jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Sören Jansen | Stephan Walleck | Anja Stammler | Hartmut Bögge | Thorsten Glaser
Source: Zeitschrift für anorganische und allgemeine Chemie (article, 2025-11-17)
Field: Chemistry — Inorganic Chemistry

Influence of Asymmetry on the Molecular and Electronic Structures of μ‐Oxo Diferric Complexes μ‐Oxo‐bridged diferric complexes serve as models for nonheme diiron proteins to elucidate their molecular and electronic structures and to gain insight into their reactivities. A bis(tetradentate) dinucleating ligand system with two tert ‐amine and two pyridine donors per ligand compartment has been developed. The introduction of a 6‐methyl substituent at the pyridines lengthens the MN py bonds by steric repulsion, resulting in less electron donation to the metal ions. Herein, μ‐oxo diferric complex with an asymmetric dinucleating ligand that has 6‐methyl substituents only in one of the ligand‐compartments is presented. The molecular structure exhibits different FeN py bond lengths. The two different Fe III sites in the asymmetric complex show only one quadrupole doublet while the quadrupole doublets for the two symmetric complexes differ significantly. There are two 6 A → 4 T 1 transitions, both of which are shifted to a higher energy compared to symmetric complexes, demonstrating the influence of asymmetry on electronic structures. This is supported by electrochemical investigations. The oxidation of Fe III to Fe IV is 80 mV more difficult, and the reduction of Fe III to Fe II is 230 mV more difficult, compared to the symmetric complexes. The origin of this effect is discussed, which is probably caused by an overcompensating charge donation of the μ‐oxo ligand. Steric effects ; Ligand (biochemistry) ; Pyridine ; Substituent ; Asymmetry ; Quadrupole ; Electronic effect ; Metal Metal-Catalyzed Oxygenation Mechanisms ; Magnetism in coordination complexes ; Metalloenzymes and iron-sulfur proteins
Authors: Yusuf Kerem Bostan | Elanur Hut | Cem Sanga | Nadire Nayir | Ayşe Erol | Yue Wang | Fahrettin Sarcan
Source: npj 2D Materials and Applications (article, 2025-11-30)
Field: Materials Science — Materials Chemistry

Chemical treatment-induced indirect-to-direct bandgap transition in MoS2: impact on excitonic emission Abstract Effective doping is crucial for overcoming performance limitations in two-dimensional (2D) transition metal dichalcogenide (TMD) devices. For light-emitting applications, however, doping must increase carrier injection without quenching excitonic emission. While chemical treatment with 1,2-dichloroethane (DCE) has been demonstrated as an effective post-growth n-doping method for 2D TMDs, its effects on optical properties, specifically the retention of optical characteristics and excitonic behaviour, remain unclear. Here, we investigate the layer- and time-dependent optical effects of DCE on molybdenum disulfide (MoS₂) using photoluminescence (PL) spectroscopy and Density Functional Theory (DFT). Our results show that DCE treatment rapidly reduces the indirect bandgap transition, while leaving the direct transition unaffected. DFT confirms that chlorine atoms bind to sulphur vacancies, creating in-gap states that facilitate non-radiative recombination and suppress the indirect PL. This work demonstrates DCE can selectively engineer the optical band structure in MoS₂, paving the way for more efficient 2D optoelectronic devices. Photoluminescence ; Density functional theory ; Doping ; Quenching (fluorescence) ; Band gap ; Spectroscopy ; Exciton ; Spontaneous emission ; Atom (system on chip) 2D Materials and Applications ; Quantum Dots Synthesis And Properties ; Catalysis and Hydrodesulfurization Studies
Authors: Sobhana Reshma | Elambalassery G. Jayasree
Source: ChemPlusChem (article, 2025-04-15)
Field: Chemistry — Organic Chemistry

Carbonyl and Carbonyl‐N‐Heterocyclic Carbene‐Ligated Iron Complexes as Catalysts for Markovnikov‐Selective Alkyne Hydrothiolation and Hydroselenation Reactions: A Mechanistic Study In the present work, iron carbonyl-catalyzed hydrothiolation/hydroselenation of alkynes has been studied computationally. The catalytic efficiency of inexpensive iron carbonyls and three iron-N-heterocyclic carbene (NHC)-based complexes-Fe(NHC)<sub>ax</sub>(CO)<sub>4</sub>, Fe(NHC)<sub>eq</sub>(CO)<sub>4</sub>, and Fe(aNHC)<sub>ax</sub>(CO)<sub>4</sub>-is evaluated. The results demonstrate significantly reduced energy barriers for the catalytic reactions compared to uncatalyzed gas-phase reactions. A high degree of regioselectivity for the Markovnikov product is observed, validating the effectiveness of these complexes in producing Markovnikov vinyl sulfides/selenides. An alternative catalytic pathway involving alkyne insertion into the MS/Se and MH bonds is also explored, and it is found that the catalyst regio- and stereoselectively leads to the formation of Markovnikov product in MS/Se insertion pathway and Z-anti-Markovnikov product in MH insertion pathway, consistent with the existing literature reports. Markovnikov's rule ; Chemistry ; Regioselectivity ; Catalysis ; Alkyne ; Combinatorial chemistry ; Medicinal chemistry ; Organic chemistry Sulfur-Based Synthesis Techniques ; Catalytic Alkyne Reactions ; Cyclopropane Reaction Mechanisms
Authors: Gester G. Gutiérrez | Fernando Rivas-Valdés | Bárbara P. Benavente | René Olivares‐Navarrete | Matías I. Hepp | Ricardo Barra | Roberto Urrutia
Source: International Journal of Molecular Sciences (article, 2025-10-22)
Field: Materials Science — Materials Chemistry

Toxicological Responses of Photosynthetic Genes in Chlorella vulgaris Exposed to Environmentally Relevant Concentrations of TiO2 Nanoparticles Engineered nanoparticles are increasingly released into aquatic environments, raising concerns about their effects on primary producers. Titanium dioxide nanoparticles (TiO<sub>2</sub> NPs), one of the most widely used nanomaterials, are frequently detected at low concentrations in surface waters. Here, we investigated the impact of environmentally relevant TiO<sub>2</sub> NP concentrations (1.1-17.6 µg/L) on the freshwater microalga <i>Chlorella vulgaris</i> by combining standardized growth inhibition bioassays with transcriptional analysis of photosynthesis-related genes. Cultures were exposed for 72 h following OECD TG 201, and cell density, growth factor (GF), and specific growth rate (µ) were determined to validate bioassay reliability. Gene expression of six photosynthetic genes (<i>atpB</i>, <i>psaA</i>, <i>psaB</i>, <i>psaD</i>, <i>psbA</i>, and <i>rbcL</i>) was quantified by RT-qPCR and normalized against 18S rRNA. Statistical analyses included Shapiro-Wilk and Levene's tests, followed by one-way ANOVA with Bonferroni or Dunnett T3 post hoc corrections. The results showed a hormetic growth response, with stimulation at intermediate NP concentrations and no inhibition at the highest dose. At the molecular level, <i>rbcL</i> was significantly repressed at 1.1-4.4 µg/L, while <i>psaA</i> and <i>psaD</i> were upregulated at 8.8-17.6 µg/L, indicating compensatory reinforcement of photosystem I. These divergent transcriptional trajectories demonstrate that molecular endpoints reveal sublethal effects not evident from cell counts alone. Overall, this study highlights the potential of photosynthesis-related genes as early biomarkers for detecting nanoparticle-induced stress in aquatic primary producers. Bioassay ; Chlorella vulgaris ; Photosynthesis ; Hormesis ; Gene ; Growth inhibition ; Gene expression ; Photosynthetic efficiency ; Cyanobacteria Nanoparticles: synthesis and applications ; Algal biology and biofuel production
Authors: Aidan P. McKay | David B. Cordes | Mohd Abdul Fatah Abdul Manan
Source: Acta Crystallographica Section E Crystallographic Communications (article, 2025-12-08)
Field: Chemistry — Organic Chemistry

Different intermolecular interactions in solvated and unsolvated isatin-based dithiocarbazate imine derivatives The syntheses and structures of 2-fluoro-benzyl (<i>Z</i>)-2-(2-oxoindolin-3-yl-idene)hydrazine-1-carbodi-thio-ate dimethyl sulfoxide monosolvate, C<sub>16</sub>H<sub>12</sub>FN<sub>3</sub>OS<sub>2</sub>·C<sub>2</sub>H<sub>6</sub>OS (<b>1</b>) and 2-fluoro-benzyl (<i>Z</i>)-2-(5-bromo-2-oxoindolin-3-yl-idene)hydrazine-1-carbodi-thio-ate, C<sub>16</sub>H<sub>11</sub>BrFN<sub>3</sub>OS<sub>2</sub> (<b>2</b>) are reported. Both structures feature a <i>Z</i>-configuration with respect to the C=N bond and the fluoro-benzyl ring is approximately orthogonal to the isatin moiety. For <b>1</b>, the crystal packing features weak C<sub>ar</sub>-H⋯S (ar = aromatic) hydrogen bonds that link adjacent mol-ecules in a <i>C</i>(10) fashion to form pleated chains propagating along [001] and short S⋯O contacts between dimethyl sulfoxide solvent mol-ecules forming chains along [010]. The N-H hydrogen bond donors in <b>1</b> form either intra-molecular or discrete N-H⋯O<sub>(DMSO)</sub> hydrogen bonds. In <b>2</b>, alternating <i>R</i> <sup>2</sup> <sub>2</sub>(8)-type pairwise N-H⋯O hydrogen bonds and short F⋯Br contacts link the mol-ecules into chains propagating along [210]. The later unsolvated structure is of notably poorer quality and exhibits disorder in its <i>o</i>-fluoro-benzyl group, with a 180° flip and a small twist around the S-C bond. These findings are consistent with the results of Hirshfeld surface analyses. Hydrogen bond ; Intermolecular force ; Ring (chemistry) ; Crystal structure ; Steric effects ; Dimethyl sulfoxide ; Imine Organometallic Compounds Synthesis and Characterization ; Crystal structures of chemical compounds ; Crystallography and molecular interactions
Authors: Ana Cremades | Pedro Hidalgo | David Maestre | Ruth Martínez‐Casado | Emilio Nogales | Beatriz Rodríguez | G. Cristian Vásquez | Bianchi Méndez
Source: Advanced Materials (review, 2025-12-19)
Field: Materials Science — Materials Chemistry

Opportunities of Semiconducting Oxide Nanostructures as Advanced Luminescent Materials in Photonics The luminescence properties of semiconductors are key to the development of photonics. In recent years, the targeted semiconductor materials have shifted from narrow-bandgap to wide- and ultra-wide-bandgap ones, which means spanning the domains of operation for devices beyond those possible with conventional semiconductors in the fields of high-power devices and deep-ultraviolet photodetectors. Furthermore, materials nanostructures with one or more dimensions at the nanoscale drive additional novelties in their optical properties, boosting innovative features. The next step in advanced materials necessarily goes through the quantum - photonic link, in which electromagnetic waves and electronic quantum states display all possible degrees of freedom. To achieve effective advances in this field, both innovative research in materials science and the development of suitable strategies to assess the quantum signatures in the material systems under study are required. This work reviews the fascinating light emission and confinement in wide and ultra-wide bandgap semiconducting oxides of technological interest in nanostructured form, focusing on their luminescence and the key role they can play in future quantum photonic technologies, such as single photon sources and quantum sensing. Finally, an outlook on future avenues in research is outlined. Photonics ; Quantum dot ; Semiconductor ; Luminescence ; Nanostructure ; Photon ; Quantum ; Band gap ; Nanoscopic scale Silicon Nanostructures and Photoluminescence ; Ga2O3 and related materials ; Luminescence Properties of Advanced Materials
Authors: Lin Miao | Dong-Mei Zhu | Cai‐Ming Liu | Yi‐Quan Zhang | Hui‐Zhong Kou
Source: Magnetochemistry (article, 2025-08-07)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Synthesis, Crystal Structures and Magnetic Properties of Lanthanide Complexes with Rhodamine Benzoyl Hydrazone Ligands Given the outstanding magnetic characteristics of lanthanide ions, the development of mononuclear or multinuclear lanthanide complexes becomes imperative. Previous research showed that a series of mononuclear Dy(III) complexes of rhodamine benzoyl hydrazone Schiff base ligands exhibit remarkable single-molecule magnetic properties and fluorescence. In this study, we used analogous ligands to synthesize lanthanide complexes [Dy(HL1-o)(NO3)2(CH3OH)2]NO3·CH3OH (complex 1·MeOH) and tetranuclear complexes [Ln4(L1-c)2(L2)2(μ3-OH)2(NO3)2(CH3OH)4](NO3)2·2CH3CN·5CH3OH·2H2O (Ln = Dy, complex 2; Ln = Gd, complex 3). Magnetic susceptibility measurements show that 1·2H2O is a single-molecule magnet, 2 shows slow magnetic relaxation and 3 is a magnetic cooling material with the magnetic entropy change of 9.81 J kg−1 K−1 at 2 K and 5 T. The theoretical calculations on 1·MeOH indicate that it shows good magnetic anisotropy with the calculated energy barrier of 194.6 cm−1. Lanthanide ; Hydrazone ; Crystal structure ; Rhodamine ; Chemistry ; Materials science ; Crystallography ; Stereochemistry ; Organic chemistry ; Fluorescence Magnetism in coordination complexes ; Lanthanide and Transition Metal Complexes ; Metal complexes synthesis and properties
Authors: Nikolai Kocherginsky
Source: Biomedical Journal of Scientific & Technical Research (article, 2025-11-18)
Field: Materials Science — Surfaces, Coatings and Films

Comments Regarding a Paper “Impact of pH-dependent Dynamics of Human Serum Proteins on Dialysis Membranes: Cryptographic Structure Assessment, Synchrotron Imaging of Membrane-Protein Adsorption, and Molecular Docking Studies”, Colloids and Surfaces B: Biointerfaces 246 (2025) 114354. Development of hemodialysis membranes and processes should be based on knowledge of membrane physicochemical properties, including interactions with blood proteins. Here we analyze a unique approach to characterize blood protein transport inside the dialysis membrane and results describing pH effects on these processes. Membrane ; Dialysis ; Synchrotron ; Membrane protein ; Docking (animal) ; Colloid ; Nanobiotechnology Polymer Surface Interaction Studies ; Dialysis and Renal Disease Management ; Chemical and Physical Properties in Aqueous Solutions
Authors: Zhanargul Koshetova | Guldana Daulet | Assel Ten | Raushan B. Koizhaiganova | Lyailya Baktybayeva | Tolganay Zharkynbek | Alexey Zazybin | Т. М. Сейлханов | Nurgul Zhumanova | Valery M. Dembitsky | V. К. Yu
Source: Molecules (article, 2025-10-11)
Field: Chemistry — Organic Chemistry

Design, Characterization, and Hematopoietic Efficacy of a Fluorinated Pyrazolopiperidine Inclusion Complex A novel inclusion complex of a fluorinated pyrazolopiperidine derivative (5-benzyl-7-(2-fluorobenzylidene)-2,3-bis(2-fluorophenyl)-3,3a,4,5,6,7-hexahydro-2H-pyrazolo [4,3-c]pyridine hydrochloride, PP·HCl) with β-cyclodextrin (<b>PPβCD</b>) was designed, synthesized, and characterized as a potential therapeutic agent for chemotherapy-induced myelosuppression and lymphopenia. Encapsulation of PP within β-cyclodextrin increased aqueous solubility by approximately 3.4-fold and improved dissolution rate by 2.8-fold compared with the free compound. Structural analysis using IR, ^1H/^13C NMR, and TLC confirmed the formation of a stable 1:1 host-guest complex, and the disappearance of free PP signals further supported complete encapsulation. In vivo evaluation in a cyclophosphamide-induced myelosuppression model demonstrated that <b>PPβCD</b> accelerated hematopoietic recovery, restoring leukocyte and erythrocyte counts 35-40% faster than methyluracil, without any signs of systemic toxicity. These findings indicate that β-cyclodextrin complexation significantly enhances solubility, dissolution, and biological efficacy of the pyrazolopiperidine scaffold, supporting further preclinical development of <b>PPβCD</b> as a supportive therapy for chemotherapy-related hematological complications. Haematopoiesis ; In vivo ; Solubility ; Aqueous solution ; In vitro ; Dissolution ; Drug Quinazolinone synthesis and applications ; Cancer therapeutics and mechanisms ; Chronic Lymphocytic Leukemia Research
Authors: Lyazat Tolymbekova | А. Колпек | Eldar Kopishev | Arailym Tursynova | Гайни Сейтенова
Source: КазУТБ (article, 2025-06-28)
Field: Materials Science — General Materials Science

ANALYSIS OF METHODS TO IMPROVE THE STRENGTH AND HEAT RESISTANCE OF COMPOSITE MATERIALS Modern composites occupy an important place in the production of high-strength materials due to their lightness, strength, heat resistance, ability to retain their performance properties and the possibility of modification for certain tasks. The article presents modern methods of improving mechanical properties and heat resistance of metal and polypropylene-based composites, their key characteristics, as well as modern processing technologies and innovative combinations with other materials. Particular attention is paid to the prospects for the development of composites with high temperature resistance through the introduction of reinforcing refractory particles, the use of carbon fibers and nanotubes, phosphorus-containing flame retardants, lignin, elastomers, thermoplastics, which opens up new opportunities for their exploitation. Modification of polypropylene using various fillers, such as polyamides, chalk fillers, and carbon nanoparticles, significantly improves its performance characteristics, including strength, thermal stability, and electrical conductivity. This opens up new horizons for the use of polypropylene composites in conditions of high loads and high temperatures, which is important for the sustainable development of the electronics industry and other high-tech areas. Metal and polypropylene-based composites have the potential for application in high temperatures and aggressive environments due to the possibility of modifying their structure and composition. The methods and technologies presented in the article allow expanding their functional capabilities, including integration with innovative components. Composite number ; Heat resistance ; Materials science ; Composite material ; Resistance (ecology) ; Structural engineering ; Engineering ; Biology Material Properties and Applications ; Mechanical and Thermal Properties Analysis ; Advanced Theoretical and Applied Studies in Material Sciences and Geometry
Authors: Zhang Yanwei | Wang Xin | Li Fuhao | Ren Jianyong | Liguo Yang
Source: Zeitschrift für Kristallographie - New Crystal Structures (article, 2025-12-27)
Field: Chemistry — Inorganic Chemistry

Crystal structure of μ <sub>4</sub> -oxido-tetrakis(μ <sub>4</sub> -methanolato-κ <sup>2</sup> <i>O:O</i> ′)tetrakis(μ <sub>2</sub> - <i>N</i> ′-(3-ethoxy-2-hydroxy-benzylidene)-2-hydroxy-benzohydrazide κ <sup>5</sup> <i>N,O,O</i> ′: <i>O</i> ′, <i>O</i> ″)tetracer(III)–methanol–triethylamine (1/2/2), C <sub>82</sub> H <sub>102</sub> Ce <sub>4</sub> N <sub>10</sub> O <sub>23</sub> Abstract C 82 H 102 Ce 4 N 10 O 23 , tetragonal, I 4 1 / a , a = 24.615(3) Å, c = 29.035(3) Å, V = 17592(4) Å 3 , Z = 8, R gt ( F ) = 0.0311, wR ref ( F 2 ) = 0.0821, T = 298 K. Crystal structure ; X-ray crystallography ; Crystal (programming language) ; Hexagonal crystal system ; Orthorhombic crystal system Metal-Organic Frameworks: Synthesis and Applications ; Magnetism in coordination complexes ; Metal complexes synthesis and properties
Authors: Bhuvnesh Kumar Singh | Neelanchal Trivedi | Anil Kumar | Vivek Kumar
Source: Journal of Advanced Scientific Research (article, 2025-05-31)
Field: Chemistry — Spectroscopy

Eco-friendly HPLC Strategies for Pharmaceutical Analysis The pharmaceutical business has a significant challenge in the worldwide need to adapt processes to green analytical chemistry (GAC) standards.One of the most common procedures employed at different points in the pharmaceutical manufacturing process is high-performance liquidchromatography (HPLC), which results in massive amounts of organic hazardous waste. Therefore, it is important to incorporate GAC conceptsinto pharmaceutical research and analysis. Although there has been a rise in recent years in the number of papers detailing green chromatographytechniques, they have not yet been widely adopted by the pharmaceutical industry. Reasons for this include analysts’ doubts about whetheror not they have met the method’s requirements, a lack of time to make the necessary adaptations to their standard HPLC instruments, anda lack of relevant experience. This chapter provides a high-level review of green strategies for liquid chromatography (LC) that can be simplyapplied to common instruments for creating environmentally friendly HPLC approaches in pharmaceutical analysis. The goal is to motivatethe analytical community within the pharmaceutical sector business to not only develop new green methods but also to transition the wellestablishedtraditional HPLC methods into environmentally green sustainable alternatives. Environmentally friendly ; Pharmaceutical industry ; High-performance liquid chromatography ; Hazardous waste ; Business ; Biochemical engineering ; Computer science ; Chemistry ; Risk analysis (engineering) ; Engineering ; Chromatography ; Medicine ; Pharmacology ; Waste management Analytical Chemistry and Chromatography ; Chemistry and Chemical Engineering ; Analytical Methods in Pharmaceuticals
Authors: Aymeric Jugan | Sylvain Marinel | Loïc Le Pluart | Théotim Marie | Romuald Herbinet | Charles Manière
Source: Journal of Materials Engineering and Performance (article, 2025-05-09)
Field: Chemistry — Organic Chemistry

Elaboration of Printable Nanopowder Zirconia Suspensions for Vat Photopolymerization Photopolymer ; Materials science ; Elaboration ; Cubic zirconia ; Chemical engineering ; Composite material ; Nanotechnology ; Polymer ; Ceramic ; Polymerization ; Humanities Photopolymerization techniques and applications ; Additive Manufacturing and 3D Printing Technologies ; Advanced Polymer Synthesis and Characterization
Authors: Harish Pemmiraju | Rajesh Viswanathan
Source: ChemRxiv (preprint, 2025-06-04)
Field: Chemistry — Organic Chemistry

Direct [3+2] Cycloaddition-Dearomative-Alkylation Cascade: Simple Terminal Alkynes to Indoline-fused-3,4-Pyrroles Natural products offer powerful bioactive compounds that serve as leads for new-age therapeutics. Alkaloid natural products containing C3-alkylated indolines embed an all-carbon quarternary ring system that is we documented as a privileged scaffold in natural product chemistry and drug design. Inspired by the Nocardioazines A and B that are prenylated, bioactive pyrroloindoline natural products, isolated from Nocardiopsis, we envisioned that Indoline-fused- 3,4-pyrroles offer a new scaffold to explore their biological importance. A biomimetic pathway that provides access to 6-5-6-5 and 6-5-7-5 C3-alkylated indoline-3,4-pyrrole fusion products that are new to heterocyclic chemistry is described. The reactivity profile presented in the form of a cascade process, executed smoothly as a single-pot reaction is unprecedented for three reasons, with isolated yields being high to excellent. The entire process works without any protecting groups while functionalizing two aromatic rings and the process offers indolines tethered with pyrrole at the C2 position with high regioselectivity. In summary, simple alkynes are transformed dramatically into complex natural-product-like cores smoothly, with broad substrate scope Indoline ; Cycloaddition ; Alkylation ; Cascade ; Terminal (telecommunication) ; Simple (philosophy) ; Chemistry ; Combinatorial chemistry ; Stereochemistry ; Organic chemistry ; Computer science ; Catalysis ; Computer network Synthesis and Characterization of Pyrroles