jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: J. Srin | M. S. Jagatheeshwaran | S. Vishvanathperumal | G. Anand
Source: Research Square (preprint, 2023-10-10)
Field: Materials Science — Polymers and Plastics

The effect of nanosilica on mechanical and swelling resistance properties of ternary rubber (NR/SBR/NBR) blends nanocomposites <title>Abstract</title> The production of a new class of plastics with improved properties can be achieved through polymer blends rather than using individual components. This study involved the preparation of nanocomposites using melt compounding, where ternary blends comprising natural rubber (NR), styrene-butadiene rubber (SBR), and acrylonitrile rubber (NBR) were combined with nanosilica (NS). In the present study, silica nanoparticles (NS) were prepared from rice husk ash to be utilized as a nanofiller in rubber nanocomposites. Subsequently, the study investigated the mechanical properties of these ternary NR/SBR/NBR blend nanocomposites. Throughout the study, the NR/SBR/NBR content remained constant at 30/30/40 phr, and an ultrablend 4000 at 3 phr was used as a compatibilizer, while varying the fractions of nanosilica. The study's results demonstrated that introducing nanofillers led to a notable enhancement in the stability of both scorch time and the optimal cure time of the nanocomposites. Moreover, the nanosilica content was directly proportional to the increase in tensile strength, stress at 100% elongation, elongation at break %, abrasion resistance, and compression set of the nanocomposites. However, the mole percent uptake exhibited a noteworthy decrease as the nanosilica content increased. Further analysis using FESEM of the tensile fracture surfaces revealed that the inclusion of nanosilica in the nanocomposites led to better adhesion of NR/SBR/NBR rubber and enhanced tensile properties. This study demonstrates the potential of utilizing nanocomposites in polymer blends to enhance the overall performance of elastomers. Materials science ; Natural rubber ; Ultimate tensile strength ; Nanocomposite ; Composite material ; Tear resistance ; Elongation ; Elastomer ; Styrene-butadiene ; Polymer blend ; Compounding ; Ternary operation ; Polymer ; Copolymer ; Styrene Polymer Nanocomposites and Properties ; Polymer Nanocomposite Synthesis and Irradiation ; biodegradable polymer synthesis and properties
Authors: Selin Işık | A. G. Usman
Source: Journal of the Turkish Chemical Society Section A Chemistry (article, 2023-02-08)
Field: Chemistry — Spectroscopy

Applications of New Generation Solvents for Extraction of Herbal Products Prior to Atomic and Molecular Analysis In this review, an up to date and current knowledge of some of the green solvents, which includes supercritical fluids extraction (SFE), switchable polarity solvents (SPS), and natural deep eutectic solvents (NADES) are discussed with more emphasis on the extraction of active components of herbal products. Different scientific articles and books have been researched and reviewed to explain the applications of new generation solvents for extraction of herbal products prior to atomic and molecular analysis from the past until now. Currently, the most of techniques used in processing herbal products involve the use of extraction methods. Therefore, trends in extraction methods focuses mainly on finding reasonable solutions that minimizes the use of toxic solvents and allows the usage of renewable and green solvents from natural products, which ensure high quality and safe extracts. In future, SFE is definitely going to be on the industrial scale due to its numerous applications in the large scale especially for herbal, food, cosmetics and pharmaceutical products etc. Extraction (chemistry) ; Cosmetics ; Supercritical fluid extraction ; Biochemical engineering ; Supercritical fluid ; Process engineering ; Eutectic system ; Chemistry ; Nanotechnology ; Materials science ; Organic chemistry ; Engineering Analytical Chemistry and Chromatography ; Ionic liquids properties and applications ; Analytical chemistry methods development
Authors: Semira Bener | Ewa Pavlová | Hynek Beneš | Ondřej Sedláček
Source: Polymer Chemistry (article, 2023-01-01)
Field: Materials Science — Polymers and Plastics

Thioether-based poly(2-oxazoline)s: from optimized synthesis to advanced ROS-responsive nanomaterials Intelligent redox-responsive polymers, such as thioether-containing poly(2-oxazoline)s, facilitate drug delivery and triggered release in biomedical applications. Thioether ; Oxazoline ; Nanomaterials ; Drug delivery ; Redox ; Chemistry ; Polymer ; Materials science ; Combinatorial chemistry ; Nanotechnology ; Polymer chemistry ; Organic chemistry ; Catalysis Synthesis and properties of polymers ; Advanced Polymer Synthesis and Characterization ; Covalent Organic Framework Applications
Authors: Kazuki Miwa | Tomoya Yokota | Qian Wang | Takahiro Sakurai | Heike Fliegl | Dage Sundholm | Hiroshi Shinokubo
Source: ChemRxiv (preprint, 2023-08-28)
Field: Materials Science — Materials Chemistry

Metallaantiaromaticity of 10-Platinacorrole Complexes The aromaticity of cyclic π-conjugated organometallic compounds is known as metallaaromaticity. π-Conjugated metallacycles, such as metallabenzenes and metallapentalenes, have been investigated in order to understand the involvement of the d electrons from the metal center in the π-conjugated systems of the organic ligands. Here, we report the synthesis of Pd(II) 10-platinacorrole complexes with cyclooctadiene (COD) and norbornadiene (NBD) ligands. While the Pd(II) 10-platinacorrole COD complex adopts a distorted structure without showing appreciable antiaromaticity, the corresponding NBD complex exhibits distinct antiaromatic character due to its highly planar conformation. Detailed density-functional-theory (DFT) calculations revealed that two d orbitals are involved in the macrocyclic π-conjugation. We furthermore demonstrated that Craig–Möbius antiaromaticity is not present in the studied system. The synthesis of 10-platinacorroles enables the systematic comparison of the antiaromaticity and aromaticity of closely related porphyrin analogues, providing a better understanding of π-conjugation that involves d orbitals. Antiaromaticity ; Aromaticity ; Conjugated system ; Chemistry ; Atomic orbital ; Ring (chemistry) ; Density functional theory ; Porphyrin ; Stereochemistry ; Computational chemistry ; Crystallography ; Electron ; Photochemistry ; Molecule ; Organic chemistry ; Physics Porphyrin and Phthalocyanine Chemistry ; Synthesis and Properties of Aromatic Compounds ; Surface Chemistry and Catalysis
Authors: Madeline E. Ruos | R. Garrison Kinney | Oliver T. Ring | Abigail G. Doyle
Source: ChemRxiv (preprint, 2023-05-11)
Field: Chemistry — Organic Chemistry

A general photocatalytic strategy for nucleophilic amination of primary and secondary benzylic C–H bonds We report a visible-light photoredox-catalyzed method that enables nucleophilic amination of primary and secondary benzylic C(sp3)–H bonds. A novel amidyl radical precursor and organic photocatalyst operate in tandem to transform primary and secondary benzylic C(sp3)–H bonds into carbocations via sequential hydrogen atom transfer (HAT) and oxidative radical-polar crossover (ORPC). The resulting carbocation can be intercepted by a variety of N centered nucleophiles, including nitriles (Ritter reaction), amides, carbamates, sulfonamides, and azoles for the construction of pharmaceutically-relevant C(sp3)–N bonds under unified reaction conditions. Mechanistic studies indicate that HAT is amidyl radical-mediated and that the photocatalyst operates via a reductive quenching pathway. These findings establish a mild, metal-free, and modular protocol for the rapid diversification of C(sp3)–H bonds to a library of aminated products. Chemistry ; Nucleophile ; Amination ; Carbocation ; Primary (astronomy) ; Photocatalysis ; Combinatorial chemistry ; Photochemistry ; Tandem ; Hydrogen bond ; Photoredox catalysis ; Medicinal chemistry ; Organic chemistry ; Catalysis ; Molecule Radical Photochemical Reactions ; Sulfur-Based Synthesis Techniques ; Catalytic C–H Functionalization Methods
Authors: Siyi Ding
Source: Zeitschrift für Kristallographie - New Crystal Structures (article, 2023-05-30)
Field: Materials Science — Materials Chemistry

The crystal structure of 2,2-bis(3-methoxyphenyl)-1-tosyl-1,2-dihydro-<sup> </sup>2λ<sup>4</sup>,3λ<sup>4</sup> -[1,3,2]diazaborolo[4,5,1<i>-ij</i>]quinoline - dichloromethane (1/1) Abstract C 31 H 29 N 2 BO 4 Cl 2 , triclinic, <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <m:mrow> <m:mi>P</m:mi> <m:mover accent="true"> <m:mn>1</m:mn> <m:mo>‾</m:mo> </m:mover> </m:mrow> </m:math> $P\overline{1}$ (no. 1), a = 8.7365(3) Å, b = 11.9533(4) Å, c = 14.3566(5) Å, α = 85.7280(10)°, β = 74.8450(10)°, γ = 85.1990(10)°, V = 1439.88(9) Å 3 , Z = 2, R gt ( F ) = 0.0478, w R ref ( F 2 ) = 0.1176, T = 298 K. Triclinic crystal system ; Physics ; Crystal structure ; Crystallography ; Chemistry Luminescence and Fluorescent Materials ; Organoboron and organosilicon chemistry ; Molecular Sensors and Ion Detection
Authors: Qian‐Feng Qiu | Zhenhuan Sun | Danielle Joubran | Xiang Li | Joshua Wan | Klaus Schmidt‐Rohr | Grace G. D. Han
Source: Angewandte Chemie (article, 2023-01-23)
Field: Materials Science — Materials Chemistry

Optically Controlled Recovery and Recycling of Homogeneous Organocatalysts Enabled by Photoswitches Abstract We address a critical challenge of recovering and recycling homogeneous organocatalysts by designing photoswitchable catalyst structures that display a reversible solubility change in response to light. Initially insoluble catalysts are UV‐switched to a soluble isomeric state, which catalyzes the reaction, then back‐isomerizes to the insoluble state upon completion of the reaction to be filtered and recycled. The molecular design principles that allow for the drastic solubility change over 10 times between the isomeric states, 87 % recovery by the light‐induced precipitation, and multiple rounds of catalyst recycling are revealed. This proof of concept will open up opportunities to develop highly recyclable homogeneous catalysts that are important for the synthesis of critical compounds in various industries, which is anticipated to significantly reduce environmental impact and costs. Homogeneous ; Solubility ; Catalysis ; Chemistry ; Precipitation ; Combinatorial chemistry ; Homogeneous catalysis ; Chemical engineering ; Nanotechnology ; Materials science ; Photochemistry ; Organic chemistry ; Thermodynamics ; Physics Photochromic and Fluorescence Chemistry ; Sulfur-Based Synthesis Techniques ; Synthesis of Indole Derivatives
Authors: Manjur O. Akram | John R. Tidwell | Jason L. Dutton | Caleb D. Martin
Source: ChemRxiv (preprint, 2023-06-01)
Field: Chemistry — Organic Chemistry

Bis(1-methyl-ortho-carboranyl)borane The Lewis superacid, bis(1-methyl-ortho-carboranyl)borane, is rapidly accessed in two steps. It is a very effective hydroboration reagent capable of B–H addition to alkenes, alkynes, and cyclopropanes. To date, this is the first Lewis superacidic secondary borane and most reactive neutral hydroboration reagent. Hydroboration ; Borane ; Superacid ; Chemistry ; Reagent ; Lewis acids and bases ; Allylic rearrangement ; Organic chemistry ; Medicinal chemistry ; Catalysis Organoboron and organosilicon chemistry ; Boron Compounds in Chemistry ; Chemical Synthesis and Reactions
Authors: Panna Vezse | Dániel Ster | Ádám Golcs | Péter Huszthy | Tünde Tóth
Source: Periodica Polytechnica Chemical Engineering (article, 2023-09-27)
Field: Chemistry — Spectroscopy

Two Acridone Units in One Crown Ether We present here a critical overview on the effects of the second heterocyclic subunit in a bisacridino-crown ether by the discussion of its role in modulating optochemical behavior and preference in molecular recognition. The preparation of a new bisacridono-crown ether is presented including synthetic difficulties, and its fluorescence properties and selectivity in formation of inclusion complexes with various cations are evaluated in the light of reported analogues. Acridone ; Crown ether ; Ether ; Selectivity ; Chemistry ; Stereochemistry ; Combinatorial chemistry ; Organic chemistry ; Ion Molecular Sensors and Ion Detection ; Nonlinear Optical Materials Research ; Luminescence and Fluorescent Materials
Authors: Yuxing Wang | Sébastien Rochat
Source: ChemRxiv (preprint, 2023-07-19)
Field: Materials Science — Materials Chemistry

Microporous Polymers as Light Absorbers for Luminescent Solar Concentrators Luminescent solar concentrators (LSCs) hold the promise to make solar electricity more affordable by reducing the need for expensive photovoltaic cells and enabling less conventional forms of photovoltaics such as solar windows or roofs, and other architectural elements. Here we demonstrate the use of a polymer of intrinsic microporosity (PIM-1) as an efficient light absorber in an LSC, combined with a red-emitting dye. The prepared prototype LSC displays a good photoluminescence quantum yield (65.3 %) and performance metrics that show promise for the use of microporous polymers as light harvesters. This work significantly broadens the potential applications of PIMs beyond their traditional functions in molecular separations and other adsorption-based processes. Microporous material ; Photovoltaics ; Photovoltaic system ; Materials science ; Polymer ; Luminescence ; Optoelectronics ; Photoluminescence ; Nanotechnology ; Composite material ; Engineering ; Electrical engineering Covalent Organic Framework Applications ; Perovskite Materials and Applications ; Porphyrin and Phthalocyanine Chemistry
Authors: R Hema Krishna | A.V.V.S. Swamy
Source: International Journal of Chemical Research and Development (article, 2023-01-01)
Field: Chemistry — Organic Chemistry

Review on the chemical changes in the vegetable oils release harmful carcinogens upon deep fry or reused The objective of the present review is on Chemical Changes In the vegetable oils release harmful carcinogens upon deep fry or reused. Depending on what it is you&#39;re cooking, refined oils can be reheated the following number of times: For breaded or battered foods – three to four times. For clean frying, such as making chips or crisps – eight times, although you could reuse it far more than that if you replenish it with fresh oil after the eighth time. Vegetable oils, as used in foods, are comprised of complex mixtures of triacylglycerols (TAGs; usually > 95%) with some minor amounts of diacylglycerols (usually < 5%). Other minor components are tocopherols/tocotrienols (up to 900 mg kg−1) and phytosterol esters/phytosterols (up to 1%). Reusing cooking oil in food preparation, especially during deep-frying, is a common practice to save costs. Repeated heating of the oil accelerates oxidative degradation of lipids, forming hazardous reactive oxygen species and depleting the natural antioxidant contents of the cooking oil. Repeatedly heated cooking oils can generate varieties of compounds, including polycyclic aromatic hydrocarbons, some of which have been reported as carcinogenic. Heating for prolonged periods as well as exposure to air/oxidation are known to decrease the nutritive value of oils. Thermal decomposition of flavanols and poly phenols has been reported after heating of oil at 220 °C for 100 min and on storage at 25 °C for 2 weeks. Food science ; Deep frying ; Chemistry ; Vegetable oil ; Carcinogen ; Antioxidant ; Phytosterol ; Phenols ; Lipid oxidation ; Environmental chemistry ; Organic chemistry Edible Oils Quality and Analysis ; Potato Plant Research
Authors: Gabriela Borin Barin | Marco Di Giovannantonio | Thorsten G. Lohr | Shantanu Mishra | Amogh Kinikar | Mickael L. Perrin | Jan Overbeck | Michel Calame | Xinliang Feng | Román Fasel | Pascal Ruffieux
Source: arXiv (Cornell University) (preprint, 2023-07-31)
Field: Materials Science — Materials Chemistry

On-surface synthesis and characterization of Teranthene and Hexanthene: Ultrashort graphene nanoribbons with mixed armchair and zigzag edges Graphene nanoribbons (GNRs) exhibit a broad range of physicochemical properties that critically depend on their width and edge topology. While the chemically stable GNRs with armchair edges (AGNRs) are semiconductors with width-tunable band gap, GNRs with zigzag edges (ZGNRs) host spin-polarized edge states, which renders them interesting for applications in spintronic and quantum technologies. However, these states significantly increase their reactivity. For GNRs fabricated via on-surface synthesis under ultrahigh vacuum conditions on metal substrates, the expected reactivity of zigzag edges is a serious concern in view of substrate transfer and device integration under ambient conditions, but corresponding investigations are scarce. Using 10-bromo-9,9':10',9''-teranthracene as a precursor, we have thus synthesized hexanthene (HA) and teranthene (TA) as model compounds for ultrashort GNRs with mixed armchair and zigzag edges, characterized their chemical and electronic structure by means of scanning probe methods, and studied their chemical reactivity upon air exposure by Raman spectroscopy. We present a detailed identification of molecular orbitals and vibrational modes, assign their origin to armchair or zigzag edges, and discuss the chemical reactivity of these edges based on characteristic Raman spectral features. Zigzag ; Graphene nanoribbons ; Raman spectroscopy ; Graphene ; Materials science ; Reactivity (psychology) ; Substrate (aquarium) ; Atomic orbital ; Nanotechnology ; Spintronics ; Chemical physics ; Condensed matter physics ; Electron ; Chemistry ; Ferromagnetism ; Optics ; Geometry ; Physics Graphene research and applications ; Molecular Junctions and Nanostructures ; Quantum and electron transport phenomena
Authors: Purshotham P. Katti | K Rao | S Sharma | M Adhikari | Y Liu | G Liu | Z Liu | S Tjong | D Thornley | F Russell | A Seyeux | J Bennett | C Bentley | R Javaherdashti | A Dolati | J Culp | J Stanford | M Shah | S Al-Thabaiti | A Khan
Source: European Chemical Bulletin (article, 2023-08-09)
Field: Materials Science — Surfaces, Coatings and Films

CORROSION-RESISTANT METALNANOPARTICLE COMPOSITE COATINGS FOR INDUSTRIAL APPLICATIONS: EFFECT OF NISO4, NICL2, MO, NH4CL, AND H3BO3 CONCENTRATIONS ON NANO PARTICLE CONCENTRATION Corrosion is a persistent and costly issue in various industrial applications, necessitating the development of effective solutions to mitigate its impact. Corrosion-resistant metal-nanoparticle composite coatings have emerged as a promising approach to combat this problem. In this study, the aim is to investigate the influence of varying concentrations of NiSO4, NiCl2, Mo, NH4Cl, and H3BO3 on the nano-particle concentration within these composite coatings. The experimental procedure involved the preparation of composite coatings by dispersing metal nanoparticles within a suitable matrix material. To enhance corrosion resistance, we selected Nickel sulfate (NiSO4), Nickel chloride (NiCl2), Molybdenum (Mo), Ammonium chloride (NH4Cl), and boric acid (H3BO3) as metal precursor solutions. Different concentrations of these precursor solutions were utilized to explore their impact on the distribution of nanoparticles.Characterization of the coatings was conducted using advanced analytical techniques, Eenergy-dispersive X-ray spectroscopy (EDS). Image analysis methods were employed to quantitatively assess the concentration of nanoparticles in the composite coatings.The results demonstrate the significant influence of NiSO4, NiCl2, Mo, NH4Cl, and H3BO3 concentrations on the nanoparticle distribution within the coatings. By optimizing the combination of these metal precursor solutions, a highly dispersed and uniform nanoparticle distribution can be achieved, leading to improved corrosion resistance in the coatings Corrosion ; Materials science ; Nanoparticle ; Composite number ; Nickel ; Chloride ; Boric acid ; Particle (ecology) ; Chemical engineering ; Metallurgy ; Metal ; Ammonium chloride ; Composite material ; Nanotechnology ; Chemistry Electron and X-Ray Spectroscopy Techniques ; Corrosion Behavior and Inhibition ; Petroleum Processing and Analysis
Authors: Qingdong Hu | Chang Guo
Source: Angewandte Chemie (article, 2023-06-07)
Field: Chemistry — Organic Chemistry

Platinum/Copper Dual‐Catalyzed Asymmetric Vinylogous Addition Reactions for the Synthesis of Functionalized Indoles Abstract The development of multicomponent ligands to improve catalytic reactivity and selectivity remains a significant challenge for the synthesis of chiral building blocks. Here, a modular synthesis of structurally diverse multiligated platinum complexes, characterized by X‐ray crystallography, was revealed to open up a previously inaccessible reaction space. A library of more than 16 binary component‐ligated platinum complexes was identified as a practical toolkit to enable faster screening. The isolated bench‐stable Pt II (oxazoline)(phosphine) complex paired with a chiral copper complex exhibits fundamentally new cooperative reactivity. The newly designed Pt/Cu dual catalytic system contributed to the development of highly enantioselective vinylogous addition reactions between a Pt‐activated electrophilic α,β‐unsaturated carbene and a Cu‐activated nucleophile, resulting in a reliable process for the asymmetric synthesis of valuable functionalized indoles in good yields and excellent enantioselectivities. Enantioselective synthesis ; Chemistry ; Combinatorial chemistry ; Nucleophile ; Reactivity (psychology) ; Electrophile ; Catalysis ; Phosphine ; Platinum ; Oxazoline ; Carbene ; Selectivity ; Palladium ; Coupling reaction ; Organic chemistry Catalytic Alkyne Reactions ; Asymmetric Hydrogenation and Catalysis ; Catalytic C–H Functionalization Methods
Authors: Fatih İslamoğlu | Naciye Erdoğan | Esra Hacifazlioğlu
Source: International Journal of Biology and Chemistry (article, 2023-12-25)
Field: Chemistry — Organic Chemistry

Theoretical determination of electronic, geometric and spectroscopic properties of some 1,2,4-triazol derivatives In this study, molecular geometric optimization of five 4,5-dihydro-1H-1,2,4-triazol-5-one derivative compounds was obtained using Density Functional Theory, (DFT, B3LYP)/ Hartree Fock, (HF, B3LYP) methods on the basis set of 6-311G (d,p) in order to find the most stable geometric shape of the studied compounds. FT-IR and UV-vis spectral values were performed by using gauge independent atomic orbital (GIAO) methods with Gaussian G09W package program. IR frequency datas of investigated five compounds were calculated in gas phases and are multiplied with appropriate scala factors. The identification of the calculated IR data was performed in the veda4f program. Additionally, bond angles, bond lengths, dipole moments, highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energy and total energy, mulliken charges and molecular electrostatic potential (MEP) of five compounds were calculated using same methods and set. HOMO/LUMO ; Basis set ; Molecular geometry ; Molecular orbital ; Chemistry ; Density functional theory ; Bond length ; Mulliken population analysis ; Computational chemistry ; Dipole ; Molecule ; Physical chemistry ; Organic chemistry Synthesis and Characterization of Heterocyclic Compounds ; Synthesis and biological activity ; Synthesis and Biological Evaluation