jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Fuming Li | Shilie Pan | Zhihua Yang
Source: Materials Chemistry Frontiers (article, 2021-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Enhanced birefringence and suppressed second harmonic generation response mechanism in nonlinear optical materials <i>via</i> structural fine-tuning The microscopic anionic groups with special arrangement are crucial in determining optical properties of optical functional materials. The fluorooxo-functional units BO x F 4-x affect optical properties for nonlinear optical material fluorooxoborates. Birefringence ; Nonlinear optical ; Materials science ; Second-harmonic generation ; Optical materials ; Optoelectronics ; Mechanism (biology) ; Nonlinear optics ; Nonlinear system ; Optics ; Physics ; Laser Crystal Structures and Properties ; Nonlinear Optical Materials Research ; Nonlinear Optical Materials Studies
Authors: Ádám Tajti | Botond Dániel Kovács | Nóra Popovics-Tóth | Franc Perdih | Erika Bálint
Source: Tetrahedron (article, 2021-11-01)
Field: Chemistry — Organic Chemistry

Microwave-assisted synthesis of benzo[b]phosphole oxide derivatives by oxidative addition of acetylenes and secondary phosphine oxides or alkyl phenyl-H-phosphinates A new and practical microwave (MW)-assisted method was developed for the fast and efficient oxidative addition of secondary phosphine oxides or alkyl phenyl-H-phosphinates and acetylenes. The reaction was optimized in respect of the oxidative agent, the reaction time, the temperature and the molar ratio of the starting materials. The protocol developed enabled the synthesis of novel benzo[b]phosphole oxide derivatives under mild conditions for a short reaction time. By the use of special reagents, such as alkyl phenyl-H-phosphinates or ethyl phenylpropiolate, reactive groups (phosphinic acid ester and carboxylic ester) could be integrated into the benzophosphole skeleton, which may be further functionalized towards various synthetic directions, therefore, fine-tuning the optical properties of the target molecules. The crystal structure of a benzo[b]phosphole oxide derivative was investigated by X-Ray diffraction, which gave structural information about the compound and its molecular interactions in the crystal. Chemistry ; Phosphole ; Alkyl ; Phosphine ; Reagent ; Phosphine oxide ; Medicinal chemistry ; Organic chemistry ; Oxide ; Crystal structure ; Molecule ; Combinatorial chemistry ; Catalysis Organophosphorus compounds synthesis ; Sulfur-Based Synthesis Techniques ; Radical Photochemical Reactions
Authors: Magdalena M. Kleybolte | Malte Winnacker
Source: Macromolecular Rapid Communications (article, 2021-05-07)
Field: Materials Science — Biomaterials

<i>β</i>‐Pinene‐Derived Polyesteramides and Their Blends: Advances in Their Upscaling, Processing, and Characterization Terpene-based polyesteramides (PEAs) are sustainable and have a variety of favorable properties, making them suitable for a wide range of applications and for contribution to a much more sustainable polymer industry. This work focuses on the synthesis of the lactam from β-pinene and its copolymerization with ε-caprolactone. An important step in synthesizing β-pinene lactam is the oxidation of β-pinene to nopinone. To make the established oxidative cleavage more sustainable and efficient, the required amounts of Al<sub>2</sub> O<sub>3</sub> and KMnO<sub>4</sub> are significantly reduced by using H<sub>2</sub> SO<sub>4</sub> as a catalyst. For the Beckmann rearrangement various catalysts and co-reagents are screened. Among these, the reaction with tosyl chloride is found the most favorable. Subsequently, the chain lengths of the β-pinene-based PEAs are remarkably increased from 6000 g mol<sup>-1</sup> to more than 25 100 g mol<sup>-1</sup> by fine-tuning reaction time, temperature, and decreasing catalyst and initiator concentrations. Also, different catalysts for polymerization are tested. The resulting material shows melting temperatures of ≈55 °C and decomposition temperatures of 354 °C or higher. Processing via melt pressing or casting turned out to be quite difficult due to the polymer's brittleness. Furthermore, regarding biomedical applications, blends of PEA with polyethylene glycol were successfully prepared, yielding a more hydrophilic material. Pinene ; Catalysis ; Materials science ; Polymerization ; Chemical engineering ; Copolymer ; Reagent ; Polymer ; Organic chemistry ; Casting ; Chemistry ; Polymer chemistry ; Metallurgy biodegradable polymer synthesis and properties ; Carbon dioxide utilization in catalysis ; Chemical Synthesis and Reactions
Authors: Bastian Haehnle | P. Schuster | Lisa Chen | Alexander J. C. Kuehne
Source: Small (article, 2021-05-21)
Field: Materials Science — Materials Chemistry

All‐Conjugated Polymer Core–Shell and Core–Shell–Shell Particles with Tunable Emission Profiles and White Light Emission Future applications of conjugated polymer particles (CPP) in medicine, organic photonics, and optoelectronics greatly depend on high performance and precisely adjustable optical properties of the particles. To meet these criteria, current particle systems often combine conjugated polymers with inorganic particles in core-shell geometries, extending the possible optical characteristics of CPP. However, current conjugated polymer particles are restricted to a single polymer phase composed of a distinct polymer or a polymer blend. Here, a synthetic toolbox is presented that enables the synthesis of monodisperse core-shell and core-shell-shell particles, which consist entirely of conjugated polymers but of different types in the core and the shells. Seeded and fed-batch dispersion polymerizations based on Suzuki-Miyaura-type cross-coupling are investigated. The different approaches allow accurate control over the created interface between the conjugated polymer phases and thus also over the energy transfer phenomena between them. This approach opens up completely new synthetic freedom for fine tuning of the optical properties of CPP, enabling, for example, the synthesis of individual white light-emitting particles. Shell (structure) ; Materials science ; Core (optical fiber) ; Conjugated system ; Polymer ; White light ; Nanotechnology ; Composite material ; Optoelectronics Luminescence and Fluorescent Materials ; Covalent Organic Framework Applications ; Conducting polymers and applications
Authors: Omar Salinas | Jiaze Xie | R. Papoular | Noah E. Horwitz | Erik Elkaı̈m | Alexander S. Filatov | John S. Anderson
Source: Dalton Transactions (article, 2021-01-01)
Field: Chemistry — Inorganic Chemistry

Steric and electronic effects of ligand substitution on redox-active Fe <sub>4</sub> S <sub>4</sub> -based coordination polymers One of the notable advantages of molecular materials is the ability to precisely tune structure, properties, and function via molecular substitutions. While many studies have demonstrated this principle with classic carboxylate-based coordination polymers, there are comparatively fewer examples where systematic changes to sulfur-based coordination polymers have been investigated. Here we present such a study on 1D coordination chains of redox-active Fe<sub>4</sub>S<sub>4</sub> clusters linked by methylated 1,4-benzene-dithiolates. A series of new Fe<sub>4</sub>S<sub>4</sub>-based coordination polymers were synthesized with either 2,5-dimethyl-1,4-benzenedithiol (DMBDT) or 2,3,5,6-tetramethyl-1,4-benzenedithiol (TMBDT). The structures of these compounds have been characterized based on synchrotron X-ray powder diffraction while their chemical and physical properties have been characterized by techniques including X-ray photoelectron spectroscopy, cyclic voltammetry and UV-visible spectroscopy. Methylation results in the general trend of increasing electron-richness in the series, but the tetramethyl version exhibits unexpected properties arising from steric constraints. All these results highlight how substitutions on organic linkers can modulate electronic factors to fine-tune the electronic structures of metal-organic materials. Steric effects ; Ligand (biochemistry) ; Crystallinity ; Linker ; Coordination polymer ; Polymer ; Chemistry ; Redox ; Substitution (logic) ; Electronic structure ; Sulfur ; Coordination complex ; Crystallography ; Stereochemistry ; Computational chemistry ; Inorganic chemistry ; Organic chemistry ; Metal ; Computer science Metal-Organic Frameworks: Synthesis and Applications ; Corrosion Behavior and Inhibition ; Magnetism in coordination complexes
Authors: Felipe A. Larrain | Canek Fuentes‐Hernandez | Yi-Chien Chang | Victor A. Rodriguez-Toro | Silja Abraham | Bernard Kippelen
Source: ACS Applied Materials & Interfaces (article, 2021-05-07)
Field: Materials Science — Polymers and Plastics

Increasing Volume in Conjugated Polymers to Facilitate Electrical Doping with Phosphomolybdic Acid Molecular p-type electrical dopants have been proven useful to fine-tune the optoelectronic properties of bulk organic semiconductors and their interfaces. Here, the volume in polymer films and its role in solution-based electrical p-type doping using phosphomolybdic acid (PMA) are studied. The polymer film volume was controlled using two approaches. One is based on heating both the PMA solution and the film prior to immersion. The second is based on coating the polymer film with a liquid blend that contains the PMA solution and a swelling solvent. <sup>31</sup>P NMR and FTIR experiments indicate that the Keggin structure appears to be preserved throughout the doping process. Results show that increasing the polymer volume facilitates the infiltration of the PMA Keggin structure, which results in an increased electrical p-type doping level. Materials science ; Phosphomolybdic acid ; Polymer ; Doping ; Chemical engineering ; Solvent ; Dopant ; Fourier transform infrared spectroscopy ; Coating ; Volume (thermodynamics) ; Polymer chemistry ; Organic chemistry ; Composite material ; Optoelectronics ; Catalysis Conducting polymers and applications ; Luminescence and Fluorescent Materials ; Polyoxometalates: Synthesis and Applications
Authors: Guosheng Fang | Hongyu Wang | Changwu Zheng | Lu Pan | Gang Zhao
Source: Organic & Biomolecular Chemistry (article, 2021-01-01)
Field: Chemistry — Organic Chemistry

Enantioselectivity switch in asymmetric Michael addition reactions using phosphonium salts Efficient access to two enantiomers of one chiral compound is critical for the discovery of drugs. However, it is still a challenging problem owing to the difficulty in obtaining two enantiomers of one chiral catalyst. Here, we report a general method to obtain both enantiomeric products via fine tuning the hydrogen-bonding interactions of phosphonium salts. Amino acid derived phosphonium salts and dipeptide derived phosphonium salts exhibited different properties for controlling the transition state, which could efficiently promote the Michael addition reaction to give opposite configurations of products with high yields and enantioselectivities. Preliminary investigations on the mechanism of the reaction and applications of the products were also performed. Michael reaction ; Phosphonium ; Enantioselective synthesis ; Catalysis ; Chemistry ; Combinatorial chemistry ; Addition reaction ; Organic chemistry Asymmetric Synthesis and Catalysis ; Axial and Atropisomeric Chirality Synthesis ; Molecular spectroscopy and chirality
Authors: Sara Battista | Vincenzo Marsicano | Antonio Arcadi | Luciano Galantini | Massimiliano Aschi | Elena Allegritti | Alessandra Del Giudice | Luisa Giansanti
Source: Colloids and Interfaces (article, 2021-05-07)
Field: Materials Science — Materials Chemistry

UV Properties and Loading into Liposomes of Quinoline Derivatives The scientific relevance of quinolines is strictly linked to the fine-tuning of their features by functionalizing the heterocyclic core. Consequently, the compounds of this class are very versatile and can be used as possible drugs for a lot of medical applications. In this work, the inclusion of eight synthetic quinoline derivatives in liposomes formulated with different lipids was investigated in terms of the encapsulation efficiency and to highlight the effect on the liposome size distribution and thermotropic behavior. Excellent encapsulation was accomplished with all the quinoline/phospholipid combinations. Differences in the interactions at the molecular level, dependent on the quinoline molecular scaffolds and lipid structure, were observed, which could significantly bias the interaction with the drug and its release in pharmaceutical applications. Experiments in combination with computational studies demonstrated that the UV absorption of quinolines with expanded conjugation could be affected by the environment polarity. This was probably due to a solvent-dependent ability of these quinolines to stack into aggregates, which could also occur upon inclusion into the lipid bilayer. Quinoline ; Liposome ; Thermotropic crystal ; Chemistry ; Combinatorial chemistry ; Bilayer ; Phospholipid ; Solvent ; Lipid bilayer ; Molecule ; Organic chemistry ; Membrane ; Liquid crystalline ; Biochemistry ; Polymer Luminescence and Fluorescent Materials ; Lipid Membrane Structure and Behavior ; Supramolecular Chemistry and Complexes
Authors: Marharyta Blazhynska | Alexander Kyrychenko | Oleg N. Kalugin
Source: The Journal of Physical Chemistry C (article, 2021-05-25)
Field: Chemistry — Organic Chemistry

pH-Responsive Coating of Silver Nanoparticles with Poly(2-(<i>N</i>,<i>N</i>-dimethylamino)ethyl methacrylate): The Role of Polymer Size and Degree of Protonation “Smart” nanomaterials composed of inorganic nanoparticles (NPs) and synthetic polymers represent an exciting and rapidly growing interdisciplinary area of materials science and engineering. Specifically, the coating of NPs with “smart” polymers capable of responding to applied external stimuli makes them promising for various biomedical applications, including drug delivery, tissue engineering, and medical diagnostics. In this work, we present an atomistic molecular dynamics (MD) simulation study of a silver NP (AgNP) grafted with a single-chain poly(2-(N,N-dimethylamino)ethyl methacrylate) (PDMAEMA). PDMAEMA possesses ionizable side-chain groups −N(CH3)2, which can be converted into charged moieties upon solution acidification so that this makes the whole macromolecule to be pH responsive. We examined the pH-responsive adsorption of PDMAEMA onto the AgNP as a function of the polymer chain length (220–660 units) and the degree of protonation α. We found out that, in the neutral state at α = 0, the PDMAEMA chain was collapsed and adsorbed onto the AgNP due to the weak non-covalent interactions through the neutral dimethylamino moieties. Partial protonation of these side groups at α = 0.3–0.7 triggers ionic interactions, which drive the unfolding of the polymer chain toward an aqueous solution due to the electrostatic Coulombic repulsion between the generated charges. In the charged state at α = 1, the complete ionization of PDMAEMA side groups increases its solubility that leads to the substantial decrease in the polymer–NP interactions, followed by desorption of the polymer from the inorganic core. Thus, the gradual changes in the protonation degree of PDMAEMA fine-tune a balance of hydrophilic versus hydrophobic NP–polymer interactions and govern the shape, size, and water-protecting efficiency of the polymeric shell. Finally, our MD simulations demonstrated that such pH-adaptive behavior of PDMAEMA makes it promising for the development of a wide range of new generations of “intelligent” polymer coatings for metal NPs. Protonation ; Methacrylate ; Polymer ; Polyelectrolyte ; Polymer chemistry ; Nanoparticle ; Ionic bonding ; Chemistry ; Aqueous solution ; Solubility ; Chemical engineering ; Materials science ; Nanotechnology ; Organic chemistry ; Monomer ; Ion Advanced Polymer Synthesis and Characterization ; Nanoparticle-Based Drug Delivery ; Surfactants and Colloidal Systems
Authors: Lei Kang | Fang Wang | Jinlong Zhang | Huameng Yang | Chungu Xia | Jinlong Qian | Gaoxi Jiang
Source: Organic Letters (article, 2021-02-18)
Field: Chemistry — Organic Chemistry

High Chemo-/Stereoselectivity for Synthesis of Polysubstituted Monofluorinated Pyrimidyl Enol Ether Derivatives A novel intramolecular Smiles rearrangement of α-fluoro-β-keto-pyrimidylsulfones (usually used as a carbon nucleophile) was developed, providing a versatile avenue for synthesis of tri/tetra-substituted monofluorinated pyrimidyl enol ethers. Among these, diverse (<i>Z</i>)-monofluorovinylsulfones and sulfinates were efficiently assembled by adding extra electrophile and fine-tuning reaction conditions. The process is triggered by a keto-enol tautomerism from enol oxyanion to pyrimidine 2-carbon, completely different from the classical carbon nucleophilic addition reaction approach. Chemistry ; Enol ; Nucleophile ; Electrophile ; Stereoselectivity ; Tautomer ; Intramolecular force ; Enol ether ; Combinatorial chemistry ; Organic chemistry ; Catalysis Sulfur-Based Synthesis Techniques ; Synthesis and Catalytic Reactions ; Fluorine in Organic Chemistry
Authors: Shoichi Kutsumizu | Akane Kawafuchi | Yasuhisa Yamamura | Taro Udagawa | Takashi Otaki | Masaki Masuda | Yohei Miwa | Kazuya Saito
Source: Chemistry - A European Journal (article, 2021-05-25)
Field: Chemistry — Organic Chemistry

Stabilization of Bicontinuous Cubic Phase and Its Two‐Sided Nature Produced by Use of Siloxane Tails and Introduction of Molecular Nonsymmetry A recent intriguing finding that a helical network arrangement forms the bicontinuous cubic phase is attracting great attention for the possibility of new routes to asymmetric synthesis by achiral molecules. However, the design of the molecular structure for the cubic phase is still unrevealed. In this work, a nonsymmetric core molecule with larger naphthalene and smaller benzene moieties at each side of the central linkage and the same disiloxanyldecyloxy terminal at both terminals is shown to be the first example of molecule forming both single-layered and double-layered core assembly modes in the Ia3d phase as a single molecule system. The molecule forms the former mode at high temperatures as a thermodynamically stable phase, similarly to the symmetric naphthalene core system, whereas, on cooling below a temperature (∼350 K), a metastable Ia3d phase forms a double-layered core state down to room temperature, which is common to the benzene core system. As another effect of the nonsymmetric core, the cubic phase is maintained at room temperature for more than 100 days with slight distortion. Infrared spectral studies and quantum chemical calculations suggested the easy transformation between the two core assembly modes. The core nonsymmetry can be a versatile fine-tuning of the core assembly mode and phase stability for the cubic phase molecules. Phase (matter) ; Molecule ; Materials science ; Metastability ; Crystallography ; Chemical physics ; Chemistry ; Organic chemistry Supramolecular Chemistry and Complexes ; Crystallography and molecular interactions ; Porphyrin and Phthalocyanine Chemistry
Authors: Alessia D’Andrea | Leonardo Severini | Fabio Domenici | С.Б. Дабагов | Valeria Guglielmotti | D. Hampai | Laura Micheli | E. Placidi | Mattia Titubante | Claudia Mazzuca | Gaio Paradossi | Antonio Palleschi
Source: ACS Applied Materials & Interfaces (article, 2021-05-14)
Field: Materials Science — Materials Chemistry

Ultrasound-Stimulated PVA Microbubbles for Adhesive Removal from Cellulose-Based Materials: A Groundbreaking Low-Impact Methodology In this work, we shed new light on ultrasound contrast agents applied to the field of cultural heritage as an invaluable fine-tune cleaning tool for paper artworks. In this context, one of the primary and challenging issues is the removal of modern adhesives from paper artifacts. Modern adhesives are synthetic polymers whose presence enhances paper degradation and worsens its optical features. A thorough analytical and high-spatial-resolution combined study was successfully performed to test the capability of poly(vinyl alcohol)-based microbubbles stimulated by a proper noninvasive 1 MHz ultrasound field exposure in removing these adhesives from paper surfaces, in the absence of volatile invasive and toxic chemicals and without damaging paper and/or leaving residues. We demonstrate that poly(vinyl alcohol)-shelled microbubbles are suitable for interacting with paper surfaces, targeting and boosting in a few minutes the nondamaging removal of adhesive particles from paper samples thanks to their peculiar shell composition together with their ultrasound dynamics. Microbubbles ; Materials science ; Adhesive ; Vinyl alcohol ; Context (archaeology) ; Cellulose ; Ultrasound ; Polymer ; Nanotechnology ; Composite material ; Chemical engineering ; Acoustics Ultrasound and Cavitation Phenomena ; Electrospun Nanofibers in Biomedical Applications ; Pickering emulsions and particle stabilization
Authors: Arpan Datta Sarma | Carlos Eloy Federico | Frida Nzulu | Marc Weydert | Pierre Verge | Daniel F. Schmidt
Source: Polymers (article, 2021-10-20)
Field: Materials Science — Polymers and Plastics

Multipurpose Processing Additives for Silica/Rubber Composites: Synthesis, Characterization, and Application Processing additives are a special group of chemicals included in rubber formulations to facilitate the flowability of the resultant compounds. Their addition generally affects the cured properties of the subsequent rubber composites, and fine-tuning of the compound formulation is therefore required. In this work, an attempt has been made to address this issue through the preparation of new bio-based processing additives capable of promoting the mixing of the rubber compound while at the same time enhancing mechanical properties following curing. A significant decrease in the mixing energy at the first stage of mixing (~10%) has been observed by substituting only a small percentage of the conventional petroleum-derived process oil with aminated epoxidized soybean oil. Concomitantly, it is found that this aminated epoxidized soybean oil promotes rubber curing and increases the tensile strength of the final composite by ~20% compared to the control. Natural rubber ; Curing (chemistry) ; Materials science ; Composite material ; Ultimate tensile strength ; Soybean oil ; Mixing (physics) ; Composite number ; Vulcanization ; Epoxidized soybean oil ; Organic chemistry ; Chemistry Polymer Nanocomposites and Properties ; biodegradable polymer synthesis and properties ; Polymer crystallization and properties