jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Saravanan Gowrisankar | Christopher A. Hosier | Peter R. Schreiner | Stefanie Dehnen
Source: ChemPhotoChem (article, 2022-07-25)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Manipulating White‐Light Generation in Adamantane‐Like Molecules via Functional Group Substitution Abstract Certain adamantane (Ad)‐like molecules, either clusters of the type [(R′T) 4 E 6 ] with inorganic cores (R′=cyclic/aromatic organic substituent; T=Si, Ge, Sn; E=S, Se, Te) or adamantane derivatives [(R′C) 4 (CH 2 ) 6 ]=AdR′ 4 , display extreme nonlinear optical properties, which can lead to white‐light emission when exposed to near infrared light. While previous studies have established some requirements for these compounds to generate white light, the ability to tailor this effect remains elusive. Here we evaluate the impact of a variety of inorganic and organic compounds with Ad‐like cores as well as various functional groups on white‐light generation (WLG). We show that polarization and electron density localization are influenced by the type of the functional group R in [(R‐PhSn) 4 S 6 ] in particular, according to DFT computations. While these groups do not have a large impact on the maximum emission wavelengths, they do significantly affect the laser power threshold for the occurrence of WLG. Adamantane ; Substituent ; Molecule ; Density functional theory ; Chemistry ; Polarization (electrochemistry) ; Infrared ; Materials science ; Crystallography ; Photochemistry ; Stereochemistry ; Computational chemistry ; Physics ; Organic chemistry ; Optics ; Physical chemistry Organic and Molecular Conductors Research ; Nonlinear Optical Materials Research ; Photochemistry and Electron Transfer Studies
Authors: Lídia A. S. Cavaca | Jaime A. S. Coelho | Susana D. Lucas | Rui M. S. Loureiro | Rafael F. A. Gomes | Carlos A. M. Afonso
Source: Reaction Chemistry & Engineering (article, 2022-11-24)
Field: Chemistry — Inorganic Chemistry

Upgrading furanic platforms to α-enaminones: tunable continuous flow hydrogenation of bio-based cyclopentenones Continuous flow hydrogenation of trans- 4,5-diamino cyclopentenones to diamino cyclopentanones and base-promoted elimination originates α-enaminones. The strategy is applied to the short synthesis of reported ATP-sensitive potassium channel agonist. Flow chemistry ; Continuous flow ; Agonist ; Chemistry ; Combinatorial chemistry ; Potassium ; Base (topology) ; Potassium channel ; Organic chemistry ; Catalysis ; Biochemical engineering ; Mathematics ; Biochemistry ; Biology ; Biophysics ; Engineering Asymmetric Hydrogenation and Catalysis ; Catalysis for Biomass Conversion ; Innovative Microfluidic and Catalytic Techniques Innovation
Authors: Igor D. Borges | Angélica Navarrete | Gerardo Aguirre | Antônio S. N. Aguiar | Solemar S. Oliveira | Ademir J. Camargo | Hamilton B. Napolitano
Source: Journal of the Brazilian Chemical Society (article, 2022-01-01)
Field: Chemistry — Inorganic Chemistry

Synthesis and Molecular Modeling Study of Two Bromo-Dimethoxybenzaldehydes This work describes the synthesis, molecular structure, and packaging of the compounds 6-bromo-2,3-dimethoxybenzaldehyde (6-BRB) and 5-bromo-2,3-dimethoxybenzaldehyde (5-BRB). Characterization in the solid-state was carried out by X-ray diffraction, and the analysis of the interactions was described by the Hirshfeld surface, which helps in understanding the effect of replacing the bromine position in the aromatic ring. Both compounds (6-BRB and 5-BRB) crystallized in the space group P21/c and are stabilized with C–HO interactions, but only the 6-BRB has a halogen-type interaction. Theoretical calculations, carried out by the density functional theory at the CAM-B3LYP/6-311++G(d,p) level of theory in gas phase, provided information on their electronic properties. The geometric properties were compared to experimental data, and the analyses of the frontier molecular orbitals and the molecular electrostatic potential (MEP) maps were obtained to predict the physical-chemical properties. The supramolecular arrangements were analyzed throughout complexation interactions and corrected by counterpoise method. Hyperconjugation energies were employed to examine the stability of the intermolecular interactions of the compounds. The interaction intensities were determined through the topological parameters obtained through the quantum theory of atoms in molecules model. Density functional theory ; Chemistry ; Natural bond orbital ; Computational chemistry ; Molecular orbital ; Intermolecular force ; Counterpoise ; Molecule ; Supramolecular chemistry ; Ring (chemistry) ; Halogen ; Aromaticity ; Crystallography ; Chemical physics ; Basis set ; Organic chemistry Crystal structures of chemical compounds ; Structural and Chemical Analysis of Organic and Inorganic Compounds ; Nonlinear Optical Materials Research
Authors: Konthoujam James Singh | Hao-Hsuan Ciou | Ya-Hui Chang | Yen-Shou Lin | Hsiang‐Ting Lin | Po‐Cheng Tsai | Shih‐Yen Lin | Min‐Hsiung Shih | Hao‐Chung Kuo
Source: Nanomaterials (article, 2022-01-27)
Field: Materials Science — Materials Chemistry

Optical Mode Tuning of Monolayer Tungsten Diselenide (WSe2) by Integrating with One-Dimensional Photonic Crystal through Exciton–Photon Coupling Two-dimensional materials, such as transition metal dichalogenides (TMDs), are emerging materials for optoelectronic applications due to their exceptional light-matter interaction characteristics. At room temperature, the coupling of excitons in monolayer TMDs with light opens up promising possibilities for realistic electronics. Controlling light-matter interactions could open up new possibilities for a variety of applications, and it could become a primary focus for mainstream nanophotonics. In this paper, we show how coupling can be achieved between excitons in the tungsten diselenide (WSe<sub>2</sub>) monolayer with band-edge resonance of one-dimensional (1-D) photonic crystal at room temperature. We achieved a Rabi splitting of 25.0 meV for the coupled system, indicating that the excitons in WSe<sub>2</sub> and photons in 1-D photonic crystal were coupled successfully. In addition to this, controlling circularly polarized (CP) states of light is also important for the development of various applications in displays, quantum communications, polarization-tunable photon source, etc. TMDs are excellent chiroptical materials for CP photon emitters because of their intrinsic circular polarized light emissions. In this paper, we also demonstrate that integration between the TMDs and photonic crystal could help to manipulate the circular dichroism and hence the CP light emissions by enhancing the light-mater interaction. The degree of polarization of WSe<sub>2</sub> was significantly enhanced through the coupling between excitons in WSe<sub>2</sub> and the PhC resonant cavity mode. This coupled system could be used as a platform for manipulating polarized light states, which might be useful in optical information technology, chip-scale biosensing and various opto-valleytronic devices based on 2-D materials. Tungsten diselenide ; Exciton ; Photonics ; Optoelectronics ; Photon ; Nanophotonics ; Materials science ; Photonic crystal ; Circular polarization ; Monolayer ; Polarization (electrochemistry) ; Light emission ; Physics ; Optics ; Nanotechnology ; Condensed matter physics ; Transition metal ; Chemistry 2D Materials and Applications ; Perovskite Materials and Applications ; Strong Light-Matter Interactions
Authors: Dániel Zámbó | Dávid Kovács | Gergely Südi | András Deák
Source: Particle & Particle Systems Characterization (article, 2022-12-17)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Surface Modification of Gold Nanoprisms and Their Self‐Assembly with Nanospheres Abstract Controlled surface modification of gold particles is of central importance for the preparation of functional nano‐objects, which can be used both in fundamental research and in advanced photonic or nanomedicine applications. In this study, the surface modification of gold nanoprisms using different thiols, namely cysteamine, (16‐mercaptohexadecyl)trimethylammonium bromide (MTAB), and α‐methoxy‐ω‐mercapto polyethylene glycol (mPEG‐SH (5000 Da)) is investigated. The aim is to prepare binary surface‐modified thiol/PEG patchy gold nanoprisms, where the tips/edges and the face regions of the particles are covered by different thiol moieties. By investigating the time evolution of the prisms’ extinction spectra at different capping ligand concentration levels, the conditions to prepare such “patchy” particles are identified. While significantly faster adsorption kinetics are observed for MTAB compared to cysteamine, both molecule types can be used to prepare binary surface‐modified thiol/PEG particles. Prisms modified with only MTAB or PEG and subsequently assembled with negatively charged spheres show that MTAB forms hetero‐aggregates with the spheres, while PEG prevents particle attachment. For thiol (cysteamine or MTAB)/PEG binary surface‐modified prisms, it is found that the efficiency of sphere attachment at the tip/side region during self‐assembly is rather low, most likely due to the presence of PEG. PEG ratio ; Cysteamine ; Self-assembly ; Surface modification ; Colloidal gold ; Polyethylene glycol ; Chemistry ; Polystyrene ; Particle (ecology) ; Nanotechnology ; Chemical engineering ; Thiol ; Nanoparticle ; Polymer chemistry ; Materials science ; Polymer ; Organic chemistry ; Physical chemistry Gold and Silver Nanoparticles Synthesis and Applications ; Nanocluster Synthesis and Applications ; Pickering emulsions and particle stabilization
Authors: Christian Ritschel | Joanna Napp | Frauke Alves | Claus Feldmann
Source: Nanoscale (article, 2022-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Monitoring nanoparticle dissolution <i>via</i> fluorescence-colour shift [La(OH)]<sup>2+</sup>[ICG]<sup>-</sup><sub>2</sub> and [La(OH)]<sup>2+</sup><sub>2</sub>[PTC]<sup>4-</sup> inorganic-organic hybrid nanoparticles (IOH-NPs) with indocyanine green (ICG) and perylene-3,4,9,10-tetracarboxylate (PTC) as fluorescent dye anions are used for emission-based monitoring of the dissolution of nanoparticles. Whereas ICG shows a deep red emission in the solid [La(OH)]<sup>2+</sup>[ICG]<sup>-</sup><sub>2</sub> IOH-NPs, the emission of PTC in the solid [La(OH)]<sup>2+</sup><sub>2</sub>[PTC]<sup>4-</sup> IOH-NPs is completely quenched due to π-stacking. After nanoparticle dissolution, the emission of freely dissolved ICG is weak, whereas freely dissolved PTC shows intense green emission. We report on the synthesis of IOH-NPs and nanoparticle characterization as well as on the fluorescence properties and how to avoid undesirable energy transfer between different fluorescent dyes. The emission shift from red (intact solid nanoparticles) to green (freely dissolved dye anions), indicating nanoparticle dissolution, is shown for aqueous systems and verified <i>in vitro</i>. Based on this first proof-of-the-concept, the IOH-NP marker system can be interesting to monitor nanoparticle dissolution in cells and tissues of small animals and to evaluate cell processes and/or drug-delivery strategies. Dissolution ; Nanoparticle ; Fluorescence ; Materials science ; Nanotechnology ; Chemical engineering ; Optics Gold and Silver Nanoparticles Synthesis and Applications ; Nanoplatforms for cancer theranostics ; Nanoparticles: synthesis and applications
Authors: Vivek Trivedi | Adejumoke Lara Ajiboye | Nichola J. Coleman | Ruchir Bhomia | Marion Bascougnano
Source: Polymers (article, 2022-07-11)
Field: Materials Science — Polymers and Plastics

Melting Point Depression of Poly(ethylene oxide)-Poly(propylene oxide)-Poly(ethylene oxide) Triblock Polymers in Supercritical Carbon Dioxide in the Presence of Menthol as a Solid Co-Plasticiser The melting behaviour of the triblock polymers, Pluronic F38, F68, F77, F108, and F127, was investigated in pressurised CO<sub>2</sub> and in the presence of menthol. The melting points of the polymers combined with 0, 10, 25, and 50 wt% of menthol were studied at atmospheric pressure and compared with those at 10 and 20 MPa in supercritical carbon dioxide (scCO<sub>2</sub>). The highest melting point depressions of 16.8 ± 0.5 °C and 29.0 ± 0.3 °C were observed at 10 and 20 MPa, respectively. The melting point of triblock polymers in pressurised CO<sub>2</sub> was found to be dependent on molecular weight, poly(propylene oxide) (PPO) content, and menthol percentage. The melting point of most of the polymers studied in this work can be reduced to room temperature, which can be pivotal to the formulation development of thermolabile substances using these polymers. Ethylene oxide ; Plasticizer ; Materials science ; Melting-point depression ; Supercritical carbon dioxide ; Poly ethylene ; Propylene oxide ; Polymer ; Oxide ; Supercritical fluid ; Carbon dioxide ; Menthol ; Chemical engineering ; Polymer chemistry ; Melting point ; Copolymer ; Ethylene ; Organic chemistry ; Chemistry ; Composite material ; Catalysis Polymer Foaming and Composites ; Phase Equilibria and Thermodynamics ; Polymer crystallization and properties
Authors: Giuseppe Soavi | Alessandro Pedrini | Anjali Devi Das | Francesca Terenziani | Roberta Pinalli | Neal Hickey | Barbara Medagli | Silvano Geremia | Enrico Dalcanale
Source: Chemistry - A European Journal (article, 2022-02-24)
Field: Chemistry — Organic Chemistry

Encapsulation of Trimethine Cyanine in Cucurbit[8]uril: Solution versus Solid‐State Inclusion Behavior Inclusion of polymethine cyanine dyes in the cavity of macrocyclic receptors is an effective strategy to alter their absorption and emission behavior in aqueous solution. In this paper, the effect of the host-guest interaction between cucurbit[8]uril (CB[8]) and a model trimethine indocyanine (Cy3) on dye spectral properties and aggregation in water is investigated. Solution studies, performed by a combination of spectroscopic and calorimetric techniques, indicate that the addition of CB[8] disrupts Cy3 aggregates, leading to the formation of a 1 : 1 host-guest complex with an association constant of 1.5×10<sup>6</sup> M<sup>-1</sup> . At concentrations suitable for NMR experiments, the slow formation of a supramolecular polymer was observed, followed by precipitation. Single crystals X-ray structure elucidation confirmed the formation of a polymer with 1 : 1 stoichiometry in the solid state. Cyanine ; Chemistry ; Aqueous solution ; Stoichiometry ; Supramolecular chemistry ; Cucurbituril ; Polymer ; Molecule ; Physical chemistry ; Organic chemistry ; Fluorescence Supramolecular Chemistry and Complexes ; Molecular Sensors and Ion Detection ; Crystallography and molecular interactions
Authors: Ge Ma | Qianshu Wang | Jun Ye | Lifan He | Longhai Guo | Xiaoyu Li | Teng Qiu | Xinlin Tuo
Source: Molecules (article, 2022-11-05)
Field: Materials Science — Polymers and Plastics

The Multi-Step Chain Extension for Waterborne Polyurethane Binder of Para-Aramid Fabrics The comprehensive balance of the mechanical, interfacial, and environmental requirements of waterborne polyurethane (WPU) has proved challenging, but crucial in the specific application as the binder for high-performance polymer fiber composites. In this work, a multi-step chain extension (MCE) method was demonstrated using three kinds of small extenders and one kind of macro-chain extender (CE) for different chain extension steps. One dihydroxyl blocked small molecular urea (1,3-dimethylolurea, DMU) was applied as one of the CEs and, through the hybrid macrodiol/diamine systems of polyether, polyester, and polysiloxane, the WPU was developed by the step-by-step optimization on each chain extending reaction via the characterization on the H-bonding association, microphase separation, and mechanical properties. The best performance was achieved when the ratio of polyether/polyester was controlled at 6:4, while 2% of DMU and 1% of polysiloxane diamine was incorporated in the third and fourth chain extension steps, respectively. Under the condition, the WPU exhibited not only excellent tensile strength of 30 MPa, elongation of break of about 1300%, and hydrophobicity indicated by the water contact angle of 98°, but also effective interfacial adhesion to <i>para</i>-aramid fabrics. The peeling strength of the joint based on the polysiloxane incorporated WPU after four steps of chain extension was 430% higher than that prepared through only two steps of chain extension. Moreover, about 44% of the peeling strength was sustained after the joint had been boiling for 40 min in water, suggesting the potential application for high-performance fabric composites. Materials science ; Polyurethane ; Ultimate tensile strength ; Aramid ; Polyester ; Composite material ; Contact angle ; Diamine ; Polymer ; Fiber ; Polymer chemistry Polymer composites and self-healing ; Synthesis and properties of polymers ; Silicone and Siloxane Chemistry
Authors: P. Esteban | Fernando Herrera | Daniel San Martín | Amparo Luna | Pedro Almendros
Source: Advanced Synthesis & Catalysis (article, 2022-08-10)
Field: Chemistry — Organic Chemistry

Regioselectivity Switch Based on the Stoichiometry: Stereoselective Synthesis of Trisubstituted Vinyl Epoxides by Cu‐Catalyzed 3‐<i>exo</i>‐<i>trig</i> Cyclization of α‐Allenols Abstract Typical transition metal‐catalyzed oxycyclization of allenols takes place at the terminal allene carbon via a 5‐ endo path and forms dihydrofurans. A copper‐catalyzed protocol brought about a reversed regioselectivity, generating a series of trisubstituted epoxides through a 3‐ exo‐ cyclization/sulfonylation cascade. The current stoichiometry control of regioselectivity may open singular opportunities in chemical transformations. magnified image Regioselectivity ; Chemistry ; Allene ; Stoichiometry ; Stereoselectivity ; Catalysis ; Organic chemistry Catalytic C–H Functionalization Methods ; Catalytic Alkyne Reactions ; Asymmetric Hydrogenation and Catalysis
Authors: Qi Zhu | Yang Guo | Bing Chen | Yanze Wang | Hao Suo | Xin Zhang | Jun Fan | Feng Wang
Source: Chemistry of Materials (article, 2022-08-17)
Field: Materials Science — Materials Chemistry

Doping-Mediated Size and Structure Tailoring of CaS Nanocrystals Lanthanide-doped CaS crystals are extensively studied as light-emitting materials, but the investigation of CaS nanocrystals is largely lagging. This work reports a doping-induced modification of surface charge density and the local coordination environment in CaS:Ce nanocrystals, which offers precise control over the nanocrystal size (39–14 nm) and emission color (green to yellow). Our mechanistic investigations, corroborated by theoretical calculations, reveal a S-enriched nanocrystal surface that accommodates excess charges of the aliovalent lanthanide dopants. Owing to the altered surface structure, we identify a dark Ce state that selectively extinguishes light emission of the CaS:Ce nanocrystals. We demonstrate that the doping-induced surface effects can be offset by coating the CaS:Ce nanocrystals with an undoped CaS shell, giving rise to a shell-thickness-dependent emission. Our findings suggest that nanocrystals may respond differently to impurity dopants than the corresponding bulk crystals, thereby giving rise to extended control over materials properties for applications such as optical encryption. Nanocrystal ; Dopant ; Materials science ; Doping ; Nanotechnology ; Lanthanide ; Optoelectronics ; Chemistry ; Ion Quantum Dots Synthesis And Properties ; Luminescence Properties of Advanced Materials ; Nanocluster Synthesis and Applications
Authors: David Guzmán | Miguel A. Romero | José A. González‐Delgado | Jesús F. Arteaga | Uwe Pischel
Source: The Journal of Organic Chemistry (article, 2022-03-25)
Field: Chemistry — Organic Chemistry

Metal-Mediated Organocatalysis in Water: Serendipitous Discovery of Aldol Reaction Catalyzed by the [Ru(bpy)<sub>2</sub>(nornicotine)<sub>2</sub>]<sup>2+</sup> Complex The [Ru(bpy)<sub>2</sub>(Nor)<sub>2</sub>]<sup>2+</sup> complex (Nor = nornicotine) is an efficient catalyst for the aldol reaction of acetone with activated benzaldehydes in a buffered aqueous solution. The metal plays the role of an activator for the nornicotine organocatalyst ligands. The resulting catalytic activity is potentiated by a factor of about 4.5 as compared to free nornicotine. Similar rate enhancements can be achieved by using Zn(II) cations as the activator. The observations are rationalized with the reduced basicity of the pyrrolidine N in nornicotine due to the enhanced electron withdrawal of the metal-complexed pyridyl moiety. Chemistry ; Nornicotine ; Catalysis ; Aldol reaction ; Pyrrolidine ; Moiety ; Metal ; Medicinal chemistry ; Acetone ; Stereochemistry ; Photochemistry ; Organic chemistry ; Alkaloid Asymmetric Synthesis and Catalysis ; Catalytic C–H Functionalization Methods ; Oxidative Organic Chemistry Reactions
Authors: Kevin Sartori | Dris Ihiawakrim | Christophe Lefèvre | Solenn Réguer | Cristian Mocuta | Sylvie Bégin‐Colin | Fadi Choueikani | Benoît P. Pichon
Source: Materials Advances (article, 2022-01-01)
Field: Materials Science — Materials Chemistry

A detailed investigation of the core@shell structure of exchanged coupled magnetic nanoparticles after performing solvent annealing Solvent annealing at around 300 °C resulted in a significant modification of the structure and the magnetic properties of core–shell metal oxide nanoparticles as shown by DANES and XMCD. Annealing (glass) ; Nanoparticle ; Materials science ; Solvent ; Oxide ; Magnetic nanoparticles ; Metal ; Chemical engineering ; Nanotechnology ; Crystallography ; Chemistry ; Metallurgy ; Organic chemistry Magnetic Properties and Synthesis of Ferrites ; Magnetic properties of thin films ; Iron oxide chemistry and applications
Authors: Tal Rosner | Nicholas G. Pavlopoulos | Hagit Shoyhet | Mathias Micheel | Maria Wächtler | Noam Adir | Lilac Amirav
Source: Nanomaterials (article, 2022-09-25)
Field: Materials Science — Materials Chemistry

The Other Dimension—Tuning Hole Extraction via Nanorod Width Solar-to-hydrogen generation is a promising approach to generate clean and renewable fuel. Nanohybrid structures such as CdSe@CdS-Pt nanorods were found favorable for this task (attaining 100% photon-to-hydrogen production efficiency); yet the rods cannot support overall water splitting. The key limitation seems to be the rate of hole extraction from the semiconductor, jeopardizing both activity and stability. It is suggested that hole extraction might be improved via tuning the rod's dimensions, specifically the width of the CdS shell around the CdSe seed in which the holes reside. In this contribution, we successfully attain atomic-scale control over the width of CdSe@CdS nanorods, which enables us to verify this hypothesis and explore the intricate influence of shell diameter over hole quenching and photocatalytic activity towards H<sub>2</sub> production. A non-monotonic effect of the rod's diameter is revealed, and the underlying mechanism for this observation is discussed, alongside implications towards the future design of nanoscale photocatalysts. Nanorod ; Materials science ; Extraction (chemistry) ; Nanoscopic scale ; Hydrogen production ; Quenching (fluorescence) ; Photocatalysis ; Semiconductor ; Rod ; Nanotechnology ; Hydrogen ; Optoelectronics ; Chemical engineering ; Optics ; Chemistry ; Catalysis ; Physics Quantum Dots Synthesis And Properties ; Advanced Photocatalysis Techniques ; Chalcogenide Semiconductor Thin Films