jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Jun Qian | Liang Ma | Yida Wang
Source: Zeitschrift für Kristallographie - New Crystal Structures (article, 2024-07-22)
Field: Chemistry — Organic Chemistry

Crystal structure of (3,6-di(2-pyridyl)-4-methylphenyl pyridazine-<i>k</i> <sup>2</sup> <i>N,N</i>′)-bis(1-phenyl-pyrazole-<i>κ</i> <sup>2</sup> <i>C,N</i>) iridium(III) hexafluorophosphate, C<sub>39</sub>H<sub>29</sub>F<sub>6</sub>IrN<sub>8</sub>P Abstract C 39 H 29 F 6 IrN 8 P, orthorhombic, Pbca (no. 61), a = 19.6205(7) Å, b = 16.2026(6) Å, c = 23.0700(8) Å, V = 7334.0(5) Å 3 , Z = 8, R gt ( F ) = 0.0258, wR ref ( F 2 ) = 0.0611, T = 293 K. Pyridazine ; Pyrazole ; Crystal structure ; Chemistry ; Crystallography ; X-ray crystallography ; Crystal (programming language) ; Medicinal chemistry ; Stereochemistry ; Physics ; Diffraction Synthesis and Reactivity of Heterocycles ; Catalytic Cross-Coupling Reactions ; Luminescence and Fluorescent Materials
Authors: Linhua Shen
Source: theses.fr (ABES) (article, 2024-12-18)
Field: Chemistry — Organic Chemistry

De nouvelles approches pour la modification d'acides aminés et de peptides L'intérêt des acides aminés et des peptides en tant qu'agents thérapeutiques est en constante croissance, en raison de leurs faibles toxicités et leur grande spécificité vis-à-vis des cibles biologiques. Ces propriétés font des acides aminés et des peptides des candidats prometteurs pour le traitement de diverses pathologies. Toutefois, les peptides formés exclusivement d'acides aminés naturels présentent souvent des limitations pharmacocinétiques et pharmacodynamiques. La diversité structurelle des acides aminés peut être considérablement étendue par l'incorporation d'acides aminés non naturels, permettant ainsi de moduler des propriétés clés telles que la stabilité métabolique, la biodisponibilité, la perméabilité membranaire, l'immunogénicité et la toxicité. L'objectif de cette thèse de doctorat est de présenter plusieurs méthodes innovantes de modification et de fonctionnalisation des peptides en introduisant des motifs facile prépad'accès ou disponibles dans le commerce, tels que les halogénures d'aryle et les iodoglycals. Nous décrivons d'abord la synthèse efficace de thioglycopeptides et d'thio-oligosaccharides via un couplage palladocatalysé entre des peptides natifs contenant une cystéine avec des iodoglycals. Ensuite, une nouvelle méthode palladocatalysée d'introduction du groupementthiométhyl (-SMe) a été développée en utilisant du méthanethiolate de sodium (NaSCH₃) dans des conditions douces et écocompatibles, applicable à une grande variété de composés et de molécules bioactives, y compris des médicaments et de long peptides. De plus, des expériences de marquage isotopique démontrent la praticité de cette méthode. Enfin, nous avons développé un système catalytique électrochimique à base de nickel pour l'arylation (hétéro)selective, de peptides contenant de la cystéine, démontrant son utilité dans la synthèse de peptides cycliques avec une haute compatibilité des groupes fonctionnels. Peptide fragment ; Agrégation ; Posttranslational modification Click Chemistry and Applications ; Chemical Synthesis and Analysis ; Sulfur-Based Synthesis Techniques
Authors: Heri Septya Kusuma | Muhammad Redo Ramadhan | Dyan Hatining Ayu Sudarni | Debora Engelien Christa Jaya | Dwi Kurnia Afifah | Safinah Annajah Nasution | Deva Meida Fachri | Ratu Kalya Mongilong
Source: Egyptian Journal of Chemistry (article, 2024-09-02)
Field: Chemistry — Organic Chemistry

Optimization for Synthesis of Solid Alcohol from Supernatant-Waste Cooking Oil using Box-Behnken Design This study investigates the optimization of solid alcohol synthesis from Supernatant-Waste Cooking Oil (S-WCO) using Response Surface Methodology (RSM) combined with Box-Behnken Design (BBD). The primary objective was to determine the optimal conditions for maximizing the yield of solid alcohol by systematically varying three key parameters: mass of oil (5, 10, 15 g), NaOH to oil ratio (0.100, 0.175, 0.250 g/g), and heating time (20, 30, 40 minutes). The experimental findings revealed that the yield of solid alcohol ranged from 81.20% to 87.67%, with the highest yield achieved at mass of oil of 11.14 g, NaOH to oil ratio of 0.20 g/g, and heating time of 25.70 minutes. The desirability value for these conditions was calculated to be 0.911, indicating the process's high efficiency. Analysis of variance (ANOVA) substantiated the model's significance, highlighting the critical influence of both linear and quadratic terms, particularly the NaOH to oil ratio and heating time.The results have profound implications for scaling up the process in industrial contexts, offering a promising solution for waste management and alternative energy production. Future research should explore the potential of alternative catalysts and further process optimizations to enhance the economic and environmental benefits of this method. Box–Behnken design ; Alcohol ; Cooking oil ; Waste management ; Pulp and paper industry ; Chromatography ; Response surface methodology ; Environmental science ; Process engineering ; Materials science ; Chemistry ; Engineering ; Organic chemistry ; Biodiesel Chemical Synthesis and Reactions
Authors: Guillermo Hernandez‐Ramirez | José de Jesús Araiza Ibarra | Jorge Vargas
Source: Superficies y Vacío (article, 2024-12-26)
Field: Materials Science — Materials Chemistry

Pair distribution function analysis for Pt-Pd-Co atomic mobility in nanoparticles Through the in-situ monitoring of fuel cells in oxidation-reduction processes with ternary nanoparticles (Pt-Pd-Co), the Pair Distribution Function (PDF) is created by the Fourier transform of the high-energy X-ray diffraction pattern of the sample. Lattice deformations in nanostructures have been shown to be reflected in the oscillation of the peaks of the atomic PDF. Analyses have revealed that there is atomic mobility within the nanoparticles. Thus, in this work we study the effect on PDF of different internal variables for nanoparticles modeled based on data from a previous interdisciplinary study by a third party, the variables include temperature, vacancies and atomic species distribution. Several atomic structural models were created, and molecular dynamics simulations were applied to them using LAMMPS and the Modified Embedded Atom Method (MEAM) for the atomic interaction. The PDF’s generated from the models were compared to experimental data and the best match was identified. It is shown that a non-uniform distribution of the elements of the ternary system within the structures is the cause of the lattice strain oscillations for the nanostructures, mainly the radial distribution of Co turns out to have a greater effect on the peaks of interest in the PDF altering the general structure of the nanoparticles. Nanoparticle ; Pair distribution function ; Materials science ; Function (biology) ; Distribution function ; Chemistry ; Atomic physics ; Analytical Chemistry (journal) ; Nanotechnology ; Physics ; Thermodynamics ; Environmental chemistry ; Quantum mechanics X-ray Diffraction in Crystallography
Authors: Anna L. Makarova | Alexander L. Kwiatkowski | A. I. Kuklin | Yu. M. Chesnokov | Olga E. Philippova | Andrey V. Shibaev
Source: Polymers (article, 2024-05-17)
Field: Chemistry — Organic Chemistry

Dual Semi-Interpenetrating Networks of Water-Soluble Macromolecules and Supramolecular Polymer-like Chains: The Role of Component Interactions Dual networks formed by entangled polymer chains and wormlike surfactant micelles have attracted increasing interest in their application as thickeners in various fields since they combine the advantages of both polymer- and surfactant-based fluids. In particular, such polymer-surfactant mixtures are of great interest as novel hydraulic fracturing fluids with enhanced properties. In this study, we demonstrated the effect of the chemical composition of an uncharged polymer poly(vinyl alcohol) (PVA) and pH on the rheological properties and structure of its mixtures with a cationic surfactant erucyl bis(hydroxyethyl)methylammonium chloride already exploited in fracturing operations. Using a combination of several complementary techniques (rheometry, cryo-transmission electron microscopy, small-angle neutron scattering, and nuclear magnetic resonance spectroscopy), we showed that a small number of residual acetate groups (2-12.7 mol%) in PVA could significantly reduce the viscosity of the mixed system. This result was attributed to the incorporation of acetate groups in the corona of the micellar aggregates, decreasing the molecular packing parameter and thereby inducing the shortening of worm-like micelles. When these groups are removed by hydrolysis at a pH higher than 7, viscosity increases by five orders of magnitude due to the growth of worm-like micelles in length. The findings of this study create pathways for the development of dual semi-interpenetrating polymer-micellar networks, which are highly desired by the petroleum industry. Micelle ; Polymer ; Chemical engineering ; Rheometry ; Pulmonary surfactant ; Small-angle neutron scattering ; Materials science ; Rheology ; Viscosity ; Small-angle X-ray scattering ; Polymer chemistry ; Cationic polymerization ; Neutron scattering ; Aqueous solution ; Chemistry ; Organic chemistry ; Composite material ; Scattering Surfactants and Colloidal Systems ; Petroleum Processing and Analysis ; Enhanced Oil Recovery Techniques
Authors: Rajesh R. Parmar | Priyanka Patil | Dr.Chainesh Shah | D. J. Upadhyay
Source: International Journal of Pharmaceutical Research and Applications (review, 2024-05-01)
Field: Chemistry — Spectroscopy

A Review Article on Method Development and Validation of Verapamil by RP-HPLC Method High performance liquid chromatography, one of the most powerful analytical techniques utilized in the separation, identification, and quantification of complex mixtures. Reverse-phase or RP-HPLC is commonly practiced in high performance liquid chromatography because this technique has the advantages of versatility and appropriateness for more hydrophobic compounds. Fundamentals and Practices of Reversed-Phase HPLC: Part II -- RPHPLC column configurations. It consists of the concept of separation, types of stationary and mobile phases with the variables concerned with the separation. This review discusses the necessity for development and validation of such methods along with its pharmaceutical and food industry purposes as well as environmental analysis benefits by RP-HPLC. Among the latest developments in RP-HPLC, new stationary and mobile phases for high-performance liquid chromatography based on hydrophobic interactions have also emerged. Changes like RP-HPL down-sizing techniques and coupled For have also gained prominence. In reversed-phase high-performance liquid chromatography, short for RP-HPLC, the separation of molecules takes place based on their hydrophobicity. Separation is based on the hydrophobic binding of the solute molecule from the mobile phase to immobilized hydrophobic ligands attached to the stationary phase, or sorbent. High-performance liquid chromatography ; Chromatography ; Hydrophilic interaction chromatography ; Chemistry ; Reversed-phase chromatography ; Stationary phase ; Phase (matter) ; Sizing ; Organic chemistry Analytical Chemistry and Chromatography ; Analytical Methods in Pharmaceuticals ; Chromatography in Natural Products
Authors: Vishnu Kiran Manam
Source: Journal of Advances in Microbiology Research (article, 2024-07-01)
Field: Materials Science — Materials Chemistry

Silver nanoparticles from chemical synthesis: Assessing their role in antibacterial strategies Silver nanoparticles (AgNPs) have emerged as potent antibacterial agents due to their unique physicochemical properties and broad-spectrum activity. This study focuses on silver nanoparticles synthesized through chemical methods, evaluating their structural and functional characteristics for antibacterial efficacy. The synthesis process involves chemical reduction techniques, producing nanoparticles with controlled size, shape, and stability. Advanced analytical methods such as UV-Vis spectroscopy, Thermogravimetric Analysis (TGA), Transmission Electron Microscopy (TEM), and X-Ray Diffraction (XRD) were employed to characterize the synthesized nanoparticles. The antibacterial activity was assessed against Gram-positive and Gram-negative bacterial strains using standard antibiotics, revealing significant inhibitory effects attributed to the ability of the nanoparticles to disrupt bacterial membranes and generate Reactive Oxygen Species (ROS). Furthermore, the study examines the influence of nanoparticle concentration, size, and surface modification on their antibacterial potency. The findings highlight the potential of chemically synthesized AgNPs as innovative solutions for combating bacterial infections, offering insights into their integration into biomedical and environmental applications. Silver nanoparticle ; Nanoparticle ; Nanotechnology ; Materials science Nanoparticles: synthesis and applications
Authors: Jacopo Nicoletti | Leonardo Puppulin | Julie Routurier | Saimir Frroku | Nouha Loudhaief | Claudia Crestini | Alvise Perosa | Maurizio Selva | Matteo Gigli | Domenico De Fazio | Giovanni A. Salvatore
Source: arXiv (Cornell University) (preprint, 2024-07-26)
Field: Materials Science — Polymers and Plastics

Enhanced Piezoelectricity in Sustainable-by-design Chitosan Nanocomposite Elastomers for Prosthetics, Robotics, and Circular Electronics Piezoelectricity, the generation of electric charge in response to mechanical stress, is a key property in both natural and synthetic materials. This study significantly boosts the piezoelectric response of chitosan, a biodegradable biopolymer, by integrating chitin/chitosan nanocrystals into natural chitosan-based thin film elastomers. The resulting materials achieve d$_{33}$ values of 15-19 pmV$^{-1}$, a marked improvement over the 5-9 pmV$^{-1}$ observed in pure chitosan films thanks to increased crystallinity from the nanocrystals. We utilize piezoresponse force microscopy (PFM) to accurately measure the d$_{33}$ coefficient, employing an engineered extraction method that eliminates the electrostatic contribution, which can overestimate the piezoelectric response. The resulting chitosan elastomers exhibit elastic deformation up to 40\% strain and a Young's modulus of approximately 100 MPa, similar to soft tissues. These properties, along with the fact that the employed materials can be entirely crafted from upcycled biowaste, make these elastomers ideal for prosthetics, wearable devices, energy harvesters, and sustainable transducers. Our findings underscore the potential of chitosan-based piezoelectric materials for advanced applications in biotechnology, soft robotics, and the green Internet of Things. Electronics ; Robotics ; Nanocomposite ; Elastomer ; Piezoelectricity ; Materials science ; Chitosan ; Soft robotics ; Composite material ; Mechanical engineering ; Engineering ; Artificial intelligence ; Computer science ; Robot ; Electrical engineering ; Chemical engineering Conducting polymers and applications ; Advanced Sensor and Energy Harvesting Materials ; Dielectric materials and actuators
Authors: Antonia Toska | Dominique Foix | Antoine Bousquet | Nang-Htay Yin | Christophe Pécheyran | Joachim Allouche
Source: Journal of Analytical Atomic Spectrometry (article, 2024-01-01)
Field: Chemistry — Inorganic Chemistry

Iron quantification at the sub femtogram level in magnetite hybrid silica methacrylate core–shell nanocomposite particles by sp-ICP-MS This study highlights the application of single particle (sp)-ICP-MS as a valuable tool to monitor the distribution ofiron oxide nanoparticles in hybrid organic–inorganic core-shell silica/PMMA nanocomposites. Nanocomposite ; Magnetite ; Iron oxide ; Particle (ecology) ; Chemistry ; Methacrylate ; Magnetite Nanoparticles ; Inductively coupled plasma mass spectrometry ; Nanoparticle ; Iron oxide nanoparticles ; Shell (structure) ; Chemical engineering ; Materials science ; Chromatography ; Nanotechnology ; Magnetic nanoparticles ; Mass spectrometry ; Composite material ; Polymer ; Organic chemistry ; Metallurgy ; Monomer Radioactive element chemistry and processing ; Analytical chemistry methods development ; Iron oxide chemistry and applications
Authors: Jeongmin Kim | Benjamin Rotenberg
Source: arXiv (Cornell University) (preprint, 2024-05-29)
Field: Chemistry — Physical and Theoretical Chemistry

Donnan equilibrium in charged slit-pores from a hybrid nonequilibrium Molecular Dynamics / Monte Carlo method with ions and solvent exchange Ion partitioning between different compartments (\emph{e.g.} a porous material and a bulk solution reservoir), known as Donnan equilibrium, plays a fundamental role in various contexts such as energy, environment, or water treatment. The linearized Poisson-Boltzmann (PB) equation, capturing the thermal motion of the ions with mean-field electrostatic interactions, is practically useful to understand and predict ion partitioning, despite its limited applicability to conditions of low salt concentrations and surface charge densities. Here, we investigate the Donnan equilibrium of coarse-grained dilute electrolytes confined in charged slit-pores in equilibrium with a reservoir of ions and solvent. We introduce and use an extension to confined systems of a recently developed hybrid nonequilibrium molecular dynamics / grand canonical Monte Carlo simulation method ("H4D"), which enhances the efficiency of solvent and ion-pair exchange via a fourth spatial dimension. We show that the validity range of linearized PB theory to predict the Donnan equilibrium of dilute electrolytes can be extended to highly charged pores, by simply considering \textit{renormalized} surface charge densities. We compare with simulations of implicit solvent models of electrolytes and show that in the low salt concentrations and thin electric double layer limit considered here, an explicit solvent has a limited effect on the Donnan equilibrium and that the main limitations of the analytical predictions are not due to the breakdown of the mean-field description, but rather to the charge renormalization approximation, because it only focuses on the behavior far from the surfaces. Non-equilibrium thermodynamics ; Monte Carlo method ; Ion ; Solvent ; Molecular dynamics ; Chemical physics ; Statistical physics ; Chemistry ; Materials science ; Thermodynamics ; Physics ; Computational chemistry ; Organic chemistry Electrostatics and Colloid Interactions ; Electrochemical Analysis and Applications ; Fuel Cells and Related Materials
Authors: Kennedy Mawunya Hayibor | Yukinari Sunatsuki | Takayoshi Suzuki
Source: SSRN Electronic Journal (preprint, 2024-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Synthesis and Characterization of Iron(Ii) Complex with Unsymmetrical Heterocyclic (2-Pyridyl)(4-Imidazolyl)Azine Azine ; Characterization (materials science) ; Chemistry ; Combinatorial chemistry ; Stereochemistry ; Organic chemistry ; Materials science ; Nanotechnology Magnetism in coordination complexes ; Synthesis and Reactivity of Heterocycles ; Lanthanide and Transition Metal Complexes
Authors: Fatih Algı | Meltem Alp
Source: Mugla Journal of Science and Technology (article, 2024-12-10)
Field: Chemistry — Spectroscopy

REDUCED GRAPHENE OXIDE AND Tb-DO3A CONJUGATE AS LUMINESCENT CHEMOSENSOR FOR AGILE DETECTION OF HYDROXYL RADICAL The development of chemosensors for the detection of hydroxyl radicals (HO•) is a challenging task since HO• has an exceptionally short lifetime (in vivo half-life of 1 ns). In this work, we have designed and synthesized a versatile probe, viz. Tb@rGO, for the detection of HO• amongst the biologically important ions and reactive oxygen species (ROS). Our design is based on covalent conjugation of reduced graphene oxide (rGO) with terbium (III)-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (Tb-DO3A). Tb@rGO is characterized by traditional spectroscopic methods including XRD, SEM, TEM, and zeta potential analysis. Furthermore, we elaborate the photophysical properties of Tb@rGO. Accordingly, our results attest that Tb@rGO has unique luminescence features, rendering it highly effective in the detection of HO•. Remarkably, Tb@rGO is highly selective to HO• among many biologically important species in 0.1 M pH 7.4 phosphate buffered saline solution. It is also noteworthy that the limit of detection (LOD) is 0.92 M for HO•. Therefore, this novel material hold promises as selective turn-off luminescent HO• probe. Luminescence ; Graphene ; Detection limit ; Oxide ; Hydroxyl radical ; Terbium ; Covalent bond ; Chemistry ; Radical ; Fluorescence ; Photochemistry ; Combinatorial chemistry ; Materials science ; Nuclear chemistry ; Nanotechnology ; Organic chemistry ; Chromatography Molecular Sensors and Ion Detection ; Luminescence and Fluorescent Materials ; Electrochemical sensors and biosensors
Authors: Francesco Brasili | Angela Capocefalo | Giovanni Del Monte | Rodrigo Rivas-Barbosa | Javier Pérez | Edouard Chauveau | F. Bordi | Rizza, Carlo | Domenico Truzzolillo | Emanuela Zaccarelli | Simona Sennato
Source: arXiv (Cornell University) (preprint, 2024-07-03)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Linking structure and optical properties of plasmonic nanoparticles on tunable spherical surfaces The complexation of plasmonic nanoparticles (NPs) and thermoresponsive microgels is widely exploited for applications, but a microscopic description of the mechanisms governing the spatial organization of the NPs is still lacking. Combining small angle X-ray scattering, state-of-the-art simulations and a simple toy model, we uncover how the volume phase transition of microgels controls NP-NP interactions, establishing for the first time a microscopic link between plasmon coupling and NP local structure. Our study paves the way to experimentally investigate phase transitions on controlled curved surfaces at the nanoscale. Plasmon ; Materials science ; Nanotechnology ; Optoelectronics Gold and Silver Nanoparticles Synthesis and Applications
Authors: María Virginia Sosa | Kashif Hussain | Eduardo Prieto | Tatiana Da Ros | Muhammad Raza Shah | Fernando S. Garcı́a Einschlag | Ezequiel Wolcan
Source: Physical Chemistry Chemical Physics (article, 2024-12-10)
Field: Chemistry — Spectroscopy

A water-responsive calix[4]resorcinarene system: self-assembly and fluorescence modulation This study explores how water content modulates the self-assembly and fluorescence behavior of two novel calix[4]resorcinarene macrocycles. These macrocycles transition from large, flattened structures in pure THF to large giant vesicles (500-5000 nm) coexisting with small micelles (3.4-3.5 nm) as the water percentage in THF/water mixtures increases up to 53%. At higher water percentages, the assemblies become smaller, forming unimodal micelles with diameters of approximately 140-160 nm. Fluorescence quenching is observed upon water addition, attributed to nonradiative deactivation. These findings highlight water as a key regulator of the assembly and fluorescence of these calix[4]resorcinarene macrocycles, paving the way for further development of water-responsive calixarene systems. Resorcinarene ; Calixarene ; Fluorescence ; Micelle ; Chemistry ; Quenching (fluorescence) ; Self-assembly ; Photochemistry ; Organic chemistry ; Molecule ; Aqueous solution ; Optics Molecular Sensors and Ion Detection ; Supramolecular Chemistry and Complexes ; Luminescence and Fluorescent Materials