jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Stephanie S. Delancey | Reese A. Clendening | Mat­thias Zeller | Tong Ren
Source: Acta Crystallographica Section C Structural Chemistry (article, 2022-08-30)
Field: Chemistry — Inorganic Chemistry

Geometric isomers of dichloridoiron(III) complexes of CTMC (5,7,12,14-tetramethyl-1,4,8,11-tetraazacyclotetradecane) Both trans and cis iron-CTMC complexes, namely, trans-dichlorido[(5SR,7RS,12RS,14SR)-5,7,12,14-tetramethyl-1,4,8,11-tetraazacyclotetradecane]iron(III) tetrachloridoferrate, [Fe(C<sub>14</sub>H<sub>32</sub>N<sub>4</sub>)Cl<sub>2</sub>][FeCl<sub>4</sub>] (1a), the analogous chloride methanol monosolvate, [Fe(C<sub>14</sub>H<sub>32</sub>N<sub>4</sub>)Cl<sub>2</sub>]Cl·CH<sub>3</sub>OH (1b), and cis-dichlorido[(5SR,7RS,12SR,14RS)-5,7,12,14-tetramethyl-1,4,8,11-tetraazacyclotetradecane]iron(III) chloride, [Fe(C<sub>14</sub>H<sub>32</sub>N<sub>4</sub>)Cl<sub>2</sub>]Cl (2), were successfully synthesized and structurally characterized using X-ray diffraction. The coordination geometry of the macrocycle is dependent on the stereoisomerism of CTMC. The packing of these complexes appears to be strongly influenced by extensive hydrogen-bonding interactions, which are in turn determined by the nature of the counter-anions (1a versus 1b) and/or the coordination geometry of the macrocycle (1a/1b versus 2). These observations are extended to related ferric cis- and trans-dichloro macrocyclic complexes. Chemistry ; Chloride ; Cis–trans isomerism ; Crystallography ; Methanol ; Ferric ; Coordination geometry ; Hydrogen bond ; Iron(III) chloride ; Molecule ; Stereochemistry ; Medicinal chemistry ; Inorganic chemistry ; Organic chemistry Metal-Catalyzed Oxygenation Mechanisms ; Metal complexes synthesis and properties ; Magnetism in coordination complexes
Authors: Kiran Taksande
Source: SPIRE - Sciences Po Institutional REpository (preprint, 2022-03-23)
Field: Chemistry — Inorganic Chemistry

Exploration of the Ionic Conduction Properties of Porous MOF Materials The conductivity performance of a new series of chemically stable proton conducting Metal Organic Frameworks (MOFs) as well as a superionic molecular crystal was explored. The contribution of this PhD was to (i) select a variety of architectures and functionalities of robust MOFs/superionic molecular solids and (ii) characterize and rationalize their conducting performance over various temperature/humidity conditions. We designed two series of MOFs to achieve promising proton-conducting performance, using distinct approaches to modulate the concentration of Brønsted acidic sites and charge carriers and further boost the conductivity properties. First, a multicomponent ligand replacement strategy was successfully employed to elaborate a series of multivariate sulfonic-based solids MIP-207-(SO3H-IPA)x-(BTC)1–x which combine structural integrity with high proton conductivity values (e.g., σ = 2.6 × 10–2 S cm–1 at 363 K/95% Relative Humidity -RH-). Secondly, a proton conducting composite was prepared through the impregnation of an ionic liquid (1-Ethyl-3-methylimidazolium chloride, EMIMCl) in the mesoporous MIL-101(Cr)-SO3H. The resulting composite displaying high thermal and chemical stability, exhibits outstanding proton conductivity not only at the anhydrous state (σ473 K = 1.5 × 10-3 S cm-1) but also under humidity (σ(343 K/60%-80%RH) ≥ 0.10 S cm-1) conditions. Finally, the ionic conducting properties of another class of porous solids, considering a zirconium-formate molecular solid containing KCl ion pairs (ZF-3) were explored. ZF-3 switches from an insulator (σ = 5.1 x 10-10 S cm-1 at 363 K/0% RH) to a superionic conductor upon hydration (σ = 5.2 x 10-2 S cm-1 at 363 K/95 % RH), in relation with the boost of Cl- dynamics upon water adsorption. Noteworthy, quantum- and force-field based simulations were combined with the experimental approach to elucidate the microscopic mechanisms at the origin of the ionic conducting properties of the studied materials. This fundamental knowledge will serve to create novel robust superionic conductors with outstanding performances that will pave the way towards appealing societal applications for clean energy production. Porosity ; Ionic bonding ; Materials science ; Thermal conduction ; Chemical engineering ; Composite material ; Engineering ; Ion ; Chemistry ; Organic chemistry Metal-Organic Frameworks: Synthesis and Applications ; Semiconductor materials and devices ; Catalytic Processes in Materials Science
Authors: Tin V. T. Nguyen | Jérôme Waser
Source: ChemRxiv (preprint, 2022-01-27)
Field: Chemistry — Organic Chemistry

Direct Light Activation of Hypervalent Iodine Reagents: Substrate-Controlled C-C or C-H Alkynylation of Cyclopropanes We report the direct light activation of ethynylbenziodoxolone (EBX) reagents for the oxyalkynylation of aryl- and amino-cyclopropanes as well as styrenes. Irradiation with visible light at 440 nm promoted the reaction without the need of a photocatalyst. By the choice of the aryl group on the cyclopropane, it was possilbe to completely switch the outcome of the reaction from the oxyalkynylation of the C-C bond to the alkynylation of the C-H bond. This effect has been speculatively attributed to the conformational control induced by the aryl group on the cyclopropane ring Hypervalent molecule ; Cyclopropane ; Aryl ; Reagent ; Alkynylation ; Chemistry ; Iodine ; Substrate (aquarium) ; Photochemistry ; Ring (chemistry) ; Medicinal chemistry ; Visible spectrum ; Stereochemistry ; Catalysis ; Organic chemistry ; Materials science ; Alkyl Oxidative Organic Chemistry Reactions ; Radical Photochemical Reactions ; Catalytic C–H Functionalization Methods
Authors: Monique Farrell | A. K. Pradhan
Source: Micro (article, 2022-11-21)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Visual Detection of Biomolecules Using Concentration Dependent Induced Aggregation of Plasmonic Gold Nanoparticles Significant advancement has occurred in the detection methods of solution-based analytes. High-pressure liquid chromatography, gas chromatography, and other systems used for analyses are quite expensive. Therefore, there is a need for new methods and for the visible detection of analytes. Here, we demonstrate that 3-aminopropyl triethoxysilane (APTES) could impact the stability, optical, and morphology of gold nanoparticles (AuNps) in a colloidal solution. These impacts can be used to create a sensitive visual detection system. The strong impact of the APTES concentration on the ultraviolet–visible absorption spectra of the solutions is illustrated, which displays systematic and extensive red shifts. The presence of denatured proteins within a therapeutic drug product can induce a series of adverse effects. This report describes a fast, low cost, sensitive, and user-friendly platform where the plasmonic nanoparticles create visual biosensing of denatured proteins. Artificially heat stressed ferritin, glutathione, and insulin coupled to AuNps are exposed to ATES and upon denaturation of the protein or peptide, systematic blue or red shifts are observed in the absorbance spectra of the AuNps/biomolecules, and aminosilane solution. This serves as a proof-of-concept for a fast in-solution detection method for heat-stressed proteins or peptides. Biomolecule ; Colloidal gold ; Biosensor ; Triethoxysilane ; Analyte ; Absorbance ; Chemistry ; Nanoparticle ; Plasmon ; Plasmonic nanoparticles ; Chromatography ; Nanotechnology ; Materials science ; Organic chemistry ; Biochemistry Gold and Silver Nanoparticles Synthesis and Applications ; Advanced Nanomaterials in Catalysis ; Biosensors and Analytical Detection
Authors: Meng-yao LU | Xiang-an SONG | Sheng‐Nan Zou | Yong Zhang
Source: Chinese Journal of Luminescence (article, 2022-01-01)
Field: Materials Science — Materials Chemistry

Recent Progress of Thermally Activated Delayed Fluorescent Materials Based on Pyrimidine and Its Derivative Acceptors å§å¶å¯ä½ä¸ºæå»ºDâAåç­æ¿æ´»å»¶è¿è§å ï¼TADFï¼ææçå¸¸ç¨åä½ï¼å ¶å¼ºå¸çµå­ç¹æ§åçµæ´»çåä»£æåºæå©äºå½¢æå¤æ ·çåå­ç»æï¼ä¸ºå®ç°é«æçææºçµè´åå æä¾äºå¯è½ãè¿å¹´æ¥ï¼åºäºå§å¶åä½çåå­ç»æè®¾è®¡åå¾äºéè¦è¿å±ï¼ç ç©¶æ¹åä»ä»¥DâAâDåä¸ºä¸»çå¯¹ç§°åå­éæ¸åä¸å¯¹ç§°åå­è¿æ¸¡ãå¹ååæ¯TADFææçä¸ç±»æ°ååä½ï¼å ·æè¯å¹¶å§å¶çç¨ ç¯ç»æï¼å»¶å±çå ±è½­å¹³é¢ä½¿å ¶è¡¨ç°åºè¯å¥½æ½åï¼éè¿åççåå­ä¿®é¥°ï¼è½å¤æææ¹åå¨ä»¶çåå æ§è½ãæ¬æä»¥å§å¶åä½æ ¸ä¸ºåºç¡ï¼å´ç»åå­ç»æãå ç©çç¹æ§åOLEDå¨ä»¶æ§è½ç­é®é¢ï¼ç®è¦æ»ç»äºåºäºå§å¶åå ¶è¡çç©å¹åååä½çç­æ¿æ´»å»¶è¿è§å ææç ç©¶è¿å±ï¼å¹¶å¯¹å¹åååºTADFåå­å¹¿éçåå±åæ¯è¿è¡äºå±æã Materials science ; OLED ; Fluorescence ; Pyrimidine ; Derivative (finance) ; Photochemistry ; Nanotechnology ; Optics ; Stereochemistry ; Chemistry ; Physics ; Business Polyoxometalates: Synthesis and Applications ; Metal-Organic Frameworks: Synthesis and Applications ; Multicomponent Synthesis of Heterocycles
Authors: Tsu-Ting Lee | Edward Yi Chang
Source:  (article, 2022-02-05)
Field: Materials Science — Materials Chemistry

Improved Performance of MoS2 FETs using AlN/Al2 O3 dielectric and Plasma Enhanced Atomic Layer Deposition (PEALD) Molybdenum disulfide (MoS2 ) transistors are emerging as an exciting material system for future electronics due to their unique electrical properties, twodimensional (2D) nature and atomically thin geometry. This ultra-thin-body (UTB) semiconductor considerably reduces current leakage and enables gate-to-channel control. The homogeneous growth of sub-10 nm dielectrics on 2D materials remains challenging. We demonstrate high-performance MoS2 FETs at low temperature (150°C) using the plasma-enhanced Atomic layer deposition (PEALD) technique. The device exhibits a high on/off current ratio of about 106 , the field-effect mobility of 9.5 cm2 /Vs, and a subthreshold swing (SS) of 171 mV/dec, which is comparable to the similar structure of the top gate device. In addition, we have demonstrated contact resistance on back-gate MoS2 FETs with and without dielectric capping Atomic layer deposition ; Materials science ; Optoelectronics ; Molybdenum disulfide ; Dielectric ; Transistor ; Gate dielectric ; Semiconductor ; Nanotechnology ; High-κ dielectric ; Plasma ; Field-effect transistor ; Thin film ; Voltage ; Electrical engineering ; Composite material 2D Materials and Applications ; MXene and MAX Phase Materials ; Ferroelectric and Negative Capacitance Devices
Authors: Julia Katharina Binder | Tanja Gulder
Source: ChemRxiv (preprint, 2022-03-22)
Field: Chemistry — Inorganic Chemistry

Terpene Cyclase Mimicking Chlorine-Induced Polyene Cyclizations Nature forges a plethora of structurally divers polyenes with high efficiency and selectivity in a single cyclization step from achiral precursor. Imitating this powerful strategy has been the subject of numerous synthetic efforts. While bromo- and iodocyclizations have recently been successfully implemented, chlorocyclizations have been scantly investigated. Here, we present a selective and generally applicable biomimetic concept on a direct chlorination-induced polyene cyclization by utilizing a confined HFIP-chlorenium network inspired by the enzymatic pocket of terpene cyclases. Chloro-iodanes proved to be superior as electrophilic chlorine source. Together with catalytic amounts of saccharine in HFIP, a manifold of different alkenes with various inter- and intramolecular nucleophiles were converted with high yields and selectivities (up to 78% yield and d.r. >95:5). The cyclization platform was even extended to several structurally challenging terpenes and terpenoid carbon frameworks. NMR experiments revealed attractive non-covalent interactions between the F-alcohol and the lactone moiety in chloro-iodanes that are probably facilitating the chlorocyclization. The present results mark another milestone in the biomimetic cyclization of polyenes, allowing direct and selective access to these powerful molecules. Polyene ; Terpene ; Chemistry ; Electrophile ; Nucleophile ; Moiety ; Intramolecular force ; Combinatorial chemistry ; Chlorine ; Organic chemistry ; Catalysis Vanadium and Halogenation Chemistry ; Oxidative Organic Chemistry Reactions ; Marine Sponges and Natural Products
Authors: Linhai Jiang | Xiaobing Zuo | Jianping Li | Nathaniel J. Traaseth | Kent Kirshenbaum
Source: Angewandte Chemie (article, 2022-04-13)
Field: Materials Science — Biomaterials

Programmed Supramolecular Assemblies Using Orthogonal Pairs of Heterodimeric Coiled Coil Peptides Despite recent progress, it remains challenging to program biomacromolecules to assemble into discrete nanostructures with pre-determined sizes and topologies. We report here a novel strategy to address this challenge. By using two orthogonal pairs of heterodimeric coiled coils as the building blocks, we constructed six discrete supramolecular assemblies, each composed of a prescribed number of coiled coil components. Within these assemblies, different coiled coils were connected via end-to-side covalent linkages strategically pre-installed between the non-complementary pairs. The overall topological features of two highly complex assemblies, a "barbell" and a "quadrilateral" form, were characterized experimentally and were in good agreement to the designs. This work expands the design paradigms for peptide-based discrete supramolecular assemblies and will provide a route for de novo fabrication of functional protein materials. Coiled coil ; Supramolecular chemistry ; Quadrilateral ; Topology (electrical circuits) ; Nanotechnology ; Covalent bond ; Materials science ; Chemistry ; Crystallography ; Physics ; Mathematics ; Combinatorics ; Biochemistry Supramolecular Self-Assembly in Materials ; Advanced biosensing and bioanalysis techniques ; Polydiacetylene-based materials and applications
Authors: Tobias Dunaj | Christoph M. Feil | Martin Nieger | Dietrich Gudat
Source: Zeitschrift für anorganische und allgemeine Chemie (article, 2022-07-04)
Field: Chemistry — Organic Chemistry

Adducts of Diaminophosphines with Organoboranes Abstract Reactions of chlorodiaminophosphines (R 2 N) 2 PCl (R=Et, i Pr) with organoborohydrides M[BR′ n H 4‐n ] (M=Na, Li; n=1–3; R′=alkyl, Ph, CN) proceed via H/Cl metathesis to furnish secondary phosphines and boranes which may either combine to afford isolable donor‐acceptor adducts (R 2 N) 2 P(H)−BR′ n H 3‐n , coexist without any sign of mutual interaction, or give rise to mixtures comprising both a labile phosphine borane and its constituents in a temperature dependent equilibrium. Stable phosphine complexes of BH 2 CN and BH 2 Ph react with KN(SiMe 3 ) 2 under PH‐bond metalation to afford spectroscopically detectable diaminophosphide boranes whose usability as nucleophilic building blocks is illustrated by trapping one specimen in a PC‐bond formation reaction with an alkyl halide. The selectivity of the individual H/Cl‐metathesis and electrophilic substitution steps as well as the thermal stability of the various reaction products depend subtly on the Lewis acidity of the borane fragment and on steric factors. Several complexes of (iPr 2 N)‐substituted phosphines with cyano‐ and phenylborane were characterized by single‐crystal XRD. Chemistry ; Borane ; Metathesis ; Steric effects ; Boranes ; Adduct ; Medicinal chemistry ; Electrophile ; Phosphine ; Nucleophile ; Alkyl ; Frustrated Lewis pair ; Salt metathesis reaction ; Stereochemistry ; Lewis acids and bases ; Organic chemistry ; Boron ; Catalysis ; Polymerization Organoboron and organosilicon chemistry ; Asymmetric Hydrogenation and Catalysis ; Organometallic Complex Synthesis and Catalysis
Authors: Mrudhula Baskaran
Source: International Journal for Research in Applied Science and Engineering Technology (article, 2022-01-22)
Field: Chemistry — Inorganic Chemistry

Fabrication of Dip Coated ZnO Nanorods for Organic Dye Sensitized Solar Cells Abstract: Dye sensitized solar cell (DSSC) are new type of solar cell, has aroused worldwide attention which arises from its merits of low cost, ease of fabrication and environmental friendliness, etc. The development history, basic structure and working principle of the DSSC are introduced briefly, and the classification and development of DSSC are stated in detail. Dye sensitizers are divided into two major categories organic dyes and metal-organic compounds, and organic dyes can roughly be classified into several parts. A new form of solar cell is being investigated using a dye-sensitized solar cell (DSSC) using an inorganic semiconductor, due to the anticipated less costing solution to standard solid-state equipment. The formulation of effective solar cell contains countless semiconducting materials. This was an initiative of the researchers to study the fabricated of the natural dye sensitized solar cells for sol-gel dipping coated zinc oxide nanorod and also more voluminous in surface. Moreover, the corresponding assumptions and measures on how to improve the energy efficiency of the DSSCs are proposed, and finally the trends and promising prospects are presented. Keywords: ZnO Nanorods, Dye Sensitized Solar Cells (DSSC), Organic Solar Cell, Dip Coating Method Dye-sensitized solar cell ; Nanorod ; Solar cell ; Materials science ; Fabrication ; Nanotechnology ; Organic solar cell ; Hybrid solar cell ; Coating ; Organic dye ; Optoelectronics ; Chemical engineering ; Polymer solar cell ; Chemistry ; Composite material ; Electrode ; Polymer ; Medicine Pigment Synthesis and Properties ; TiO2 Photocatalysis and Solar Cells
Authors: Lea Gundorff Nielsen | Anne Kathrine Ravnsborg Hansen | Patrycja Stachelek | Róbert Pál | Thomas Just Sørensen
Source: ChemRxiv (preprint, 2022-11-10)
Field: Materials Science — Materials Chemistry

1-Azathioxanthone Appended Europium(III) Complexes with Excita-tion at 405 nm: Consequences for Lanthanide Luminescence based Bioimaging on Commercial Microscopes Since the pioneering report by Selvin, we have been fascinated by the potential of using lanthanide lu-minescence in bioimaging. The uniquely narrow emission lines and long luminescence lifetimes both provide the potential for background free images together with full certainty of probe localization. General use of lanthanide based bioimaging was first challenged by low brightness, and later by the need of UV (<405 nm) excitation sources not present in commercial microscopes. Here, three lantha-nide-based imaging probes were synthesized, characterized, and used in bioimaging on dedicated as well as commercial microscopes. It was proven without doubt that the lanthanide complexes enter the cells and luminesce internally. Even so, no lanthanide luminescence were recovered on the commercial microscopes. Thus, it was concluded that even though the commercial microscopes are capable of single photon detection, lanthanide luminescence based bioimaging still requires dedicated hardware. Lanthanide ; Luminescence ; Microscope ; Europium ; Luminescent Measurements ; Materials science ; Nanotechnology ; Brightness ; Chemistry ; Optoelectronics ; Optics ; Physics ; Organic chemistry Lanthanide and Transition Metal Complexes ; bioluminescence and chemiluminescence research ; Medical Imaging Techniques and Applications
Authors: Peng-Jen Chen
Source: Frontiers in Materials (article, 2022-07-22)
Field: Materials Science — Materials Chemistry

Tunable Topological Phase Transition in Two-Dimensional Ternary Transition Metal Halides TiXI (X = P and As) With first-principles calculations we predict tunable topological phase transition in two-dimensional (2D) ternary transition metal halides α -Ti X I ( X = P and As) via strain engineering. Besides, changing the number of stacking layers or van der Waals interlayer spacing can also result in topological phase transition in few-layer Ti X I. The on-site Coulomb U of Ti atoms is neither tunable nor empirical in this work. Instead, it is evaluated by the density functional perturbation theory and hence the results are more accurate. The tunable topological phase of 2D α -Ti X I via strain engineering makes them promising in spintronics devices that exploit quantum spin Hall effect. Furthermore, the topological edge states of the single-layer TiAsI exhibit interesting feature. They do not cross at the time-reversal invariant momenta (TRIM) where the band inversion occurs. Instead, they extend over the whole one-dimensional Brillouin zone and cross at the other TRIM. While all requirements of Z 2 topological phase are fulfilled, it is rare especially for those with direct gap. The linear bulk bands around and at Γ point may be the reason for the unusual crossing. Topology (electrical circuits) ; Topological order ; Brillouin zone ; Phase transition ; Density functional theory ; Condensed matter physics ; Spintronics ; Ternary operation ; Materials science ; Quantum phase transition ; Phase diagram ; Phase (matter) ; Physics ; Quantum ; Quantum mechanics ; Ferromagnetism 2D Materials and Applications ; MXene and MAX Phase Materials ; Electronic and Structural Properties of Oxides
Authors: Anna Kaczmarek‐Kędziera | Borys Ośmiałowski | Piotr S. Żuchowski | Dariusz Kędziera
Source: Frontiers in Chemistry (article, 2022-01-05)
Field: Chemistry — Physical and Theoretical Chemistry

Supramolecular Approach to Tuning the Photophysical Properties of Quadrupolar Squaraines In the present study, the influence of the hydrogen bonding for the one- and two-photon absorption of the prototypical squaraine dye is investigated with quantum chemistry tools. The central squaraine unit is bound by strong hydrogen bonds with 4-substituted N,N'-diphenylurea and, alternatively, N,N'-diphenylthiourea molecules, which affects to a high extend the properties of the squaraine electron accepting moiety, thus shifting its maximum absorption wavelength and enhancing the TPA cross section. The replacement of oxygen by sulfur atoms in the squaraine central ring, known to affect its photophysical behavior, is considered here as the way of modifying the strength and nature of the intermolecular contacts. Additionally, the influence of the oxygen-by-sulfur replacement is also considered in the N,N'-diphenylurea moiety, as the factor affecting the acidity of the N-H protons. The introduction of the sequence of the substituents of varying electron-donating or electron-withdrawing characters in the position 4 of N,N'-diphenyl(thio)urea subsystems allows to finely tune the hydrogen bonding with the central squaraine unit by further modification of the N-H bond characteristics. All of these structural modifications lead to the controlled adjustment of the electron density distribution, and thus, the properties affected such as transition moments and absorption intensity. <i>Ab initio</i> calculations provide strong support for this way of tailoring of one- or two-photon absorption due to the obtained strong hypsochromic shift of the maximum one-photon absorption wavelength observed particularly for thiosquaraine complexes and an increase in the TPA wavelength together with the increase in the TPA cross section. Moreover, the source of the strong modification of the thiosquaraine OPA in contrast to the pristine oxosquaraine upon N,N'-diphenyl(thio)urea substitution is determined. Furthermore, for the first time, the linear dependence of the non-additivity in the interaction energy on the Hammett substituent constant is reported. The stronger the electron-donating character of the substituent, the larger the three-body non-additive components and the larger their percentage to the total interaction energy. Supramolecular chemistry ; Materials science ; Chemistry ; Nanotechnology ; Crystallography ; Crystal structure Photochemistry and Electron Transfer Studies ; Spectroscopy and Quantum Chemical Studies ; Porphyrin and Phthalocyanine Chemistry