jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Philippe Ochsenbein | M. Bonin | Farzaneh Fadaei‐Tirani | M. H. Lemée-Cailleau | Jérôme Kieffer | Daniel Görl | M. El-Hajji | Kurt Schenk
Source: CrystEngComm (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

A score and nine years of irbesartan Irbesartan exists as tautomers A and B in diverse solvent mixtures. Homogeneous nucleation gives (pseudo)polymorphs with layer-wise or columnar growth. The desmotropes present different habits, thermal expansions, stabilities and phase transitions. Irbesartan ; Nucleation ; Homogeneous ; Tautomer ; Solvent ; Materials science ; Phase (matter) ; Crystallography ; Chemical physics ; Chemistry ; Thermodynamics ; Organic chemistry ; Internal medicine ; Physics ; Medicine Crystallization and Solubility Studies ; Crystallography and molecular interactions ; Chemical Thermodynamics and Molecular Structure
Authors: Mahsa Haddadi Moghaddam | Sarika Sharma | Dae-Hwan Park | Dai Sik Kim
Source: arXiv (Cornell University) (preprint, 2024-11-06)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Tuning One Dimensional Plasmonic Gap at Nanometer Scale for Advanced SERS Detection The hotspots, which are typically found in nanogaps between metal structures, are critical for the enhancement of the electromagnetic field. Surface-enhanced Raman scattering (SERS), a technique known for its exceptional sensitivity and molecular detection capability, relies on the creation of these hotspots within nanostructures, where localized surface plasmon resonance (LSPR) amplifies Raman signals. However, creating adjustable nanogaps on a large scale remains challenging, particularly for applications involving biomacromolecules of various sizes. The development of tunable plasmonic nanostructures on flexible substrates represents a significant advance in the creation and precise control of these hotspots. Our work introduces tunable nanogaps on flexible substrates, utilizing thermally responsive materials to allow real-time control of gap width for different molecule sizes. Through advanced nanofabrication techniques, we have achieved uniform, tunable nanogaps over large areas wafer scale, enabling dynamic modulation of SERS signals. This approach resulted in an enhancement factor of over 10^7, sufficient for single-molecule detection, with a detection limit as low as 10^-12 M. Our thermally tunable nanogaps provide a powerful tool for precise detection of molecules and offer significant advantages for a wide range of sensing and analytical applications Nanometre ; Plasmon ; Nanotechnology ; Materials science ; Scale (ratio) ; Nanoscopic scale ; Optoelectronics ; Physics Gold and Silver Nanoparticles Synthesis and Applications ; Advanced Nanomaterials in Catalysis ; Advanced biosensing and bioanalysis techniques
Authors: Khushboo Kumari
Source: African Journal of Biomedical Research (article, 2024-09-30)
Field: Materials Science — Materials Chemistry

Fine Tuning ThePhysical Properties (Structural And Magnetic) Of Sol-Gel Derived Cobalt Ferrite (CoFe2O4)Using Calcination. Spinel Cobalt ferrite (CoFe2O4) is made via a sol-gel technique based on citrate precursors and further calcined at 600, 700, and 800℃ for two hours. Purity of materials with spinel crystal symmetry indexed to Fd3m space group is confirmed by the X-ray diffraction pattern. To determine the size of crystallites and the lattice strains present in samples, the Williamson-Hall plot is analysed. The lattice parameters &nbsp;exhibits observable increase as a result of induced lattice strain, with sample calcined at 800℃ having maximum value. WH analysis&nbsp; is backed by SEM morphological images. The FTIR spectrum and the XRD data are also in agreement. Samples' magnetic properties range from magnetization values of 47.62 to 71.11 emu/g and retentivity values of 21.19 to 37.16 emu/g.The increased value of coercivity from 454 to 1467 Gauss due to controlled calcination is interesting. Consequently, the impact of calcination temperature on CoFe2O4 for improvement of its physical properties is explored in this paper. Calcination ; Cobalt ferrite ; Cobalt ; Sol-gel ; Materials science ; Ferrite (magnet) ; Chemical engineering ; Metallurgy ; Chemistry ; Composite material ; Nanotechnology ; Engineering ; Catalysis Magnetic Properties and Synthesis of Ferrites
Authors: Gleb V. Morozkov | Artem A. Troickiy | Alexei D. Averin | Alexander Yu. Mitrofanov | Anton S. Abel | I. P. Beletskaya
Source: Molecules (article, 2024-11-25)
Field: Chemistry — Organic Chemistry

Visible Light Photoredox Catalysis in the Synthesis of Phosphonate-Substituted 1,10-Phenanthrolines Photoredox-catalyzed phosphonylation of bromo-substituted 1,10-phenanthrolines under visible light irradiation was studied. The reaction was shown to proceed under mild conditions with Eosin Y as a photocatalyst in DMSO under blue light irradiation. It is transition-metal-free and affords the target phosphonate-substituted 1,10-phenanthrolines in moderate yields (26-51%) in 22 to 40 h. The rate and selectivity of the reaction depend largely on the position of the bromine atom, as well as on the nature and position of other substituents in the 1,10-phenanthroline core. Photoredox catalysis ; Phosphonate ; Visible spectrum ; Catalysis ; Photochemistry ; Chemistry ; Combinatorial chemistry ; Photocatalysis ; Materials science ; Organic chemistry ; Optoelectronics Radical Photochemical Reactions ; Sulfur-Based Synthesis Techniques ; Catalytic C–H Functionalization Methods
Authors: Angelica Artasensi | Laura Fumagalli
Source: Molbank (article, 2024-04-24)
Field: Chemistry — Organic Chemistry

2S-(1RS-benzyloxy-hex-5-enyl)-2,3-dihydro-1,4-benzodioxine In medicinal chemistry, the precise configuration of molecules is a crucial determinant of their pharmacological properties. Hence, the introduction of a new chiral center during the synthetic pathway involves the assignment of configuration. Herein we assign, by means of molecular modeling 1H and 2D Nuclear Overhauser Effect NMR techniques, the configuration of the two diastereomers 2S-(1R-benzyloxy-hex-5-enyl)-2,3-dihydro-1,4-benzodioxine and 2S-(1S-benzyloxy-hex-5-enyl)-2,3-dihydro-1,4-benzodioxine, which are useful to synthetize analogs of the potent and highly selective dipeptidyl peptidase IV and carbonic anhydrase inhibitor recently published. Chemistry ; Stereochemistry ; Combinatorial chemistry Radical Photochemical Reactions ; Chemical Synthesis and Analysis ; Synthesis and Catalytic Reactions
Authors: J. E. G. Townsend | Ravi Kashikar | S. Lisenkov | I. Ponomareva
Source: arXiv (Cornell University) (preprint, 2024-03-15)
Field: Materials Science — Materials Chemistry

Ferroelectric phases and phase transitions in CsGeBr$_3$ induced by mechanical load First-principles-based atomistic simulations are used to reveal ferroelectric phases and phase transitions induced in a semiconductor ferroelectric, CsGeBr$_3$, by external loads: hydrostatic pressure, uniaxial and biaxial stresses, and misfit strain. Hydrostatic pressure was found to suppress the Curie point at the rate -0.45$T_C(0)$ K/GPa, where $T_C(0)$ is the zero pressure Curie temperature. Stresses and misfit strains were found to induce additional ferroelectric phase transitions and phases not available under normal conditions. We find that tensile load significantly enhances both the Curie temperature and spontaneous polarization, while compressive load has the opposite effect but with the difference that the Curie temperature is only slightly suppressed. The isothermal dependencies of polarization on pressure and stresses are highly nonlinear, which could result in large nonlinear piezoelectric responses. The phase diagrams reveal the diversity of the phases accessible through mechanical load, which include tetragonal, orthorhombic and monoclinic symmetries in addition to the rhombohedral and cubic ones realizable under normal conditions. We believe that this work reveals the potential of Ge-based halide perovskites for applications in energy converting devices, which is especially significant in the current pursuit of environmental friendly lead-free technologies. Ferroelectricity ; Materials science ; Phase (matter) ; Phase transition ; Condensed matter physics ; Optoelectronics ; Physics ; Dielectric Solid-state spectroscopy and crystallography ; Crystal Structures and Properties ; Acoustic Wave Resonator Technologies
Authors: . .
Source: IOSR Journal of Applied Chemistry (article, 2024-10-01)
Field: Materials Science — Biomaterials

Unlocking The Potential Of Natural Polymers: A Comparative Study For Innovative Drug Delivery Systems This study aims to characterize and compare four biopolymers - pectin, guar gum, xanthan gum, and sodium alginate - for their potential use in drug delivery systems by evaluating their hydrophilicity, pH sensitivity, and thermosensitivity. Biopolymer films were prepared and subjected to water absorption tests for hydrophilicity, gravimetric analysis in varying pH conditions for pH sensitivity, and weight change measurements after heat exposure for thermosensitivity. Each test was conducted in five trials to ensure reliability. Pectin demonstrated the highest responsiveness across all tests, showing rapid water absorption (6.46 seconds), significant pH sensitivity (0.53g weight change in acidic conditions), and high thermosensitivity (0.378g weight change). Guar gum showed moderate responsiveness, while xanthan gum and sodium alginate exhibited the most stability across varying conditions. Pectin's high responsiveness suggests suitability for smart, multi-stimuli-responsive systems. Guar gum's moderate responsiveness indicates potential for controlled release formulations. The stability of xanthan gum and sodium alginate makes them ideal for applications requiring consistent drug release in diverse physiological environments. This study offers a comprehensive, comparative analysis of four widely used biopolymers, filling a gap in the existing literature. The results provide a foundation for developing tailored, sustainable drug delivery systems, contributing to the advancement of personalized medicine and environmentally friendly pharmaceutical practices Drug delivery ; Natural polymers ; Natural (archaeology) ; Drug ; Nanotechnology ; Polymer ; Biochemical engineering ; Computer science ; Materials science ; Engineering ; Pharmacology ; Medicine ; Geology biodegradable polymer synthesis and properties ; Nanoparticle-Based Drug Delivery ; Advanced Drug Delivery Systems
Authors: Elshen N. Aliyev | Arash Mobaraki | Hâldun Sevinçli | Seymur Jahangirov
Source: arXiv (Cornell University) (preprint, 2024-12-08)
Field: Materials Science — Materials Chemistry

Thermodynamic Favorability of the 1T Phase over the 1H Phase in Group III Metal Monochalcogenide Zigzag Nanoribbons Owing to the promising optoelectronic and thermoelectric properties of two-dimensional (2D) group III-VI materials (MXs), their nanoribbons (NRs) have attracted notable attention as an emerging class of quasi-one-dimensional (quasi-1D) nanostructures. Due to the fact that the most stable 2D monolayer polymorph of MXs is the 1H phase, to date, existing studies in the literature have predominantly focused on the NRs formed from 1H phase MXs. Nevertheless, NRs of the 1T phase have received little to no attention. Employing ab initio simulations based on density functional theory, we systematically compared the thermodynamic stability of hydrogen passivated and unpassivated 1T and 1H ZNRs of GaS, GaSe, and InSe. Our results reveal that non-polar 1T phase MX ZNRs are thermodynamically more favorable than polar 1H MX ZNRs at widths up to 34 nm, a range that is realizable through contemporary experimental fabrication techniques. Furthermore, unlike metallic 1H ZNRs, 1T ZNRs remain semiconductor and retain a Mexican-hat-shaped top valence bands. Complementarily, hydrogenation energies of 1T InSe ZNRs are positive, and due to the edge-localized states, the 1T unpassivated ZNRs possess nearly flat top valence bands. Our findings serve as a compass for subsequent synthesis pathways of group III-VI NRs. Zigzag ; Phase (matter) ; Group (periodic table) ; Metal ; Materials science ; Condensed matter physics ; Chemistry ; Mathematics ; Physics ; Metallurgy ; Geometry 2D Materials and Applications ; Quantum Dots Synthesis And Properties ; Chalcogenide Semiconductor Thin Films
Authors: Ming Bao | Yi Zhou | Haoxuan Yuan | Guizhi Dong | Chao Li | Xiongda Xie | Kewei Chen | Kemiao Hong | Zhi‐Xiang Yu | Xinfang Xu
Source: Angewandte Chemie (article, 2024-05-22)
Field: Chemistry — Organic Chemistry

Catalytic (4+2) Annulation <i>via</i> Regio‐ and Enantioselective Interception of in‐situ Generated Alkylgold Intermediate Abstract A regio‐ and stereoselective stepwise (4+2) annulation of N ‐propargylamides and α,β‐unsaturated imines/ketones has been accomplished with synergetic catalysis by a combination of a gold‐complex and a chiral quinine‐derived squaramide (QN‐SQA), leading to highly functionalized chiral tetrahydropyridines/dihydropyrans in good to high yields with generally excellent enantioselectivity. Mechanistic studies and DFT calculations indicate that the in situ formed alkylgold species is the key intermediate in this transformation, and the amide group served as a traceless directing group in this highly selective transformation. This method complements the enantioselective (4+2) annulation of allene reagents, providing the formal internal C−C π‐bond cycloaddition products, which is challenging and remains elusive. Enantioselective synthesis ; Annulation ; In situ ; Catalysis ; Chemistry ; Combinatorial chemistry ; Interception ; Stereochemistry ; Organic chemistry ; Biology Asymmetric Synthesis and Catalysis ; Asymmetric Hydrogenation and Catalysis ; Axial and Atropisomeric Chirality Synthesis
Authors: Alexandre Abhervé | Nabil Mroweh | HengBo Cui | Reìzo Kato | Nicolas Vanthuyne | Pere Alemany | Enric Cañadell | Narcis Avarvari
Source: Nanoscale (article, 2024-11-22)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Enantiomorphic single component conducting nickel(<scp>ii</scp>) and platinum(<scp>ii</scp>) bis(diethyl-dddt) crystalline complexes Monoanionic and neutral nickel(II) and platinum(II) bis(dithiolene) complexes based on the 5,6-diethyl-5,6-dihydro-1,4-dithiin-2,3-dithiolate (de-dddt) chiral ligand have been prepared in racemic and enantiopure forms. Neutral closed-shell species have been generated from monoanionic precursors upon electrocrystallization. The racemic anionic (TBA)[Ni(<i>S</i>,<i>S</i>-de-dddt)(<i>R</i>,<i>R</i>-de-dddt)] complex crystallized in the centrosymmetric space group <i>P</i>2<sub>1</sub>/<i>c</i>, while the neutral complexes crystallized in the enantiomorphic tetragonal space group <i>P</i>4<sub>1</sub>2<sub>1</sub>2 or <i>P</i>4<sub>3</sub>2<sub>1</sub>2. Very subtle conformational differences concerning the orientation of the ethyl substituents are observed between the racemic and the enantiopure compounds, thus impacting the intermolecular interactions at the nanoscale level. Indeed, in the former, the ethyl substituents are all-axial in both independent complexes, while in the latter, one of the independent complexes shows a mixed (eq, eq, ax, ax) conformation and the other independent complex of the asymmetric unit shows the all-axial conformation. Such a tenuous difference at the molecular/nanoscale level strongly impacts the conductivity of the materials. Temperature dependent high pressure single crystal conductivity measurements show activated conductivity for all the materials, with room temperature conductivity values of up to 1.3 × 10<sup>-3</sup> S cm<sup>-1</sup> for [Ni(<i>S</i>,<i>S</i>-de-dddt)<sub>2</sub>] at 12.3 GPa and 3.0 × 10<sup>-4</sup> S cm<sup>-1</sup> for [Pt(<i>R</i>,<i>R</i>-de-dddt)<sub>2</sub>] at 12.9 GPa. Nevertheless, the racemic compounds are more conductive, <i>i.e.</i> 3.8 × 10<sup>-2</sup> S cm<sup>-1</sup> for [Ni(<i>rac</i>-de-dddt)<sub>2</sub>] at 10.0 GPa and 1.5 × 10<sup>-3</sup> S cm<sup>-1</sup> for [Pt(<i>rac</i>-de-dddt)<sub>2</sub>] at 10.5 GPa, in agreement with the shorter and more numerous S⋯S intermolecular contacts observed in the crystal structures of the racemic complexes. Moreover, a detailed analysis of DFT calculations suggests that smaller band gaps and higher conductivities should occur for the racemic solids and for the Pt <i>versus</i> Ni complexes. Nickel ; Platinum ; Component (thermodynamics) ; Chemistry ; Materials science ; Metallurgy ; Organic chemistry ; Catalysis ; Physics Organic and Molecular Conductors Research ; Magnetism in coordination complexes ; Polyoxometalates: Synthesis and Applications
Authors: Jana Juráková | Vinicius Tadeu Santana | Ján Pavlik | Ján Moncol | Ivan Nemec | Miguel Clemente-León | Senthil Kumar Kuppusamy | Mario Ruben | Erik Čižmár | Ivan Šalitroš
Source: Repository KITopen (Karlsruhe Institute of Technology) (article, 2024-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Magnetic anisotropy and slow relaxation of magnetisation in double salts containing four- and six-coordinate cobalt( ii ) complex ions Magnetization ; Ion ; Relaxation (psychology) ; Magnetic anisotropy ; Anisotropy Magnetism in coordination complexes ; Magneto-Optical Properties and Applications ; Magnetic and transport properties of perovskites and related materials
Authors: Kaitlin M. Hartung | Ellen M. Sletten
Source: The Journal of Organic Chemistry (article, 2024-12-19)
Field: Chemistry — Organic Chemistry

Achieving Olympicene Functionalization Three Ways Polycyclic aromatic hydrocarbons (PAHs) and their derivatives are of interest in many fields, from materials science to supramolecular chemistry. 6<i>H</i>-Benzo[<i>cd</i>]pyrene, or olympicene, is a PAH bearing a central <i>sp</i><sup>3</sup>-carbon bridge. We sought methods to modify this center position while maintaining stable tetrahedral geometry. Here, we characterize reactivity patterns of three olympicene core starting materials, with two of the three leading to center functionalization of the olympicene core, including the first use of 5<i>H</i>-benzo[<i>cd</i>]pyren-5-one as an olympicene synthon. Synthon ; Surface modification ; Pyrene ; Supramolecular chemistry ; Chemistry ; Reactivity (psychology) ; Dendrimer ; Core (optical fiber) ; Nanotechnology ; Combinatorial chemistry ; Stereochemistry ; Organic chemistry ; Materials science ; Molecule ; Physical chemistry Synthesis and Properties of Aromatic Compounds ; Synthetic Organic Chemistry Methods ; Fullerene Chemistry and Applications
Authors: Fei Yu | R. Paxton Thedford | Thomas A. Tartaglia | Sujit Sheth | Guillaume Freychet | William R. T. Tait | Peter A. Beaucage | William L. Moore | Yuanzhi Li | Jörg G. Werner | Julia Thom-Levy | Sol M. Grüner | R. B. van Dover | Ulrich Wiesner
Source: arXiv (Cornell University) (preprint, 2024-10-06)
Field: Materials Science — Materials Chemistry

3D printed mesoporous superconductors with periodic order on three length scales and enhanced properties via block copolymer directed self-assembly Solution-based soft matter self-assembly (SA) promises unique materials properties from approaches including additive manufacturing/three-dimensional (3D) printing. We report direct ink writing derived, hierarchically porous transition metal nitride superconductors (SCs) and precursor oxides, structure-directed by Pluronics-family block copolymer (BCP) SA and heat treated in various environments. SCs with periodic lattices on three length scales show record nanoconfinement-induced upper critical field enhancements correlated with BCP molar mass, attaining values of 50 T for NbN and 8.1 T for non-optimized TiN samples, the first mapping of a tailorable SC property onto a macromolecular parameter. They reach surface areas above 120 m$^2$/g, the highest reported for compound SCs to date. Embedded printing enables the first BCP directed mesoporous non-self-supporting helical SCs. Results suggest that additive manufacturing may open pathways to mesoporous SCs with not only a variety of macroscopic form factors but enhanced properties from intrinsic, SA-derived mesostructures with substantial academic and technological promise. Copolymer ; Mesoporous material ; Superconductivity ; Block (permutation group theory) ; Materials science ; Self-assembly ; Order (exchange) ; Nanotechnology ; Condensed matter physics ; Composite material ; Geometry ; Mathematics ; Physics ; Chemistry ; Polymer ; Catalysis Block Copolymer Self-Assembly ; Mesoporous Materials and Catalysis ; Advanced Polymer Synthesis and Characterization
Authors: Sergei M. Butorin
Source: arXiv (Cornell University) (preprint, 2024-09-25)
Field: Chemistry — Inorganic Chemistry

On the band gap variation in CH$_3$NH$_3$Pb(I$_{1-x}$Br$_x$)$_3$ The electronic structure and the band gap behavior of CH$_3$NH$_3$Pb(I$_{1-x}$Br$_x$)$_3$ for $x$=0.25, 0.33, 0.50, 0.67, 0.75, 1.00 were studied using the full-relativistic density-functional-theory calculations. A combination of the parameter-free Armiento-Kümmel generalized gradient approximation exchange functional with the nonseparable gradient approximation Minnesota correlation functional was employed. The calculated band gap sizes for the CH$_3$NH$_3$Pb(I$_{1-x}$Br$_x$)$_3$ series were found to be similar to the experimentally measured values. While the change of the optimized lattice parameter with an increasing Br content can be described by a linear fit, the calculated band gap variation exhibits rather a quadratic-like behavior over the $x$ region of the cubic crystal structure. While the experimental reports are divided on whether the bowing parameter value is being very small or significant, our calculated results support the latter case. Variation (astronomy) ; Crystallography ; Chemistry ; Materials science ; Physics ; Astrophysics Inorganic Fluorides and Related Compounds ; Solid-state spectroscopy and crystallography
Authors: Jinyi Wang | Bowen Fan | JS Song | Chen Chen | Yuan Ji | Jincheng Yu
Source: Crystals (article, 2024-11-26)
Field: Materials Science — Materials Chemistry

Hierarchical Nanostructured Copper by Dealloying MnCu Alloy Ribbon for High-Performance Glucose Sensing Electrochemical glucose sensing is vital for biomedical applications, particularly in diabetes management and continuous health monitoring. Among electrochemical sensors, non-enzyme-based sensors offer advantages such as cost-effectiveness, robust anti-interference capabilities, and environmental stability compared to enzyme-based ones. This study focuses on the development of non-enzyme-based glucose sensors utilizing hierarchical nanostructured copper (Cu) electrodes. The electrodes are fabricated by selectively dissolving components from an alloy precursor. Specifically, MnCu alloy ribbons prepared by melt rolling were used due to their favorable properties, and electrochemical dealloying was employed to create nanostructured Cu with high electrocatalytic activity for glucose oxidation. Three-dimensional bicontinuous nanoporous copper with an average pore size of 34 nm~86 nm and an average ligament size range of 45 nm~125 nm can be obtained. The optimized hierarchical nanostructured Cu electrodes exhibited excellent performance, including high sensitivity (0.652 mA·mM−1·cm−2), a wide linear detection range (0.001 mM to 1.5 mM), a low detection limit (0.73 μM), and a rapid response time. This work demonstrates the potential of nanostructured Cu in the advancement of non-enzyme-based glucose sensors. Ribbon ; Copper ; Alloy ; Materials science ; Metallurgy ; Nanotechnology ; Composite material Nanoporous metals and alloys ; Supercapacitor Materials and Fabrication ; Nanomaterials for catalytic reactions