jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Steven A. Kivelson | Akshat Pandey | Anisha G. Singh | A. Kapitulnik | I. R. Fisher
Source: Physical review. B./Physical review. B (article, 2023-11-17)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Emergent <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi mathvariant="double-struck">Z</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math> symmetry near a charge density wave multicritical point We consider the critical behavior associated with incommensurate unidirectional charge-density-wave ordering in a weakly orthorhombic system subject to uniaxial strain as an experimentally significant example of $U(1)\ifmmode\times\else\texttimes\fi{}U(1)$ multicriticality. We show that, depending on microscopic details, the phase diagram can have qualitatively different structures which can involve a vestigial metanematic critical point, a pair of tricritical points, a decoupled tetracritical point, or (at least at mean-field level) a bicritical point. We analyze the emergent symmetries in the critical regime and find that these can---at least in some cases---involve an emergent ${\mathbb{Z}}_{2}$ order parameter symmetry. Phase diagram ; Tricritical point ; Orthorhombic crystal system ; Symmetry (geometry) ; Homogeneous space ; Order (exchange) ; Physics ; Mathematical physics ; Condensed matter physics ; Phase (matter) ; Mathematics ; Geometry ; Quantum mechanics ; Diffraction Iron-based superconductors research ; Organic and Molecular Conductors Research ; Physics of Superconductivity and Magnetism
Authors: Tim Patten | Nico Graw | Sebastian Friedl | Dietmar Stalke | Anna Krawczuk
Source: Advanced Optical Materials (article, 2023-03-09)
Field: Materials Science — Materials Chemistry

An investigation of Solid‐State Emission of Halogenated Diphenyl Phosphanyl Anthracenes Abstract In today's world, the development and research of optoelectronic materials and devices based on solid‐state luminescence is essential. Due to their versatile application possibilities, e.g. as light‐emitting diodes or lasers, they are already indispensable. This work presents three halogenated anthracene derivatives [9‐PPh 2 ‐10‐X‐(C 14 H 8 )] and their respective photoluminescent behavior in solution and in the solid state. The formation of halogen–π interactions in the solid state leads to unanticipated luminescence properties for the chlorinated species, resulting in a strong bathochromic shift, green fluorescence and a longer lifetime. In contrast, the other two derivatives, which in turn form only weak π–π interactions due to a small overlap of the anthracene rings, barely change their luminescence behavior in the solid state. By employing additional charge density studies, the structure–property correlation is also investigated. In particular, focus is given to halogen bonding and halogen–π interactions and their influence on photophysical properties of the studied compounds. Through the new knowledge gained, this study will help in the future development and selective application of the photophysical properties of solid‐state luminescent materials. Bathochromic shift ; Luminescence ; Materials science ; Anthracene ; Halogen ; Solid-state ; Photoluminescence ; Fluorescence ; Photochemistry ; Nanotechnology ; Optoelectronics ; Physical chemistry ; Organic chemistry ; Chemistry ; Optics ; Alkyl Luminescence and Fluorescent Materials ; Crystallography and molecular interactions ; Organic and Molecular Conductors Research
Authors: Elgun E. Hasanov | Ravan A. Rahimov | Yusif Abdullayev | Gulnara A. Ahmadova
Source: ChemistrySelect (article, 2023-12-19)
Field: Chemistry — Organic Chemistry

Symmetric and Dissymmetric Pseudo‐gemini Amphiphiles Based on Propoxylated Ethyl Piperazine and Fatty Acids Abstract Novel symmetric and dissymmetric pseudo‐gemini surfactants are synthesized using ethylpiperazine, propylene oxide and six different fatty acids (capric, lauric, myristic, palmitic, stearic, oleic) as starting materials. The synthesis follows a simple pathway excluding heating or catalyst. Important surface activity properties including critical micelle concentration (CMC), surface tension at CMC (γCMC), surface pressure at CMC (πCMC), negative logarithm of concentration to achieve 20 mN/m reduction in surface tension (pC20), minimum area at interface (Amin) and maximum surface excess concentration (Γmax) are obtained through surface tension and electrolytic conductivity measurements. Antimicrobial properties of the synthesized amphiphiles are evaluated using disk diffusion method and are compared to those of standard antibiotic agents. Particle size distribution patterns are obtained using dynamic light scattering (DLS). This work investigates the effect of dissymmetry on various surface activity and antimicrobial properties. Dissymmetric pseudo‐gemini amphiphiles have a few times higher CMC compared to analogous symmetric surfactants. However, better antimicrobial properties are observed when there is some dissymmetry between hydrophobic groups. Surface tension ; Critical micelle concentration ; Stearic acid ; Lauric acid ; Chemistry ; Amphiphile ; Myristic acid ; Materials science ; Micelle ; Organic chemistry ; Polymer chemistry ; Chemical engineering ; Fatty acid ; Palmitic acid ; Copolymer ; Thermodynamics ; Polymer Surfactants and Colloidal Systems ; Advanced Polymer Synthesis and Characterization ; Photochemistry and Electron Transfer Studies
Authors: Ivan A. Skvortsov | Alexey E. Chufarin | Mark V. Zaitsev | Gayane A. Kirakosyan | Pavel A. Stuzhin
Source: Asian Journal of Organic Chemistry (article, 2023-09-28)
Field: Materials Science — Materials Chemistry

First Subphthalocyanine Analogue with Fused 6<i>H</i>‐1,4‐diazepine Ring and its Conversion to Aminobenzamide Derivative Abstract Mixed cyclization of 5,7‐diphenyl‐6 H ‐1,4‐diazepine 2,3‐dicarbonitrile and tetrafluorophthalonitrile in the presence of boron trichloride affords along with symmetrical perfluorinated subphthakocyanine, [F 12 s Pc], two novel subporphyrazine‐type products which were isolated by column chromatography and characterized by mass‐sprectometry, NMR, IR, UV‐VIS and fluorescent spectroscopy. It was established that co‐cyclomerization of dinitriles is accompanied by electrophilic chlorination of 1,4‐diazepine ring by evolved Cl 2 resulting in formation of dibenzosubporphyrazine [F 8 s Pc1] with fused 6‐chloro‐5,7‐diphenyl‐6 H ‐1,4‐diazepine fragment. According to DFT modelling and 1 H NMR data, a more stable diastereomer with an axial Cl atom is formed and no inversion of the 1,4‐diazepine ring is observed. Hydrolytic cleavage of the 1,4‐diazepine fragment in [F 8 s Pc1] is observed upon chromatography or in the presence of a strong acid (CF 3 COOH) and leads to 2‐amino‐3‐benzamide substituted dibenzo subporphyrazine [F 8 s Pc2]. Fluorescence of [F 8 s Pc1] (Φ F =0.03) is ca 10 times lower than for [F 12 s Pc] (Φ F =0.28) due to the combined effect of intramolecular charge transfer (ICT) from the donor diazepine ring to the acceptor s Pc macrocycle and heavy atom effect of chlorine. Fluorescence of [F 8 s Pc2] is almost completely quenched by ICT from −NH 2 group to the electron‐deficient subporphyrazine core (Φ F &lt;0.001), but addition of acid leads to protonation of the amino group and switch‐ON the fluorescence. Therefore, aminobenzamide substituted subporphyrazines can be considered as perspective pH‐sensitive fluorophores. Chemistry ; Diazepine ; Protonation ; Ring (chemistry) ; Electrophile ; Medicinal chemistry ; Stereochemistry ; Fluorescence ; Intramolecular force ; Catalysis ; Organic chemistry Porphyrin and Phthalocyanine Chemistry ; Metal-Catalyzed Oxygenation Mechanisms ; Photochromic and Fluorescence Chemistry
Authors: Nádia E. Santos | Joana Catarina Mendes | Susana S. Braga
Source: Molecules (review, 2023-02-08)
Field: Materials Science — Materials Chemistry

The Gemstone Cyborg: How Diamond Films Are Creating New Platforms for Cell Regeneration and Biointerfacing Diamond is a promising material for the biomedical field, mainly due to its set of characteristics such as biocompatibility, strength, and electrical conductivity. Diamond can be synthesised in the laboratory by different methods, is available in the form of plates or films deposited on foreign substrates, and its morphology varies from microcrystalline diamond to ultrananocrystalline diamond. In this review, we summarise some of the most relevant studies regarding the adhesion of cells onto diamond surfaces, the consequent cell growth, and, in some very interesting cases, the differentiation of cells into neurons and oligodendrocytes. We discuss how different morphologies can affect cell adhesion and how surface termination can influence the surface hydrophilicity and consequent attachment of adherent proteins. At the end of the review, we present a brief perspective on how the results from cell adhesion and biocompatibility can make way for the use of diamond as biointerface. Diamond ; Biocompatibility ; Biointerface ; Materials science ; Nanotechnology ; Adhesion ; Microcrystalline ; Cell adhesion ; Chemistry ; Composite material ; Metallurgy Diamond and Carbon-based Materials Research ; Polymer Surface Interaction Studies ; Force Microscopy Techniques and Applications
Authors: Leyre Aldaz‐Caballero | Ulises R. Rodríguez‐Mendoza | V. Lavı́n | Patrizia Canton | Antonio Benayas | Riccardo Marin
Source: Advanced Sensor Research (article, 2023-08-31)
Field: Materials Science — Materials Chemistry

Copper Indium Sulfide Quantum Dots as Nanomanometers: Influence of Size and Composition Abstract Mechanical forces control the function of organisms and mediate the interaction between biological systems and their environments. Knowledge of these forces will increase the understanding of biological processes and can support the development of novel diagnostic and therapeutic procedures. Although techniques like atomic force microscopy and droplet insertion method allow measuring forces over a broad range of values, they are invasive and lack versatility. A promising way to overcome these hurdles is luminescent nanomanometry. Quantum dots (QDs) specifically have optical properties that depend on their size because of the quantum confinement, which makes them responsive to applied forces. Yet, a fine understanding of how fundamental parameters affect the response to applied stress is required before a QD family can be credibly proposed as luminescent nanomanometers. Here, a thorough study is conducted on how size and stoichiometry affect the nanomanometry performance of CuInS 2 QDs. The studied QDs feature pressure‐dependent photoluminescence in the red/near‐infrared range, which can enable the measurement of mechanical forces in the range of physiological relevance in a remote and minimally invasive way. It is shown that tuning size and stoichiometry can simultaneously enhance the CuInS 2 QDs’ brightness and response to applied pressure, thus providing guidelines for better luminescent nanomanometers. Quantum dot ; Luminescence ; Indium ; Photoluminescence ; Nanotechnology ; Materials science ; Lead sulfide ; Stoichiometry ; Range (aeronautics) ; Brightness ; Optoelectronics ; Infrared ; Chemistry ; Optics ; Physics ; Composite material ; Physical chemistry Quantum Dots Synthesis And Properties ; Polymer Surface Interaction Studies ; Nanocluster Synthesis and Applications
Authors: Fanni Bugyi | Lilla Turiák | László Drahos | Gábor Tóth
Source: Journal of Mass Spectrometry (article, 2023-07-18)
Field: Chemistry — Spectroscopy

Optimization of reversed‐phase solid‐phase extraction for shotgun proteomics analysis Reversed-phase solid-phase extraction (SPE) is the method of choice for the purification of proteomics samples. Even though the efficacy of SPE methods is sample type-dependent, the manufacturers' protocols are used in most studies. Using an optimized SPE method can lead to a substantial gain in identification and recovery. In this tutorial, we give a brief introduction to the most important parameters influencing SPE performance, and we present a short workflow (16 measurements) for optimizing the SPE procedure. This is complemented by method performance assessment instructions and a short troubleshooting guide to help users further understand and investigate their SPE methods. Solid phase extraction ; Shotgun proteomics ; Chemistry ; Troubleshooting ; Chromatography ; Workflow ; Sample preparation ; Extraction (chemistry) ; Identification (biology) ; Proteomics ; Computer science ; Database Advanced Proteomics Techniques and Applications ; Mass Spectrometry Techniques and Applications ; Molecular Biology Techniques and Applications
Authors: Raja K. Rit | Hongyi Li | Stephen P. Argent | Katherine M. P. Wheelhouse | Simon Woodward | Hon Wai Lam
Source: Advanced Synthesis & Catalysis (article, 2023-01-24)
Field: Chemistry — Inorganic Chemistry

A Scalable Synthesis of Chiral Himbert Diene Ligands for Asymmetric Catalysis Abstract Chiral dienes are important ligands in asymmetric catalysis but they are less accessible than other commonly used ligands such as chiral bisphosphines. Here, we show that intramolecular [4+2] cycloaddition of a simply attained chiral allenecarboxanilide readily affords pseudoenantiomeric bicyclo[2.2.2]octa‐2,5‐dienes containing an alkenyl bromide, which can be readily functionalized to give diverse chiral diene ligands. The synthesis is straightforward and easily conducted on multigram scales. These ligands exhibit high performance in nine types of enantioselective Rh(I)‐catalyzed 1,4‐addition or 1,2‐addition reactions. magnified image Chemistry ; Enantioselective synthesis ; Diene ; Intramolecular force ; Cycloaddition ; Catalysis ; Combinatorial chemistry ; Bicyclic molecule ; Bromide ; Stereochemistry ; Organic chemistry Asymmetric Hydrogenation and Catalysis ; Synthetic Organic Chemistry Methods ; Asymmetric Synthesis and Catalysis
Authors: João Elias F. S. Rodrigues | Angelika D. Rosa | Gastón Garbarino | Tetsuo Irifune | J. L. Martı́nez | J. A. Alonso | Olivier Mathon
Source: Chemistry of Materials (article, 2023-06-20)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Evidence for a Pressure-Induced Phase Transition in the Highly Distorted TlNiO<sub>3</sub> Nickelate Rare-earth perovskite nickelates RNiO3 (R stands for Y, rare earths, Tl or Bi) have attracted wide attention in the past few decades because of their unique electronic properties that emerge from the insulator–metal transition (IMT). This transition can be tuned by chemical substitutions or by external variables, like pressure and temperature, but the mechanism of this transition still remains debated. While most previous studies focused on nickelates with partially filled 4f cations on the R site, here we studied the mechanism of the pressure-induced phase transition on a rare Tl3+ nickelate, which comprises fully filled 4f orbitals. We probed the pressure-induced structural and electronic changes taking place at the bulk, medium, and local atomic level at room temperature by using synchrotron X-ray diffraction (XRD), X-ray absorption near edge structure (XANES), and extended X-ray absorption fine structure (EXAFS) as probing techniques, respectively. High-resolution XRD data under ambient conditions show evidence for the monoclinic phase of TlNiO3, as characterized by the charge ordering between Ni3−δ and Ni3+δ in the insulator regime. High-pressure XRD data elucidated an anomaly in the evolution of the lattice parameters at 10.8 GPa, which we assigned to the structural transition P21/n → Pbnm. High-pressure EXAFS data at the Ni K-edge provide a solid proof for a short-order charge disproportionation under near ambient conditions. The Ni–O pair-bond compression curves unveiled an isotropic overlapping Ni t2g6eg1 → O 2p, with an anomaly at 10.8 GPa. The pressure evolution of the bond-distance variance (Debye–Waller exponents) lodged a hardening at this pressure point, suggesting constrained atomic displacements in the average range of ±0.04(5) Å. We propose that this reduced motional freedom could be linked to an electron–phonon coupling, which is the driving force behind the mechanisms of the IMT. We demonstrated that the XANES technique can be applied to ascertain the pressure-induced transition, by tracking the anomalous behavior of the position and width (full width at half-maximum) of the XANES features. Extended X-ray absorption fine structure ; XANES ; Materials science ; X-ray absorption spectroscopy ; Ambient pressure ; Phase transition ; Monoclinic crystal system ; Electronic structure ; Crystallography ; Disproportionation ; Bond length ; Condensed matter physics ; Absorption spectroscopy ; Crystal structure ; Chemistry ; Thermodynamics ; Physics ; Spectral line Magnetic and transport properties of perovskites and related materials ; Thermal Expansion and Ionic Conductivity ; Ferroelectric and Piezoelectric Materials
Authors: Elek Ferencz | Éva-Katalin Kelemen | Mona Obreja | Gergő Tóth | Melinda Urkon | Arnold Zöldhegyi | Emese Sipos | Zoltán‐István Szabó
Source: International Journal of Molecular Sciences (article, 2023-11-08)
Field: Chemistry — Spectroscopy

The Applicability of Chromatographic Retention Modeling on Chiral Stationary Phases in Reverse-Phase Mode: A Case Study for Ezetimibe and Its Impurities Mechanistic modeling is useful for predicting and modulating selectivity even in early chromatographic method development. This approach is also in accordance with current analytical quality using design principles and is highly welcomed by the authorities. The aim of this study was to investigate the separation behavior of two different types of chiral stationary phases (CSPs) for the separation of ezetimibe and its related substances using the mechanistic retention modeling approach offered by the Drylab software (version 4.5) package. Based on the obtained results, both CSPs presented with chemoselectivity towards the impurities of ezetimibe. The cyclodextrin-based CSP displayed a higher separation capacity and was able to separate seven related substances from the active pharmaceutical ingredient, while the cellulose-based column enabled the baseline resolution of six impurities from ezetimibe. Generally, the accuracy of predicted retention times was lower for the polysaccharide CSP, which could indicate the presence of additional secondary interactions between the analytes and the CSP. It was also demonstrated that the combination of mechanistic modeling and an experimental design approach can be applied to method development on CSPs in reverse-phase mode. The applicability of the methods was tested on spiked artificial placebo samples, while intraday and long-term (2 years) method repeatability was also challenged through comparing the obtained retention times and resolution values. The results indicated the excellent robustness of the selected setpoints. Overall, our findings indicate that the chiral columns could offer orthogonal selectivity to traditional reverse-phase columns for the separation of structurally similar compounds. Ezetimibe ; Repeatability ; Quality by Design ; Chromatography ; Selectivity ; Chemistry ; Impurity ; Resolution (logic) ; Active ingredient ; Chiral stationary phase ; Analytical Chemistry (journal) ; High-performance liquid chromatography ; Computer science ; Organic chemistry ; Particle size Analytical Chemistry and Chromatography ; Protein purification and stability ; Microfluidic and Capillary Electrophoresis Applications
Authors: Jian Zhang | Qian Liu | Gabriela Borin Barin | Peipei Chen | Kläus Müllen | Pascal Ruffieux | Román Fasel | Jin Zhang | Michel Calame | Mickael L. Perrin
Source: Materials for Quantum Technology (article, 2023-09-01)
Field: Materials Science — Materials Chemistry

Double quantum dots in atomically-precise graphene nanoribbons Abstract Bottom-up synthesized graphene nanoribbons (GNRs) are precise quantum materials, offering a high degree of tunability of their physical properties. While field-effect transistors and single quantum dot (QD) devices have been reported, the fabrication of double QD devices using GNRs remains challenging due to their nanometer-scale dimensions. In this study, we present a multi-gate double QD device based on atomically precise GNRs that are contacted by a pair of single-walled carbon nanotube electrodes. At low temperatures, the device can be tuned with multiple gates and reveals triangular features characteristic for charge transport through a double QD system. From these features, the QD level spacing, as well as the interdot tunnel coupling and lead-dot tunnel couplings are extracted. Double QD systems serve as essential building blocks for developing different types of qubits based on atomically precise GNRs. Quantum dot ; Materials science ; Carbon nanotube ; Graphene nanoribbons ; Fabrication ; Nanometre ; Nanotechnology ; Transistor ; Optoelectronics ; Graphene ; Electrode ; Qubit ; Coupling (piping) ; Quantum ; Voltage ; Physics ; Quantum mechanics Graphene research and applications ; Quantum and electron transport phenomena ; Molecular Junctions and Nanostructures
Authors: Nimisha Jain | Angelina Mary | Tanu Singh | Srushti Gadiyaram | Jyoti Joshi | D. Amilan Jose | Abbas Raja Naziruddin
Source: European Journal of Inorganic Chemistry (article, 2023-06-30)
Field: Materials Science — Materials Chemistry

Terpyridine Based Heteroleptic Ruthenium Complexes: Influence of Donor and Acceptor Ligands in Photosensitization Abstract We report heteroleptic ruthenium complexes of terpyridine (tpy) ligands with directly linked carboxylic acid anchors. These complexes feature methyl or methoxy‐substituted 4′−Ph tpy as donor ligands. We prepared these heteroleptic complexes from the ruthenium (II) precursor via a milder route to preclude the homoleptic complex formation. The donor−acceptor arrangement of tpy ligands in these ruthenium complexes renders visible light absorption giving metal and ligand‐to‐ligand charge transfer excitations at c.a . 490 nm. We evaluate the effect of the tpy donor substituents on the light‐harvesting ability in Dye‐Sensitized Solar Cells (DSSCs) and compare their photosensitizing ability with heteroleptic complexes bearing phenyl spacer at the acceptor end. Further, scrutinizing their photovoltaic performance, we studied their electron transfer kinetics in DSSCs using electrochemical impedance spectroscopy. This paper presents the structure‐photosensitization relationship of these heteroleptic ruthenium complexes through a combined experimental and computational approach. Ruthenium ; Homoleptic ; Chemistry ; Terpyridine ; Ligand (biochemistry) ; Photochemistry ; Acceptor ; Combinatorial chemistry ; Metal ; Catalysis ; Organic chemistry Polyoxometalates: Synthesis and Applications ; Conducting polymers and applications ; Porphyrin and Phthalocyanine Chemistry