jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: X. S. Liu | Z. T. Shen | F. J. Wang | G. Q. Li | M. Y. Wang | X. K. Hao | W. F. Zhang
Source: The Journal of Physical Chemistry C (article, 2020-07-08)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Band Gap Engineering in NaBiO<sub>3</sub>·2H<sub>2</sub>O/NaBiO<sub>3</sub>·<i>x</i>H<sub>2</sub>O Heterostructures for High Photoelectronic Response High photoelectronic response with a broad spectral range in photoelectric materials is of great importance for photovoltaic and photocatalytic applications. However, the existing photoelectric materials, such as TiO2 and α-Fe2O3, exhibit only high photoelectronic response or only broad spectral response because of the wide band gap limitation of light absorbance or low photogenerated charge separation efficiency. Here, we report NaBiO3·2H2O annealed at a given temperature to form NaBiO3·2H2O/NaBiO3·xH2O heterostructures, which efficiently drives the photogenerated charge separation in a broad spectral range. The best performance of the wide photoelectronic response and high surface photovoltage was obtained in the sample annealed at 130 °C. The high surface photovoltage with a wide spectral range is attributed to the band gap engineering of NaBiO3·2H2O/NaBiO3·xH2O heterostructures for efficient photogenerated charge separation. These findings regarding the use of optimized NaBiO3·2H2O/NaBiO3·xH2O heterostructures suggest that fine-tuning the heterostructure of the photoelectric materials is an effective approach for improving the photoelectrical performance in optoelectronic applications. Photoelectric effect ; Heterojunction ; Surface photovoltage ; Band gap ; Photoconductivity ; Charge carrier ; Semiconductor ; Photovoltaic system Multiferroics and related materials ; Advanced Photocatalysis Techniques ; Iron oxide chemistry and applications
Authors: Takahide Shimada | Shigeki Mori | Masatoshi Ishida | Hiroyuki Furuta
Source: Beilstein Journal of Organic Chemistry (article, 2020-04-01)
Field: Materials Science — Materials Chemistry

Regioselectively α- and β-alkynylated BODIPY dyes via gold(I)-catalyzed direct C–H functionalization and their photophysical properties A series of α- and β-ethynyl-substituted BODIPY derivatives (<b>3a</b>, <b>4a</b>, <b>5a, 5b</b>, <b>6a, 6b</b>) were synthesized by gold(I)-catalyzed direct C-H alkynylation reactions of dipyrromethane and BODIPY, respectively, with ethynylbenziodoxolone (EBX) in a regioselective manner. Depending on the position of the ethynyl substituent in the BODIPY skeleton, the photophysical properties of the resulting α- and β-substituted BODIPYs are notably altered. The lowest S<sub>0</sub>-S<sub>1</sub> transition absorbance and fluorescence bands are both bathochromically shifted as the number of substituents increases, while the emission quantum yields of the β-ethynylated derivatives are significantly lower than those of α-ethynylated ones. The current method should be useful for fine-tuning of the photophysical properties of BODIPY dyes as well as for constructing BODIPY-based building cores for functional π-materials. BODIPY ; Chemistry ; Regioselectivity ; Photochemistry ; Fluorescence ; Substituent ; Catalysis ; Combinatorial chemistry ; Organic chemistry Luminescence and Fluorescent Materials ; Nanoplatforms for cancer theranostics ; Polydiacetylene-based materials and applications
Authors: Yanying Qi | Endre Fenes | Hongfei Ma | Yalan Wang | Kumar R. Rout | Terje Fuglerud | Marco Piccinini | De Chen
Source: The Journal of Physical Chemistry C (article, 2020-04-24)
Field: Materials Science — Materials Chemistry

Cluster-Size-Dependent Interaction between Ethylene and CuCl<sub>2</sub> Clusters Supported via γ-Alumina Alumina-supported copper chloride serves as an industrial catalyst for ethylene oxychlorination, resulting from its high activity and selectivity. A better understanding of the detailed active site structure and reaction mechanism is highly desired. The present work aims to explore the dependence of the structure of active sites and the adsorption of ethylene on differently sized (CuCl2)n (n = 1–4) clusters supported by γ-Al2O3. The effect of the support facets (i.e., (110) and (100) surfaces) on the interface structures between the active component CuCl2 and the support was also investigated. The stronger CuCl2–support interaction was found on the (110) surface compared to the (100) surface, which is attributed to the stronger Lewis acidity of Al of the (110) surface. The adsorption strength of (CuCl2)n) (n = 1–4) clusters becomes weak with the increment of cluster size on the (110) surface. The cluster size has a profound influence on the interaction between ethylene and the clusters. Ethylene binds to a copper atom on the small clusters (i.e., CuCl2 and (CuCl2)2), while it extracts two chlorine atoms to form dichloroethane from the large clusters (i.e., (CuCl2)3 and (CuCl2)4), which explains the high activity of catalysts with high loadings upon exposure to ethylene. The effects of cluster size and alumina facets on the short d-band center and the Bader charge of the active sites result in the distinct formation energy of the chlorine vacancy and the interaction energy between C2H4 and the clusters. Thus, an improved catalyst could be achieved by the modification of the surface electronic structure via fine-tuning the support or adding promoters. Ethylene ; Cluster (spacecraft) ; Catalysis ; Copper ; Adsorption ; Vacancy defect ; Chlorine ; Chemistry ; Binding energy ; Chloride ; Copper chloride ; Atom (system on chip) ; Inorganic chemistry ; Chemical physics ; Crystallography ; Physical chemistry ; Atomic physics ; Organic chemistry Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions ; Nanomaterials for catalytic reactions
Authors: Asmita Sen | Nidhi Vyas | Bhawana Pandey | Gopalan Rajaraman
Source: Dalton Transactions (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Deciphering the mechanism of oxygen atom transfer by non-heme Mn<sup>IV</sup>–oxo species: an<i>ab initio</i>and DFT exploration Oxygen atom transfer (OAT) reactions employing transition metal-oxo species have tremendous significance in homogeneous catalysis for industrial use. Understanding the structural and mechanistic aspects of OAT reactions using high-valent metal-oxo species is of great importance to fine-tune their reactivity. Herein we examine the reactivity of a non-heme high-valent oxo-manganese(iv) complex, [Mn<sup>IV</sup>H<sub>3</sub>buea(O)]<sup>-</sup> towards a variety of substrates such as PPh<sub>2</sub>Me, PPhMe<sub>2</sub>, PCy<sub>3</sub>, PPh<sub>3</sub>, and PMe<sub>3</sub> using density functional theory as well as ab initio CASSCF/NEVPT2 methods. We have initially explored the structure and bonding of [Mn<sup>IV</sup>H<sub>3</sub>buea(O)]<sup>-</sup> and its congener [Mn<sup>IV</sup>H<sub>3</sub>buea(S)]<sup>-</sup>. Our calculations affirm an S = 3/2 ground state of the catalyst with the S = 5/2 and S = 1/2 excited states predicted to be too high lying in energy to participate in the reaction mechanism. Our ab initio CASSCF/NEVPT2 calculations, however, reveal a strong multi-reference character for the ground S = 3/2 state with many low-lying quartets mixing significantly with the ground state. This opens up various reaction channels, and the admixed wave-function evolves during the reaction with the excited triplet dominating the ground state wave-function at the reactant complex. Our calculations predict the following pattern of reactivity, PCy<sub>3</sub> < PMe<sub>3</sub> < PPh<sub>3</sub> < PPhMe<sub>2</sub> < PPh<sub>2</sub>Me for the OAT reaction with the Mn<sup>IV</sup>[double bond, length as m-dash]O species which correlates well with the experimental observations. Detailed electronic structure analysis of the transitions states reveal that these substrates react via an unusual low-energy δ-type pathway where a spin-up electron from the substrate is transferred to the δ*<sub>x<sup>2</sup>-y<sup>2</sup></sub> orbital of the Mn<sup>IV</sup>[double bond, length as m-dash]O facilitated by its multi-reference character. The unusual reactivity observed here has implications in understanding the reactivity of [Mn4Ca] species in photosystem II. Chemistry ; Ab initio ; Reactivity (psychology) ; Atom (system on chip) ; Oxygen atom ; Ab initio quantum chemistry methods ; Character (mathematics) ; Oxygen ; Heme ; Computational chemistry ; Chemical physics ; Atomic physics ; Crystallography ; Physics ; Molecule ; Organic chemistry Catalytic Processes in Materials Science ; CO2 Reduction Techniques and Catalysts ; Metal-Catalyzed Oxygenation Mechanisms
Authors: Jessica P. M. Ribeiro | Patrícia V. Mendonça | Jorge F. J. Coelho | Krzysztof Matyjaszewski | Arménio C. Serra
Source: Polymers (review, 2020-06-01)
Field: Materials Science — Surfaces, Coatings and Films

Glycopolymer Brushes by Reversible Deactivation Radical Polymerization: Preparation, Applications, and Future Challenges The cellular surface contains specific proteins, also known as lectins, that are carbohydrates receptors involved in different biological events, such as cell-cell adhesion, cell recognition and cell differentiation. The synthesis of well-defined polymers containing carbohydrate units, known as glycopolymers, by reversible deactivation radical polymerization (RDRP) methods allows the development of tailor-made materials with high affinity for lectins because of their multivalent interaction. These polymers are promising candidates for the biomedical field, namely as novel diagnostic disease markers, biosensors, or carriers for tumor-targeted therapy. Although linear glycopolymers are extensively studied for lectin recognition, branched glycopolymeric structures, such as polymer brushes can establish stronger interactions with lectins. This specific glycopolymer topology can be synthesized in a bottlebrush form or grafted to/from surfaces by using RDRP methods, allowing a precise control over molecular weight, grafting density, and brush thickness. Here, the preparation and application of glycopolymer brushes is critically discussed and future research directions on this topic are suggested. Glycopolymer ; Polymer ; Polymerization ; New horizons ; Lectin ; Radical polymerization ; Chemistry ; Adhesion ; Grafting ; Nanotechnology ; Materials science ; Polymer chemistry ; Combinatorial chemistry ; Biochemistry ; Organic chemistry Polymer Surface Interaction Studies ; Nanoparticle-Based Drug Delivery ; Hydrogels: synthesis, properties, applications
Authors: Chao Dong | Qun Yu | Runping Ye | Panpan Su | Jian Liu | Guanghui Wang
Source: Angewandte Chemie (article, 2020-06-26)
Field: Chemistry — Organic Chemistry

Hollow Carbon Sphere Nanoreactors Loaded with PdCu Nanoparticles: Void‐Confinement Effects in Liquid‐Phase Hydrogenations Abstract Nanoreactors with hollow structures have attracted great interest in catalysis research due to their void‐confinement effects. However, the challenge in unambiguously unraveling these confinement effects is to decouple them from other factors affecting catalysis. Here, we synthesize a pair of hollow carbon sphere (HCS) nanoreactors with presynthesized PdCu nanoparticles encapsulated inside of HCS (PdCu@HCS) and supported outside of HCS (PdCu/HCS), respectively, while keeping other structural features the same. Based on the two comparative nanoreactors, void‐confinement effects in liquid‐phase hydrogenation are investigated in a two‐chamber reactor. It is found that hydrogenations over PdCu@HCS are shape‐selective catalysis, can be accelerated (accumulation of reactants), decelerated (mass transfer limitation), and even inhibited (molecular‐sieving effect); conversion of the intermediate in the void space can be further promoted. Using this principle, a specific imine is selectively produced. This work provides a proof of concept for fundamental catalytic action of the hollow nanoreactors. Nanoreactor ; Void (composites) ; Catalysis ; Nanoparticle ; Materials science ; Nanotechnology ; Chemical engineering ; Chemistry ; Organic chemistry ; Composite material Nanomaterials for catalytic reactions ; Catalysis and Hydrodesulfurization Studies ; Electrocatalysts for Energy Conversion
Authors: Piera Eusepi | Lisa Marinelli | Fátima García‐Villén | Ana Borrego‐Sánchez | Ivana Cacciatore | Antonio Di Stefano | César Viseras
Source: Materials (article, 2020-04-10)
Field: Materials Science — Polymers and Plastics

Carvacrol Prodrugs with Antimicrobial Activity Loaded on Clay Nanocomposites The resultant hybrids successfully controlled conversion of the prodrugs to carvacrol, avoiding premature degradation of the drug. Carvacrol ; Nanocomposite ; Antimicrobial ; Materials science ; Composite material ; Chemistry ; Organic chemistry Polymer Synthesis and Characterization ; Clay minerals and soil interactions ; Synthesis of Tetrazole Derivatives
Authors: Bünyamin Özkaya | Christina L. Bub | Frédéric W. Patureau
Source: Chemical Communications (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Step and redox efficient nitroarene to indole synthesis Step and redox efficiencies are a rising priority in synthetic method development, in order to make synthetic processes more sustainable and more affordable. Herein, a step and redox efficient nitroarene to indole synthesis is developed, in sharp contrast to the rich literature on the construction of indoles. Elemental zinc was found to be the best terminal reductant. Indole test ; Redox ; Combinatorial chemistry ; Chemistry ; Zinc ; Oxidation reduction ; Organic chemistry ; Biochemistry Nanomaterials for catalytic reactions ; Synthesis of Indole Derivatives ; Catalytic C–H Functionalization Methods
Authors: Samia Benmansour | Carlos J. Gómez‐García | Carlos J. Gómez-García
Source: General Chemistry (article, 2020-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Heterometallic Anilato-Based Layered Magnets In this review, we present the recent use of anilato-based ligands (derivatives of the 3,6-disubstituted-2,5-dihydroxy-1,4-benzoquinone dianion = C6O4X2 2-) to build heterometallic 2D magnets. Among the different metal couples, the Mn(II)Cr(III)-containing layers are, by far, the most studied and characterized ones. We will show the structures and properties of the extended families of layered magnets formulated as Magnet ; Materials science ; Engineering ; Mechanical engineering Magnetic Properties of Alloys ; Inorganic Chemistry and Materials ; Magnetic and transport properties of perovskites and related materials
Authors: Alejandro Cadranel | Philipp Haines | Ramandeep Kaur | Arjun Menon | Peter W. Münich | Peter R. Schol | Dirk M. Guldi
Source: Advanced Energy Materials (article, 2020-11-30)
Field: Materials Science — Materials Chemistry

Photon‐ and Charge‐Management in Advanced Energy Materials: Combining 0D, 1D, and 2D Nanocarbons as well as Bulk Semiconductors with Organic Chromophores Abstract In this contribution, seminal works in the area of photon‐ and charge‐management are highlighted with focus on covalent electron donor‐acceptor conjugates built around porphyrins (Ps), on one hand, and 0D, 1D, and 2D nanocarbons, on the other hand. Photons in these conjugates are managed by Ps, while 0D, 1D, and 2D nanocarbons serve as the active component, which enable managing charges. With a few leading examples, it can be explored much beyond the simple photon‐ and charge‐management characterization and emphasize photovoltaics and photocatalysis to convert and store energy. This contribution concludes by highlighting recent progress in mixing and matching the unique charge‐management features of nanocarbons in the design of multidimensional nanocarbons. Materials science ; Nanotechnology ; Chromophore ; Semiconductor ; Organic semiconductor ; Photon ; Characterization (materials science) ; Charge (physics) ; Photovoltaics ; Acceptor ; Photocatalysis ; Optoelectronics ; Photochemistry ; Catalysis ; Photovoltaic system ; Organic chemistry ; Chemistry ; Physics ; Optics ; Electrical engineering Porphyrin and Phthalocyanine Chemistry ; Graphene research and applications ; Fullerene Chemistry and Applications
Authors: Elizabeth Hampson | Jamie M. Cameron | Julie A. Watts | Graham N. Newton
Source: Chemical Communications (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Transition metal decorated soft nanomaterials through modular self-assembly of an asymmetric hybrid polyoxometalate An asymmetrically functionalised Wells-Dawson organic-inorganic hybrid polyoxometalate has been post-functionalised by Pt<sup>2+</sup> coordination, and demonstrates self-assembly into surface-decorated micellar nanostructures. This multifunctional hybrid material is found to be a redox-active soft nanomaterial and demonstrates a new molecular design strategy with potential for applications in photo- or electro-catalysis. Polyoxometalate ; Nanomaterials ; Self-assembly ; Nanotechnology ; Modular design ; Materials science ; Nanostructure ; Transition metal ; Soft materials ; Chemistry ; Catalysis ; Organic chemistry ; Computer science Polyoxometalates: Synthesis and Applications ; Nanocluster Synthesis and Applications ; Advanced Nanomaterials in Catalysis
Authors: Jack Payne | Paul McKeown | Gabriele Kociok‐Köhn | Matthew D. Jones
Source: Chemical Communications (article, 2020-01-01)
Field: Materials Science — Biomaterials

Novel hybrid aluminium(<scp>iii</scp>)–catalen complexes as highly active catalysts for lactide polymerisation: towards industrial relevance Herein, we report a series of highly active Al(iii)-complexes based on a novel hybrid ligand: the catalen. Their application in the production of polylactide under both solution, and industrially preferred melt conditions, is demonstrated. Potential structural diversification to broaden initiator scope is discussed. Catalysis ; Lactide ; Aluminium ; Polymerization ; Chemistry ; Polymer chemistry ; Combinatorial chemistry ; Organic chemistry ; Polymer biodegradable polymer synthesis and properties ; Carbon dioxide utilization in catalysis ; Polyoxometalates: Synthesis and Applications
Authors: Ramiro Barraza | Matthew J. Allen
Source: Molecules (review, 2020-08-26)
Field: Chemistry — Organic Chemistry

Lanthanide Luminescence in Visible-Light-Promoted Photochemical Reactions The excitation of lanthanides with visible light to promote photochemical reactions has garnered interest in recent years. Lanthanides serve as initiators for photochemical reactions because they exhibit visible-light-promoted 4f→5d transitions that lead to emissive states with electrochemical potentials that are more negative than the corresponding ground states. The lanthanides that have shown the most promising characteristics for visible-light promoted photoredox are Sm<sup>II</sup>, Eu<sup>II</sup>, and Ce<sup>III</sup>. By understanding the effects that ligands have on the 5d orbitals of Sm<sup>II</sup>, Eu<sup>II</sup>, and Ce<sup>III</sup>, luminescence and reactivity can be rationally modulated using coordination chemistry. This review briefly overviews the photochemical reactivity of Sm<sup>II</sup>, Eu<sup>II</sup>, and Ce<sup>III</sup> with visible light; the properties that influence the reactivity of these ions; and the research that has been reported towards modulating their photochemical-relevant properties using visible light and coordination chemistry. Photochemistry ; Lanthanide ; Visible spectrum ; Reactivity (psychology) ; Chemistry ; Luminescence ; Atomic orbital ; Coordination complex ; Ion ; Materials science ; Optoelectronics ; Metal ; Organic chemistry Radical Photochemical Reactions ; Polyoxometalates: Synthesis and Applications ; CO2 Reduction Techniques and Catalysts
Authors: Felipe Fantuzzi | Marco Antônio Chaer Nascimento | Bojana Ginovska | R. Morris Bullock | Simone Raugei
Source: Dalton Transactions (article, 2020-11-20)
Field: Chemistry — Organic Chemistry

Splitting of multiple hydrogen molecules by bioinspired diniobium metal complexes: a DFT study Splitting of molecular hydrogen (H<sub>2</sub>) into bridging and terminal hydrides is a common step in transition metal chemistry. Herein, we propose a novel organometallic platform for cleavage of multiple H<sub>2</sub> molecules, which combines metal centers capable of stabilizing multiple oxidation states, and ligands bearing positioned pendant basic groups. Using quantum chemical modeling, we show that low-valent, early transition metal diniobium(ii) complexes with diphosphine ligands featuring pendant amines can favorably uptake up to 8 hydrogen atoms, and that the energetics are favored by the formation of intramolecular dihydrogen bonds. This result suggests new possible strategies for the development of hydrogen scavenger molecules that are able to perform reversible splitting of multiple H<sub>2</sub> molecules. Molecule ; Quantum chemical ; Metal ; Hydrogen ; Hydrogen molecule ; Computational chemistry ; Nanotechnology ; Chemical physics ; Chemistry ; Materials science ; Group 2 organometallic chemistry ; Organic chemistry Organometallic Complex Synthesis and Catalysis ; Hydrogen Storage and Materials ; Asymmetric Hydrogenation and Catalysis
Authors: Zi‐Han Li | Yuan‐Qi Zhai | Weipeng Chen | Qian‐Cheng Luo | Tian Han | Yan‐Zhen Zheng
Source: Inorganic Chemistry Frontiers (article, 2020-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Breaking the axiality of pentagonal–bipyramidal dysprosium(<scp>iii</scp>) single-molecule magnets with pyrazolate ligands Ten air-stable dysprosium(<sc>iii</sc>) SMMs with destroyed pentagonal-bipyramidal geometry imposed by axial bidentate-chelating pyrazolate ligands are studied, showing substitutional effect on axial ligands and no effect on equatorial ligands. Dysprosium ; Pentagonal bipyramidal molecular geometry ; Crystallography ; Denticity ; Chelation ; Chemistry ; Molecule ; Trigonal bipyramidal molecular geometry ; Stereochemistry ; Inorganic chemistry ; Crystal structure ; Organic chemistry Magnetism in coordination complexes ; Lanthanide and Transition Metal Complexes ; Porphyrin and Phthalocyanine Chemistry
Authors: N. A. Grunwald | Pierre Lhuissier | L. Salvò | Julie Villanova | Norbert H. Menzler | Olivier Guillon | Christophe Martín | Robert Vaßen
Source: Journal of Materials Science (article, 2020-06-19)
Field: Materials Science — Materials Chemistry

In situ investigation of atmospheric plasma-sprayed Mn–Co–Fe–O by synchrotron X-ray nano-tomography Abstract Applying atmospherically plasma-sprayed (APS) Mn 1.0 Co 1.9 Fe 0.1 O 4 (MCF) protective coatings on interconnector steels minimized the chromium-related degradation within solid oxide fuel cell stack-tests successfully. Post-test characterization of the coatings disclosed a severe microstructural and phase evolution. A self-healing of micro-cracks, the formation and agglomeration of small pores, the occurrence of a dense spinel layer at the surface and a strong elemental de-mixing were reported in ex situ experiments. In the present publication, we prove for the first time these mechanisms by tracking the microstructure in situ at a single APS coating using synchrotron X-ray nano-tomography at the European Synchrotron Radiation Facility. Therefore, a 100-µm-long cylindrical sample with a diameter of 123 µm was cut from an APS-MCF free-standing layer and measured within a high-temperature furnace. All microstructural changes mentioned above could be verified. Porosity measurements reveal a decrease in the porosity from 9 to 3% during the annealing, which is in good accordance with the literature. Additionally, a partial detachment of an approximately 5-µm-thick layer at the sample surface is observed. The layer is dense and does not exhibit any cracks which are penetrating the layer. This kind of shell is assumed to be gastight and thus protecting the bulk from further oxidation. Materials science ; Porosity ; Microstructure ; Synchrotron radiation ; Annealing (glass) ; Spinel ; Synchrotron ; Coating ; Oxide ; Composite material ; Atom probe ; Metallurgy ; Analytical Chemistry (journal) ; Optics Advancements in Solid Oxide Fuel Cells ; Electronic and Structural Properties of Oxides ; Advanced materials and composites