jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Zsófia Császár | Tatjána Juzsakova | Miklós Jakab | Szabolcs Balogh | Ágnes Szegedi | Hanna E. Solt | Jenő Hancsók | József Bakos | Gergely Farkas
Source: Topics in Catalysis (article, 2021-08-27)
Field: Materials Science — Materials Chemistry

Continuous Flow Friedel–Crafts Alkylation Catalyzed by Silica Supported Phosphotungstic Acid: An Environmentally Benign Process Abstract Six silica-supported phosphotungstic acid catalysts (PTA/SiO 2 ) of different composition (20–70 wt% PTA content) have been synthesized and characterized by elemental analysis, BET, BJH, NH 3 -TPD methods, FT-IR spectroscopy of adsorbed pyridine and 1 H MAS NMR techniques. The new composite catalysts were first applied in the Friedel–Crafts alkylation of toluene with 1-octene as a benchmark process under batch conditions in order to screen their activity and recyclability. The combined analytical techniques together with the catalytic studies enabled the identification of the main factors affecting the activity of the catalysts. Based on these preliminary experiments, the best performing catalyst system (50 wt% PTA/SiO 2 ) was investigated in continuous flow mode using an in-house-made flow reactor. The thorough screening of the reaction conditions (temperature, toluene/1-octene molar ratio and flow rate) provided firm evidence that the 50 wt% PTA/SiO 2 composite is highly active, selective and stable catalyst under mild reaction conditions even at elevated flow rate. Additionally, the catalyst used in the flow mode could successfully be regenerated and reused in the alkylation process. Phosphotungstic acid ; Catalysis ; Toluene ; Alkylation ; Chemistry ; Friedel–Crafts reaction ; MCM-41 ; Volumetric flow rate ; Nuclear chemistry ; Chemical engineering ; Organic chemistry ; Mesoporous material Polyoxometalates: Synthesis and Applications ; Chemical Synthesis and Reactions ; Mesoporous Materials and Catalysis
Authors: Tomohiro Ishiyama | Takuya Yamaguchi | Takahisa Omata
Source: Journal of the Ceramic Society of Japan (article, 2021-12-31)
Field: Materials Science — Materials Chemistry

Proton-conducting phosphate glass: Recent development as an electrolyte in intermediate temperature fuel cells Recently, it has been reported that phosphate glasses with high proton conductivity in the intermediate temperature range have been successfully developed using a proton carrier injection technique with a high concentration for electrochemical ion substitution. In this review, we summarize the characteristics of the bonding states between protons and oxygen in phosphates and the concepts of material design for achieving high proton conductivity in phosphate materials. This paper introduces a carrier proton injection technique called the alkali-proton substitution (APS) method, which was developed as a process for increasing the concentration of proton carriers and required a breakthrough in the conventional approach to the development of phosphate-glass-based proton conductors. Additionally, the knowledge obtained regarding the correlations between glass components, glass structure, and proton mobility is summarized. This paper also describes the characteristics of proton-conductive phosphate glasses prepared using the APS method, demonstrating that they have the unique property of being able to carry only protons as charge carriers in any atmosphere. In conclusion, future strategies for improving proton conductivity and the potential for developing new applications are discussed. Proton ; Materials science ; Conductivity ; Phosphate ; Phosphate glass ; Electrolyte ; Proton transport ; Electrical conductor ; Proton conductor ; Chemical engineering ; Composite material ; Optoelectronics ; Electrode ; Chemistry ; Physical chemistry ; Nuclear physics ; Organic chemistry ; Doping Advancements in Solid Oxide Fuel Cells ; Fuel Cells and Related Materials ; Solid-state spectroscopy and crystallography
Authors: Martha Kafetzi | Stergios Pispas
Source: Polymers (article, 2021-01-21)
Field: Chemistry — Organic Chemistry

Effects of Hydrophobic Modifications on the Solution Self-Assembly of P(DMAEMA-co-QDMAEMA)-b-POEGMA Random Diblock Copolymers In this work, the synthesis and the aqueous solution self-assembly behavior of novel partially hydrophobically modified poly(2-(dimethylamino) ethyl methacrylate)-b-poly(oligo(ethylelene glycol) methyl ether methacrylatetabel) pH and temperature responsive random diblock copolymers (P(DMAEMA-co-Q<sub>6/12</sub>DMAEMA)-<i>b</i>-POEGMA), are reported. The chemical modifications were accomplished via quaternization with 1-iodohexane (Q<sub>6</sub>) and 1-iodododecane (Q<sub>12</sub>) and confirmed by <sup>1</sup>H-NMR spectroscopy. The successful synthesis of PDMAEMA-<i>b</i>-POEGMA precursor block copolymers was conducted by RAFT polymerization. The partial chemical modification of the diblocks resulted in the permanent attachment of long alkyl chains on the amine groups of the PDMAEMA block and the presence of tertiary and quaternary amines randomly distributed within the PDMAEMA block. Light scattering techniques confirmed that the increased hydrophobic character results in the formation of nanoaggregates of high mass and tunable pH and temperature response. The characteristics of the aggregates are also affected by the aqueous solution preparation protocol, the nature of the quaternizing agent and the quaternization degree. The incorporation of long alkyl chains allowed the encapsulation of indomethacin within the amphiphilic diblock copolymer aggregates. Nanostructures of increased size were detected due to the encapsulation of indomethacin into the interior of the hydrophobic domains. Drug release studies demonstrated that almost 50% of the encapsulated drug can be released on demand by aid of ultrasonication. Copolymer ; Amphiphile ; Methacrylate ; Polymer chemistry ; Alkyl ; Polymerization ; Chemistry ; Aqueous solution ; Ethylene glycol ; Self-assembly ; Materials science ; Organic chemistry ; Polymer Advanced Polymer Synthesis and Characterization ; Surfactants and Colloidal Systems ; Hydrogels: synthesis, properties, applications
Authors: Simon Werner | Tobias Vollgraff | Jörg Sundermeyer
Source: Chemistry - A European Journal (article, 2021-05-25)
Field: Chemistry — Organic Chemistry

Tetrasubstituted Peropyrenes Formed by Reductive Aromatization: Synthesis, Functionalization and Characterization The chromophore class of 1,3,8,10-tetrasubstituted peropyrenes was effectively synthesized from peropyrenequinone via a Zn-mediated reductive aromatization approach. In one step, a symmetric functionalization of the peropyrene backbone introducing silylethers (2,3), pivaloyl (4), triflyl (5) and also phosphinite (6) groups was established. Furthermore, the potential of using 4 and 5 in transition metal catalysed cross couplings was explored leading to 1,3,8,10-tetraaryl (8-11) and tetraalkynyl (7) peropyrenes. The influence of various substituents on the optoelectronic properties of these π-system extended peropyrenes was investigated in solid state by means of X-ray crystallography, in solution by means of UV-Vis and fluorescence spectroscopy and by their redox properties studied via cyclic voltammetry. By comparison with DFT and TD-DFT calculations, it could be elucidated that introduction of a broad variety of substituents in such versatile one or two step procedures leads to peropyrenes with easily tunable HOMO and LUMO energies ranging in a gap window of 0.8 eV. The frontier molecular orbital energies identify the target molecules as promising candidates for hole transporting semiconductors. Aromatization ; HOMO/LUMO ; Cyclic voltammetry ; Surface modification ; Chromophore ; Molecule ; Chemistry ; Photochemistry ; Transition metal ; Ferrocene ; Redox ; Reductive elimination ; Combinatorial chemistry ; Materials science ; Electrochemistry ; Physical chemistry ; Inorganic chemistry ; Organic chemistry ; Catalysis ; Electrode Synthesis and Properties of Aromatic Compounds ; Organic Electronics and Photovoltaics ; Luminescence and Fluorescent Materials
Authors: Pavel I. Semenyuk | Lidia P. Kurochkina | Lauri Mäkinen | Vladimir I. Muronetz | Sami Hietala
Source: Polymers (article, 2021-10-19)
Field: Materials Science — Biomaterials

Thermocontrolled Reversible Enzyme Complexation-Inactivation-Protection by Poly(N-acryloyl glycinamide) A prospective technology for reversible enzyme complexation accompanied with its inactivation and protection followed by reactivation after a fast thermocontrolled release has been demonstrated. A thermoresponsive polymer with upper critical solution temperature, poly(<i>N</i>-acryloyl glycinamide) (PNAGA), which is soluble in water at elevated temperatures but phase separates at low temperatures, has been shown to bind lysozyme, chosen as a model enzyme, at a low temperature (10 °C and lower) but not at room temperature (around 25 °C). The cooling of the mixture of PNAGA and lysozyme solutions from room temperature resulted in the capturing of the protein and the formation of stable complexes; heating it back up was accompanied by dissolving the complexes and the release of the bound lysozyme. Captured by the polymer, lysozyme was inactive, but a temperature-mediated release from the complexes was accompanied by its reactivation. Complexation also partially protected lysozyme from proteolytic degradation by proteinase K, which is useful for biotechnological applications. The obtained results are relevant for important medicinal tasks associated with drug delivery such as the delivery and controlled release of enzyme-based drugs. Enzyme ; Chemistry ; Acryloyl chloride ; Polymer chemistry ; Biochemistry ; Organic chemistry ; Polymer ; Copolymer Nanoparticle-Based Drug Delivery ; Advanced Polymer Synthesis and Characterization ; Hydrogels: synthesis, properties, applications
Authors: Jinhui Xu | Jilei Cao | Xiangyang Wu | Han Wang | Xiaona Yang | Xinxin Tang | Ren Wei Toh | Rong Zhou | Ming Da Lee | Jie Wu
Source: ChemRxiv (preprint, 2021-06-09)
Field: Chemistry — Organic Chemistry

Unveiling Extreme Photoreduction Potentials of Donor-Acceptor Cyanoarenes to Access Aryl Radicals from Aryl Chlorides Since the seminal work of Zhang in 2016, donor-acceptor cyanoarene-based fluorophores, such as 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN), have been widely applied in photoredox catalysis, and used as excellent metal-free alternatives to noble metal Ir- and Ru-based photocatalysts. However, all the reported photoredox reactions involving this chromophore family are based on harnessing the energy from a single visible light photon, with a limited range of redox potentials from -1.92 V to +1.79 V. Here, we document the unprecedented discovery that this family of fluorophores can undergo consecutive photoinduced electron transfer (ConPET) to achieve very high reduction potentials. One of the newly synthesized catalysts, 2,4,5-tri(9H-carbazol-9-yl)-6-(ethyl(phenyl)amino)isophthalonitrile (3CzEPAIPN), possesses a long-lived (12.95 ns) excited radical anion form, 3CzEPAIPN&lt;sup&gt;•&lt;/sup&gt;&lt;sup&gt;−&lt;/sup&gt;*, which can be used to activate reductively recalcitrant aryl chlorides (E&lt;sub&gt;red &lt;/sub&gt;≈ -1.9 to -2.9 V) under mild conditions. The resultant aryl radicals can be engaged in synthetically valuable aromatic C-B, C-P, and C-C bond formation to furnish arylboronates, arylphosphonium salts, arylphosphonates, and spirocyclic cyclohexadienes, respectively. Aryl ; Chemistry ; Photochemistry ; Chromophore ; Photoredox catalysis ; Radical ; Acceptor ; Catalysis ; Excited state ; Aryl radical ; Electron transfer ; Redox ; Electron acceptor ; Electron donor ; Medicinal chemistry ; Photocatalysis ; Organic chemistry ; Alkyl Radical Photochemical Reactions ; Catalytic C–H Functionalization Methods ; Sulfur-Based Synthesis Techniques
Authors: Benjamin P. A. Gabriele | Craig J. Williams | Matthias E. Lauer | Brian Derby | Aurora J. Cruz‐Cabeza
Source: CrystEngComm (article, 2021-01-01)
Field: Chemistry — Physical and Theoretical Chemistry

Probing anisotropic mechanical behaviour in carbamazepine form III Nanoindentation measurements in single crystals of carbamazepine form III show that the (020) face is stiffer and harder than the (002) and (101) faces. AFM imaging and molecular simulations reveal that the (020) plane is the most likely slip plane. Nanoindentation ; Carbamazepine ; Anisotropy ; Materials science ; Plane (geometry) ; Slip (aerodynamics) ; Crystallography ; Composite material ; Optics ; Chemistry ; Geometry ; Physics ; Psychology ; Thermodynamics ; Mathematics Crystallography and molecular interactions ; Surface Chemistry and Catalysis ; Crystallization and Solubility Studies
Authors: Jing Zhu | Shiqing Xu | Lei Lei | Feifei Huang | Zhen Xiao
Source: Chinese Optics Letters (article, 2021-01-01)
Field: Materials Science — Materials Chemistry

Empowering perovskite PbTiO3 nanoparticles with enhanced up-conversion luminescence and thermal sensitivity by introducing Er3+ dopant Up-convertion (UC) perovskite Er 3+ -doped PbTiO 3 (Er-PTO) nanoparticles with green and red emissions were synthesized via the hydrothermal method. The UC properties were manipulated by adjusting the concentration of Er 3+ ions dopant. The green emission intensity was decreased as the doping concentration increased from 1% to 4% (mole fraction), whereas the red emission intensity was increased. The influences of Er 3+ ions on the temperature-sensing performance were further investigated. The results demonstrated that Er-PTO nanoparticles with doping 1% Er 3+ ions possessed a sensitivity of 3.1 10 -3 K -1 at 475 K, presenting a high potential in optical heating devices. Materials science ; Dopant ; Luminescence ; Doping ; Ion ; Perovskite (structure) ; Emission intensity ; Nanoparticle ; Hydrothermal circulation ; Mole fraction ; Analytical Chemistry (journal) ; Intensity (physics) ; Optics ; Optoelectronics ; Nanotechnology ; Chemical engineering ; Physical chemistry ; Chemistry ; Crystallography ; Chromatography ; Physics Luminescence Properties of Advanced Materials ; Perovskite Materials and Applications ; Solid State Laser Technologies
Authors: Thomas Dumas | Matthieu Virot | Denis Menut | Christelle Tamain | Cyril Micheau | Sandrine Dourdain | Olivier Diat
Source: Journal of Synchrotron Radiation (article, 2021-12-15)
Field: Chemistry — Inorganic Chemistry

Size and structure of hexanuclear plutonium oxo-hydroxo clusters in aqueous solution from synchrotron analysis The size and shape of a water-soluble hexanuclear plutonium cluster were probed by combining synchrotron small-angle X-ray scattering (SAXS) and extended X-ray absorption fine structure (EXAFS). A specific setup coupling both techniques and dedicated to radioactive samples on the MARS beamline endstation at Synchrotron SOLEIL is described. The plutonium hexanuclear cores are well stabilized by the 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ligands and this allows a good evaluation of the setup to probe the very small plutonium core. The results show that, in spite of the constrained conditions required to avoid any risk of sample dispersion, the flux and the sample environment are optimized to obtain a very good signal-to-noise ratio, allowing the detection of small plutonium aggregates in an aqueous phase. The structure of the well defined hexanuclear cluster has been confirmed by EXAFS measurements in solution and correlated with SAXS data processing and modelling. An iterative comparison of classical fit models (Guinier or sphere form factor) with the experimental results allowed a better interpretation of the SAXS signal that will be relevant for future work under environmentally relevant conditions. Synchrotron ; Plutonium ; Cluster (spacecraft) ; Small-angle X-ray scattering ; Extended X-ray absorption fine structure ; Synchrotron radiation ; Scattering ; Beamline Radioactive element chemistry and processing ; Lanthanide and Transition Metal Complexes ; Spectroscopy and Quantum Chemical Studies
Authors: Max Roemer | Sinead T. Keaveney | Vinícius R. Gonçales | Jiaxin Lian | James E. Downes | Shreedhar Gautam | J. Justin Gooding | Barbara A. Messerle
Source: Catalysis Science & Technology (article, 2021-11-08)
Field: Chemistry — Organic Chemistry

Engineering regioselectivity in the hydrosilylation of alkynes using heterobimetallic dual-functional hybrid catalysts The synthesis and characterization of carbon black supported rhodium and iridium heterobimetallic hybrid catalysts and their application in the hydrosilylation of alkynes is described. Hydrosilylation ; Regioselectivity ; Catalysis ; Iridium ; Rhodium ; Dual (grammatical number) ; Chemistry ; Dual role ; Combinatorial chemistry ; Polymer chemistry ; Characterization (materials science) ; Organic chemistry ; Materials science ; Nanotechnology Organoboron and organosilicon chemistry ; Asymmetric Hydrogenation and Catalysis ; Catalytic Cross-Coupling Reactions
Authors: Azizah M. Malebari | Rakia Abd Alhameed | Zainab M. Almarhoon | Muhammad Farooq | Mohammad Ahmad Wadaan | Anamika Sharma | Beatriz G. de la Torre | Fernando Alberício | Ayman El‐Faham
Source: Molecules (article, 2021-02-22)
Field: Chemistry — Organic Chemistry

The Antiproliferative and Apoptotic Effect of a Novel Synthesized S-Triazine Dipeptide Series, and Toxicity Screening in Zebrafish Embryos Several derivatives containing morpholine/piperidine, anilines, and dipeptides as pending moieties were prepared using <i>s</i>-triazine as a scaffold. These compounds were evaluated for their anticancer activity against two human breast cancer cell lines (MCF-7 and MDA-MB-231), a colon cancer cell line (HCT-116), and a non-tumorigenic cell line (HEK 293). Tamoxifen was used as a reference. Animal toxicity tests were carried out in zebrafish embryos. Most of these compounds showed a higher activity against breast cancer than colon cancer. Compound <b>3a</b>-which contains morpholine, aniline, and glycylglycinate methyl ester-showed a high level of cytotoxicity against MCF-7 cells with IC<sub>50</sub> values of less than 1 µM. This compound showed a much lower level of toxicity against the non-tumorigenic HEK-293 cell line, and in the in vivo studies using zebrafish embryos. Furthermore, it induced cell cycle arrest at the G2/M phase, and apoptosis in MCF-7 cells. On the basis of our results, <b>3a</b> emerges as a potential candidate for further development as a therapeutic drug to treat hormone receptor-positive breast cancer. Zebrafish ; Cytotoxicity ; Chemistry ; Apoptosis ; Toxicity ; Morpholine ; In vivo ; Cell culture ; HEK 293 cells ; Cancer research ; Pharmacology ; In vitro ; Biochemistry ; Biology ; Receptor Synthesis and Characterization of Heterocyclic Compounds ; Click Chemistry and Applications ; Synthesis of Tetrazole Derivatives
Authors: Dimuthu Wijethunge | Lei Zhang | Cheng Tang | Stefano Sanvito | Aijun Du
Source: Applied Surface Science (article, 2021-09-13)
Field: Materials Science — Materials Chemistry

Interfacing 2D VS2 with Janus MoSSe: Antiferromagnetic electric polarization and charge transfer driven Half-metallicity Spintronics ; Janus ; Condensed matter physics ; Antiferromagnetism ; Materials science ; Fermi level ; Electric field ; Polarization (electrochemistry) ; Ferromagnetism ; Nanotechnology ; Chemistry ; Physics ; Electron 2D Materials and Applications ; MXene and MAX Phase Materials ; ZnO doping and properties
Authors: Marta Rubio-Camacho | Maria José Martínez-Tomé | Amalia Mira | Ricardo Mallavia | C. Reyes Mateo
Source: International Journal of Molecular Sciences (article, 2021-09-04)
Field: Materials Science — Materials Chemistry

Formation of Multicolor Nanogels Based on Cationic Polyfluorenes and Poly(methyl vinyl ether-alt-maleic monoethyl ester): Potential Use as pH-Responsive Fluorescent Drug Carriers In this study, we employed the copolymer poly(methyl vinyl ether-alt-maleic monoethyl ester) (PMVEMA-Es) and three fluorene-based cationic conjugated polyelectrolytes to develop fluorescent nanoparticles with emission in the blue, green and red spectral regions. The size, Zeta Potential, polydispersity, morphology, time-stability and fluorescent properties of these nanoparticles were characterized, as well as the nature of the interaction between both PMVEMA-Es and fluorescent polyelectrolytes. Because PMVEMA-Es contains a carboxylic acid group in its structure, the effects of pH and ionic strength on the nanoparticles were also evaluated, finding that the size is responsive to pH and ionic strength, largely swelling at physiological pH and returning to their initial size at acidic pHs. Thus, the developed fluorescent nanoparticles can be categorized as pH-sensitive fluorescent nanogels, since they possess the properties of both pH-responsive hydrogels and nanoparticulate systems. Doxorubicin (DOX) was used as a model drug to show the capacity of the blue-emitting nanogels to hold drugs in acidic media and release them at physiological pH, from changes in the fluorescence properties of both nanoparticles and DOX. In addition, preliminary studies by super-resolution confocal microscopy were performed, regarding their potential use as image probes. Polyelectrolyte ; Zeta potential ; Ionic strength ; Fluorescence ; Cationic polymerization ; Nanoparticle ; Dispersity ; Polymer chemistry ; Copolymer ; Nanogel ; Self-healing hydrogels ; Chemistry ; Drug carrier ; Maleic acid ; Drug delivery ; Materials science ; Organic chemistry ; Polymer ; Aqueous solution ; Nanotechnology Luminescence and Fluorescent Materials ; Carbon and Quantum Dots Applications ; Nanoplatforms for cancer theranostics
Authors: Erwan Le Goué | Christian Gardrat | Mélanie Romain | Manuela Rollini | Christine Moresoli | Véronique Coma
Source: Food Hydrocolloids (article, 2021-09-23)
Field: Materials Science — Biomaterials

Effect of oleic acid on the release of tetrahydrocurcumin in chitosan-based films Oleic acid ; Chemistry ; Carboxymethyl cellulose ; Chitosan ; Fourier transform infrared spectroscopy ; Antioxidant ; Penetration (warfare) ; Curcumin ; Nuclear chemistry ; Organic chemistry ; Chemical engineering ; Biochemistry Nanocomposite Films for Food Packaging ; Polysaccharides and Plant Cell Walls ; Polysaccharides Composition and Applications
Authors: Bibhisan Roy | Iván Maisuls | Jianyu Zhang | Felix C. Niemeyer | Fabio Rizzo | Christoph Wölper | Constantin G. Daniliuc | Ben Zhong Tang | Cristian A. Strassert | Jens Voskuhl
Source: Angewandte Chemie (article, 2021-10-25)
Field: Materials Science — Materials Chemistry

Mapping the Regioisomeric Space and Visible Color Range of Purely Organic Dual Emitters with Ultralong Phosphorescence Components: From Violet to Red Towards Pure White Light Abstract We mapped the entire visible range of the electromagnetic spectrum and achieved white light emission (CIE: 0.31, 0.34) by combining the intrinsic ns‐fluorescence with ultralong ms‐phosphorescence from purely organic dual emitters. We realized small molecular materials showing high photoluminescence quantum yields (Φ L ) in the solid state at room temperature, achieved by active exploration of the regioisomeric substitution space. Chromophore stacking‐supported stabilization of triplet excitons with assistance from enhanced intersystem crossing channels in the crystalline state played the primary role for the ultra‐long phosphorescence. This strategy covers the entire visible spectrum, based on organic phosphorescent emitters with versatile regioisomeric substitution patterns, and provides a single molecular source of white light with long lifetime (up to 163.5 ms) for the phosphorescent component, and high overall photoluminescence quantum yields (up to Φ L =20 %). Phosphorescence ; Photoluminescence ; Intersystem crossing ; Chromophore ; Photochemistry ; Stacking ; Visible spectrum ; Chemistry ; Fluorescence ; Quantum yield ; Exciton ; Materials science ; Optoelectronics ; Optics ; Excited state ; Physics ; Organic chemistry ; Atomic physics ; Singlet state Luminescence and Fluorescent Materials ; Organic Light-Emitting Diodes Research ; Perovskite Materials and Applications