jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Alexandra I. Zvyagina | Alena D. Naumova | Natalia V. Kuzmina | Alexander G. Martynov | Yulia G. Gorbunova | Maria A. Kalinina
Source: Macroheterocycles (article, 2021-01-01)
Field: Materials Science — Materials Chemistry

Surfactant-Assisted Lateral Self-Assembly of One-Dimensional Supramolecular Aggregates of Lutetium Double-Decker Phthalocyaninates The development of feasible strategies for integrating 1D organic semiconductors into films is a challenging issue for organic electronics exploiting planar architectures of microelectronic devices. Herein we describe the method of planar organization of 1D supramolecular aggregates assembled from lutetium crown-substituted double-decker phthalocyaninate into ordered ultrathin films. The method utilizes the Langmuir-Blodgett technique in combination with adding tert-butylamine during the synthesis of the supramolecular aggregates. The atomic force microscopy examination of the resulting films shows that the introduction of surfactant promotes spreading of hydrophobic aggregates on the water subphase yielding ordered ultrathin layers. The size of aggregates can be controlled by varying the ratio of the phthalocyanine ligands and surfactant in the system. The size of the aggregates increases with the concentration of the surfactant, whereas the morphology of the films evolves from a filamentary continuous structure to individual nanowires immobilized in the surfactant layer. The proposed strategy can be used to obtain ordered coatings from 1D aggregates from various organic discotics with semiconductor properties. Lutetium ; Pulmonary surfactant ; Supramolecular chemistry ; Self-assembly ; Materials science ; Chemistry ; Nanotechnology ; Crystallography ; Crystal structure ; Metallurgy Porphyrin and Phthalocyanine Chemistry ; Mesoporous Materials and Catalysis ; Supramolecular Self-Assembly in Materials
Authors: Maxime Ayer | Rico S. Bolli | Anthony S. R. Chesman | Craig M. Forsyth | Justine L. Jeffery | Andris J. Liepa | Karolina M. Morawska | Théo Ozga | Craig L. Francis
Source: ARKIVOC (article, 2021-11-16)
Field: Chemistry — Organic Chemistry

Some new 2,8-disubstituted-1,7-dicyano-3,9-diazaperylenes Concise synthetic protocols for a range of new 2,8-disubstituted-1,7-dicyano-3,9-diazaperylenes, starting from commercially available 1,5-diaminoanthraquinone, have been developed, which enable the introduction of various tertiary-amino, substituted-ethynyl, and aryl groups at the C2 and C8 positions, as well as incorporation of aryl-amino groups at the C4 and C10 positions, of the rare 3,9-diazaperylene system. This methodology should enable tuning of physical and optoelectronic properties and may find use in the discovery of new materials for organic photovoltaic devices or other organic electronic applications. Chemistry ; Medicinal chemistry Synthesis and Properties of Aromatic Compounds ; Porphyrin and Phthalocyanine Chemistry ; Organic Chemistry Cycloaddition Reactions
Authors: Mmushi M. Moeng | Frederick P. Malan | Simon Lotz | Daniela I. Bezuidenhout
Source: Journal of Molecular Structure (article, 2021-12-04)
Field: Chemistry — Organic Chemistry

Fischer carbene complexes of cobalt(I): Synthesis and structure Three different aryl substrates thiophene (ThH), ferrocene (FcH) and p-bromodimethylaniline (p-DMABr) were lithiated and reacted with [Co(CO)4SnPh3], according to the Fischer carbene protocol. The products [CoSnPh3(CO)3{C(OEt)R}] (R =Th, 1, p-DMA, 2 and R = Fc, 3) were analysed to unravel the role of the aryl carbene substituent in stabilizing intermediates and final products. The ethoxy carbene complexes were aminolysed by in situ generated HNMe2 to afford [CoSnPh3(CO)3{C(NMe2)R}] (R =Th, 4, p-DMA, 5) and with N,N-dimethylethylenediamine [CoSnPh3(CO)3{C(NHCH2CH2NMe2)R}] (R = p-DMA, 6) in high yields. The trigonal Co(CO)3 in the equatorial plane is very stable and efforts to displace a carbonyl in 6 was unsuccessful, both by heating and irradiation. The role of the aryl carbene substituents in stabilizing the electrophilic carbene carbon was investigated and studied by NMR spectroscopy in solution and single crystal X-ray structure determinations. Carbene ; Chemistry ; Aryl ; Substituent ; Electrophile ; Transition metal carbene complex ; Medicinal chemistry ; Cobalt ; Ferrocene ; Alkoxy group ; Thiophene ; Nuclear magnetic resonance spectroscopy ; Stereochemistry ; Organic chemistry ; Alkyl ; Catalysis ; Physical chemistry N-Heterocyclic Carbenes in Organic and Inorganic Chemistry ; Organometallic Complex Synthesis and Catalysis ; Coordination Chemistry and Organometallics
Authors: Shinya Furukawa
Source: Journal of the Japan Petroleum Institute (article, 2021-12-31)
Field: Materials Science — Materials Chemistry

Development of Highly Efficient Catalysts for DeNO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; and Alkane Dehydrogenation Based on Multimetallic Alloys Bimetallic alloys are widely used and studied as catalyst materials, but development of highly efficient catalysts using only two metal elements has limits. In this study, a series of multimetallic catalysts were developed for deNOx reactions and alkane dehydrogenation based on advanced catalyst design concepts using alloy materials. Two strategies based on pseudo-binary alloys and surface modification of intermetallic compounds were employed. Pseudo-binary alloy, in which a part of the constituent metal in a binary intermetallic compound is substituted with a third metal, allows construction of trimetallic active sites with flexibly optimized atomic ratio and catalytic characteristics. Surface modification of intermetallic compounds allows selective blocking of undesirable active sites catalyzing side reactions, and construction of a sterically hindered reaction environment for selective hydrogenation. High catalytic activity, selectivity, and stability were achieved by appropriately applying these materials and design concepts. Outstandingly high stability (almost no deactivation at 600 °C for a month) was achieved for propane dehydrogenation. Dehydrogenation ; Intermetallic ; Bimetallic strip ; Catalysis ; Alloy ; Selectivity ; Materials science ; Alkane ; Propane ; Metal ; Chemical engineering ; Chemistry ; Combinatorial chemistry ; Organic chemistry ; Metallurgy Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions
Authors: William Bro‐Jørgensen | Marc H. Garner | Gemma C. Solomon
Source: ChemRxiv (preprint, 2021-06-30)
Field: Materials Science — Materials Chemistry

Quantification of the Helicality of Helical Molecular Orbitals The frontier molecular orbital (MO) topology of linear carbon molecules, such as polyynes, can be visually identified as helices. However, there is no clear way to quantify the helical curvature of these π-MOs and it is thus challenging to quantify correlations between the helical curvature and molecular properties. In this paper, we develop a method that enables us to compute the helical curvature of MOs based on their nodal planes. Using this method, we define a robust way of quantifying the helical nature of MOs (helicality) by their deviation from a perfect helix. We explore several limiting cases, including polyynes, metallacumulenes, cyclic allenes, and spiroconjugated sys- tems where the change in helical curvature is subtle, yet clearly highlighted with this method. For example, we show that strain only has a minor effect on the helicality of the frontier orbitals of cycloallenes and that the MOs of spiroconjugated systems are close to perfect helices around the spiro-carbon. Our work provides a well-defined method for assessing orbital helicality beyond visual inspection of MO isosurfaces, thus paving the way for future studies of how the helicality of π-MOs affects molecular properties. Curvature ; Molecular orbital ; Atomic orbital ; Limiting ; Topology (electrical circuits) ; Helix (gastropod) ; Physics ; Molecule ; Computer science ; Mathematics ; Geometry ; Combinatorics ; Quantum mechanics ; Biology ; Engineering Carbon Nanotubes in Composites ; Fullerene Chemistry and Applications ; Synthesis and Properties of Aromatic Compounds
Authors: Aiting Kai | Benjamin D. Egleston | Rob Clowes | Michael E. Briggs | Andrew I. Cooper | Rebecca L. Greenaway
Source: ChemRxiv (preprint, 2021-06-03)
Field: Materials Science — Materials Chemistry

Modular Type III Porous Liquids based on Porous Organic Cage Microparticles The dispersion of particulate porous solids in size-excluded liquids has emerged as a method to create Type III porous liquids, mostly using insoluble microporous materials such as metal-organic frameworks (MOFs) and zeolites. Here, we present the first examples of Type III porous liquids based on porous organic cages (POCs). By exploiting the solution processability of the POCs, racemic and quasiracemic cage microparticles were formed by chiral recognition. Dispersion of these porous microparticles in a range of size-excluded liquids, including oils and ionic liquids, formed stable POC-based Type III porous liquids. The flexible pairing between the solid POC particles and a carrier liquid allows the formation of a range of compositions, pore sizes, and other physicochemical properties to suit different applications and operating conditions. For example, we show that it is possible to produce porous liquids with relatively low viscosities (7-14 mpa∙s) or high thermal stability (325 °C). A 12.5 wt. % Type III porous liquid comprising racemic POC microparticles and an ionic liquid, [BPy][NTf&lt;sub&gt;2&lt;/sub&gt;], shows a CO&lt;sub&gt;2&lt;/sub&gt; working capacity (104.30 μmol/g&lt;sub&gt;L&lt;/sub&gt;) that is significantly higher than the neat ionic liquid (37.27 μmol/g&lt;sub&gt;L&lt;/sub&gt;) between 25 °C and 100 °C. This liquid is colloidally stable and can be recycled at least 10 times without loss of CO&lt;sub&gt;2&lt;/sub&gt; capacity. Ionic liquid ; Porosity ; Microporous material ; Chemical engineering ; Dispersion (optics) ; Materials science ; Porous medium ; Thermal stability ; Chemistry ; Organic chemistry ; Composite material ; Catalysis Covalent Organic Framework Applications ; Metal-Organic Frameworks: Synthesis and Applications ; Supramolecular Chemistry and Complexes
Authors: Alain Krief
Source: ARKIVOC (article, 2021-03-30)
Field: Chemistry — Organic Chemistry

Pyrethroid insecticides.Chapter III: Synthesis of 3-phenoxy mandelonitrile Racemic and enantiopure 3-phenoxymandelonitrile are valuable building blocks for the synthesis of pyrethrin insecticides cypermethrin and deltamethrin. Their synthesis involves two crucial steps: the synthesis of 3-phenoxybenzaldehyde which is produced through ether coupling, and its hydrocyanation. Pyrethroid ; Chemistry ; Organic chemistry ; Pesticide ; Agronomy Structural and Chemical Analysis of Organic and Inorganic Compounds ; Pesticide Exposure and Toxicity ; Chemical Reaction Mechanisms
Authors: Hiago Maurilio Lopes Carvalho | Mariama Rebello Sousa Dias | Anibal Bezerra
Source: Research Square (preprint, 2021-07-13)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Anisotropic optical response of gold-silver alloys Abstract Gold and silver alloys enable novel opportunities for engineering materials with distinct optical responses. Here we investigate the optical properties of gold and silver (Ag x Au 1−x) structures using First-Principle Density Functional Theory (DFT) for gold concentrations varying from 0% up to 100% with steps of 25%. Results of the optical permittivity are analyzed with the independent particle approximation and compared with previously reported theoretical and experimental works. The pure systems and the ones with unbalanced concentrations exhibit isotropic optical responses. The Ag 0.50 Au 0.50 shows an anisotropic response among the y-direction and the xz-direction, mainly in the intraband transition energy range. The anisotropy is elucidated in terms of the d-orbitals density of states and the charge distribution with the structure. The anisotropic optical response can be the origin of the discrepancies among reported experimental results for structures with the same stoichiometry. Anisotropy ; Isotropy ; Density functional theory ; Materials science ; Optical anisotropy ; Condensed matter physics ; Stoichiometry ; Range (aeronautics) ; Atomic orbital ; Permittivity ; Particle (ecology) ; Optics ; Optoelectronics ; Physics ; Chemistry ; Dielectric ; Computational chemistry ; Physical chemistry ; Electron ; Quantum mechanics ; Composite material Gold and Silver Nanoparticles Synthesis and Applications ; Spectroscopy and Quantum Chemical Studies ; Surface and Thin Film Phenomena
Authors: Min-Sook Baek | Kyeong-Cheol Baek | Yoon-Ja Kim | Dong‐Joo Yoon
Source: Scholars Journal of Engineering and Technology (article, 2021-01-29)
Field: Materials Science — Materials Chemistry

Development of Austenite Fe Alloy for Melted Zinc Coating Facilities Using the DV-Xα Methods In this study, the material used in the hot dip galvanizing equipment was poorly corrosion-resistant, so it was performed to solve the cost and time problems caused by equipment replacement. The theoretical calculation was performed using the DV-X method (Discrete Variational Local-density approximation method). The alloy (STS316L) of the equipment currently used has a austenite phase. Therefore, the theoretical calculation was performed by applying Fm-3m, which is a cubic structure. The new alloy was chosen by designing theoretical values close to existing materials. Considering elements that contribute to corrosion, most have high prices. Therefore, the design was completed by adjusting the content using only the components of the reference material in the theoretical design. The final design alloys were chosen as SWA6. Designed SWA6 were dissolved and prepared using an induction furnace. After the heat treatment process was completed, the corrosion rate of the alloys was confirmed by using the potentiodynamic polarization test. The surface of the prepared alloys were processed horizontally and then polished to # 1200 using sand paper to perform potentiodynamic polarization test. 316L: 0.9599 mpy (mils / year), SWA6: 0.828 mpy, alloys designed than 316L had a lower corrosion rate. Therefore, the designed alloy was expected to have better erosion resistance. Alloy ; Austenite ; Materials science ; Metallurgy ; Zinc ; Coating ; Composite material ; Microstructure Metal Alloys Wear and Properties ; Metallurgy and Material Forming ; Microstructure and Mechanical Properties of Steels
Authors: Doğu Ramazanoğlu | Zaman Adnan MOHAMMED | Maher Khalid
Source:  (article, 2021-11-28)
Field: Chemistry — Spectroscopy

Investigation Usability of Biosorbents Obtained from Orange peels in Heavy Metal Adsorption Bu çalışmada, Cu2+, Ni2+ ve Co2+ ağır metal iyonlarını çözeltilerinden uzaklaştırılması için portakal kabuğu bazlı altı farklı biyosorbent üretilmiştir. Ayrıca, bu biyosorbentlerin, fiziksel özelliklerinin ve adsorpsiyon kapasitesinin yağ ve mısır nişastası içeriğinden nasıl etkilendiği araştırıldı. Biyosorbentlerin adsorpsiyon performanslarının belirlenmesi için alevli atomik absorpsiyon spektroskopisi (FAAS) kullanılmıştır. Biyosorbentlerin yoğunluğu ise ASTM D 792 standartlarına göre belirlenmiştir. Sonuç olarak, işlem görmemiş portakal kabukları, 24 °C&amp;#039;de, 175 rpm karıştırma hızında ve 30 dakika boyunca; 4,87 ppm Co2+ iyonu, 5,83 ppm Ni2+ iyonu ve 4,29 ppm Cu2+ iyonu değerleriyle en iyi biyosorbent olmuştur. Usability ; Adsorption ; Orange (colour) ; Chemistry ; Computer science ; Human–computer interaction ; Organic chemistry ; Food science Adsorption, diffusion, and thermodynamic properties of materials ; Freezing and Crystallization Processes
Authors: Victor G. Ivanov | G. G. Tsutsumanova | N. D. Todorov | Stoyan C. Russev | M. V. Abrashev | A. V. Lukoyanov
Source: Preprints.org (preprint, 2021-10-28)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Silver Flowerlike Structures for Surface-Enhanced Raman Spectroscopy Micro- and nanoflowers are a class of materials composed of particles with high surface-to-volume ratio. They are being extensively studied in the last decade due to simple preparation protocols and promising applications in biosensing, as drug delivery agents, for water purification and so on. Flowerlike objects, due to their highly irregular surface, may act also as plasmonic materials, providing resonant coupling between optical waves and surface plasmon excitations. This fact infers for the possibility to use micro- and nanoflowers as effective surface-enhanced Raman scattering (SERS) substrate materials. Here, we report on the design and Raman enhancement properties of silver flowerlike structures, deposited on aluminum surface. A simple and cost-effective fabrication method is described, which leads to SERS substrates of high developed surface area. The morphology of the silver flowers on a nanoscale is characterized by self-organized quasiperiodic stacks of nanosheets, which act as plasmonic cavity-resonators. The substrates were tested against rhodamine-6G (R6G) water solutions of concentration varying between 10&amp;ndash;3 M and 10&amp;ndash;7 M. Optimal SERS enhancement factors of up to 105 were established at R6G concentrations in the range 10&amp;ndash;6 &amp;ndash; 10&amp;ndash;7 M. Rhodamine 6G ; Materials science ; Raman scattering ; Raman spectroscopy ; Plasmon ; Nanotechnology ; Substrate (aquarium) ; Surface-enhanced Raman spectroscopy ; Biosensor ; Surface plasmon ; Chemical engineering ; Optoelectronics ; Optics ; Molecule ; Chemistry Gold and Silver Nanoparticles Synthesis and Applications ; Laser-Ablation Synthesis of Nanoparticles ; Electrohydrodynamics and Fluid Dynamics
Authors: Chương V. Nguyen | Nguyen N. Hieu | Nguyễn Văn Hiếu
Source: VNU Journal of Science Mathematics - Physics (article, 2021-06-30)
Field: Materials Science — Materials Chemistry

Theoretical Prediction of the Structural and Electronic Properties of a Single Layer Graphene-like Two-dimensional Janus GaInSTe This paper constructs a new type of two-dimensional graphene-like Janus GaInSTe monolayer and systematically investigates its structural and electronic properties as well as the effect of external electric field using first-principles calculations. In the ground state, Janus GaInSTe monolayer is dynamically stable with no imaginary frequencies in its phonon spectrum and possesses a direct band gap semiconductor. The band gap of Janus GaInSTe monolayer can be tuned by applying an electric field, which leads the different transitions from semiconductor to metal, and from indirect to direct band gap. These findings show a great potential application of Janus GaInSTe material for designing next-generation devices. Janus ; Monolayer ; Semiconductor ; Band gap ; Materials science ; Condensed matter physics ; Electric field ; Graphene ; Direct and indirect band gaps ; Phonon ; Nanotechnology ; Optoelectronics ; Physics ; Quantum mechanics 2D Materials and Applications ; Energy Harvesting in Wireless Networks ; Satellite Communication Systems
Authors: Sujin Lee | Byungjoon Min | Junhyeok Bang
Source: Research Square (preprint, 2021-10-11)
Field: Materials Science — Materials Chemistry

Substrate Effect on Hydrogen Evolution Reaction in Two-Dimensional Mo2C Monolayers Abstract The physical and chemical properties of atomically thin two-dimensional (2D) materials can be modified by the substrates. In this study, the substrate effect on the electrocatalytic hydrogen evolution reaction (HER) in 2D Mo 2 C monolayers was investigated using first principles calculations. The isolated Mo 2 C monolayer shows large variation in HER activity depending on hydrogen coverage: it has relatively low activity at low hydrogen coverage but high activity at high hydrogen coverage. Ag, Au, Cu, and graphene were used as substrates to study the substrate effect. While the effects of the Au and graphene substrates on the HER activity are insignificant, Ag and Cu substrates improve the HRE activity, especially at low hydrogen coverage, by modifying the valence electrons in the Mo 2 C layer; therefore, the HER activity of the Mo 2 C monolayer becomes high for any hydrogen coverage. Our results suggest that, in two-dimensional electrocatalysis, the substrate has a degree of freedom to tune the catalytic activity. Monolayer ; Hydrogen ; Graphene ; Substrate (aquarium) ; Catalysis ; Valence (chemistry) ; Electrocatalyst ; Materials science ; Valence electron ; Chemical engineering ; Photochemistry ; Chemistry ; Chemical physics ; Electron ; Nanotechnology ; Electrode ; Physical chemistry ; Organic chemistry ; Electrochemistry ; Physics MXene and MAX Phase Materials ; 2D Materials and Applications ; Electrocatalysts for Energy Conversion
Authors: Ivan V. Zhukov | Alexey S. Kiryutin | Mikhail S. Panov | Natalya N. Fishman | Olga B. Morozova | Nikita N. Lukzen | Konstantin L. Ivanov | Hans‐Martin Vieth | R.Z. Sagdeev | Alexandra V. Yurkovskaya
Source:  (preprint, 2021-02-16)
Field: Chemistry — Spectroscopy

Exchange interaction in short lived flavin adenine dinucleotidebiradical in aqueous solution revisited by CIDNP and nuclearmagnetic relaxation dispersion Abstract. Flavin adenine dinucleotide (FAD) is an important cofactor in many light-sensitive enzymes. The role of the adenine moiety of FAD in light induced electron transfer was obscured because it involves an adenine radical, short-lived with a weak chromophore. However, an intramolecular electron transfer from adenine to flavin was revealed several years ago by R. Kaptein by using chemically induced dynamic nuclear polarization (CIDNP). The question whether one or two types of biradicals of FAD in aqueous solution are formed stays unresolved so far. In the present work, we revisited the CIDNP study of FAD using a robust mechanical sample shuttling setup covering a wide magnetic field range with sample illumination by a light emitting diode. Also, a cost efficient fast field cycling apparatus with high spectral resolution detection up to 16.4 T for nuclear magnetic relaxation dispersion studies was built based on a 700 MHz NMR spectrometer. Site-specific proton relaxation dispersion data for FAD show a strong restriction of the relative motion of its isoalloxazine and adenine rings with coincident correlation times for adenine, flavin and their ribityl-phosphate linker. This finding is consistent with the assumption that the molecular structure of FAD is rigid and compact. The structure with close proximity of the isoalloxazine and purine moieties is favorable for reversible light induced intramolecular electron transfer from adenine to triplet excited flavin with formation of a transient spin-correlated triplet biradical F•−-A•+. Spin selective recombination of the biradical leads to the formation of CIDNP with a common emissive maximum at 4.0 mT detected for adenine and flavin protons. Careful correction of the CIDNP data for relaxation losses during sample shuttling shows that only a single maximum of CIDNP is formed in the magnetic field range from 0.1 mT to 9 T; thus, only one type of FAD biradical is detectable. Modeling of the CIDNP field dependence provides good agreement with the experimental data for a normal distance distribution between the two radical centers around 0.89 nm and an effective electron exchange interaction of −2.0 mT. CIDNP ; Flavin adenine dinucleotide ; Flavin group ; Chemistry ; Photochemistry ; Intramolecular force ; Electron transfer ; Flavoprotein ; Cofactor ; Polarization (electrochemistry) ; Stereochemistry ; Physical chemistry ; Enzyme Advanced NMR Techniques and Applications ; Electron Spin Resonance Studies ; Photoreceptor and optogenetics research