jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Yeong Jun Son | Dongyoung Kim | Jae Wan Park | Kwangwook Ko | Youngseob Yu | Seung Jun Hwang
Source: Journal of the American Chemical Society (article, 2024-10-18)
Field: Chemistry — Inorganic Chemistry

Heteromultimetallic Platform for Enhanced C–H Bond Activation: Aluminum-Incorporated Dicopper Complex Mimicking Cu-ZSM-5 Structure and Oxidative Reactivity Bimetallic complexes have sparked interest across various chemical disciplines, driving advancements in research. Recent advancements in this field have shed light on complex reactions in metalloenzymes and unveiled new chemical transformations. Two primary types of bimetallic platforms have emerged: (1) systems where both metals actively participate in reactivity, and (2) systems where one metal mediates the reaction while the other regulates reactivity. This study introduces a novel multinucleating ligand platform capable of integrating both types of bimetallic systems. To demonstrate the significance of this platform, we synthesized a unique dicopper complex incorporating aluminum in its coordination environment. This complex serves as the first structural model for the active site in copper-based zeolites, highlighting the role of aluminum in hydrogen atom abstraction reactivity. Comparative studies of oxidative C-H bond activation revealed that the inclusion of aluminum significantly alters the thermodynamic driving force (by -11 kcal mol<sup>-1</sup>) for bond activation and modifies the proton-coupled electron-transfer reaction mechanism, resulting in a 14-fold rate increase. Both computational and experimental data support the high modularity of this multinucleating ligand platform, offering a new approach to fine-tune the reactivity of bimetallic complexes. Chemistry ; Reactivity (psychology) ; Aluminium ; Oxidative phosphorylation ; ZSM-5 ; Catalysis ; Organic chemistry ; Biochemistry ; Molecular sieve Metal-Catalyzed Oxygenation Mechanisms ; Catalytic C–H Functionalization Methods ; Synthesis and Catalytic Reactions
Authors: Fatima Youness | Zainah A. AlDhawi | Mahmoud A. Abdulhamid | Rana A. Bilbeisi
Source: Separation and Purification Technology (article, 2024-12-27)
Field: Materials Science — Biomaterials

Surface engineering of electrospun polyvinyl chloride nanofibrous membranes with zeolitic imidazolate framework for effective oil spill removal Polyvinyl chloride ; Membrane ; Electrospinning ; Chemical engineering ; Nanofiber ; Zeolitic imidazolate framework ; Polyvinyl alcohol ; Materials science ; Chemistry ; Polymer ; Adsorption ; Composite material ; Organic chemistry ; Metal-organic framework ; Engineering Electrospun Nanofibers in Biomedical Applications ; Electrohydrodynamics and Fluid Dynamics ; Surface Modification and Superhydrophobicity
Authors: Miguel Coronado | Mohammad Babazadeh | Ebrahim Rezaei | Janusz A. Koziński
Source: Chemical Engineering Journal (article, 2024-07-30)
Field: Chemistry — Analytical Chemistry

Complete oxidation of trans-4-pentylcyclohexanecarboxylic acid by catalytic ozonation using alumina supported bi-metallic copper-magnesium oxides Copper ; Magnesium ; Metal ; Catalysis ; Chemistry ; Inorganic chemistry ; Organic chemistry Petroleum Processing and Analysis ; Radioactive element chemistry and processing ; Hydrocarbon exploration and reservoir analysis
Authors: Anqun Su | Dabo Jiang | Wenwei Hu | Shuting Liang | Kai Yu | Weijie Zhou | Jing Wang | Zaihui Fu | Yachun Liu | Jianxin Liu
Source: Journal of Organometallic Chemistry (article, 2024-10-28)
Field: Materials Science — Materials Chemistry

Hybridizing engineering strategy of decatungstate III: Transition metal modified carbon quantum dot-regulated photo-catalytic oxidation performance of decatungstate Chemistry ; Transition metal ; Photochemistry ; Catalysis ; Quantum dot ; Optoelectronics ; Organic chemistry ; Physics Advanced Nanomaterials in Catalysis ; Carbon and Quantum Dots Applications ; Advanced Photocatalysis Techniques
Authors: Wiktor Kasprzyk | Piotr P. Romańczyk | Stefan S. Kurek | Tomasz Świergosz
Source: Nanoscale (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

A switchable green emitting dye and its phenomenal properties: implications for the photoluminescence features of carbon dots New molecular fluorophores are constantly being discovered in post-synthetic mixtures of carbon dots (CDs), prompting researchers to elucidate their role in the optical properties of these nanomaterials. It has been reported that the green-emitting fluorophore that forms during the synthesis of popular citric acid/urea CDs is HPPT (4-hydroxy-1<i>H</i>-pyrrolo[3,4-<i>c</i>]pyridine-1,3,6(2<i>H</i>,5<i>H</i>)-trione). However, due to the low concentration of HPPT-like molecules within the structure of CDs, their actual binding and contribution to the optical properties of CDs has not so far been convincingly confirmed. In this joint experimental and quantum chemical study, we show that HPPT is a strong acid and only its anionic form, HPPT<sup>-</sup>, present in solutions of pH 0-10, is emissive. Next, its fluorescence can be switched off rapidly in strongly alkaline environments as a result of HPPT<sup>-</sup> hydrolysis, leading to the opening of its pyrrole ring and formation of CDPC (3-carbamoyl-2,6-dihydroxypyridine-4-carboxylic acid), existing as the CDPC<sup>2-</sup> dianion under these conditions. Eventually, we found that the ring opening hydrolysis is reversible and the green emission may be restored in acidic environments. The kinetics and mechanism of this hydrolysis were also revealed. The optical features of citric acid (CA)-urea CDs under various conditions were compared with a simpler CD system prepared by treating the CDs obtained from CA solely with HPPT<sup>-</sup> (HPPT@CDs). Our results indicate the feasibility of the post-synthetic modification of HPPT<sup>-</sup> present in the structures of CA-urea CDs and HPPT@CDs. Without HPPT<sup>-</sup> they emit blue fluorescence only. Thus, this makes the nanosystem switch the PL emission colour reversibly from green to blue owing to the opening and closing of the pyrrole ring in HPPT-like molecules. More importantly, the latter process may be considered a first step toward genuine fine tuning of the PL emission colour from CDs. These findings are of general importance to the further development of citric acid-based CDs with tailored properties. Photoluminescence ; Materials science ; Carbon fibers ; Nanotechnology ; Optoelectronics ; Composite material ; Composite number Carbon and Quantum Dots Applications ; Nanocluster Synthesis and Applications ; Luminescence and Fluorescent Materials
Authors: Karoline E. García-Pedraza | Jaime R. Ayala | Udani K. Wijethunga | Alice R. Giem | George Agbeworvi | Sarbajit Banerjee | David F. Watson
Source: Nano Research (article, 2024-11-18)
Field: Materials Science — Materials Chemistry

Heterostructures of Ni(II)-doped CdS quantum dots and β-Pb0.33V2O5 nanowires: Enhanced charge separation and redox photocatalysis via doping of QDs We synthesized heterostructures by tethering Ni(II)-doped CdS (Ni:CdS) quantum dots (QDs) to β-Pb0.33V2O5 nanowires (NWs) using L-cysteine as a molecular linker, and we evaluated the influence of doping on their redox photocatalytic reactivity. We initially hypothesized that incorporating Ni:CdS QDs into heterostructures could alter excited-state dynamics and mechanisms, and that the localization of excited electrons on Ni 3d states could promote redox photocatalytic mechanisms including reduction of CO2. Isolated Ni:CdS QDs were ferromagnetic, and they exhibited enhanced photocatalytic hydrogen evolution and photostability relative to undoped CdS QDs. Both Pb0.33V2O5/CdS heterostructures (with undoped QDs) and Pb0.33V2O5/Ni:CdS heterostructures (with Ni(II)-doped QDs) exhibited substantial energetic overlap between valence-band states of QDs and intercalative mid-gap states of β-Pb0.33V2O5 NWs. Within Pb0.33V2O5/CdS heterostructures, photoexcitation of CdS QDs was followed by rapid (50–100 ps) transfer of both holes and electrons to β-Pb0.33V2O5 NWs. In contrast, within Pb0.33V2O5/Ni:CdS heterostructures, holes were transferred from Ni:CdS QDs to β-Pb0.33V2O5 NWs within 100 ps, but electrons were transferred approximately 20-fold more slowly. This difference in electron- and hole-transfer kinetics promoted charge separation across the Pb0.33V2O5/Ni:CdS interface and enabled the photocatalytic reduction of CO2 to CO, CH4, and HCO2H with > 99.9% selectivity relative to the reduction of H+ to H2. These results highlight the opportunity to fine-tune dynamics and mechanisms of excited-state charge-transfer, and mechanisms of subsequent redox half-reactions, by doping QDs within heterostructures. Moreover, they reveal the promise of heterostructures comprising QDs and MxVyO5 materials as CO2-reduction photocatalysts. Quantum dot ; Doping ; Heterojunction ; Photocatalysis ; Nanowire ; Materials science ; Redox ; Optoelectronics ; Nanotechnology ; Chemistry ; Catalysis Quantum Dots Synthesis And Properties ; Advanced Photocatalysis Techniques ; Chalcogenide Semiconductor Thin Films
Authors: Salvatore Scavuzzo | Silvia Zecchi | Giovanni Cristoforo | Carlo Rosso | Daniele Torsello | G. Ghigo | Luca Lavagna | Mauro Giorcelli | Alberto Tagliaferro | Marco Etzi | Mattia Bartoli
Source: C – Journal of Carbon Research (article, 2024-09-05)
Field: Materials Science — Polymers and Plastics

Miscanthus-Derived Biochar as a Platform for the Production of Fillers for the Improvement of Mechanical and Electromagnetic Properties of Epoxy Composites The production of multipurpose sustainable fillers is a matter of great interest, and biochar can play a pivotal role. Biochar is a biomass-derived carbon source that can act as a versatile platform for the engineering of fillers as neat or functionalized materials. In this work, we investigate the utilization of 800 °C annealed Miscanthus-derived biochar as a filler for the production of epoxy composites with promising mechanical and electrical properties. We also used it in the production of an iron-rich hybrid filler in order to fine-tune the surface and bulk properties. Our main findings reveal that hybrid composites containing 20 wt.% biochar exhibit a 27% increase in Young’s modulus (YM), reaching 1.4 ± 0.1 GPa, while the ultimate tensile strength (UTS) peaks at 30.3 ± 1.8 Mpa with 10 wt.% filler, a 27% improvement over pure epoxy. However, higher filler loadings (20 wt.%) result in decreased UTS and maximum elongation. The optimal toughness of 0.58 ± 0.14 MJ/m³ is observed at 5 wt.% filler content. For organic composites, YM sees a notable increase of 90%, reaching 2.1 ± 0.1 Gpa at 20 wt.%, and UTS improves by 32% with the same filler content. Flexural tests indicate an enhanced elastic modulus but reduced maximum elongation as filler content rises. Electromagnetic evaluations show that hybrid fillers maintain a primarily dielectric behavior with a negligible impact on permittivity, while biochar–epoxy composites exhibit increased conductivity at higher filler loadings, suitable for high-frequency applications. In light of these results, biochar-based fillers demonstrate significant potential for enhancing the mechanical and electrical properties of epoxy composites. Biochar ; Miscanthus ; Epoxy ; Composite material ; Materials science ; Pyrolysis ; Waste management ; Engineering ; Bioenergy ; Biofuel Natural Fiber Reinforced Composites ; Electromagnetic wave absorption materials ; Advanced Cellulose Research Studies
Authors: Yang Gao | Bing-Feng Qian | Hua‐Tian Shi | Ai‐Quan Jia | Qunbo Mei | Qian‐Feng Zhang
Source: Inorganica Chimica Acta (article, 2024-06-02)
Field: Chemistry — Organic Chemistry

Dinitrogen-bridged ruthenium(II) complexes featuring dithiocarbamate ligands Dithiocarbamate ; Ruthenium ; Chemistry ; Combinatorial chemistry ; Medicinal chemistry ; Catalysis ; Organic chemistry Organometallic Compounds Synthesis and Characterization ; Metal complexes synthesis and properties ; Organometallic Complex Synthesis and Catalysis
Authors: José P. L. Roque | Cláudio M. Nunes | Fumito Saito | Bastian Bernhardt | Rui Fausto | Peter R. Schreiner
Source: ChemistryEurope (article, 2024-11-13)
Field: Chemistry — Physical and Theoretical Chemistry

Competitive Heavy‐Atom Tunneling Reactions Controlled Through Electronic Effects Abstract Controlling QMT reactivity remains exceptionally challenging and largely unexplored, as it requires rationales distinctly different from those used for classical chemical reactivity. Herein, we investigated how QMT reactivity can be controlled using electronic substituent effects. Benzazirines, which have the exceptional feature to react via two competitive QMT pathways, were used as model compounds. Three novel derivatives with increasingly stronger electron‐donating substituents at C4 [R = OH, N(CH 3 ) 2 , and N(CH 2 ) 4 ] were generated in argon matrices at 3 K. Remarkably, different QMT selectivities were observed in all benzazirines. As the electron‐donating strength of the substituent increases, the QMT ring‐opening to nitrene starts to compete with the QMT ring‐expansion to ketenimine, becoming the dominant process for the strongest electron‐donating substituent [N(CH 2 ) 4 ]. A theoretical analysis of the substituent effects on the QMT reactivity of benzazirines was performed and compared with the experimental data for these and other C4 derivatives. Overall, the results compellingly demonstrate how subtle changes in electronic effects can be used to fine‐tune QMT selectivity. Substituent ; Chemistry ; Reactivity (psychology) ; Ring (chemistry) ; Ketenimine ; Nitrene ; Delocalized electron ; Stereochemistry ; Computational chemistry ; Medicinal chemistry ; Photochemistry ; Organic chemistry ; Catalysis Chemical Reactions and Mechanisms ; Chemical Reaction Mechanisms ; Synthesis and Catalytic Reactions
Authors: Junling He | Yong Tang | Chiliang Lin | Shuangqing Peng | Stig Pedersen‐Bjergaard | Frederik André Hansen | Chen Zhou
Source: Food Chemistry (article, 2024-12-27)
Field: Chemistry — Analytical Chemistry

Electromembrane extraction of multi-class prohibited/restricted veterinary drugs from food samples – Exploring liquid membrane composition Composition (language) ; Membrane ; Veterinary Drugs ; Extraction (chemistry) ; Food science ; Veterinary drug ; Chemistry ; Chromatography ; Veterinary medicine ; Medicine ; Biochemistry ; Art Analytical chemistry methods development ; Electrochemical sensors and biosensors ; Electrochemical Analysis and Applications
Authors: Zikang Yang | Xinwei Li | Tingting Sun | Jiqing Bian | Xiaoyu Bu | Xichuan Ge | Jing Sun | Zugang Liu | Zhigang Xie | Peng Xi | Qi Ai | Chao Wei | Baoxiang Gao
Source: Analytical Chemistry (article, 2024-07-18)
Field: Chemistry — Spectroscopy

Multicolor Tuning of Perylene Diimides Dyes for Targeted Organelle Imaging In Vivo The adjustment of the emission wavelengths and cell permeability of the perylene diimides (PDI) for multicolor cell imaging is a great challenge. Herein, based on a bay-region substituent engineering strategy, multicolor perylene diimides (<b>MCPDI</b>) were rationally designed and synthesized by introducing azetidine substituents on the bay region of PDIs. With the fine-tuned electron-donating ability of the azetidine substituents, these <b>MCPDI</b> showed high brightness, orange, red, and near infrared (NIR) fluorescence along with Stokes shifts increasing from 35 to 110 nm. Interestingly, azetidine substituents distorted to the plane of the <b>MCPDI</b> dyes, and the twist angle of monosubstituted <b>MCPDI</b> was larger than that of disubstituted <b>MCPDI</b>, which might efficiently decrease their π-π stacking. Moreover, all of these <b>MCPDI</b> dyes were cell-permeable and selectively stained various organelles for multicolor imaging of multiple organelles in living cells. Two-color imaging of lipid droplets (LDs) and other organelles stained with <b>MCPDI</b> dyes was performed to reveal the interaction between the LDs and other organelles in living cells. Furthermore, a NIR-emitting <b>MCPDI</b> dye with a mitochondria-targeted characteristic was successfully applied for tumor-specific imaging. The facile synthesis, excellent stability, high brightness, tunable fluorescence emission, and Stokes shifts make these <b>MCPDI</b> promising fluorescent probes for biological applications. Perylene ; Chemistry ; Organelle ; In vivo ; Photochemistry ; Biophysics ; Nanotechnology ; Molecule ; Biochemistry ; Organic chemistry Molecular Sensors and Ion Detection ; Luminescence and Fluorescent Materials ; Photochromic and Fluorescence Chemistry
Authors: Juti Rani Deka | Diganta Saikia | Ning-Fang Lu | Chieh‐Yu Chen | Hsien‐Ming Kao | Yung‐Chin Yang
Source: Nanomaterials (article, 2024-11-13)
Field: Materials Science — Materials Chemistry

Bimetallic NiCo Nanoparticles Embedded in Organic Group Functionalized Mesoporous Silica for Efficient Hydrogen Production from Ammonia Borane Hydrolysis In this study, bimetallic NiCo nanoparticles (NPs) were encapsulated within the mesopores of carboxylic acid functionalized mesoporous silica (CMS) through the chemical reduction approach. Both NaBH<sub>4</sub> and NH<sub>3</sub>BH<sub>3</sub> were used as reducing agents to reduce the metal ions simultaneously. The resulting composite was used as a catalyst for hydrolysis of ammonia borane (NH<sub>3</sub>BH<sub>3</sub>, AB) to produce H<sub>2</sub>. The bimetallic NiCo NPs supported on carboxylic group functionalized mesoporous silica, referred to as Ni<sub>x</sub>Co<sub>100-x</sub>@CMS, exhibited significantly higher catalytic activity for AB hydrolysis compared to their monometallic counterparts. The remarkable activity of Ni<sub>x</sub>Co<sub>100-x</sub>@CMS could be ascribed to the synergistic contributions of Ni and Co, redox reaction during the hydrolysis, and the fine-tuned electronic structure. The catalytic performance of the Ni<sub>x</sub>Co<sub>100-x</sub>@CMS nanocatalyst was observed to be dependent on the composition of Ni and Co. Among all the compositions investigated, Ni<sub>40</sub>Co<sub>60</sub>@CMS demonstrated the highest catalytic activity, with a turn over frequency (TOF) of 18.95 mol<sub>H2</sub>min<sup>-1</sup>mol<sub>catalyst</sub><sup>-1</sup> and H<sub>2</sub> production rate of 8.0 L min<sup>-1</sup>g<sup>-1</sup>. The activity of Ni<sub>40</sub>Co<sub>60</sub>@CMS was approximately three times greater than that of Ni@CMS and about two times that of Co@CMS. The superior activity of Ni<sub>40</sub>Co<sub>60</sub>@CMS was attributed to its finely-tuned electronic structure, resulting from the electron transfer of Ni to Co. Furthermore, the nanocatalyst exhibited excellent durability, as the carboxylate group in the support provided a strong metal-support interaction, securely anchoring the NPs within the mesopores, preventing both agglomeration and leakage. Ammonia borane ; Bimetallic strip ; Borane ; Mesoporous material ; Hydrolysis ; Nanoparticle ; Mesoporous silica ; Ammonia ; Materials science ; Chemistry ; Hydrogen production ; Hydrogen ; Inorganic chemistry ; Organic chemistry ; Chemical engineering ; Catalysis ; Nanotechnology Hydrogen Storage and Materials ; Ammonia Synthesis and Nitrogen Reduction ; Hybrid Renewable Energy Systems
Authors: Gleb Ivanushkin | Ibrahim Khalil | Mostafa Torka Beydokhti | Aram L. Bugaev | Juna Bae | Thibaut Donckels | Michiel Dusselier
Source: Microporous and Mesoporous Materials (article, 2024-12-10)
Field: Chemistry — Inorganic Chemistry

The pursuit of framework zinc affirmation in zincosilicate zeolites: Clues from conventional and spectroscopic characterization Characterization (materials science) ; Zinc ; Chemistry ; Materials science ; Nanotechnology ; Organic chemistry Zeolite Catalysis and Synthesis ; Crystal Structures and Properties ; Chemical Synthesis and Characterization
Authors: Fabio Falcioni | Sophie Bennett | Pallas Stroer-Jarvis | Paul L. A. Popelier
Source: Molecules (article, 2024-02-28)
Field: Chemistry — Physical and Theoretical Chemistry

Probing Non-Covalent Interactions through Molecular Balances: A REG-IQA Study The interaction energies of two series of molecular balances (1-X with X = H, Me, OMe, NMe<sub>2</sub> and 2-Y with Y = H, CN, NO<sub>2</sub>, OMe, NMe<sub>2</sub>) designed to probe carbonyl…carbonyl interactions were analysed at the B3LYP/6-311++G(d,p)-D3 level of theory using the energy partitioning method of Interacting Quantum Atoms/Fragments (IQA/IQF). The partitioned energies are analysed by the Relative Energy Gradient (REG) method, which calculates the correlation between these energies and the total energy of a system, thereby explaining the role atoms have in the energetic behaviour of the total system. The traditional "back-of-the-envelope" open and closed conformations of molecular balances do not correspond to those of the lowest energy. Hence, more care needs to be taken when considering which geometries to use for comparison with the experiment. The REG-IQA method shows that the 1-H and 1-OMe balances behave differently to the 1-Me and 1-NMe<sub>2</sub> balances because the latter show more prominent electrostatics between carbonyl groups and undergoes a larger dihedral rotation due to the bulkiness of the functional groups. For the 2-Y balance, REG-IQA shows the same behaviour across the series as the 1-H and 1-OMe balances. From an atomistic point of view, the formation of the closed conformer is favoured by polarisation and charge-transfer effects on the amide bond across all balances and is counterbalanced by a de-pyramidalisation of the amide nitrogen. Moreover, focusing on the oxygen of the amide carbonyl and the α-carbon of the remaining carbonyl group, electrostatics have a major role in the formation of the closed conformer, which goes against the well-known n-π* interaction orbital overlap concept. However, REG-IQF shows that exchange-correlation energies overtake electrostatics for all the 2-Y balances when working with fragments around the carbonyl groups, while they act on par with electrostatics for the 1-OMe and 1-NMe<sub>2</sub>. REG-IQF also shows that exchange-correlation energies in the 2-Y balance are correlated to the inductive electron-donating and -withdrawing trends on aromatic groups. We demonstrate that methods such as REG-IQA/IQF can help with the fine-tuning of molecular balances prior to the experiment and that the energies that govern the probed interactions are highly dependent on the atoms and functional groups involved. Chemistry ; Dihedral angle ; Amide ; Covalent bond ; Potential energy ; Conformational isomerism ; Electrostatics ; Computational chemistry ; Crystallography ; Molecule ; Atomic physics ; Physical chemistry ; Physics ; Hydrogen bond ; Organic chemistry Crystallography and molecular interactions ; Solid-state spectroscopy and crystallography ; Thermal and Kinetic Analysis