jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Gaurav Bahuguna | Snehraj Gaur | Avit Patel | Mohit Verma | S. Kiruthika | Ritu Gupta
Source: Materials Research Bulletin (article, 2023-08-25)
Field: Materials Science — Materials Chemistry

Deciphering the influence of fluorine on the electrochemical performance of MAX and derived MXene by selective electrophilic fluorination MXenes ; Electrochemistry ; Fluorine ; Materials science ; Electronegativity ; Electrophile ; Electrolyte ; Chemical engineering ; Chemistry ; Nanotechnology ; Electrode ; Organic chemistry ; Physical chemistry ; Catalysis MXene and MAX Phase Materials ; 2D Materials and Applications ; Electromagnetic wave absorption materials
Authors: Yumei Zhu | Jorge Escorihuela | Haiying Wang | Andrew C.‐H. Sue | Han Zuilhof
Source: Molecules (article, 2023-10-10)
Field: Chemistry — Organic Chemistry

Tunable Supramolecular Ag+-Host Interactions in Pillar[n]arene[m]quinones and Ensuing Specific Binding to 1-Alkynes We developed an improved, robust synthesis of a series of pillar[<i>6</i>]arenes with a varying number (0-3) of quinone moieties in the ring. This easy-to-control variation yielded a gradually less electron-rich cavity in going from zero to three quinone units, as shown from the strength of host-guest interactions with silver ions. Such macrocycle-Ag<sub>2</sub> complexes themselves were shown to display an unprecedented, sharp distinction between terminal alkynes, which strongly bound to such complexes, and internal alkynes, internal alkenes and terminal alkenes, which do hardly bind. Quinone ; Supramolecular chemistry ; Pillar ; Chemistry ; Ring (chemistry) ; Terminal (telecommunication) ; Stereochemistry ; Crystallography ; Molecule ; Organic chemistry Supramolecular Chemistry and Complexes ; Porphyrin and Phthalocyanine Chemistry ; Magnetism in coordination complexes
Authors: Usana Mahanitipong | Jakkrit Tummachote | Wachirawit Thoopbucha | Wasawat Inthanusorn | Metha Rutnakornpituk
Source: Discover Nano (article, 2023-11-02)
Field: Chemistry — Organic Chemistry

Anionic polymer-coated magnetic nanocomposites for immobilization with palladium nanoparticles as catalysts for the reduction of 4-nitrophenol This study focuses on the synthesis of magnetite nanoparticles (MNP) coated with poly(poly(ethylene glycol) methacrylate) (PPEGMA) and/or poly(acrylic acid) (PAA) to anchor palladium nanoparticles (Pd) for their application as recyclable catalysts in the reduction of 4-nitrophenol (4NP). It was hypothesized that the abundance of oxygen atoms in PPEGMA enabled coordination with the Pd and provided good water dispersibility of the nanocomposites, while anionic PAA stabilized Pd and reduced the catalyst aggregation through electrostatic repulsion. Three different polymer coatings on MNP (PAA, PPEGMA, and PAA-co-PPEGMA polymers) were investigated to assess their influence on both the catalytic activity and reusability of the catalysts. Transmission electron microscopy (TEM) analysis indicated the distribution of spherical Pd nanoparticles (3-5 nm in diameter) and MNP (9-12 nm in diameter). Photocorrelation spectroscopy (PCS) revealed an average hydrodynamic size of the catalysts ranging from 540 to 875 nm in diameter, with a negative charge on their surface. The Pd content of the catalysts ranged from 4.30 to 6.33% w/w. The nanocomposites coated with PAA-co-PPEGMA polymers exhibited more favorable catalytic activity in the 4NP reduction than those coated with PAA or PPEGMA homopolymers. Interestingly, those containing PAA (e.g., PAA and PAA-co-PPEGMA polymers) exhibited good reusability for the 4NP reduction with a slight decrease in their catalytic performance after 26 cycles. This indicates the important role of carboxyl groups in PAA in maintaining high tolerance after multiple uses. Catalysis ; Polymer ; Palladium ; Materials science ; Polymer chemistry ; Methacrylate ; Nanoparticle ; Nanocomposite ; Copolymer ; Chemical engineering ; Chemistry ; Nanotechnology ; Organic chemistry ; Composite material Nanomaterials for catalytic reactions ; Advanced Photocatalysis Techniques ; Ammonia Synthesis and Nitrogen Reduction
Authors: Gavin Hum | Si Jia Isabel Phang | How Chee Ong | Félix León | Shina Quek | Yi Xin Joycelyn Khoo | Chenfei Li | Yongxin Li | Jack K. Clegg | Jesús Dı́az | Mihaiela C. Stuparu | Felipe Garcı́a
Source: Journal of the American Chemical Society (article, 2023-06-02)
Field: Chemistry — Organic Chemistry

Main Group Molecular Switches with Swivel Bifurcated to Trifurcated Hydrogen Bond Mode of Action Artificial molecular machines have captured the full attention of the scientific community since Jean-Pierre Sauvage, Fraser Stoddart, and Ben Feringa were awarded the 2016 Nobel Prize in Chemistry. The past and current developments in molecular machinery (rotaxanes, rotors, and switches) primarily rely on organic-based compounds as molecular building blocks for their assembly and future development. In contrast, the main group chemical space has not been traditionally part of the molecular machine domain. The oxidation states and valency ranges within the p-block provide a tremendous wealth of structures with various chemical properties. Such chemical diversity─when implemented in molecular machines─could become a transformative force in the field. Within this context, we have rationally designed a series of NH-bridged acyclic dimeric cyclodiphosphazane species, [(μ-NH){PE(μ-N<sup>t</sup>Bu)<sub>2</sub>PE(NH<sup>t</sup>Bu)}<sub>2</sub>] (E = O and S), bis-P<sup>V</sup><sub>2</sub>N<sub>2</sub>, displaying bimodal bifurcated R<sup>2</sup><sub>1</sub>(8) and trifurcated R<sup>3</sup><sub>1</sub>(8,8) hydrogen bonding motifs. The reported species reversibly switch their topological arrangement in the presence and absence of anions. Our results underscore these species as versatile building blocks for molecular machines and switches, as well as supramolecular chemistry and crystal engineering based on cyclophosphazane frameworks. Chemistry ; Molecular machine ; Supramolecular chemistry ; Context (archaeology) ; Hydrogen bond ; Nanotechnology ; Molecular recognition ; Valency ; Molecule ; Crystallography ; Crystal structure ; Organic chemistry ; Paleontology Supramolecular Chemistry and Complexes ; Molecular Sensors and Ion Detection ; Crystallography and molecular interactions
Authors: Siheng Qian | Jing Hu | Xiaobing Wang | Lifeng Yang | Xian Suo | Zhengbao Wang | Xili Cui | Huabin Xing
Source: AIChE Journal (article, 2023-03-30)
Field: Chemistry — Inorganic Chemistry

Anion‐pillared microporous material incorporated mixed‐matrix fiber adsorbents for removal of trace propyne from propylene Abstract Separation and purification of light hydrocarbons have been the critical processes for producing basic chemicals and polymers in petrochemical industry. Adsorbents with high performance are highly demanded for the separation of light hydrocarbons. However, the adsorbents filling in the packed bed when evaluated will inevitably induce reduced performance and increased pressure drop that considerably impede their application. Herein, mixed‐matrix fiber adsorbents with anion‐pillared hybrid microporous materials (SIFSIX‐2‐Cu‐i) embedded within poly (ether sulfone) (PES) are constructed to enable an energy‐efficient propylene/propyne separation. Owing to the sufficient binding sites and abundant channels for selective gas transfer, the fiber adsorbents achieve high C 3 H 4 uptake capacity of 0.963 mmol g −1 in the propylene/propyne (99/1) mixture breakthrough experiments. Moreover, fiber adsorbents exhibit good tolerance toward high gas velocity and show distinctively low pressure drop, which will be advantageous in industrial applications. This work provides a strategy for fabricating high‐performance mixed‐matrix fiber adsorbents. Microporous material ; Adsorption ; Petrochemical ; Fiber ; Sorption ; Chemical engineering ; Materials science ; Polymer ; Pressure drop ; Propyne ; Air separation ; Matrix (chemical analysis) ; Organic chemistry ; Chemistry ; Composite material ; Oxygen Metal-Organic Frameworks: Synthesis and Applications ; Membrane Separation and Gas Transport ; Covalent Organic Framework Applications
Authors: Mário Vale | Ana C. Marques
Source: Gels (article, 2023-09-01)
Field: Materials Science — Materials Chemistry

Mechanistic Study of the Formation of Multicomponent Oxide Porous Microspheres (MICROSCAFS®) by Cryo-Scanning Electron Microscopy Multicomponent oxide microspheres with interconnected macroporosity (MICROSCAFS<sup>®</sup>) are new materials with great potential as support materials for photocatalysis, optimized for real life applications and for other uses that are still being explored. They are obtained from an adapted sol-gel process combined with phase separation phenomena that occur within the water droplets of an emulsion. We present here a methodology based on cryogenic scanning electron microscopy (cryo-SEM) that allows, with minimal specimen preparation, the direct and in situ visualization of 'wet' alkoxide-derived microstructures, for the mechanistic study of the complex process of MICROSCAFS<sup>®</sup> generation. It is simultaneously combined with energy dispersive X-ray spectroscopy (EDS) to visualize phase separation phenomena and study the chemical elemental composition at specific regions of the sample and reaction times. Scanning electron microscope ; Materials science ; Chemical engineering ; Porosity ; Oxide ; Energy-dispersive X-ray spectroscopy ; Photocatalysis ; Emulsion ; Phase (matter) ; Porous medium ; Environmental scanning electron microscope ; Microstructure ; Spectroscopy ; Nanotechnology ; Chemistry ; Catalysis ; Composite material ; Organic chemistry Mesoporous Materials and Catalysis ; Pickering emulsions and particle stabilization ; Aerogels and thermal insulation
Authors: Rui Huang | Stefano Fedeli | Cristina‐Maria Hirschbiegel | Xianzhi Zhang | Vincent M. Rotello
Source: ACS Nanoscience Au (article, 2023-11-08)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Modulation of Gold Nanoparticle Ligand Structure–Dynamic Relationships Probed Using Solution NMR Ligand dynamics plays a critical role in the chemical and biological properties of gold nanoparticles (AuNPs). In this study, ligands featuring hydrophobic alkanethiol interiors and hydrophilic shells were used to systematically examine the effects of ligand headgroups on the ligand dynamics. Solution nuclear magnetic resonance (NMR) spectroscopy provided quantitative insight into the monolayer ligand dynamics. Notably, the introduction of hydrophobic moieties to the cationic headgroups significantly decreased ligand conformational mobility; however, variations in hydrophobicity among these moieties had a limited effect on this reduction. Further examination of ligand dynamics under various physiological conditions, including ionic strength and temperature, showed that ligands bound to the AuNP surface become less conformationally mobile with an increase in ionic strength or decreasing temperature. This exploration of ligand dynamics provides insight into designing nanoparticles tailored to specific biological applications. Ligand (biochemistry) ; Chemistry ; Colloidal gold ; Nanoparticle ; Ionic strength ; Monolayer ; Ionic bonding ; Nuclear magnetic resonance spectroscopy ; Cationic polymerization ; Resonance (particle physics) ; Chemical physics ; Nanotechnology ; Stereochemistry ; Materials science ; Ion ; Physical chemistry ; Organic chemistry ; Receptor ; Aqueous solution Gold and Silver Nanoparticles Synthesis and Applications ; Electrochemical Analysis and Applications ; Nanoparticle-Based Drug Delivery
Authors: Roberto Tallarita | Lukas M. Jacobsen | Benedict J. Elvers | Stefan Richter | Siva Sankar Murthy Bandaru | Jevy V. Correia | Carola Schulzke
Source: Molecules (article, 2023-12-30)
Field: Chemistry — Organic Chemistry

Synthesis of Seven Indolizine-Derived Pentathiepines: Strong Electronic Structure Response to Nitro Substitution in Position C-9 Seven new 1,2,3,4,5-pentathiepino[6,7-<i>a</i>]indolizines were synthesized in which the pentathiepine moieties bear an indolizine backbone that is derivatized from C-H to F-, Cl-, Br-, I-, NO<sub>2</sub>-, and CH<sub>3</sub>-substitutions, respectively, in a meta position relative to the aza group on the pyridine moiety. Their preparation took place via two common steps: (i) a Sonogashira coupling between (4-substituted) 2-bromo- or 2-chloropyridines and propynyl 3,3-diethylacetal, and (ii) a ring closing reaction mediated by a molybdenum oxo-bistetrasulfido complex and elemental sulfur. The latter simultaneously facilitates the 1,2,3,4,5-pentathiepino chain/ring- and indolizine ring-formations. The fluoro derivative was addressed with 2-bromo-5-aminopyridine as the starting material via a Sandmeyer reaction. The iodo derivative was obtained from 5-bromo-2-alkynylpiridine using a metal-assisted variation of the Finkelstein reaction. The requirement to explore different reaction conditions and the varied respective yields of the final products are discussed. The influence of the distinct substitutions on the pyridine moieties, their electronic structures, and respective chemical properties was investigated through a set of spectroscopic/analytical characterizations. Intriguingly, in all cases, the nitro-substituted derivative exhibited a distinct behavior compared to the six other investigated derivatives, which was also addressed computationally. All seven new pentathiepines were crystallized, and their respective molecular structures were determined using single crystal X-ray diffraction. These structures are compared and discussed as are their respective packing patterns. Indolizine ; Chemistry ; Sonogashira coupling ; Pyridine ; Ring (chemistry) ; Derivative (finance) ; Nitro ; Moiety ; Crystal structure ; Coupling reaction ; Stereochemistry ; Medicinal chemistry ; Crystallography ; Organic chemistry ; Palladium Synthesis and Reactivity of Heterocycles ; Synthesis and pharmacology of benzodiazepine derivatives ; Cyclopropane Reaction Mechanisms
Authors: Xinmei Zhang | Yan‐Mei Bai | Lu‐Lu Ai | Fang‐Hui Wu | Wei‐Long Shan | Yan‐Shang Kang | Li Luo | Kai Chen | Fan Xu
Source: Molecules (article, 2023-06-07)
Field: Chemistry — Inorganic Chemistry

A Chiral Metal—Organic Framework Prepared on Large-Scale for Sensitive and Enantioselective Fluorescence Recognition MOF-based luminescent sensors have garnered considerable attention due to their potential in recognition and discrimination with high sensitivity, selectivity, and fast response in the last decades. Herein, this work describes the bulk preparation of a novel luminescent homochiral MOF, namely, [Cd(s-L)](NO3)2 (MOF-1), from an enantiopure pyridyl-functionalized ligand with rigid binaphthol skeleton under mild synthetic condition. Except for the features of porosity and crystallinity, the MOF-1 has also been characterized with water-stability, luminescence, and homochirality. Most important, the MOF-1 exhibits highly sensitive molecular recognition toward the4-nitrobenzoic acid (NBC) and moderate enantioselective detection of proline, arginine, and 1-phenylethanol. Enantiopure drug ; Enantioselective synthesis ; Luminescence ; Crystallinity ; Selectivity ; Fluorescence ; Metal-organic framework ; Materials science ; Ligand (biochemistry) ; Molecular recognition ; Combinatorial chemistry ; Lanthanide ; Chemistry ; Organic chemistry ; Molecule ; Crystallography ; Catalysis ; Ion ; Receptor Metal-Organic Frameworks: Synthesis and Applications ; Molecular Sensors and Ion Detection ; Advanced Nanomaterials in Catalysis
Authors: Fengfan Yang | Xiaolu Wang | Jia‐Yue Tian | Xusheng Wang | Linfeng Liang
Source: Processes (article, 2023-05-04)
Field: Chemistry — Inorganic Chemistry

Construction of Water Vapor Stable Ultramicroporous Copper-Based Metal–Organic Framework for Efficient CO2 Capture It is quite essential to obtain an excellent CO2 adsorption capacity, CO2 adsorption selectivity and water vapor stability at the same time for practical CO2 capture after combustion. Through the combination of ultramicropore and the high density of CO2-philic sites without OMSs, an ultra-microporous Cu-based metal–organic framework has been designed and synthesized, featuring a high CO2 capacity (99 cm3 g−1 and 56.6 cm3 g−1 at 273 K and 298 K, respectively), high selectivity over N2 (118 at a scale of CO2/N2 15/85, 298 K) and excellent water vapor stability, simultaneously. Theoretical calculations indicate that neighboring ketonic O atoms with suitable distance play vital roles in boosting CO2 selective capture. Microporous material ; Metal-organic framework ; Selectivity ; Adsorption ; Copper ; Water vapor ; Metal ; Chemical engineering ; Materials science ; Chemistry ; Inorganic chemistry ; Organic chemistry Metal-Organic Frameworks: Synthesis and Applications ; Covalent Organic Framework Applications ; Carbon Dioxide Capture Technologies
Authors: Masatoshi Hasegawa | Takuya Miyama | Junichi Ishii | Daisuke Watanabe | Akira Uchida
Source: Polymers (article, 2023-09-20)
Field: Materials Science — Polymers and Plastics

Colorless Polyimides Derived from 5,5′-bis(2,3-norbornanedicarboxylic anhydride): Strategies to Reduce the Linear Coefficients of Thermal Expansion and Improve the Film Toughness In this paper, novel colorless polyimides (PIs) derived from 5,5'-bis(2,3-norbornanedicarboxylic anhydride) (BNBDA) were presented. The results of single-crystal X-ray structural analysis using a BNBDA-based model compound suggested that it had a unique steric structure with high structural linearity. Therefore, BNBDA is expected to afford new colorless PI films with an extremely high glass transition temperature (<i>T</i><sub>g</sub>) and a low linear coefficient of thermal expansion (CTE) when combined with aromatic diamines with rigid and linear structures (typically, 2,2'-bis(trifluoromethyl)benzidine (TFMB)). However, the polyaddition of BNBDA and TFMB did not form a PI precursor with a sufficiently high molecular weight; consequently, the formation of a flexible, free-standing PI film via the two-step process was inhibited because of its brittleness. One-pot polycondensation was also unsuccessful in this system because of precipitation during the reaction, probably owing to the poor solubility of the initially yielded BNBDA/TFMB imide oligomers. The combinations of (1) the structural modification of the BNBDA/TFMB system, (2) the application of a modified one-pot process, in which the conditions of the temperature-rising profile, solvents, azeotropic agent, catalysts, and reactor were refined, and (3) the optimization of the film preparation conditions overcame the trade-off between low CTE and high film toughness and afforded unprecedented PI films with well-balanced properties, simultaneously achieving excellent optical transparency, extremely high <i>T</i><sub>g</sub>, sufficiently high thermal stability, low CTE, high toughness, relatively low water uptake, and excellent solution processability. Thermal expansion ; Materials science ; Toughness ; Composite material ; Thermal ; Polymer science ; Polymer chemistry ; Thermodynamics ; Physics Synthesis and properties of polymers ; Epoxy Resin Curing Processes ; Silicone and Siloxane Chemistry
Authors: Ming Chen | Fulin Yang | Defa Hou | Yunwu Zheng | Can Liu | Xu Lin | Yan Li | Hao Sun
Source: Molecules (article, 2023-07-10)
Field: Materials Science — Materials Chemistry

Preparation of Multicolor Fluorescent Carbon Dots Based on Catechol and o-Phthalaldehyde As the foremost category of carbon materials, carbon dots (CDs) have been extensively applied in many domains because of their special fluorescence features and outstanding biocompatibility. However, in early studies of fluorescent CDs, as the fluorescence wavelength of most CDs was restricted to the blue or green region and was excitation dependent, the application of CDs was limited. In this study, three representative CDs, fluorescing yellow, green, and blue, were synthesized under alkaline, neutral, and acidic circumstances, respectively, while using a hydrothermal method in which catechol and phthalaldehyde acted as carbon sources and methanol functioned as the reaction solvent. The carbon nuclei of the three fluorescent CDs all had comparable graphite structures. The diversity of photoluminescence (PL) emission from these three CDs was attributed mainly to the different sizes of the sp<sup>2</sup> conjugated structures among them. Mixing synthesized CDs with epoxy resin, three colors (yellow, green, and blue) of LED using CIE coordinates (0.40, 0.44), (0.33, 0.46), and (0.21, 0.22), respectively, were successfully prepared. Fluorescence ; Carbon fibers ; Photochemistry ; Photoluminescence ; Catechol ; Luminescence ; Methanol ; Solvent ; Chemistry ; Biocompatibility ; Materials science ; Quantum yield ; Nuclear chemistry ; Organic chemistry ; Optoelectronics ; Optics Carbon and Quantum Dots Applications ; Nanocluster Synthesis and Applications ; Graphene and Nanomaterials Applications
Authors: Siyi Ma | Fang Dong | Weiliang Han | Weigao Han | Zhicheng Tang
Source: RSC Applied Interfaces (article, 2023-10-09)
Field: Materials Science — Materials Chemistry

Engineering Pt nanoclusters on CeO<sub>2</sub> surface with abundant point defects by <i>in situ</i> confined-domain encapsulation strategy for the catalytic elimination of VOCs An in situ introduction approach of Pt species can effectively build up the point-defects on the surface of CeO 2 to promote the dispersion and anchoring of Pt species, which can accelerate the oxidation rate of the toluene molecule. Nanoclusters ; In situ ; Catalysis ; Encapsulation (networking) ; Chemical engineering ; Materials science ; Anchoring ; Toluene ; Molecule ; Nanotechnology ; Chemistry ; Organic chemistry ; Computer science Nanocluster Synthesis and Applications ; Catalytic Processes in Materials Science ; Quantum Dots Synthesis And Properties
Authors: Chandani Chitrakar | Marc Torres | Pedro Emanuel Rocha-Flores | Qichan Hu | Melanie Ecker
Source: Polymers (article, 2023-10-25)
Field: Materials Science — Polymers and Plastics

Multifaceted Shape Memory Polymer Technology for Biomedical Application: Combining Self-Softening and Stretchability Properties Thiol-ene polymers are a promising class of biomaterials with a wide range of potential applications, including organs-on-a-chip, microfluidics, drug delivery, and wound healing. These polymers offer flexibility, softening, and shape memory properties. However, they often lack the inherent stretchability required for wearable or implantable devices. This study investigated the incorporation of di-acrylate chain extenders to improve the stretchability and conformability of those flexible thiol-ene polymers. Thiol-ene/acrylate polymers were synthesized using 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (TATATO), Trimethylolpropanetris (3-mercaptopropionate) (TMTMP), and Polyethylene Glycol Diacrylate (PEGDA) with different molecular weights (Mn 250 and Mn 575). Fourier Transform Infrared (FTIR) spectroscopy confirmed the complete reaction among the monomers. Uniaxial tensile testing demonstrated the softening and stretching capability of the polymers. The Young's Modulus dropped from 1.12 GPa to 260 MPa upon adding 5 wt% PEGDA 575, indicating that the polymer softened. The Young's Modulus was further reduced to 15 MPa under physiologic conditions. The fracture strain, a measure of stretchability, increased from 55% to 92% with the addition of 5 wt% PEGDA 575. A thermomechanical analysis further confirmed that PEGDA could be used to tune the polymer's glass transition temperature (<i>T<sub>g</sub></i>). Moreover, our polymer exhibited shape memory properties. Our results suggested that thiol-ene/acrylate polymers are a promising new class of materials for biomedical applications requiring flexibility, stretchability, and shape memory properties. Materials science ; Softening ; Polymer ; Shape-memory alloy ; Shape-memory polymer ; Softening point ; Polymer science ; Composite material ; Nanotechnology Polymer composites and self-healing ; Advanced Sensor and Energy Harvesting Materials ; Advanced Polymer Synthesis and Characterization