jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Tianyu Cheng | Tianwen Bai | Die Huang | Anjun Qin | Jun Ling | Ben Zhong Tang
Source: Macromolecules (article, 2021-12-14)
Field: Chemistry — Organic Chemistry

Stereochemistry-Tunable Isocyanide-Based Polymerization Regulation of stereochemistry is one of the most important research focuses in synthetic polymer chemistry; however, this area should be further developed. In this work, a new polymerization of diisocyanoacetates and disulfonimines with tunable stereochemistry was developed. Diisocyanoacetates and disulfonimines could easily undergo polycycloaddition in the presence of CuCl/PPh3, and polyimidazolines with high weight-average molecular weights (Mw, up to 43 900) were produced in excellent yields (up to 99%). Moreover, the stereochemistry of the polymerization and the stereoregularity of the resultant polymers can be fine-tuned by triethylamine (TEA). In addition, TEA could also significantly promote the polymerization, from which polymers with much higher molecular weights (Mw up to 155 400) could be obtained in higher yields. This work not only promotes the development of the isocyanide chemistry and enriches the family of polymerizations based on triple-bond building blocks but also provides an opportunity to study the structure–property relationship of the polyimidazolines. Polymerization ; Triethylamine ; Isocyanide ; Polymer ; Chemistry ; Polymer chemistry ; Organic chemistry Synthetic Organic Chemistry Methods ; Carbon dioxide utilization in catalysis ; Synthesis and properties of polymers
Authors: Johan Cornil | Zhaoyu Hu | Marion Bouchet | Laurence A. Mulard
Source: Organic Chemistry Frontiers (article, 2021-01-01)
Field: Chemistry — Organic Chemistry

Multigram synthesis of an orthogonally-protected pentasaccharide for use as a glycan precursor in a <i>Shigella flexneri</i> 3a conjugate vaccine: application to a ready-for-conjugation decasaccharide Fine-tuned catalytic processes facilitating regio- and stereoselective conversions for the large-scale synthesis of a pentasaccharide and its oligomerization into ready-for-conjugation haptens. Chemistry ; Conjugate ; Glycan ; Shigella flexneri ; Hapten ; Combinatorial chemistry ; Stereoselectivity ; Stereochemistry ; Organic chemistry ; Catalysis ; Biochemistry ; Antigen ; Escherichia coli Carbohydrate Chemistry and Synthesis ; Glycosylation and Glycoproteins Research ; Legume Nitrogen Fixing Symbiosis
Authors: Varvara Athanasiou | Dimitra Stavroulaki | Foteini Arfara | Dimitrios Kampras | Ioannis Kleideris | Niki Roumelioti | Panagiota G. Fragouli | Georgios Patias | David M. Haddleton | Hermis Iatrou
Source: ACS Applied Nano Materials (article, 2021-11-26)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Gold Nanoparticles and Nanoshells Embedded as Core–Shell Architectures in Hybrid Poly(<scp>l</scp>-Histidine)-Containing Polymers for Photothermal Therapies We present a facile strategy for the synthesis of hybrid nanoparticles containing gold nanoshells (AuNSs) that absorb at near-infrared (NIR). Poly(ethylene oxide)-b-poly(l-histidine), poly(ethylene oxide)-b-poly(l-histidine)-b-poly(l-phenylalanine), and poly(ethylene oxide)-b-poly(l-histidine)-b-poly(γ-benzyl-l-glutamate) hybrid copolypeptides were used for the development of AuNSs. Spherical nanoparticles (NPs) were initially formed by the self-assembly of the amphiphilic hybrid polypeptides in water. The addition of HAuCl4 followed by heating, resulted in the reduction of the Au(III) by poly(l-histidine) (PHis), leading to the formation of AuNSs only at the PHis layer, thus forming a nanoshell within the preformed NPs. The NPs formed are composed of a poly(ethylene oxide) (PEO) shell, a PHis layer containing the nanoshell and a poly(l-phenylalanine) (PPhe) or poly(γ-benzyl-l-glutamate) (PBLG) core. By controlling the AuNS thickness and the core diameter by the molecular characteristics of the polymeric precursors as well as the PHis/Au(III) ratio, the optical properties of the AuNSs can be fine-tuned to absorb at a specific wavelength. Thus, we achieved a shift of the absorption peak corresponding to longitudinal surface plasmon resonance to NIR wavelengths. The size and the morphology of the polymeric NPs containing AuNSs were examined by TEM and Dynamic Light Scattering. Studies on a dilute solution of polymeric nanoparticles containing AuNSs showed that by irradiation with a low power laser at 808 nm, results to significant increase of its temperature. We present an approach for the design and facile synthesis of biocompatible polymeric nanoparticles featuring AuNSs with a peak optical absorption in the NIR that can be fine-tuned. Therefore, our aim is to present a novel and facile approach for the formation of AuNSs to be used for photothermal therapy. Nanoshell ; Materials science ; Ethylene oxide ; Nanoparticle ; Polymer ; Chemical engineering ; Surface plasmon resonance ; Polymer chemistry ; Photothermal therapy ; Nanotechnology ; Copolymer ; Composite material Gold and Silver Nanoparticles Synthesis and Applications ; Nanoparticle-Based Drug Delivery ; Nanoplatforms for cancer theranostics
Authors: Antonio Arcadi | Andrea Calcaterra | Giancarlo Fabrizi | Andrea Fochetti | Antonella Goggiamani | Antonia Iazzetti | Federico Marrone | Vincenzo Marsicano | Giulia Mazzoccanti | Andrea Serraiocco
Source: Molecules (article, 2021-06-02)
Field: Chemistry — Organic Chemistry

Synthesis of 4-Substituted-1,2-Dihydroquinolines by Means of Gold-Catalyzed Intramolecular Hydroarylation Reaction of N-Ethoxycarbonyl-N-Propargylanilines An alternative Au(I)-catalyzed synthetic route to functionalized 1,2-dihydroquinolines is reported. This novel approach is based on the use of <i>N</i>-ethoxycarbonyl protected-<i>N</i>-propargylanilines as building blocks that rapidly undergo the IMHA reaction affording the 6-<i>endo</i> cyclization product in good to high yields. In the presence of <i>N</i>-ethoxycarbonyl-<i>N</i>-propargyl-<i>meta-</i>substituted anilines, the regiodivergent cyclization at the <i>ortho</i>-/<i>para</i>-position is achieved by the means of catalyst fine tuning. Catalysis ; Intramolecular force ; Propargyl ; Chemistry ; Medicinal chemistry ; Combinatorial chemistry ; Reaction conditions ; Organic chemistry Catalytic Alkyne Reactions ; Catalytic C–H Functionalization Methods ; Cyclopropane Reaction Mechanisms
Authors: Alexander J. Cunningham | Xiantao Feng | Hu Zhang | Xavier Banquy | Jeanne Leblond Chain | X. X. Zhu
Source: Materials Today Communications (article, 2021-09-21)
Field: Chemistry — Organic Chemistry

Thermoresponsive properties of star-shaped amphiphilic block copolymers with a cholic acid core and functional amine groups Lower critical solution temperature ; Materials science ; Thermoresponsive polymers in chromatography ; Cholic acid ; Ethylene glycol ; Copolymer ; Amphiphile ; Polymer ; PEG ratio ; Polymer chemistry ; Aqueous solution ; Chemical engineering ; Organic chemistry ; Chemistry ; Bile acid Advanced Polymer Synthesis and Characterization ; Hydrogels: synthesis, properties, applications ; Nanoparticle-Based Drug Delivery
Authors: Meng Lv | Xicun Lu | Yanrong Jiang | María Eugenia Sandoval‐Salinas | David Casanova | Haitao Sun | Zhenrong Sun | Jianhua Xu | Youjun Yang | Jinquan Chen
Source: Angewandte Chemie (article, 2021-11-18)
Field: Materials Science — Materials Chemistry

Near‐Unity Triplet Generation Promoted via Spiro‐Conjugation Abstract An intersystem crossing (ISC) rate constant of 1.0×10 11 s −1 was previously registered with a spiro‐bis‐benzophenone scaffold. Triplet generation efficiency could be further enhanced by stabilizing the spiro‐charge‐transfer (CT) state and rationally designing spiro‐compounds ( SCTs ) that consist of electron‐rich diphenyl ether as the spiro‐CT donor and electron‐deficient dinaphthyl ketone as the spiro‐CT acceptor. Through fine‐tuning of the energy level between the CT and high energy triplet states, near‐unity triplet generation quantum yield was achieved and the underlying ISC mechanism is revealed by using ultrafast spectroscopy and quantum chemical calculations. Potential triplet sensitizing application was demonstrated in SCTs . Our findings suggest that a spiro‐bichromophoric molecular system with an enhanced spiro‐charge transfer warrants efficient triplet generation and is a powerful strategy of heavy‐atom‐free triplet sensitizers with predictable ISC properties. Intersystem crossing ; Benzophenone ; Chemistry ; Photochemistry ; Triplet state ; Quantum yield ; Acceptor ; Molecule ; Atomic physics ; Fluorescence ; Singlet state ; Physics ; Organic chemistry ; Excited state Luminescence and Fluorescent Materials ; Photochemistry and Electron Transfer Studies ; Porphyrin and Phthalocyanine Chemistry
Authors: Attig, Jan | Park, Jinhong | Scherer, Michael M. | Trebst, Simon | Altland, Alexander | Rosch, Achim
Source: Kölner Universitäts PublikationsServer (Universität zu Köln) (article, 2021-01-01)
Field: Materials Science — Materials Chemistry

Universal principles of moire band structures Moire materials provide a highly tunable environment for the realization of band structures with engineered physical properties. Specifically, moire structures with Fermi surface flat bands-a synthetic environment for the realization of correlated phases-have moire unit cells containing thousands of atoms and tantalizingly complex band structures. In this paper we show that statistical principles go a long way in explaining universal physical properties of these systems. Our approach builds on three conceptual elements: the presence of quantum chaos caused by the effective irregularity of the atomic configurations on short length scales, Anderson localization in momentum space, and the presence of approximate crystalline symmetries. Which of these principles dominates depends on material parameters such as the extension of the Fermi surface or the strength of the moire lattice potential. The phenomenological consequences of this competition are predictions for the characteristic group velocity of moire bands, a primary indicator for their average flatness. In addition to these generic features, we identify structures outside the statistical context, notably almost flat bands close to the extrema of the unperturbed spectra, and the celebrated zero energy 'magic angle' flat bands, where the latter require exceptionally fine tuned material parameters. Moiré pattern ; Materials science ; Computer science ; Physics ; Optics Graphene research and applications ; Matrix Theory and Algorithms ; Algebraic structures and combinatorial models
Authors: Jan Attig | Jinhong Park | Michael M Scherer | Simon Trebst | Alexander Altland | Achim Rosch
Source: 2D Materials (article, 2021-08-12)
Field: Materials Science — Materials Chemistry

Universal principles of moiré band structures Abstract Moiré materials provide a highly tunable environment for the realization of band structures with engineered physical properties. Specifically, moiré structures with Fermi surface flat bands—a synthetic environment for the realization of correlated phases—have moiré unit cells containing thousands of atoms and tantalizingly complex band structures. In this paper we show that statistical principles go a long way in explaining universal physical properties of these systems. Our approach builds on three conceptual elements: the presence of quantum chaos caused by the effective irregularity of the atomic configurations on short length scales, Anderson localization in momentum space, and the presence of approximate crystalline symmetries. Which of these principles dominates depends on material parameters such as the extension of the Fermi surface or the strength of the moiré lattice potential. The phenomenological consequences of this competition are predictions for the characteristic group velocity of moiré bands, a primary indicator for their average flatness. In addition to these generic features, we identify structures outside the statistical context, notably almost flat bands close to the extrema of the unperturbed spectra, and the celebrated zero energy ‘magic angle’ flat bands, where the latter require exceptionally fine tuned material parameters. Maxima and minima ; Realization (probability) ; Electronic band structure ; Fermi surface ; Lattice (music) ; Fermi Gamma-ray Space Telescope ; Fermi energy ; Quantum Quasicrystal Structures and Properties ; Topological Materials and Phenomena ; Quantum many-body systems
Authors: Alexandre F. Fonseca
Source: Physical review. B./Physical review. B (article, 2021-07-01)
Field: Materials Science — Materials Chemistry

Twisting or untwisting graphene twisted nanoribbons without rotation The common sense regarding twisting or untwisting a ribbon is that it requires the application of an external rotation to happen. However, at nanoscale, the application of precise amounts of rotation on a nanoribbon is not a trivial task. Here, the concept of an alternative method to add twist to or remove twist from a twisted graphene nanoribbon (TGNR) without rotation is presented and computationally demonstrated. The method consists of suspending a TGNR on two separate substrates and, by changing only their distance, the total amount of twist of the TGNR is shown to change. The possibility of fine-tuning the amount of twist of a TGNR is also shown. The concept is demonstrated through fully atomistic molecular dynamics simulations and numerical calculations of the topological parameters twist and writhe of a TGNR. It is shown that the above process satisfies the so-called linking number theorem of space curves. Besides being capable of precisely determining the total twist of a TGNR, this concept reveals a twist to writhe transition phenomenon that is tension-free and does not require controlling either the nanoribbon end-to-end distance or its critical twist density. Twist ; Writhe ; Rotation (mathematics) ; Ribbon ; Physics ; Space (punctuation) ; Molecular dynamics ; Tension (geology) ; Graphene ; Topology (electrical circuits) ; Classical mechanics ; Mathematics ; Geometry ; Computer science ; Quantum mechanics Graphene research and applications ; Carbon Nanotubes in Composites ; Molecular Junctions and Nanostructures
Authors: Arkamita Bandyopadhyay | Cihan Bacaksız | Junjie He | Thomas Frauenheim
Source: The Journal of Physical Chemistry Letters (article, 2021-11-15)
Field: Materials Science — Materials Chemistry

Tuning Magnetic Anisotropy in Two-Dimensional Metal–Semiconductor Janus van der Waals Heterostructures In the family of 2D materials, atomically thin magnetic systems are relatively new and highly exploitable. Understanding the spin symmetry in such materials has opened a new path toward controlling the magnetic texture. In this study, we have shown that the plethora of different interface formations in the Janus or pure metal-semiconductor-based van der Waals heterostructures 1T-VXY (X, Y = S, Se, Te)-Cr<sub>2</sub>A<sub>3</sub>B<sub>3</sub> (A, B = I, Cl, Br) allows us to explore and modify the spin-orbit and ligand-metal interactions to fine-tune magnetic anisotropy and different spin symmetries in these systems. We have utilized the interlayer interactions to modulate spin-orbit coupling (SOC) in heterolayers to regulate the magnetic anisotropy in such systems. We have compared systems with the same compositions and different interfaces, for example, Janus VSTe-Janus Cr<sub>2</sub>I<sub>3</sub>Br<sub>3</sub> and Janus VTeS-Janus Cr<sub>2</sub>I<sub>3</sub>Br<sub>3</sub>, to show that the first one is an Ising ferromagnet, whereas the second one is an XY ferromagnet because of the SOC effect of the heavy ligand atoms. Janus ; Condensed matter physics ; Heterojunction ; van der Waals force ; Anisotropy ; Semiconductor ; Materials science ; Metal ; Magnetic anisotropy ; Magnetic semiconductor ; Physics ; Nanotechnology ; Magnetic field ; Optoelectronics ; Quantum mechanics ; Magnetization ; Molecule ; Metallurgy 2D Materials and Applications ; Graphene research and applications ; Topological Materials and Phenomena
Authors: Milan Ambrožič | Kaushik Pal | Samo Kralj | Arbresha Hölbl
Source: Journal of Molecular Structure (article, 2021-01-07)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Nanoparticle controlled nematic macroscopic properties Liquid crystal ; Nanoparticle ; Chemistry ; Condensed matter physics ; Chemical physics ; Range (aeronautics) ; Symmetry breaking ; Symmetry (geometry) ; Nanotechnology ; Materials science ; Physics ; Composite material ; Geometry ; Quantum mechanics Liquid Crystal Research Advancements ; Photonic Crystals and Applications ; Plant Reproductive Biology
Authors: Haiyan Luo | Kun Jiang | Xiaotian Wang | Xiangfeng Liang | Huizhou Liu | Yingbo Li
Source: Journal of Molecular Liquids (article, 2021-03-25)
Field: Chemistry — Organic Chemistry

Mechanistic insight into morphological transition of Pluronic aggregates in aqueous solution via tuning hydrogen bonding strength Copolymer ; Micelle ; Hydrogen bond ; Poloxamer ; Aqueous solution ; Amphiphile ; Vesicle ; Octane ; Chemistry ; Chemical engineering ; Ether ; Polymer chemistry ; Materials science ; Molecule ; Organic chemistry ; Polymer Advanced Polymer Synthesis and Characterization ; Surfactants and Colloidal Systems ; Hydrogels: synthesis, properties, applications
Authors: Raffaele Pugliese | Fabrizio Gelain
Source: Journal of Applied Polymer Science (article, 2021-10-15)
Field: Materials Science — Biomaterials

Programmable stiffness and stress–relaxation of cross‐linked <scp>self‐assembling</scp> peptide hydrogels Abstract The use of self‐assembling peptide (SAPs) biomaterials is a promising therapeutic strategy to repair soft tissues as spinal cord, brain, liver, and pancreas. However, these latter have storage moduli, stress resistance, and stress relaxation that change depending on the anatomic region. The SAP molecules relying only on noncovalent interactions struggle to cope with such a wide range of mechanical properties. Hence, we report the design of supramolecular hydrogels based on LKLK12 SAP and SM(PEG) 24 cross‐linker to precisely tune hydrogel stiffness over the range of 5–60 kPa. We found that G' increases by ∼12 kPa, and stress resistance by ∼1 kPa for each additional 1.35 mM of SM(PEG) 24 . Furthermore, the cross‐linked SAPs self‐assemble into supramolecular β‐sheet‐containing nanofibers with stress relaxation ranging from 90 to 150 s. Lastly, post‐treatment of cross‐linked hydrogel with acetonitrile to unfold SM(PEG) 24 linker significantly improved its strain failure, reaching a breakage strain of 4612%, unprecedented for this class of SAP‐based biomaterials. This work provides a new strategy to fine tune the mechanical properties of SAP‐based hydrogels to be helpful for soft tissues regeneration. Self-healing hydrogels ; Materials science ; PEG ratio ; Stress relaxation ; Supramolecular chemistry ; Nanofiber ; Relaxation (psychology) ; Nanotechnology ; Biophysics ; Chemical engineering ; Biomedical engineering ; Polymer chemistry ; Molecule ; Composite material ; Chemistry ; Organic chemistry ; Creep Supramolecular Self-Assembly in Materials ; Silk-based biomaterials and applications ; Cellular Mechanics and Interactions
Authors: Ahmed F. Al‐Hossainy | M. Sh. Zoromba
Source: Research Square (preprint, 2021-03-19)
Field: Materials Science — Materials Chemistry

Novel synthesis, characterization and TDD-DFT computations for ZrO2-bromothymol blue nanocomposite thin film [ZrO2+BTB]C and its application Bromothymol blue ; Nanocomposite ; Characterization (materials science) ; Materials science ; Thin film ; Nanotechnology ; Chemistry ; Organic chemistry Mesoporous Materials and Catalysis ; Catalysis and Oxidation Reactions ; Transition Metal Oxide Nanomaterials
Authors: Elena Segura-Sanchis | Roberto Fenollosa | Isabelle Rodríguez | Yann Molard | Stéphane Cordier | M. Feliz | Pedro Atienzar
Source: Crystal Growth & Design (article, 2021-12-02)
Field: Chemistry — Inorganic Chemistry

Octahedral Molybdenum Cluster-Based Single Crystals as Fabry–Pérot Microresonators Single crystals built up from octahedral Mo6 cluster units, with appropriate geometry and size, constitute Fabry–Pérot-type optical microcavities with well-defined resonances. Such resonances appear in the VIS-NIR range when performing optical transmittance (OT) or photoluminescence (PL) measurements. They strongly depend on the crystal thickness and on the optical constants of the material, specifically the real and imaginary parts of the refractive index. In this work, the accurate measurement of the crystal thickness is used for the determination of the optical constants by means of a fitting process, and the preferred orientation of the crystals was determined by X-ray diffraction. Refractive index ; Fabry–Pérot interferometer ; Octahedron ; Materials science ; Photoluminescence ; Molybdenum ; Transmittance ; Diffraction ; Optics ; Crystal (programming language) ; Single crystal ; Crystallography ; Cluster (spacecraft) ; Crystal optics ; Molecular physics ; Crystal structure ; Optoelectronics ; Chemistry ; Wavelength ; Physics ; Laser Inorganic Chemistry and Materials ; MXene and MAX Phase Materials ; Nanocluster Synthesis and Applications
Authors: Rosaria Bruno | Teresa F. Mastropietro | Giovanni De Munno | Donatella Armentano
Source: Molecules (article, 2021-07-29)
Field: Chemistry — Inorganic Chemistry

A Nanoporous Supramolecular Metal–Organic Framework Based on a Nucleotide: Interplay of the π···π Interactions Directing Assembly and Geometric Matching of Aromatic Tails Self-assembly is the most powerful force for creating ordered supramolecular architectures from simple components under mild conditions. π···π stacking interactions have been widely explored in modern supramolecular chemistry as an attractive reversible noncovalent tool for the nondestructive fabrication of materials for different applications. Here, we report on the self-assembly of cytidine 5'-monophosphate (CMP) nucleotide and copper metal ions for the preparation of a rare nanoporous supramolecular metal-organic framework in water. π···π stacking interactions involving the aromatic groups of the ancillary 2,2'-bipyridine (bipy) ligands drive the self-assemblies of hexameric pseudo-amphiphilic [Cu6(bipy)6(CMP)2(µ-O)Br4]<sup>2+</sup> units. Owing to the supramolecular geometric matching between the aromatic tails, a nanoporous crystalline phase with hydrophobic and hydrophilic chiral pores of 1.2 and 0.8 nanometers, respectively, was successfully synthesized. The encoded chiral information, contained on the enantiopure building blocks, is transferred to the final supramolecular structure, assembled in the very unusual topology <b>8</b><b>T6</b>. These kinds of materials, owing to chiral channels with chiral active sites from ribose moieties, where the enantioselective recognition can occur, are, in principle, good candidates to carry out efficient separation of enantiomers, better than traditional inorganic and organic porous materials. Supramolecular chemistry ; Stacking ; Nanoporous ; Materials science ; Self-assembly ; Supramolecular assembly ; Nanotechnology ; Metal ions in aqueous solution ; Combinatorial chemistry ; Chemistry ; Metal ; Molecule ; Organic chemistry Metal-Organic Frameworks: Synthesis and Applications ; Supramolecular Self-Assembly in Materials ; Supramolecular Chemistry and Complexes
Authors: Yuzhen Lou | Damien Schapman | Dimitri Mercier | N. Ceren Süer | Tarık Eren | Pascal Thébault | Nasreddine Kébir
Source: European Polymer Journal (article, 2021-07-24)
Field: Chemistry — Organic Chemistry

Preparation of bactericidal PDMS surfaces by benzophenone photo-initiated grafting of polynorbornenes functionalized with quaternary phosphonium or pyridinium groups Benzophenone ; Cationic polymerization ; Phosphonium ; Grafting ; Pyridinium ; Chemistry ; ROMP ; Polymer chemistry ; Pentaerythritol ; Contact lens ; Contact angle ; Materials science ; Polymer ; Organic chemistry ; Metathesis ; Polymerization Antimicrobial agents and applications ; Polydiacetylene-based materials and applications ; Antimicrobial Peptides and Activities