jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Mohammad Mahdi Monadi | Morteza Rouhani | Javad Mokhtari
Source: Physica Scripta (article, 2023-04-13)
Field: Materials Science — Materials Chemistry

He adsorption and sensing properties of graphene nanoflakes doped with Mo and Nb Abstract DFT calculations have been performed to study the He adsorption on the surface of Mo-doped graphene and Nb-doped graphene nanoflakes in order to evaluate the capability of studied doped graphene sheets as effective gas sensor materials. The ω B97XD (including dispersion)/6-311++G(d,p) (LanL2DZ for Mo and Nb) level of theory were utilized in this investigation. The HOMO-LUMO gap (E g ) of the Mo-doped and Nb-doped graphene structures decreased upon He adsorption on both sheets (−37.77% and −8.33%, respectively). Therefore, the electrical conductivity of both surfaces have increased. However, alteration of the E g value in Mo-doped graphene is very higher than that of Nb-doped graphene. So, the Mo-doped graphene is more sensitive to He molecule in comparison with Nb-doped graphene and it could be used as a gas sensor material to detect He gas. Variety analyses such as natural bond orbital (NBO), density of states (DOS), electron density distribution (ED), electron localization function (ELF) and non-covalent interaction-reduced density gradient (NCI-RDG) have been carried-out in order to better evaluate the He adsorption nature on the investigated surfaces. Graphene ; Materials science ; Doping ; Adsorption ; Density functional theory ; Density of states ; Natural bond orbital ; Electron density ; Nanotechnology ; Graphene nanoribbons ; HOMO/LUMO ; Covalent bond ; Molecule ; Chemical physics ; Electron ; Physical chemistry ; Condensed matter physics ; Computational chemistry ; Optoelectronics ; Chemistry ; Physics ; Organic chemistry Graphene research and applications ; Gas Sensing Nanomaterials and Sensors ; Advancements in Battery Materials
Authors: Tianran Deng | Xiang‐Lei Han | Cheng Cheng | Xiangyuan Liu | Yang Yu | Yuhong Gao | Keqiang Wu | Zhenghua Li | Jisheng Luo | Li Deng
Source: ChemRxiv (preprint, 2023-10-13)
Field: Chemistry — Organic Chemistry

Organocatalytic Asymmetric α-C-H Functionalization of Alkyl Amines Catalytic enantioselective α-C–H functionalization of achiral amines could provide an ideal synthetic approach toward chiral amines. The alkyl amines constitute the most diverse and synthetically important class of achiral amines. However, the inert nature of the α-C–H of alkyl amines renders the activation of alkyl amines as carbanionic nucleophiles for catalytic asymmetric reactions an important yet unmet challenge. We describe here that N-arylidene alkyl amines could be activated as carbanions for asymmetric conjugate addition and Mannich reaction. In their own right, these results represent a new and generally useful approach to the synthesis of chiral α, α-dialkyl amines. More importantly, they highlight the enormous potential of N-arylidene amines as readily available and widely applicable synthons for the asymmetric synthesis of chiral amines. Synthon ; Enantioselective synthesis ; Alkyl ; Nucleophile ; Chemistry ; Carbanion ; Conjugate ; Catalysis ; Surface modification ; Combinatorial chemistry ; Organocatalysis ; Cyclic amines ; Organic chemistry Catalytic C–H Functionalization Methods ; Synthesis and Catalytic Reactions ; Asymmetric Hydrogenation and Catalysis
Authors: Annabell Martin | Pablo Rivera‐Fuentes
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2023-01-31)
Field: Chemistry — Organic Chemistry

A general strategy to develop fluorogenic polymethine dyes for bioimaging Abstract Fluorescence imaging is an invaluable tool to study biological processes and further progress depends on the development of advanced probes. Fluorogenic dyes are crucial to reach intracellular targets and label them with high specificity. Excellent fluorogenic rhodamine dyes have been reported, but they often require a long and low-yielding synthesis and are spectrally limited to the visible range. Here, we present a general strategy to transform polymethine compounds into fluorogenic dyes using an intramolecular ring closure approach. We illustrate the generality of this method by creating both spontaneously blinking and no-wash, turn-on polymethine dyes with emissions across the visible and near-infrared spectrum. These probes are compatible with self-labeling proteins and small-molecule targeting ligands and can be combined with rhodamine-based dyes for multicolor and fluorescence lifetime multiplexing imaging. This strategy provides access to bright, fluorogenic dyes that emit at wavelengths that are significantly more red-shifted than those of existing rhodamine-based dyes. Rhodamine ; Fluorescence ; Chemistry ; Intramolecular force ; Rhodamine B ; Nanotechnology ; Visible spectrum ; Photochemistry ; Combinatorial chemistry ; Materials science ; Optoelectronics ; Organic chemistry ; Optics Click Chemistry and Applications ; Biotin and Related Studies ; Advanced Fluorescence Microscopy Techniques
Authors: Thomas Nédellec | Bernard Boitrel | Stéphane Le Gac
Source: Journal of the American Chemical Society (article, 2023-12-01)
Field: Materials Science — Materials Chemistry

Parallel Chirality Inductions in Möbius Zn(II) Hexaphyrin Transformation Networks Networked chemical transformations are key features of biological systems, in which complex multicomponent interactions enable the emergence of sophisticated functions. Being interested in chirality induction phenomena with dynamic Möbius π-systems, we have designed a pair of Möbius [28]hexaphyrin ligands in order to investigate mixtures rather than isolated molecules. Thus, a hexaphyrin bearing a chiral amino arm was first optimized and found to bind a ZnOAc moiety, triggering an impressive quasi-quantitative chirality induction over the Möbius π-system. Second, this amino-type hexaphyrin was mixed with a second hexaphyrin bearing a chiral carboxylate arm, affording at first ill-defined coordination assemblies in the presence of zinc. In contrast, a social self-sorting behavior occurred upon the addition of two exogenous achiral effectors (AcO<sup>-</sup> and BuNH<sub>2</sub>), leading to a well-defined 1:1 mixture of two Möbius complexes featuring a sole Möbius twist configuration (parallel chirality inductions). We next successfully achieved compartmentalized switching, i.e., a single-component transformation from such a complex mixture. The BuNH<sub>2</sub> effector was selectively protected with Boc<sub>2</sub>O, owing to a lower reactivity of the arm's NH<sub>2</sub> function intramolecularly bound to zinc, and subsequent addition of BuNH<sub>2</sub> restored the initial mixture, retaining parallel chirality inductions (five cycles). By changing the nature and twist configuration of only one of the two complexes, at initial state or by switching, this approach enables a "two-channel" tuning of the chiroptical properties of the ensemble. Such multiple dynamic chirality inductions, controlled by selective metal-ligand recognition and chemical reactivity, set down the basis for Möbius-type stereoselective transformation networks with new functions. Chemistry ; Chirality (physics) ; Moiety ; Stereochemistry ; Carboxylate ; Ligand (biochemistry) ; Topology (electrical circuits) ; Receptor Porphyrin and Phthalocyanine Chemistry ; Axial and Atropisomeric Chirality Synthesis ; Photochromic and Fluorescence Chemistry
Authors: Farshad Farshidfar | Arash Fattahi | Ralf Brüning | D. H. Ryan | Khashayar Ghandi
Source: Journal of Advanced Ceramics (article, 2023-06-02)
Field: Materials Science — Materials Chemistry

A creative method to tune Fe–O interaction in ferrites To be able to regulate anionic oxygen position in ferrites, an original compositing method is developed by introducing a porous p-type phase in the n-type matrix of ferrite spinel semiconductors. A result of this method is the synergetic effect of enhanced mass and charge transport, that impacted the morphology and anionic oxygen position within the MgFe<sub>2</sub>O<sub>4</sub> structure. Our hypothesis is that fine tuning of the anionic oxygen position in ferrites allows us to regulate their physicochemical properties significantly, with implications for diverse applications. The electron exchange interaction between O centered and octahedral-occupying Fe centered orbitals affected both electrical and magnetic properties of the matrix significantly, supporting our hypothesis. The three-dimensional variable range electron hopping is one such effect. Spinel ; Materials science ; Ferrite (magnet) ; Oxygen ; Octahedron ; Phase (matter) ; Chemical physics ; Nanotechnology ; Crystallography ; Crystal structure ; Chemistry ; Metallurgy ; Composite material Magnetic Properties and Synthesis of Ferrites ; Multiferroics and related materials ; Iron oxide chemistry and applications
Authors: Meidi Wang | Yutong Wang | Junyi Zhao | Jiyu Zou | Xu Liang | Ziting Zhu | Jiashi Zhu | Hongjian Wang | Yuhan Wang | Fusheng Pan | Zhongyi Jiang
Source: Angewandte Chemie (article, 2023-02-04)
Field: Materials Science — Materials Chemistry

Electrochemical Interfacial Polymerization toward Ultrathin COF Membranes for Brine Desalination Abstract Ultrathin covalent organic framework (COF) membranes are urgently demanded in molecular/ionic separations. Herein, we reported an electrochemical interfacial polymerization strategy to fabricate ultrathin COF membranes with thickness of 85 nm, by actively manipulate self‐healing effect and self‐inhibiting effect. The resulting COF membrane exhibited superior performance in brine desalination with the permeation flux of 92 kg m −2 h −1 and the rejection of 99.96 %. Our electrochemical interfacial polymerization strategy enriches the fabrication approach of COF membranes and facilitates the rational design of ultrathin membranes. Membrane ; Desalination ; Interfacial polymerization ; Brine ; Polymerization ; Chemical engineering ; Materials science ; Permeation ; Electrochemistry ; Covalent bond ; Ionic bonding ; Polymer chemistry ; Chemistry ; Organic chemistry ; Monomer ; Electrode ; Polymer ; Composite material ; Physical chemistry Covalent Organic Framework Applications ; Membrane Separation Technologies ; Metal-Organic Frameworks: Synthesis and Applications
Authors: Ren Liu | Alessio Caciagli | Jiaming Yu | Xiaoying Tang | Rini Ghosh | Erika Eiser
Source: Polymers (article, 2023-01-17)
Field: Chemistry — Organic Chemistry

Dynamic Light Scattering Based Microrheology of End-Functionalised Triblock Copolymer Solutions Nano-sized particles functionalised with short single-stranded (ss)DNAs can act as detectors of complementary DNA strands. Here we consider tri-block-copolymer-based, self-assembling DNA-coated nanoparticles. The copolymers are chemically linked to the DNA strands via azide (N3) groups. The micelles aggregate when they are linked with complementary ssDNA. The advantage of such block-copolymer-based systems is that they are easy to make. Here we show that DNA functionalisation results in inter-micellar attraction, but that N3-groups that have not reacted with the DNA detector strands also change the phase behaviour of the tri-block polymer solution. We studied the triblock copolymer, Pluronic<sup>®</sup> F108, which forms spherical micelles in aqueous solutions upon heating. We find that the triblock chains ending with either an N3 or N3-DNA complex show a dramatic change in phase behaviour. In particular, the N3-functionalisation causes the chain ends to cluster below the critical micelle temperature (CMT) of pure F108, forming flower-micelles with the N3-groups at the core, while the PPO groups are exposed to the solvent. Above the CMT, we see an inversion with the PPO chains forming the micellar core, while the N3-groups are now aggregating on the periphery, inducing an attraction between the micelles. Our results demonstrate that, due to the two competing self-assembling mechanisms, the system can form transient hydrogels. Micelle ; Copolymer ; Dynamic light scattering ; Materials science ; Amphiphile ; Polymer ; Polymer chemistry ; Self-assembly ; Aqueous solution ; Chemical engineering ; Nanoparticle ; Chemistry ; Nanotechnology ; Organic chemistry Advanced Polymer Synthesis and Characterization ; Surfactants and Colloidal Systems ; Polymer Surface Interaction Studies
Authors: Ester Blanco‐López | Francisco Foubelo | María de Gracia Retamosa | José M. Sansano
Source: Organic Letters (article, 2023-10-04)
Field: Chemistry — Organic Chemistry

Stereoselective Synthesis of Densely Substituted Pyrrolidines via a [3 + 2] Cycloaddition Reaction between Chiral <i>N</i>-<i>tert</i>-Butanesulfinylazadienes and Azomethine Ylides The <i>N</i>-<i>tert</i>-butanesulfinylimine group behaves as a suitable electron-withdrawing group in 1-azadienes, allowing the diastereoselective synthesis of densely substituted pyrrolidines by 1,3-dipolar cycloadditions (1,3-DCs) with azomethylene ylides. The use of Ag<sub>2</sub>CO<sub>3</sub> as catalyst has allowed one to obtain a wide variety of proline derivatives with high regio- and diastereoselectivities. Subsequent efficient transformations provide valuable proline derivatives, some of which can be used as organocatalysts. The influence of the <i>N</i>-<i>tert</i>-butanesulfinyl group on the diastereoselectivity was studied by computational methods. Chemistry ; Stereoselectivity ; Cycloaddition ; Azomethine ylide ; Catalysis ; Proline ; Combinatorial chemistry ; Organocatalysis ; 1,3-Dipolar cycloaddition ; Reaction conditions ; Stereochemistry ; Organic chemistry ; Enantioselective synthesis ; Amino acid Cyclopropane Reaction Mechanisms ; Asymmetric Synthesis and Catalysis ; Fluorine in Organic Chemistry
Authors: Wei Wang | Yu Wang | Phillip Timmer | Alexander Spriewald Luciano | Tim Weber | Lorena Glatthaar | Yun Guo | Bernd Smarsly | Herbert Over
Source: Inorganics (article, 2023-08-07)
Field: Materials Science — Materials Chemistry

Hydrogen Incorporation in RuxTi1−xO2 Mixed Oxides Promotes Total Oxidation of Propane A rational synthetic approach is introduced to enable hydrogen insertion into oxides by forming a solid solution of a reducible oxide with a less reducible oxide as exemplified with RuO2 and TiO2 (Ru_x, a mixture of x% RuO2 with (100−x)% TiO2). Hydrogen exposure at 250 °C to Ru_x (Ru_x_250R) results in substantial hydrogen incorporation accompanied by lattice strain that in turn induces pronounced activity variations. Here, we demonstrate that hydrogen incorporation in mixed oxides promotes the oxidation catalysis of propane combustion with Ru_60_250R being the catalytically most active catalyst. Propane ; Catalysis ; Hydrogen ; Oxide ; Inorganic chemistry ; Solid solution ; Chemistry ; Mixed oxide ; Materials science ; Organic chemistry Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions ; Electrocatalysts for Energy Conversion
Authors: Koushani Kundu | Janis V. Musso | Mathis J. Benedikter | Wolfgang Frey | Katrin Gugeler | Johannes Kästner | Michael R. Buchmeiser
Source: Chemistry - A European Journal (article, 2023-06-27)
Field: Chemistry — Organic Chemistry

Neutral and Cationic Molybdenum Imido Alkylidene Cyclic Alkyl Amino Carbene (CAAC) Complexes for Olefin Metathesis The first neutral and cationic Mo imido alkylidene cyclic alkyl amino carbene (CAAC) complexes of the general formulae [Mo(N-Ar)(CHCMe<sub>2</sub> Ph)(X)<sub>2</sub> (CAAC)] and [Mo(N-Ar)(CHCMe<sub>2</sub> Ph)(X)(CAAC)][B(Ar<sup>F</sup> )<sub>4</sub> ] (X=Br, Cl, OTf, OC<sub>6</sub> F<sub>5</sub> ; CAAC=1-(2,6-iPr<sub>2</sub> -C<sub>6</sub> H<sub>3</sub> )-3,3,5,5-tetramethyltetrahydropyrrol-2-ylidene) have been synthesized from molybdenum imido bishalide alkylidene DME precursors. Different combinations of the imido and "X" ligands have been employed to understand synthetic peculiarities. Selected complexes have been characterized by single-crystal X-ray analysis. Due to the pronounced σ-donor/π-acceptor characteristics of CAACs, the corresponding neutral and cationic molybdenum imido alkylidene CAAC complexes do not require the presence of stabilizing donor ligands such as nitriles. Calculations on the PBE0-D3BJ/def2-TZVP level for PBE0-D3BJ/def2-SVP optimized geometries revealed partial charges at molybdenum similar to the corresponding molybdenum imido alkylidene N-heterocyclic carbene (NHC) complexes with a slightly higher polarization of the molybdenum alkylidene bond in the CAAC complexes. All cationic complexes have been tested in olefin metathesis reactions and showed improved activity compared to the analogous NHC complexes for hydrocarbon-based substrates, allowing for turnover numbers (TONs) up to 9500 even at room temperature. Some Mo imido alkylidene CAAC complexes are tolerant towards functional groups like thioethers and sulfonamides. Carbene ; Cationic polymerization ; Molybdenum ; Chemistry ; Alkyl ; Medicinal chemistry ; Metathesis ; Olefin metathesis ; Olefin fiber ; Stereochemistry ; Organic chemistry ; Catalysis Synthetic Organic Chemistry Methods ; N-Heterocyclic Carbenes in Organic and Inorganic Chemistry ; Organometallic Complex Synthesis and Catalysis
Authors: Alexis Wolfel | Huiyi Wang | Ernesto Rafael Osorio‐Blanco | Julián Bergueiro | Marcelo R. Romero | Cecilia I. Álvarez Igarzabal | Marcelo Calderón
Source: Polymer Chemistry (article, 2023-01-01)
Field: Materials Science — Biomaterials

Structural control and functionalization of thermoresponsive nanogels: turning cross-linking points into anchoring groups Nanogels with cleavable crosslinking points allow for nanostructure modification and functionalization with α-oxoaldehydes (glyoxylic groups). Surface modification ; Anchoring ; Chemistry ; Nanotechnology ; Combinatorial chemistry ; Materials science ; Polymer chemistry ; Cognitive science Supramolecular Self-Assembly in Materials ; Hydrogels: synthesis, properties, applications ; Advanced Polymer Synthesis and Characterization
Authors: Peng Cui | Qiulan Wu
Source: Energy Technology (article, 2023-12-06)
Field: Materials Science — Materials Chemistry

Probing the Optoelectronic Properties and Energy Conversion of Boron Nitride Quantum Dots: Impact of Oxygen Doping and Chemical Functionalization Boron nitride quantum dots (BNQDs) are emerging nanomaterials with promising applications in photocatalysis and optoelectronics. Chemical functionalization effectively tunes the optoelectronic properties and photocatalytic performance of BNQDs. This study investigates the impact of oxygen doping and functionalization with urea, thiourea, and p‐phenylenediamine (PPD) on BNQD properties. Density functional theory calculations reveal that these functional groups introduce new electronic states within the bandgap, shifting absorption spectra and reducing the bandgap due to ligand molecular orbital contributions. Functionalization also adjusts the energy‐level alignment between BNQDs and cocatalysts, enhancing interfacial charge transfer. Oxygen‐doped, chemically functionalized BNQDs exhibit significantly higher first‐order hyperpolarizability, up to 17 times greater than pristine BNQDs, enabling superior optical nonlinearities. Additionally, PPD functionalization leads to a remarkable 18.2% photocatalytic energy conversion efficiency under simulated solar irradiation. These achieved quantum yields result from bandgap engineering, expanded light harvesting, increased exciton densities, prolonged exciton lifetimes, and improved charge separation and transfer dynamics. This study provides crucial insights into property tuning mechanisms, establishing the promising potential of chemically functionalized BNQDs for energy conversion and optoelectronic technologies. Surface modification ; Materials science ; Band gap ; Boron nitride ; Density functional theory ; Quantum dot ; Photocatalysis ; Doping ; Nanotechnology ; Optoelectronics ; Nanomaterials ; Absorption (acoustics) ; Photochemistry ; Chemistry ; Computational chemistry ; Physical chemistry ; Organic chemistry ; Catalysis Luminescence and Fluorescent Materials ; Carbon and Quantum Dots Applications ; Boron and Carbon Nanomaterials Research
Authors: Tăchiță Vlad‐Bubulac | Corneliu Hamciuc | Diana Serbezeanu | Dana Mihaela Suflet | Daniela Rusu | Gabriela Lisă | Ion Anghel | Dana-Maria Preda | Totka Todorova | C. Rîmbu
Source: Preprints.org (preprint, 2023-05-08)
Field: Materials Science — Polymers and Plastics

Organophosphorus Reinforced Poly(vinyl alcohol) Nanocomposites Doped with Silver-loaded Zeolite L Nanoparticles as Sustainable Materials for Packaging Applications The sustainable development of innovative eco-friendly multifunctional nanocomposites, possessing superior characteristics, is a noteworthy topic. Novel semi-interpenetrated nanocomposite films based on poly(vinyl alcohol) covalently and thermally crosslinked with oxalic acid (OA), reinforced with a novel organophosphorus flame retardant (PFR-4) derived from co-polycondensation in solution reaction of equimolar amounts of co-monomers, namely, bis((6-oxido-6H-dibenz[c,e][1,2]oxaphosphorinyl)-(4-hydroxyaniline)-methylene)-1,4-phenylene, bisphenol S, and phenylphosphonic dichloride, in a molar ratio of 1:1:2, and additionally doped with silver-loaded zeolite L nanoparticles (ze-Ag), have been prepared by casting from solution technique. The morphology of the as prepared PVA-oxalic acid films and their semi-interpenetrated nanocomposites with PFR-4 and ze-Ag was investigated by scanning electron microscopy (SEM), while the homogeneous distribution of the organophosphorus compound and nanoparticles within the nanocomposite films has been introspected by means of energy dispersive X-ray spectroscopy (EDX). It was established that composites with a very low phosphorus content had noticeably improved flame retardancy. The peak of the heat release rate was reduced up to 55%, depending on the content of the flame retardant additive and the doping ze-Ag nanoparticles introduced into the PVA/OA matrix. The ultimate tensile strength and elastic modulus increased significantly in the reinforced nanocomposites. Considerably increased antimicrobial activity was revealed in the case of the samples containing silver-loaded zeolite L nanoparticles. Vinyl alcohol ; Nanocomposite ; Materials science ; Oxalic acid ; Nanoparticle ; Polyvinyl alcohol ; Fire retardant ; Chemical engineering ; Polymer ; Polymer chemistry ; Nuclear chemistry ; Composite material ; Organic chemistry ; Chemistry ; Nanotechnology Flame retardant materials and properties ; Polymer Science and PVC
Authors: Alex T. O’Neil | Jade Pope | John A. Harrison | Jonathan A. Kitchen
Source: European Journal of Inorganic Chemistry (article, 2023-08-14)
Field: Materials Science — Materials Chemistry

Color Tunable Emission and Oxygen Sensing from a Discrete Europium−Pyrene Assembly Abstract We report the synthesis of a new pyrene, dipicolinic acid‐based ligand ( L 1 H ) and its corresponding multi‐emissive and multifunctional europium complex [Eu( L 1 ) 3 ] that is capable of single component color switchable emission from red to blue and also white. At high concentration (10 mM) the single component system results in near pure white emission (CIE coordinates x,y=0.329, 0.324). Furthermore, the system showed ratiometric oxygen sensing with oxygen significantly quenching the pyrene centered emission but not the Eu 3+ emission, resulting in an overall emission color change from blue to red on increasing oxygen content. Chemistry ; Europium ; Pyrene ; Oxygen ; Quenching (fluorescence) ; Photochemistry ; Dipicolinic acid ; Fluorescence ; Ligand (biochemistry) ; Luminescence ; Analytical Chemistry (journal) ; Inorganic chemistry ; Organic chemistry ; Optoelectronics ; Optics ; Ion Lanthanide and Transition Metal Complexes ; Luminescence and Fluorescent Materials ; Molecular Sensors and Ion Detection