jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Xin Ding | Matti Tuikka | Kari Rissanen | Matti Haukka
Source: Crystals (article, 2019-06-24)
Field: Chemistry — Physical and Theoretical Chemistry

Extended Assemblies of Ru(bpy)(CO)2X2 (X = Cl, Br, I) Molecules Linked by 1,4-Diiodotetrafluoro-Benzene (DITFB) Halogen Bond Donors The ruthenium carbonyl compounds, Ru(bpy)(CO)2X2 (X = Cl, Br or I) act as neutral halogen bond (XB) acceptors when co-crystallized with 1,4-diiodotetrafluoro-benzene (DITFB). The halogen bonding strength of the Ru-X⋅⋅⋅I halogen bonds follow the nucleophilic character of the halido ligand. The strongest halogen bond occurs between the chlorido ligand and the iodide atoms of the DITFB. All three halogen bonded complexes form polymeric assemblies in the solid state. In Ru(bpy)(CO)2Cl2⋅DITFB (1) and in Ru(bpy)(CO)2Br2⋅DITFB (2) both halido ligands are halogen bonded to only one DITFB donor. In Ru(bpy)(CO)2I2⋅DITFB (3) only one of the halido ligands is involved in halogen bonding acting as ditopic center for two DITFB donors. The polymeric structures of 1 and 2 are isomorphic wave-like single chain systems, while the iodine complexes form pairs of linear chains attached together with weak F⋅⋅⋅O≡C interactions between the closest neighbors. The stronger polarization of the iodide ligand compared to the Cl or Br ligands favors nearly linear C-I⋅⋅⋅I angles between the XB donor and the metal complex supporting the linear arrangement of the halogen bonded chain. Halogen ; Halogen bond ; Chemistry ; Iodide ; Benzene ; Ligand (biochemistry) ; Ruthenium ; Crystallography ; Nucleophile ; Molecule ; Stereochemistry ; Photochemistry ; Inorganic chemistry ; Alkyl ; Organic chemistry ; Catalysis Crystallography and molecular interactions ; Crystal structures of chemical compounds ; Metal-Organic Frameworks: Synthesis and Applications
Authors: Eric Janusson | Noël de Kler | Laia Vilà‐Nadal | De‐Liang Long | Leroy Cronin
Source: Chemical Communications (article, 2019-01-01)
Field: Materials Science — Materials Chemistry

Synthesis of polyoxometalate clusters using carbohydrates as reducing agents leads to isomer-selection By using sugars as the reducing agents, we demonstrate that it is possible to control the self-assembly of polyoxomolybdates through selective preparation of a single heteropolyanion isomer. d-(-)-Fructose has been proved to be an effective reducing sugar compared to the chemically similar carbohydrate d-(+)-glucose. The gentle reduction results in favourable formation of the Wells-Dawson type gamma isomer in 6-fold reduced form at room temperature. Polyoxometalate ; Selection (genetic algorithm) ; Chemistry ; Combinatorial chemistry ; Stereochemistry ; Catalysis ; Biochemistry ; Computer science Polyoxometalates: Synthesis and Applications ; Metal-Organic Frameworks: Synthesis and Applications ; Advanced Nanomaterials in Catalysis
Authors: Gabriela Handzlik | Barbara Sieklucka | Hanna Tomkowiak | Andrzej Katrusiak | Dawid Pinkowicz
Source: Magnetochemistry (article, 2019-06-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

How to Quench Ferromagnetic Ordering in a CN-Bridged Ni(II)-Nb(IV) Molecular Magnet? A Combined High-Pressure Single-Crystal X-Ray Diffraction and Magnetic Study High-pressure (HP) structural and magnetic properties of a magnetic coordination polymer {[NiII(pyrazole)4]2[NbIV(CN)8]·4H2O}n (Ni2Nb) are presented, discussed and compared with its two previously reported analogs {[MnII(pyrazole)4]2[NbIV(CN)8]·4H2O}n (Mn2Nb) and {[FeII(pyrazole)4]2[NbIV(CN)8]·4H2O}n (Fe2Nb). Ni2Nb shows a significant decrease of the long-range ferromagnetic ordering under high pressure when compared to Mn2Nb, where the pressure enhances the Tc (magnetic ordering temperature), or to Fe2Nb exhibiting a pressure-induced spin crossover. The different HP magnetic responses of the three compounds were rationalized and correlated with the structural models as determined by single-crystal X-ray diffraction. Pyrazole ; Ferromagnetism ; Crystallography ; Diffraction ; Spin crossover ; X-ray crystallography ; Crystal structure ; Materials science ; Chemistry ; Magnet ; Single crystal ; Condensed matter physics ; Stereochemistry ; Optics ; Physics Magnetism in coordination complexes ; Metal complexes synthesis and properties ; Organic and Molecular Conductors Research
Authors: Pascal Rusch | Fabian Niemeyer | Denis Pluta | Björn Schremmer | Franziska Lübkemann | Marina Rosebrock | Malte Schäfer | Mandy Jahns | Peter Behrens | Nadja C. Bigall
Source: Nanoscale (article, 2019-01-01)
Field: Chemistry — Spectroscopy

Versatile route to core–shell reinforced network nanostructures In this work we present the generation of new core-shell network nanostructures of macroscopic dimensionality by a two-step process analogous to the seeded-growth method in colloidal nanoparticle modification. The nanoparticle-based core network is assembled first and in a separate second step it is coated with a continuous metal oxide shell by sol-gel methods. The interparticle contact of the nanoparticles comprising the core network is kept intact throughout the process. By analyzing the local elemental distribution, the shells can be shown to be homogeneous over the macroscopic network monolith. The shell network can be used to considerably reinforce the mechanical strength of the final core-shell network structure. Shell (structure) ; Materials science ; Nanostructure ; Nanoparticle ; Nanotechnology ; Monolith ; Core (optical fiber) ; Homogeneous ; Curse of dimensionality ; Colloid ; Chemical engineering ; Composite material ; Computer science ; Chemistry ; Physics ; Engineering ; Artificial intelligence Aerogels and thermal insulation ; Mesoporous Materials and Catalysis ; Quantum Dots Synthesis And Properties
Authors: Josefine Meurer | Julian Hniopek | Stefan Zechel | Marcel Enke | Jürgen Vitz | Michael Schmitt | Jürgen Popp | Martin D. Hager | Ulrich S. Schubert
Source: Polymers (article, 2019-11-15)
Field: Materials Science — Polymers and Plastics

Shape-Memory Metallopolymer Networks Based on a Triazole–Pyridine Ligand Shape memory polymers represent an interesting class of stimuli-responsive polymers. With their ability to memorize and recover their original shape, they could be useful in almost every area of our daily life. We herein present the synthesis of shape-memory metallopolymers in which the switching unit is designed by using bis(pyridine-triazole) metal complexes. The polymer networks were synthesized via free radical polymerization of methyl-, ethyl- or butyl-methacrylate, tri(ethylene glycol) dimethacrylate and a methacrylate moiety of the triazole-pyridine ligand. By the addition of zinc(II) or cobalt(II) acetate it was possible to achieve metallopolymer networks featuring shape-memory abilities. The successful formation of the metal-ligand complex was proven by Fourier transform infrared (FT-IR) spectroscopy and by <sup>1</sup>H NMR spectroscopy. Furthermore, the shape-recovery behavior was studied in detailed fashion and even triple-shape memory behavior could be revealed. Moiety ; Methacrylate ; Pyridine ; Polymer chemistry ; Polymer ; Materials science ; Fourier transform infrared spectroscopy ; Ligand (biochemistry) ; Polymerization ; Ethylene glycol ; Radical polymerization ; Smart material ; Chemistry ; Organic chemistry ; Nanotechnology ; Chemical engineering Polymer composites and self-healing ; Marine Sponges and Natural Products ; Conducting polymers and applications
Authors: Agata Tyszka‐Gumkowska | Grzegorz Pikus | Janusz Jurczak
Source: Molecules (article, 2019-07-19)
Field: Chemistry — Spectroscopy

Chiral Recognition of Carboxylate Anions by (R)-BINOL-Based Macrocyclic Receptors Three (<i>R</i>)-BINOL-based macrocyclic receptors obtained via double-amidation reaction were used for chiral recognition of four anions derived from α-hydroxy and α-amino acids. The structural factors of hosts and guests that affect chiral recognition processes were also investigated, indicating that the proper geometry of both receptor and guest molecules plays a crucial role in effective enantio-discrimination. Molecular recognition ; Carboxylate ; Chemistry ; Receptor ; Molecule ; Stereochemistry ; Amino acid ; Combinatorial chemistry ; Biochemistry ; Organic chemistry Molecular Sensors and Ion Detection ; Analytical Chemistry and Chromatography ; Molecular spectroscopy and chirality
Authors: Martin Koller | Paula Johanna Hesse | Gerhart Braunegg
Source: The EuroBiotech Journal (article, 2019-04-01)
Field: Materials Science — Biomaterials

Application of whey retentate as complex nitrogen source for growth of the polyhydroxyalkanoate producer <i>Hydrogenophaga pseudoflava</i> strain DSM1023 Abstract Polyhydroxyalkanoates, microbial polyesters produced in vivo starting from renewable resources, are considered the future materials of choice to compete recalcitrant petro-chemical plastic on the polymer market. In order to make polyhydroxyalkanoates market-fit, (techno)economics of their production need to be improved. Among the multifarious factors affecting costs of polyhydroxyalkanoate production, increased volumetric productivity is of utmost importance. Improving microbial growth kinetics and increasing cell density are strategies leading to a high concentration of catalytically active biomass within a short time; after changing cultivation conditions, these cells can accumulate polyhydroxyalkanoates as intracellular products. The resulting increase of volumetric productivity for polyhydroxyalkanoates can be realized by supplying complex nitrogen sources to growing microbial cultures. In the present study, the impact of different expensive and inexpensive complex nitrogen sources, in particular whey retentate, on the growth and specific growth rates of Hydrogenophaga pseudoflava was tested. Based on a detailed kinetic process analysis, the study demonstrates that especially whole (not hydrolyzed) whey retentate, an amply available surplus material from dairy industry, displays positive effects on cultivations of H. pseudoflava in defined media (increase of concentration of catalytically active biomass after 26.25 h of cultivation by about 50%, increase of specific growth rate μ from 0.28 to 0.41 1/h during exponential growth), while inhibiting effects (inhibition constant K i = 6.1 g/L) of acidically hydrolyzed whey retentate need to be overcome. Considering the huge amounts of surplus whey accruing especially in Europe, the combined utilization of whey permeate (carbon source) and whey retentate (complex nitrogen source) for biopolyester production can be considered a viable bioeconomic strategy for the next future. Polyhydroxyalkanoates ; Biomass (ecology) ; Bioplastic ; Chemistry ; Pulp and paper industry ; Food science ; Bacterial growth ; Waste management ; Bacteria ; Biology ; Engineering ; Agronomy biodegradable polymer synthesis and properties ; Microplastics and Plastic Pollution ; Electrospun Nanofibers in Biomedical Applications
Authors: Marcos Schöneborn | Thomas Harmening | J. Giménez-Mañogil | Juan Carlos Martínez-Munuera | Avelina Garcı́a-Garcı́a
Source: Materials (article, 2019-07-02)
Field: Materials Science — Materials Chemistry

Improved NOx Storage/Release Properties of Ceria-Based Lean NOx Trap Compositions with MnOx Modification Ceria/spinel-based lean NO<sub>x</sub> trap compositions with and without barium were modified with MnO<sub>x</sub> via incipient wetness impregnation. The effect of the MnO<sub>x</sub> layer on the aged materials (850 °C) as to the NO<sub>x</sub> storage and release properties was investigated via NO<sub>x</sub> adsorption (500 ppm NO/5% O<sub>2</sub>/balance N<sub>2</sub>) carried out at 300 °C in a dual-bed with a 1% Pt/Al<sub>2</sub>O<sub>3</sub> catalyst placed upstream of the samples to generate sufficient amounts of NO<sub>2</sub> required for efficient NO<sub>x</sub> storage. Subsequent temperature programmed desorption (TPD) experiments were carried out under N<sub>2</sub> from 300 °C to 700 °C. The addition of MnO<sub>x</sub> to the barium free composition led to a slightly reduced NO<sub>x</sub> storage capacity but all of the ad-NO<sub>x</sub> species were released from this material at significantly lower temperatures (ΔT ≈ 100 °C). The formation of a MnO<sub>x</sub> layer between ceria/spinel and barium had a remarkable effect on ageing stability as the formation of BaAl<sub>2</sub>O<sub>4</sub> was suppressed in favour of BaMnO<sub>3</sub>. The presence of this phase resulted in an increased NO<sub>x</sub> storage capacity and lower desorption temperatures. Furthermore, NO<sub>x</sub> adsorption experiments carried out in absence of the Pt-catalyst also revealed an unexpected high NO<sub>x</sub> storage ability at low NO<sub>2</sub>/NO ratios, which could make this composition suitable for various lean NO<sub>x</sub> trap catalysts (LNT) related applications. NOx ; Adsorption ; Calcination ; Chemical engineering ; Spinel ; Catalysis ; Chemistry ; Barium ; Desorption ; Incipient wetness impregnation ; Inorganic chemistry ; Materials science ; Metallurgy ; Organic chemistry ; Selectivity ; Combustion Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions ; Industrial Gas Emission Control
Authors: Ye Zhu | Chong Wei Tan | Shen Lin Chua | Yu Dian Lim | Boris Vaisband | Beng Kang Tay | Eby G. Friedman | Chuan Seng Tan
Source: IEEE Transactions on Components Packaging and Manufacturing Technology (article, 2019-09-11)
Field: Materials Science — Materials Chemistry

Assembly Process and Electrical Properties of Top-Transferred Graphene on Carbon Nanotubes for Carbon-Based 3-D Interconnects Carbon nanomaterials, graphene, and carbon nanotubes (CNTs) have emerged as promising materials for the integration of future advance packaging technologies. The main benefits of carbon nanomaterials include excellent electrical, thermal, and mechanical properties. In this article, the transfer process of a top graphene layer onto the as-grown CNT bundles was successfully performed with direct graphene-to-CNT contact at the interface. Four-point-probe (4PP) I-V characterization suggests that an ohmic contact was achieved between the graphene and CNTs. Low CNT bump resistance of 2.1 Ω for 90 000-μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> CNT area including the CNT-graphene contact resistance was obtained, demonstrating a reduction in the contact resistance between the CNT and Au under the same fabrication and measurement conditions. This work presents the preliminary results for the assembly process of top-transferred graphene on the CNTs and the electrical properties of direct CNT-graphene contact, paving the way for the implementation of full-carbon-based three-dimensional (3-D) interconnects. Graphene ; Materials science ; Carbon nanotube ; Contact resistance ; Ohmic contact ; Nanotechnology ; Nanomaterials ; Electrical contacts ; Graphene nanoribbons ; Carbon fibers ; Fabrication ; Sheet resistance ; Layer (electronics) ; Optoelectronics ; Composite material ; Composite number Graphene research and applications ; Carbon Nanotubes in Composites ; Thermal properties of materials
Authors: Florian Scheiflinger | Marzieh Habibi | Elham Zeynolabedini | Christof Plessl | Gabriele Wallner
Source: Journal of Radioanalytical and Nuclear Chemistry (article, 2019-09-28)
Field: Chemistry — Inorganic Chemistry

Radionuclide extraction with different ionic liquids Abstract 10 ionic liquids based on 3 different cations and 5 anions were investigated for radionuclide extraction from aqueous solutions. While uranium and 210 Po were extracted with satisfying yields irrespective of the feed solution pH, 234 Th, 226 Ra and 210 Pb extraction yields were rather low. The contact time necessary for near to complete extraction was determined as well as the conditions for successful back-extraction. The loading capacities of the ionic liquids for uranium were very high and depended on the uranyl counter-ion. From the leaching of the ionic liquids into the aqueous phase the predominant extraction mechanisms were derived. Uranyl ; Ionic liquid ; Uranium ; Extraction (chemistry) ; Leaching (pedology) ; Aqueous solution ; Chemistry ; Radionuclide ; Aqueous two-phase system ; Ion ; Ionic bonding ; Inorganic chemistry ; Radiochemistry ; Chromatography ; Materials science ; Physical chemistry ; Organic chemistry ; Metallurgy ; Soil water Radioactive element chemistry and processing ; Extraction and Separation Processes ; Ionic liquids properties and applications
Authors: Harrison G. Jones | Daniel Wrapp | Morgan S. A. Gilman | Michael B. Battles | Nianshuang Wang | Sofia Sacerdote | Gwo-Yu Chuang | Peter D. Kwong | Jason S. McLellan
Source: Acta Crystallographica Section F Structural Biology Communications (article, 2019-01-24)
Field: Materials Science — Materials Chemistry

Iterative screen optimization maximizes the efficiency of macromolecular crystallization Advances in X-ray crystallography have streamlined the process of determining high-resolution three-dimensional macromolecular structures. However, a rate-limiting step in this process continues to be the generation of crystals that are of sufficient size and quality for subsequent diffraction experiments. Here, iterative screen optimization (ISO), a highly automated process in which the precipitant concentrations of each condition in a crystallization screen are modified based on the results of a prior crystallization experiment, is described. After designing a novel high-throughput crystallization screen to take full advantage of this method, the value of ISO is demonstrated by using it to successfully crystallize a panel of six diverse proteins. The results suggest that ISO is an effective method to obtain macromolecular crystals, particularly for proteins that crystallize under a narrow range of precipitant concentrations. Crystallization ; Macromolecule ; Biochemical engineering ; Computer science ; Materials science ; Biological system ; Mathematical optimization ; Process engineering ; Chemistry ; Mathematics ; Chemical engineering ; Biology ; Engineering Enzyme Structure and Function ; Protein Structure and Dynamics ; Advanced Proteomics Techniques and Applications
Authors: Franco Concli | Lorenzo Maccioni
Source: WIT transactions on engineering sciences (article, 2019-07-15)
Field: Materials Science — Materials Chemistry

EXPERIMENTAL–NUMERICAL CALIBRATION OF THE FRACTURE LOCUS OF WEATHERING STEEL Weathering steel, specifically Cor-Ten (or CORTEN) steel is a material particularly exploited in the last century for various outdoor applications, e.g. bridges, building facades, artworks etc. In addition to a tensile strength comparable with other construction steels, the natural oxide of this material, that is common rust, has the same specific volume as the metallic core. This ensures the adhesion of the oxidized protective layer as for aluminium. Therefore, the stable rust layer protects the raw material from further corrosion. This characteristic overcomes the need for painting and maintenance. These properties boost the exploitation of Cor-Ten in several civil applications, also where safety is a fundamental requirement, e.g. guard rails used, for example, in the South-Tyrolean region along the highways. With the aim of verifying or optimizing such safety applications, it is important to know the ductile behavior of the material. Indeed, during an impact, the main purpose of the structure is to absorb energy and this implies that large deformations will take place. Experimental quasi-static tests were performed on several sample geometries made of Cor-Ten. The same tests were also numerically reproduced, to retrieve the actual stress state, quantify the plastic strain at failure and calibrate a ductile damage model. The material model is based on both the classical incremental model of plastic response with isotropic hardening and the phenomenological concept of damage in continuum mechanics. Materials science ; Isotropy ; Weathering steel ; Corrosion ; Hardening (computing) ; Weathering ; Structural engineering ; Ultimate tensile strength ; Composite material ; Engineering ; Geology ; Layer (electronics) High-Velocity Impact and Material Behavior ; Fatigue and fracture mechanics ; Structural Response to Dynamic Loads
Authors: Christian Dorfer | Dmitry Hits | Lamia Kasmi | G. Kramberger | Matteo Lucchini | M. Mikuž | R. Wallny
Source: Applied Physics Letters (article, 2019-05-20)
Field: Materials Science — Materials Chemistry

Three-dimensional charge transport mapping by two-photon absorption edge transient-current technique in synthetic single-crystalline diamond We demonstrate the application of the two-photon absorption transient current technique to wide bandgap semiconductors. We utilize it to probe charge transport properties of single-crystal Chemical Vapor Deposition (scCVD) diamond. The charge carriers, inside the scCVD diamond sample, are excited by a femtosecond laser through simultaneous absorption of two photons. Due to the nature of two-photon absorption, the generation of charge carriers is confined in space (3-dimensional, 3-D) around the focal point of the laser. Such localized charge injection allows us to probe the charge transport properties of the semiconductor bulk with a fine-grained 3-D resolution. Exploiting spatial confinement of the generated charge, the electrical field of the diamond bulk was mapped at different depths and compared to an X-ray diffraction topograph of the sample. Measurements utilizing this method provide a unique way of exploring spatial variations of charge transport properties in transparent wide-bandgap semiconductors. Diamond ; Materials science ; Transient (computer programming) ; Absorption (acoustics) ; Optoelectronics ; Current (fluid) ; Charge (physics) ; Enhanced Data Rates for GSM Evolution ; Photon ; Absorption edge ; Synthetic diamond ; Ultrafast laser spectroscopy ; Atomic physics ; Optics ; Chemical vapor deposition ; Physics ; Telecommunications Diamond and Carbon-based Materials Research ; Laser-Matter Interactions and Applications ; Force Microscopy Techniques and Applications