jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Jialin Ji | Zhengwang Li
Source: Heliyon (article, 2023-06-28)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Thermally generated Au–Ag nanostructures with tunable localized surface plasmon resonance as SERS activity substrates Various Au-Ag bimetallic alloy nanostructures were obtained as sensitive surface-enhanced Raman scattering (SERS) substrates by changing the thermal annealing sequence. The atomic force microscopy (AFM) and scanning electron microscopy (SEM) results confirm that Au/Ag bimetallic clusters and Ag-Au core-shell like structures can be designed by thermal annealing. The absorption spectra showed that the localized surface plasmon resonance (LSPR) frequency of the annealed Au/Ag bimetallic alloy structure could effectively shift from the near ultraviolet to the visible region. At the same time, the Au/Ag bimetallic alloy films modified by thermal annealing have shown satisfactory performance as SERS substrates. Raman enhancement mechanism of Au-Ag bimetallic alloy films is verified by finite-difference time-domain (FDTD) simulation results. Surface plasmon resonance ; Nanostructure ; Materials science ; Nanotechnology ; Plasmon ; Surface plasmon ; Nanoparticle ; Localized surface plasmon ; Resonance (particle physics) ; Optoelectronics ; Physics Gold and Silver Nanoparticles Synthesis and Applications ; Nanocluster Synthesis and Applications ; Quantum Dots Synthesis And Properties
Authors: Alexandros Safakas | Vasileios Ch. Kournoutis | Georgios Bampos | S. Bebelis
Source: Catalysts (article, 2023-10-04)
Field: Materials Science — Materials Chemistry

CO and Propane Combustion on La0.8Sr0.2CoxFe1−xO3−δ Perovskites: Effect of Fe-to-Co Ratio on Catalytic Activity Perovskites are promising alternative catalysts for oxidation reactions due to their lower cost compared to noble metals, and their greater thermal stability. The catalytic oxidation of CO is essential in order to control CO emissions in a series of applications whereas the catalytic combustion of propane is considered an economical and environmentally acceptable solution for energy production and gaseous pollutant management, since propane is among the organic compounds involved in photochemical reactions. This work concerns the effect of the Co/Fe ratio in the B-sites of a series of eight La0.8Sr0.2CoxFe1−xO3−δ perovskites, with x ranging from 0 to 1, on the catalytic activity towards CO and C3H8 oxidation. The perovskite oxides were synthesized using the combustion synthesis method and characterized with respect to their specific surface areas, structures, and reduction properties. Increasing the Co/Fe ratio resulted in an increase in CO and propane conversion under both oxidative and stoichiometric conditions. The increase in Co content is considered to facilitate the formation of oxygen vacancies due to the lower redox stability of the cobalt cations compared to iron cations, favoring oxygen ion mobility and oxygen exchange between the gas phase and the oxide surface, thus enhancing the catalytic performance. Catalysis ; Propane ; Perovskite (structure) ; Redox ; Inorganic chemistry ; Stoichiometry ; Chemistry ; Oxygen ; Oxide ; Combustion ; Catalytic combustion ; Oxygen storage ; Cobalt ; Chemical engineering ; Materials science ; Physical chemistry ; Organic chemistry Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions ; Electronic and Structural Properties of Oxides
Authors: Iulia Cojocariu | Silvia Carlotto | Daniel Baranowski | Matteo Jugovac | Jan Dreiser | Luca Schio | Luca Floreano | Maurizio Casarin | Vitaliy Feyer | Claus M. Schneider
Source: Journal of Materials Chemistry C (article, 2023-01-01)
Field: Materials Science — Materials Chemistry

Extended π-conjugation: a key to magnetic anisotropy preservation in highly reactive porphyrins The findings herein reported highlight the role played by planarization in quenching the reactivity and preserving the magnetic anisotropy. The effect is associated with the weakening of the ligand field, which accompanies the π-conjugation increase. Materials science ; Anisotropy ; Reactivity (psychology) ; Key (lock) ; Quenching (fluorescence) ; Ligand (biochemistry) ; Chemical-mechanical planarization ; Magnetic anisotropy ; Magnetic field ; Chemical physics ; Photochemistry ; Condensed matter physics ; Nanotechnology ; Fluorescence ; Computer science ; Chemistry ; Optics ; Magnetization ; Layer (electronics) ; Receptor ; Physics Porphyrin and Phthalocyanine Chemistry ; Magnetism in coordination complexes ; Photosynthetic Processes and Mechanisms
Authors: Juan Ventura | Clara Uriel | Ana M. Gómez | Edurne Avellanal‐Zaballa | Jorge Bañuelos | Esther Rebollar | Inmaculada García‐Moreno | J. Cristobal López
Source: Organic Letters (article, 2023-04-07)
Field: Materials Science — Materials Chemistry

4,4′-Dicyano- versus 4,4′-Difluoro-BODIPYs in Chemoselective Postfunctionalization Reactions: Synthetic Advantages and Applications The presence of F or CN substituents at boron in BODIPYs causes a dramatic effect on their reactivity, which allows their chemoselective postfunctionalization. Thus, whereas 1,3,5,7-tetramethyl B(CN)<sub>2</sub>-BODIPYs displayed enhanced reactivity in Knoevenagel condensations with aldehydes, the corresponding BF<sub>2</sub>-BODIPYs can experience selective aromatic electrophilic substitution (S<sub>E</sub>Ar) reactions in the presence of the former. These (selective) reactions have been employed in the preparation of BODIPY dimers and tetramers, with balanced fluorescence and singlet oxygen formation, and all-BODIPY trimers and heptamers, with potential application as light-harvesting systems. Chemistry ; BODIPY ; Reactivity (psychology) ; Singlet oxygen ; Electrophile ; Photochemistry ; Combinatorial chemistry ; Boron ; Fluorescence ; Knoevenagel condensation ; Oxygen ; Organic chemistry ; Catalysis Luminescence and Fluorescent Materials ; Organic Light-Emitting Diodes Research ; Nanoplatforms for cancer theranostics
Authors: Shantaram Kothavale | Saqib A. Iqbal | Emily L. Hanover | Abhishek Kumar Gupta | Eli Zysman‐Colman | Michael J. Ingleson
Source: Organic Letters (article, 2023-12-06)
Field: Chemistry — Organic Chemistry

Borylation–Reduction–Borylation for the Formation of 1,4-Azaborines Given the current interest in materials containing 1,4-azaborine units, the development of new routes to these structures is important. Carbonyl directed electrophilic borylation using BBr<sub>3</sub> is a facile method for the <i>ortho</i>-borylation of <i>N</i>,<i>N</i>-diaryl-amide derivatives. Subsequent addition of Et<sub>3</sub>SiH results in carbonyl reduction and then formation of 1,4-azaborines that can be protected <i>in situ</i> using a Grignard reagent. Overall, borylation-reduction-borylation is a one-pot methodology to access 1,4-azaborines from simple precursors. Borylation ; Chemistry ; Reagent ; Electrophile ; Combinatorial chemistry ; Reduction (mathematics) ; Amide ; Organic chemistry ; Catalysis ; Aryl Organoboron and organosilicon chemistry ; Chemical Synthesis and Analysis ; Catalytic Cross-Coupling Reactions
Authors: Chandradip Kumar Yadav | Ajaya Bhattarai | Tulasi Prasad Niraula | Amar Prasad Yadav | Manoj Kumar Adhikari | Yog Prakash Yadav | Duryodhana Yadav | Sanjay Singh
Source: Amrit Journal (review, 2023-12-31)
Field: Chemistry — Organic Chemistry

Critical Analysis of Surfactant-Dye Interaction: A Review The interaction between surfactants and dyes is fundamental in achieving the desired coloration and properties in various applications, shaping the functionality and effectiveness of dye-related processes across multiple industries. Further research and advancements in this field will continue contributing to innovative solutions and improved sustainability. While mixed surfactants offer these advantages, the choice between using a single surfactant or a mixture depends on the specific application, the desired properties, cost considerations, and compatibility with other formulation components. It's important to carefully evaluate the application requirements and conduct appropriate testing to determine the most effective approach. In this work, the physical-chemical characteristics and solubilization of reactive dyes in single and mixed micellar media are elaborated. Compared to the single-micellar medium, the mixed-micellar medium showed improved reactive dye trapping, which was attributed to the presence of both cationic and nonionic surfactants, namely cetyltrimethylammonium bromide (CTAB) and triton X-100. In this interactional study, two reactive dyes were used: Reactive Black 5 (RB) and Reactive Yellow 145 (RY). It is noteworthy to examine the modeling and micellization of mixed surfactant systems in an aqueous medium including dodecyl trimethylammonium bromide (DTAB) and sodium dodecyl sulfate (SDS). The anionic-rich and cationic-rich interactions between methylene blue (MB) and methyl orange (MO) in aqueous solutions were clearly shown in the diagram. Cationic polymerization ; Pulmonary surfactant ; Sodium dodecyl sulfate ; Bromide ; Chemistry ; Aqueous solution ; Micelle ; Methyl orange ; Chemical engineering ; Reactive dye ; Methylene blue ; Compatibility (geochemistry) ; Organic chemistry ; Dyeing ; Photocatalysis Surfactants and Colloidal Systems ; Dyeing and Modifying Textile Fibers ; Photochemistry and Electron Transfer Studies
Authors: Vitaliy Mykhaylyk | Yaroslav Zhydachevskyy | H. Kraus | Vasyl Stasiv | Grzegorz Leniec | Vasyl Hreb | L. Vasylechko | V. Sydorchuk | A. Suchocki
Source: Journal of Materials Chemistry C (article, 2023-12-22)
Field: Materials Science — Materials Chemistry

Evaluation of Li<sub>2</sub>SnO<sub>3</sub>:Cr<sup>3+</sup>, Mn<sup>4+</sup> as a dual-emitter luminescence sensor for cryogenic temperatures The sensitivity of luminescence properties in materials doped with transition metal (TM) ions to changes of temperature makes them particularly promising for thermometric applications. Luminescence ; Materials science ; Ion ; Doping ; Analytical Chemistry (journal) ; Common emitter ; Transition metal ; Radiochemistry ; Optoelectronics ; Physics ; Chemistry Luminescence Properties of Advanced Materials ; Electronic and Structural Properties of Oxides ; Gas Sensing Nanomaterials and Sensors
Authors: Mohammad Abdul Sattar
Source: ChemSusChem (article, 2023-09-25)
Field: Materials Science — Polymers and Plastics

Surface Activated Pyrolytic Carbon Black: A Dual Functional Sustainable Filler for Natural Rubber Composites The significant rise in end-of-life tires (ELTs) globally poses immediate environmental and human health risks. Therefore, to promote ELTs recycling and to reduce tire industry carbon emissions, herein we present a facile approach for fine-tuning the interfacial interactions between pyrolytic carbon black (P-CB) obtained from ELTs and natural rubber (NR) matrix using phosphonium-based ionic liquid (PIL). The reinforcing effect of PIL-activated P-CB was studied by replacing the furnace-grade carbon black (N330-CB) with varying PIL and P-CB loadings. Adding PIL improved the filler dispersion and the cross-linking kinetics with a substantially reduced zinc oxide (ZnO) loading. Considering the cross-linking and viscoelastic properties, it was concluded that the composite, P-CB/N330-CB-PIL (1.5)+ZnO (1) with half substitution of N330-CB with P-CB synergistically works with 1.5 phr PIL and 1 phr of ZnO resulting in improved dynamic-mechanical properties with a minimal loss tangent value at 60 °C (tanδ=0.0689) and improved glass transition temperature (T<sub>g</sub> =-38 °C) compared to control composite. The significant drop (~29 % lower) in tanδ could reduce fuel consumption and related CO<sub>2</sub> emissions. We envisage that this strategy opens an essential avenue for "Green Tire Technology" towards the substantial pollution abatement from ELTs and reduces the toxic ZnO. Carbon black ; Materials science ; Natural rubber ; Composite number ; Composite material ; Pyrolytic carbon ; Ionic liquid ; Carbon fibers ; Filler (materials) ; Chemical engineering ; Chemistry ; Organic chemistry ; Pyrolysis ; Catalysis Polymer Nanocomposites and Properties ; biodegradable polymer synthesis and properties ; Polymer crystallization and properties
Authors: Paul D. Miller | David A. Shultz | Joshua Mengell | Martin L. Kirk | Łukasz Wojtas
Source: Chemical Science (article, 2023-01-01)
Field: Materials Science — Materials Chemistry

Variation from closed-shell to open shell electronic structures in oligothiophene bis(dioxolene) complexes A series of oligothiophene bis(dioxolene) complexes, SQ-Th<i><sub>n</sub></i>-SQ (SQ = <i>S</i> = ½Tp<sup>Cum,Me</sup>Zn<sup>II</sup>(3-<i>tert</i>-butyl-orthosemiquinonate); Tp<sup>Cum,Me</sup> = tris(5-cumenyl-3-methylpyrazolyl)borate anion) have been synthesized, structurally characterized, and studied as a function of the number of thiophene bridging units, <i>n</i> (<i>n</i> = 0-3) using a combination of variable-temperature (VT) electronic absorption and EPR spectroscopies, and VT magnetic susceptibility measurements. The thiophene bridge bond lengths determined by X-ray crystallography display dramatic differences across the SQ-Th<i><sub>n</sub></i>-SQ series. Bridge bond deviation values (Σ|<i>Δ</i><sub>i</sub>|) display a progressive change in the nature of the bridge fragment bonding as the number of thiophene groups increases, with quinoidal bridge character for <i>n</i> = 1 (SQ-Th-SQ) and biradical character with "aromatic" bridge bond lengths for <i>n</i> = 3 (SQ-Th<sub>3</sub>-SQ). Remarkably, for <i>n</i> = 2 (SQ-Th<sub>2</sub>-SQ) the nature of the bridge fragment is intermediate between quinoid and biradical aromatic, which we describe as having open-shell character as opposed to biradicaloid since the open-shell biradical configuration does not have the correct symmetry to mix with the quinoidal ground-state configuration. This bridge bonding character is reflected in the energies of the lowest lying open-shell states for these three molecules. The SQ-Th-SQ molecule is diamagnetic at all temperatures studied, and we provide evidence for SQ-SQ antiferromagnetic exchange coupling and population of triplet states in SQ-Th<sub>2</sub>-SQ and SQ-Th<sub>3</sub>-SQ, with <b><i>J</i></b><sub>SQ-SQ</sub>(ave) = -279 cm<sup>-1</sup> (VT EPR/electronic absorption/magnetic susceptibility) and <b><i>J</i></b><sub>SQ-SQ</sub> = -117 cm<sup>-1</sup> (VT EPR/electronic absorption/magnetic susceptibility), respectively. The results have been interpreted in the context of state configurational mixing within a simplified 4-electron, 3-orbital model that explicitly contains contributions of a bridge fragment. Variable-temperature spectroscopic- and magnetic susceptibility data are consistent with two low-lying open-shell states for SQ-Th<sub>3</sub>-SQ, but three low-lying states (one closed-shell and two open-shell) for SQ-Th<sub>2</sub>-SQ. This model provides a simple symmetry-based framework to understand the continuum of electronic and geometric structures of this class of molecules as a function of the number of thiophene units in the bridge. Open shell ; Shell (structure) ; Variation (astronomy) ; Chemical physics ; Chemistry ; Materials science ; Physics ; Atomic physics ; Composite material Porphyrin and Phthalocyanine Chemistry ; Molecular Junctions and Nanostructures ; Organic and Molecular Conductors Research
Authors: Marco Schmiedtchen | Iván Maisuls | Christoph Wölper | Cristian A. Strassert | Jens Voskuhl
Source: ChemPhotoChem (article, 2023-11-14)
Field: Materials Science — Materials Chemistry

Regioisomers of Aromatic Thioethers with Aggregation‐Induced Phosphorescence Abstract In this contribution, we describe a library of nine different molecular asterisks, all based on aromatic thioethers. Here, the substitution patterns of the central core unit bearing two nitriles and the rotors featuring methoxy groups were permuted. In addition, the photophysical properties in the solid and aggregated state were investigated. X‐ray diffractometry confirmed the molecular structures. In this frame, the molecular packing in the crystal lattice of the two polymorphs of mNoM was extensively studied and a correlation between photoluminescence and secondary interactions was evaluated. In the solid state, all compounds showed emission in the yellow to red part of the electromagnetic spectrum (555–644 nm) with lifetimes of up to 25 μs and photoluminescence quantum yields of up to 47 %, depending on the substitution pattern. As all the evaluated compounds perform as good emitters with aggregation‐induced phosphorescence (AIP), these compounds can be regarded as multivalent platforms for future applications in supramolecular assemblies or as biomedical labels due to the versatile substitution patterns, manifold geometries as well as appealing photophysical properties. Phosphorescence ; Photoluminescence ; Supramolecular chemistry ; Chemistry ; Aggregation-induced emission ; Structural isomer ; Solid-state ; Crystal structure ; Photochemistry ; Crystallography ; Materials science ; Fluorescence ; Stereochemistry ; Physical chemistry ; Optoelectronics ; Physics Luminescence and Fluorescent Materials ; Molecular Sensors and Ion Detection ; Supramolecular Chemistry and Complexes
Authors: Monica Keszler | Felix Großwendt | Anna-Caroline Assmann | Martin Krengel | Fernando Maccari | Oliver Gutfleisch | Doris Sebold | Olivier Guillon | Sebastian Weber | Martin Bram
Source: Advanced Energy and Sustainability Research (article, 2023-10-26)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Direct Recycling of Hot‐Deformed Nd–Fe–B Magnet Scrap by Field‐Assisted Sintering Technology Recycling of Nd–Fe–B magnets is an ongoing challenge regarding circular economy. State‐of‐the‐art magnet production methods, such as hot deformation, have limitations with respect to direct recycling of magnet scrap particles that differ from pristine melt‐spun Nd–Fe–B powder. Recent work has shown that a combination of presintering by field‐assisted sintering technology/spark plasma sintering (FAST/SPS) and hot deformation by flash spark plasma sintering (flash SPS) has the potential to directly produce Nd–Fe–B magnets from 100% scrap material. Both processes have the capability to adjust and monitor process parameters closely, resulting in recycled magnets with properties similar to commercial magnets but made directly from crushed and recycled Nd–Fe–B powder that partially or completely replaces pristine melt‐spun Nd–Fe–B powder. Herein, a systematic study is done inserting recycled magnet particles into a flash SPS deformed magnet, considering the effects of different weight percentages of scrap material of varied particle size fractions. In some cases, coercivity H cJ of &gt;1400 kAm −1 and remanence B r of 1.1 T can be achieved with 20 wt% scrap material. The relationship between particle size fraction, oxygen uptake, and percentage of recyclate in a final magnet are all explored and discussed with respect to magnets made from pristine material. Spark plasma sintering ; Magnet ; Materials science ; Scrap ; Coercivity ; Metallurgy ; Sintering ; Ingot ; Remanence ; Particle (ecology) ; Composite material ; Magnetization ; Magnetic field ; Alloy ; Mechanical engineering ; Condensed matter physics Magnetic Properties of Alloys ; Hydrogen Storage and Materials ; Rare-earth and actinide compounds
Authors: Jessica R. Chapman | Max Paukner | Micheal Leser | Kai Wen Teng | Shohei Koide | Marlene Holder | Karim‐Jean Armache | Chris Becker | Beatrix Ueberheide | Michael Brenowitz
Source: Analytical Chemistry (article, 2023-12-04)
Field: Chemistry — Spectroscopy

Systematic Fe(II)-EDTA Method of Dose-Dependent Hydroxyl Radical Generation for Protein Oxidative Footprinting Correlating the structure and dynamics of proteins with biological function is critical to understanding normal and dysfunctional cellular mechanisms. We describe a quantitative method of hydroxyl radical generation via Fe(II)-ethylenediaminetetraacetic acid (EDTA)-catalyzed Fenton chemistry that provides ready access to protein oxidative footprinting using equipment commonly found in research and process control laboratories. Robust and reproducible dose-dependent oxidation of protein samples is observed and quantitated by mass spectrometry with as fine a single residue resolution. An oxidation analysis of lysozyme provides a readily accessible benchmark for our method. The efficacy of our oxidation method is demonstrated by mapping the interface of a RAS-monobody complex, the surface of the NIST mAb, and the interface between PRC2 complex components. These studies are executed using standard laboratory tools and a few pennies of reagents; the mass spectrometry analysis can be streamlined to map the protein structure with single amino acid residue resolution. Chemistry ; Footprinting ; Mass spectrometry ; Hydroxyl radical ; Ethylenediaminetetraacetic acid ; Residue (chemistry) ; Combinatorial chemistry ; Reagent ; Chromatography ; Biochemistry ; Radical ; Organic chemistry ; Chelation ; DNA Mass Spectrometry Techniques and Applications ; Hemoglobin structure and function ; Metal-Catalyzed Oxygenation Mechanisms
Authors: Michael E. Runda | Bastian Kremser | Fatma Feyza Özgen | Sandy Schmidt
Source: ChemCatChem (article, 2023-06-07)
Field: Chemistry — Inorganic Chemistry

An Optimized System for the Study of Rieske Oxygenase‐catalyzed Hydroxylation Reactions <i>In vitro</i> Abstract Rieske non‐heme iron oxygenases (ROs) are primarily known for their ability to catalyze the stereoselective formation of vicinal cis ‐diols in a single step, endowing valuable products for pharmaceutical and chemical applications. In addition, ROs can catalyze several other oxidation reactions with high regio‐ and stereoselectivity and typically broad substrate scope. Owing to their dependence on multicomponent electron transfer, the majority of synthetic applications of ROs relies on recombinant whole‐cell catalysts. In this context, important properties of the multicomponent system that determine the catalytic efficiency, including electron transfer via redox partner proteins, stability and uncoupling, have been investigated to a lesser extent in recent years. Here, we show for one of the most prominent ROs, the cumene dioxygenase from Pseudomonas fluorescens IP01 (CDO) that by developing and optimizing an efficient in vitro system, high catalytic activities can be achieved. In addition, we highlight that an efficient and continuous supplementation of electrons to the oxygenase is required to sustain their catalytic activity, while uncoupling can be a major limitation in CDO efficiency and stability. Chemistry ; Hydroxylation ; Oxygenase ; Catalysis ; Redox ; Stereoselectivity ; Context (archaeology) ; Combinatorial chemistry ; Substrate (aquarium) ; Heme oxygenase ; Heme ; Organic chemistry ; Enzyme Metal-Catalyzed Oxygenation Mechanisms ; Microbial bioremediation and biosurfactants ; Pharmacogenetics and Drug Metabolism