. This contrasts with the 5‐coordinate complexes obtained with the calix‐ligands that allow guest‐ligand binding and exchange. A brief overview of the coordination properties of the calix‐complexes, compared to those obtained with TMPA ligands, devoid of a cavity, highlights major differences in terms of complexation kinetics, geometry, coordination to the labile site, anion affinity, nuclearity, and stability. Chemistry ; Cobalt ; Funnel ; Combinatorial chemistry ; Inorganic chemistry ; Organic chemistry Crystallography and molecular interactions ; Supramolecular Chemistry and Complexes ; Inorganic Fluorides and Related Compounds
Authors: Larissa da Silva Marques | Michelle Weichelt | Michel Kuhfuß | Carlos R. Rambo | Tobias Fey
Source: Materials (article, 2024-07-01)
Field: Materials Science — Materials Chemistry

Novel Sol-Gel Synthesis Route for Ce- and V-Doped Ba0.85Ca0.15Ti0.9Zr0.1O3 Piezoceramics To meet the current demand for lead-free piezoelectric ceramics, a novel sol-gel synthesis route is presented for the preparation of Ba<sub>0.85</sub>Ca<sub>0.15</sub>Ti<sub>0.9</sub>Zr<sub>0.1</sub>O<sub>3</sub> doped with cerium (Ce = 0, 0.01, and 0.02 mol%) and vanadium (V = 0, 0.3, and 0.4 mol%). X-ray diffraction patterns reveal the formation of a perovskite phase (space group <i>P</i>4<i>mm</i>) for all samples after calcination at 800 °C and sintering at 1250, 1350, and 1450 °C, where it is proposed that both dopants occupy the B site. Sintering studies show that V doping allows the sintering temperature to be reduced to at least 1250 °C. Undoped BCZT samples sintered at the same temperature show reduced functional properties compared to V-doped samples, i.e., d<sub>33</sub> values increase by an order of magnitude with doping. The dissipation factor tan δ decreases with increasing sintering temperature for all doping concentrations, while the Curie temperature T<sub>C</sub> increases for all V-doped samples, reaching 120 °C for high-concentration co-doped samples. All results indicate that vanadium doping can facilitate the processing of BCZT at lower sintering temperatures without compromising performance while promoting thermal property stability. Sintering ; Materials science ; Doping ; Calcination ; Dopant ; Curie temperature ; Vanadium ; Perovskite (structure) ; Analytical Chemistry (journal) ; Ceramic ; Sol-gel ; Chemical engineering ; Mineralogy ; Composite material ; Nanotechnology ; Metallurgy ; Chromatography ; Chemistry ; Optoelectronics ; Ferromagnetism ; Condensed matter physics ; Catalysis Ferroelectric and Piezoelectric Materials ; Microwave Dielectric Ceramics Synthesis ; Acoustic Wave Resonator Technologies
Authors: A. Vijaya Bhaskar Reddy
Source: Nanomedicine & Nanotechnology Open Access (article, 2024-01-01)
Field: Materials Science — Biomaterials

Recent Breakthroughs of Nanomedicine in Medical Fields Nanomedicine refers to the application of nanoparticles for disease diagnosis and treatment. Recent progresses in nanomedicine have demonstrated significant breakthroughs in enhancing the efficiency and safety of medical treatments. The key advances in nanomedicine for targeted drug delivery systems, to treat the spinal cord diseases, to enhance immune modulation and regenerative medicine have shown promising in recent years. Despite the advancements of nanomedicine, a few challenges such as biocompatibility, toxicity, and regulatory hurdles remain. Nanomedicine ; Medicine ; Nanotechnology ; Materials science ; Nanoparticle Nanoparticle-Based Drug Delivery ; Cancer Research and Treatment ; Graphene and Nanomaterials Applications
Authors: Jamieson Brechtl | Joe Rendall | Mingkan Zhang | Michael Köehler | Kashif Nawaz | Ayyoub M. Momen
Source: Magnetochemistry (article, 2024-02-12)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Compatibility of LaFe13−x−yMnxSiyH1.6 and Eutectic Liquid GaInSn Alloy The heat transfer rate of magnetocaloric regenerators is a topic of extensive research and the cyclability of these regenerators is critical to the operation of systems with a high coefficient of performance (e.g., potentially &gt;22, significantly higher than typical vapor compression cooling technologies). To enable a high operating frequency that will result in a high specific cooling power, the heat transfer fluid should have high thermal conductivity and lower specific heat, i.e., higher thermal diffusivity. Eutectic metal alloys possess these qualities, such as gallium–indium–tin (Galinstan), whose thermal diffusivity has been found to be approximately an order of magnitude higher than water. For this study, the effects of eutectic liquid Galinstan exposure on the phase stability of LaFe13−x−yMnxSiyH1.6 magnetocaloric powders in an active magnetic regenerator device were investigated. The powders were characterized before and after exposure to Galinstan using X-ray diffraction, in which the phases were determined using the Rietveld refinement technique and X-ray fluorescence. It was found that after Galinstan exposure, hydrogen containing phases were present in the powder, suggesting that the hydrogen was lost from the magnetocaloric phase. The magnetocaloric phase degradation indicates that the powder was incompatible with the Galinstan metal in an environment with moisture. Materials science ; Eutectic system ; Magnetic refrigeration ; Thermal diffusivity ; Gallium ; Alloy ; Rietveld refinement ; Analytical Chemistry (journal) ; Thermodynamics ; Metallurgy ; Chemistry ; Crystallography ; Crystal structure ; Chromatography Magnetic and transport properties of perovskites and related materials ; Thermal Expansion and Ionic Conductivity ; Magnetic Properties of Alloys
Authors: Miloš Petković | Jelena Kotur‐Stevuljević | Predrag Jovanović | Miloš Jovanović | Nikola Mitrović | Milena Simić | Gordana Tasić | Vladimir Savić
Source: Journal of the Serbian Chemical Society (article, 2024-09-09)
Field: Chemistry — Organic Chemistry

Synthesis and in vitro study of redox properties of pyrrole and halogenated pyrrole derivatives The redox balance plays a crucial role in maintaining biological processes under normal conditions. Antioxidants inhibit and reduce harmful oxidation processes, while pro-oxidants can act as anti-cancer agents by promoting ROS-mediated cell death. The aim of this study is to compare the redox properties of seven newly synthesised tribromopyrrole derivatives with three novel and four previously synthesized non-halogenated analogues in an in vitro model (in human serum) and with exogenously induced oxidative stress. The obtained values of their oxy scores (OS) were compared and the result showed that four non-halogenated pyrrole derivatives with secondary amide group M2, M10, M11 and M12 have lower OS values than Trolox, a water-soluble analogue of vitamin E with proven antioxidant properties. All four compounds show strong resistance to oxidative stress, which is reflected in the maintenance of negative OS values when exposed to exogenous oxidative stress using TBH in the reaction mixture. This capability to resist invading ROS should be expected also in an endogenous environment, where constant prooxidant production takes place at a low, homeostatic level, but even more so in pathological conditions. The tribrominated derivative M15 showed prooxidant activity with a significantly higher OS value than all other compounds tested. The comparison of the dose-response of Trolox and the five compounds with the lowest OS also shows that compounds M2, M7 and M10 have better antioxidant activity than Trolox. Pyrrole ; Redox ; Chemistry ; In vitro ; Combinatorial chemistry ; Organic chemistry ; Biochemistry Synthesis and Characterization of Pyrroles
Authors: S.P. Desai
Source: Cureus Journal of Engineering. (article, 2024-12-30)
Field: Materials Science — Materials Chemistry

Studies on Structural, Morphological and Optoelectrical Properties of Spray-Deposited Iron-Doped Cadmium Oxide Thin Films Cadmium-based transparent conductive oxides have received much attention due to their exceptional carrier concentrations, almost metallic conductivities and simple rock salt-like crystal structure. In the present study, the effect of iron (Fe) doping on physicochemical and opto-electrical properties of spray-deposited cadmium oxide (CdO) thin film was studied by varying the doping concentration of Fe. The X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), UV-Vis spectroscopy, photoluminescence (PL) study and electrical properties using the Hall effect in Van der Pauw configuration were used to study the different physicochemical and optoelectrical properties of Fe-doped CdO thin films. The XRD patterns studied for Fe:CdO films show a polycrystalline nature and the crystallite size increases with an increase in doping concentration. FE-SEM images show an interconnected chain structure. The thickness of the films increases with an increase in doping concentration of Fe, as more nucleation sites are available. A transmittance of 76% was recorded at 550 nm wavelength for 4 at% doped Fe:CdO films. The direct band gap increases from 2.62 eV to 2.83 eV as the Fe doping concentration increases from 1 at% to 4 at% Fe:CdO films and further decreases to 2.71 eV. The PL spectrum indicates two emission peaks at 434.19 nm and 539.61 nm significantly. The electrical measurements show that Fe doping concentration in CdO film increases, the sheet resistance decreases from 2.89 Ω-1 to 2.06 Ω-1, which is attributed to the increase in mobility of carriers. The maximum mobility of 94.26 cm2/Vs is obtained for 4 at% Fe:CdO thin film. The figure of merit (Φ), a factor significant for opto-electronic applications, was found to vary between 3.40 × 10-3 Ω-1 and 31.16 × 10-3 Ω-1 for Fe: CdO films. Materials science ; Doping ; Cadmium oxide ; Cadmium ; Thin film ; Oxide ; Chemical engineering ; Iron oxide ; Metallurgy ; Nanotechnology ; Optoelectronics ZnO doping and properties ; Copper-based nanomaterials and applications ; Gas Sensing Nanomaterials and Sensors
Authors: Margarita Yanbaeva | Jan Soyka | Jana M. Holthoff | Philipp Rietsch | Elric Engelage | Adrian Ruff | Ute Resch‐Genger | Robert Weiß | Siegfried Eigler | Stefan M. Huber
Source: Chemistry - A European Journal (article, 2024-07-12)
Field: Chemistry — Organic Chemistry

Dimethylene‐Cyclopropanide Units as Building Blocks for Fluorescence Dyes Many organic dyes are fluorescent in solution. In the solid state, however, quenching processes often dominate, hampering material science applications such as light filters, light-emitting devices, or coding tags. We show that the dimethylene-cyclopropanide scaffold can be used to form two structurally different types of chromophores, which feature fluorescence quantum yields up to 0.66 in dimethyl sulfoxide and 0.53 in solids. The increased fluorescence in the solid state for compounds bearing malonate substituents instead of dicyanomethide ones is rationalized by the induced twist between the planes of the cyclopropanide core and a pyridine ligand. Fluorescence ; Computer science ; Environmental science ; Optics ; Physics Synthesis and Biological Evaluation ; Molecular Sensors and Ion Detection ; Luminescence and Fluorescent Materials
Authors: Haowen Lin | Cristian Mocuta | Rémi Arras | Céline Blaess | Brice Sarpi | Philippe Ohresser | H. Magnan | Jean-Baptiste Moussy | Cindy L. Rountree | Antoine Barbier
Source: ACS Applied Electronic Materials (article, 2024-10-10)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Unveiling and Optimizing Interface Properties of NiFe<sub>2</sub>O<sub>4</sub>/BaTiO<sub>3</sub> Heterostructures In this study, we investigate the properties, with a special focus on the magnetic attributes, of NiFe2O4 (NFO)/BaTiO3 (BTO) multiferroic heterostructures, examining individual layer thicknesses ranging from 3 to 12 nm. X-ray diffraction reveals that as BTO thickness increases, NFO transitions from a nonstrained cubic lattice to a compressively strained tetragonal lattice. In contrast, thicker NFO layers introduce enhanced tensile stresses on the BTO layer, counteracting the compressive strain originating from the SrTiO3 (STO) substrate. Piezoresponse force microscopy demonstrates that the polarization switching voltage escalates with increasing BTO layer thickness. Through X-ray magnetic circular dichroism measurements coupled with multiplet theory, we elucidate variations in the magnetic moments and ionic distributions within the NFO layers. Remarkably, a larger BTO thickness is associated with a chemical reduction of Fe ions in the NFO layer, indicative of increased oxygen vacancies, which are induced by the increasing compressive strain as evidenced by first-principles calculations. Thinner NFO layers showed increased tetrahedral (Td) site vacancies and oxygen vacancies concomitant with reduced magnetic moments, which can be optimized by either increasing NFO thickness or through air annealing at 450 °C. Combining the ionic distribution variation with in-plane lattice parameter evolution during growth, we postulated that the reduced magnetic moments originate from a 2–3 nm antiferromagnetic rock salt NiO/FeO formed at the beginning of NFO growth, while the air annealing restores the magnetism by oxidizing and arranging the NiO/FeO into spinel NFO under the synergistic effect of oxygen and heat. Air annealing at moderate temperature appears as a very efficient method to restore the magnetization of ultrathin layers of NFO, allowing us to overcome a major drawback for these compounds, which hampers their utilization in spintronics applications so far. Materials science ; Antiferromagnetism ; Annealing (glass) ; Tetragonal crystal system ; Condensed matter physics ; Non-blocking I/O ; Heterojunction ; Crystallography ; Crystal structure ; Composite material ; Chemistry ; Optoelectronics Multiferroics and related materials ; Ferroelectric and Piezoelectric Materials ; Dielectric properties of ceramics
Authors: Asmira Delic | Mikaël Lindgren | Μαρία Ψαρρού | Solon P. Economopoulos | Espen Mariussen | Alexander Krivokapić | Ole Torsæter | Mohamed Omran | Mari‐Ann Einarsrud
Source: Chemistry - A European Journal (article, 2024-01-17)
Field: Materials Science — Materials Chemistry

Design of Multi‐Luminescent Silica‐Based Nanoparticles for the Detection of Liquid Organic Compounds Tracer testing in reservoir formations is utilised to determine residual oil saturation as part of optimum hydrocarbon production. Here, we present a novel detection method of liquid organic compounds by monodisperse SiO<sub>2</sub> nanoparticles (NPs) containing two luminophores, a Eu<sup>III</sup>:EDTA complex and a newly synthesised fluorophore based on the organic boron-dipyrromethene (BODIPY)-moiety. The particles exhibited stable Eu<sup>III</sup> PL emission intensity with a long lifetime in aqueous dispersion. The fluorescence of the BODIPY was also preserved in the aqueous environment. The ratiometric PL detection technique was demonstrated by using toluene and 1-octanol as model compounds of crude oil. The optimal synthesis conditions were found to give NPs with a diameter of ~100 nm, which is suitable for transport through porous oil reservoir structures. The cytotoxicity of the NPs was confirmed to be very low for human lung cell and fish cell lines. These findings demonstrate the potential of the NPs to replace the hazardous chemicals used to estimate the residual oil saturation. Moreover, the ratiometric PL detection technique is anticipated to be of benefit in other fields, such as biotechnology, medical diagnostics, and environmental monitoring, where a reliable and safe detection of a liquid organic phase is needed. BODIPY ; Nanoparticle ; Fluorophore ; Luminescence ; Dispersity ; Aqueous solution ; Detection limit ; Fluorescence ; Toluene ; Aqueous two-phase system ; Chemistry ; Saturation (graph theory) ; Chemical engineering ; Materials science ; Nanotechnology ; Chromatography ; Organic chemistry Lanthanide and Transition Metal Complexes ; Radioactive element chemistry and processing ; Analytical chemistry methods development
Authors: Saba Aziz | Anna Grazia Monteduro | Ritu Rawat | Silvia Rizzato | Angelo Leo | Shahid Khalid | Giuseppe Maruccio
Source: Magnetochemistry (article, 2024-08-15)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Preparation and Characterization of BXFO High-Entropy Oxides Increasing demand for functional materials crucial for advancing new technologies has motivated significant scientific and industrial research efforts. High-entropy materials (HEMs), with tunable properties, are gaining attention for their use in high-frequency transformers, microwave devices, multiferroics, and high-density magnetic memory components. The initial exploration of HEMs started with high-entropy alloys (HASs), such as CrMnFeCoNi, CuCoNiCrAlxFe, and AlCoCrTiZn and paved the way for a multitude of HEM variations, including oxides, oxyfluorides, borides, carbides, nitrides, sulfides, and phosphides. In this study, we fabricated the high-entropy oxide (HEO) compound Bi0.5La0.1In0.1Y0.1Nd0.1Gd0.1FeO3 through the solid-state synthesis method. Magnetic measurements at 300 K show ferromagnetic behavior with significant coercivity. At the same time, this novel composition exhibits excellent dielectric properties and shows potential for electronic applications demonstrating that a high-entropy approach can expand the compositional range of rare earth multiferroics and improve the multifunctional properties in multiferroic applications. Characterization (materials science) ; Materials science ; Statistical physics ; Chemistry ; Nanotechnology ; Physics Magnetic and transport properties of perovskites and related materials ; Multiferroics and related materials ; Electronic and Structural Properties of Oxides
Authors: Mojgan Asadi | Ashim Nandi | Arieh Warshel
Source: ChemRxiv (preprint, 2024-04-15)
Field: Chemistry — Organic Chemistry

Computational Mechanistic Insights into Reversible and Irreversible Covalent Inhibitors Targeting SARS-CoV-2 Mpro The treatment of SARS-CoV-2 can be accomplished by an effective suppression of its 3CL protease (3CLpro), also known as the main protease (Mpro) and nonstructural protein 5 (nsp5). Covalent inhibitors can irreversibly and selectively disable the protease, particularly when they are highly exothermic. Herein we delve into the distinct kinetic behaviors exhibited by two covalently linked SARS-CoV-2 inhibitors. One of these inhibitors features a nitrile reactive group, while the other has this group replaced by an alkyne group, a less reactive electrophile. Our investigations involve the assessment of pertinent free energy surfaces through the utilization of both ab initio and empirical valence bond (EVB) simulations. The calculated free energy profiles show that substituting the nitrile group with alkyne significantly increases the overall reaction exothermicity. This leads to an efficient inhibition, even though the reaction of the nitrile group has a substantially lower barrier than the alkyne group. We examine the time-dependence of IC50 inhibition by applying a novel kinetic simulation approach, which is particularly important in studies of covalent inhibitors with a very exothermic bonding step. Our computational approach reproduces the observed binding kinetics and appears to provide a powerful tool for studies of covalent inhibitors. Covalent bond ; Nitrile ; Chemistry ; Alkyne ; Electrophile ; Combinatorial chemistry ; Protease ; Valence bond theory ; Exothermic reaction ; Computational chemistry ; Ab initio ; Stereochemistry ; Enzyme ; Organic chemistry ; Molecule ; Molecular orbital Click Chemistry and Applications ; Computational Drug Discovery Methods ; RNA Interference and Gene Delivery
Authors: Aljaž Drnovšek | Damjan Vengust | Patrik Šumandl | D. Korbar | Aleš Mrzel | M. Vilfan
Source: ChemPlusChem (article, 2024-10-24)
Field: Materials Science — Materials Chemistry

Facile Synthesis Route for Bulk Production of Complex Fullerene‐Like MoS <sub>2</sub> Nanostructures With Enhanced Tribological Properties Molybdenum-based nanoparticles are often used as oil additives to enhance a material's tribological performance. Here, we present a highly efficient synthetic route for the bulk production of two types of MoS<sub>2</sub> nanostructures: multi-wall nanotubes and fullerene-like nanostructures. The presented two-step synthesis involves the transformation of ammonium heptamolybdate tetrahydrate and aniline into precursor nanowires, which are later transformed into MoS<sub>2</sub> through heating in a H<sub>2</sub>S, H<sub>2</sub>, and argon atmosphere to approximately 800 °C. Depending on the heating rate, we successfully grew MoS<sub>2</sub> layered compounds in various shapes and sizes. The resulting structures and compositions were characterised by X-ray powder diffraction, Raman spectroscopy, energy-dispersive X-ray spectroscopy, and electron microscopy. To assess the application potential of these MoS<sub>2</sub> compounds, they were dispersed in polyalphaolefin (PAO 6) oil. Improved tribological properties were observed compared to typically used transition metal dichalcogenides. Fullerene ; Nanotechnology ; Materials science ; Nanostructure ; Tribology ; Chemical engineering ; Chemistry ; Organic chemistry ; Metallurgy 2D Materials and Applications ; Lubricants and Their Additives ; MXene and MAX Phase Materials