jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Michael J. Pung | Brandon Jolly | Chong Liu
Source: ChemRxiv (preprint, 2023-11-20)
Field: Materials Science — Materials Chemistry

Electrochemical NO Generation: Past, Present, and Future Generation of NO is crucial for many biological applications due to the antiseptic and antithrombotic properties of NO, as well as its role as a signaling molecule. Much work has been devoted to developing various methods of generating NO on demand. Recently, temporal control and fine-tunability have become highly sought after in NO generation, wherein electrochemistry has emerged as a suitable approach. Herein, we give an overview of the progress towards developing electrochemical generation of NO thus far and offer an outlook for the future of the field. Since much of electrochemical NO generation involves the use of either organometallic catalysts or catalysts inspired by enzymes, addressing challenges and limitations in electrochemical NO generation warrant collaboration between electrochemistry, organometallics, materials, and biochemistry. While the combination of electrochemistry with organometallics currently uses Cu and Fe-based catalysts, there is inspiration to discover other transition metal-based catalysts. Additionally, the combination of electrochemistry with advanced materials could result in the use of nanostructured electrodes such as nanowires and nanorods. These combinations with biochemistry allows for on demand NO generation systems to be developed in a biocompatible manner. In particular, the above propositions are taken from the well-studied CO2 reduction to CO, due to the similarities with nitrite (NO2–) reduction, which is a common NO precursor. Nanotechnology ; Electrochemistry ; Catalysis ; Materials science ; Nanowire ; Biochemical engineering ; Chemistry ; Combinatorial chemistry ; Electrode ; Engineering ; Organic chemistry Catalytic Processes in Materials Science ; Molecular Junctions and Nanostructures ; Ammonia Synthesis and Nitrogen Reduction
Authors: baiyang jiang | Yang Gao | Nathan C. Friede | Arianne C. Hunter | Dylan G. Boucher | Shelley D. Minteer | Matthew S. Sigman | Sarah E. Reisman | Phil S. Baran
Source: ChemRxiv (preprint, 2023-11-29)
Field: Chemistry — Organic Chemistry

Electrocatalytic Asymmetric Nozaki–Hiyama–Kishi Decarboxylative Coupling: Scope, Applications, and Mechanism The first general enantioselective alkyl-Nozaki-Hiyama-Kishi (NHK) coupling reactions are disclosed herein by em-ploying a Cr-electrocatalytic decarboxylative approach. Using easily accessible aliphatic carboxylic acids (via redox-active esters) as alkyl nucleophile synthons, in combination with aldehydes and enabling additives, chiral secondary alcohols are produced in good yield and high enantioselectivity under mild reductive electrolysis. This reaction, which cannot be mimicked using stoichiometric metal or organic reductants, tolerates a broad range of functional groups, and is successfully applied to dramatically simplify the synthesis of multiple medicinally relevant structures and natural products. Mechanistic studies revealed that this asymmetric alkyl e-NHK reaction was enabled by using catalytic tetrakis(dimethylamino)ethylene (TDAE) , which acts as a key reductive mediator to mediate the electrore-duction of the CrIII/chiral ligand complex. Chemistry ; Nucleophile ; Combinatorial chemistry ; Synthon ; Alkyl ; Enantioselective synthesis ; Ligand (biochemistry) ; Catalysis ; Yield (engineering) ; Organic chemistry ; Materials science Radical Photochemical Reactions ; Axial and Atropisomeric Chirality Synthesis ; Piperaceae Chemical and Biological Studies
Authors: Alba Sanz-Velasco | Olivia Amargós‐Reyes | Aya Kähäri | Sophia Lipinski | Luca M. Cavinato | Rubén D. Costa | Mauri A. Kostiainen | Eduardo Anaya‐Plaza
Source: ChemRxiv (preprint, 2023-12-03)
Field: Materials Science — Materials Chemistry

Controlling Aggregation-Induced Emission by Supramolecular Interactions and Colloidal Stability in Ionic Emitters for Light-Emitting Electrochemical Cells Chromophores face applicability limitations due to their natural tendency to aggregate, with a subsequent deactivation of their emission features. Hence, there has been a fast development of aggregation induced emission (AIE) emitters, in which non-radiative motional deactivation is inhibited. However, a fine control of their colloidal properties governing the emitting performance is fundamental for their application in thin film optoelectronics. In addition, ion-based lighting devices, such as light emitting electrochemical cells (LECs), requires the design ionic AIE emitter, whose structure allows i) an easy ion polarizability to assist charge injection and transport processes and ii) a reversible electrochemical behavior. To date, these fundamental questions have not been addressed yet. Herein, the hydrophilic/hydrophobic balance of a family of cationic tetraphenyl ethene (TPE) derivatives is finely tuned by chemical design., The hydrophilic yet repulsive effect of pyridinium-based cationic moieties is balanced with hydrophobic variables (long alkyl chains or counterion chemistry), leading to i) a control between monomeric/aggregate state ruling photoluminescence, ii) redox behavior, and iii) enhanced ion conductivity in thin films. This resulted in a LEC enhancement with the first ionic AIE emitters, reaching values of ca. 50 cd/m2 at 0.19 lm/W. Overall, this design rule will be key to advance ionic active species for optoelectronics. Counterion ; Ionic bonding ; Electrochemistry ; Polarizability ; Pyridinium ; Chemistry ; Electrochemical cell ; Ion ; Photoluminescence ; Chromophore ; Photochemistry ; Materials science ; Chemical physics ; Chemical engineering ; Electrode ; Optoelectronics ; Molecule ; Organic chemistry ; Physical chemistry Luminescence and Fluorescent Materials ; Organic Light-Emitting Diodes Research ; Ionic liquids properties and applications
Authors: Anastasia V. Artemova | Sergey S. Maklakov | Artem O. Shiryaev | Alexey V. Osipov | Dmitry A. Petrov | Konstantin N. Rozanov | Andrey N. Lagarkov
Source: Magnetism (article, 2023-04-23)
Field: Materials Science — Materials Chemistry

Influence of Hydrogen Reduction Stage Conditions on the Microwave Properties of Fine Iron Powders Obtained via a Spray-Pyrolysis Technique The relationship between the chemical purity of one-size particles and microwave properties in ferromagnetic materials is not clearly studied. Ferromagnetic nanostructured iron powders were synthesized from iron nitrate solution using ultrasonic spray-pyrolysis and then reduced in H2 flow at 350, 400, 450, and 500 °C. A rise in the concentration of solutions of a precursor from 10 to 20 wt. % led to an increase in mean particle size. The interrelationship was studied between chemical composition and the microwave dispersion of the powders obtained. An increase in the temperature of reduction changes the chemical composition and increases the amplitude of complex microwave permeability, which was studied using solid-state physics methods (XRD, STA, SEM, and VNA). It was found that annealing at 400 °C is the optimal treatment that allows the production of iron powders, consisting of about 90% of α-Fe phase, possessing a particle surface with low roughness and porosity, and demonstrating intense microwave absorption. Annealing at a higher temperature (500 °C) causes an even higher increase in permeability but leads to the destruction of nanostructured spheres into smaller particles due to grain growth. This destruction causes an abrupt increase in permittivity and therefore significantly reduces potential applications of the product. The insight into chemical–magnetic relationships of these materials enhances the data for design applications in magnetic field sensing. Materials science ; Microwave ; Annealing (glass) ; Porosity ; Chemical engineering ; Particle size ; Pyrolysis ; Iron oxide ; Hydrogen ; Chemical composition ; Ferromagnetism ; Nanoparticle ; Analytical Chemistry (journal) ; Composite material ; Metallurgy ; Nanotechnology ; Chemistry Magnetic Properties and Synthesis of Ferrites ; Iron oxide chemistry and applications ; Electromagnetic wave absorption materials
Authors: Lisa Moni | Franziska K. Merkt-Tasch | Bernd Mayer | Sergio Mulone | Thomas J. J. Müller | Renata Riva
Source: Dyes and Pigments (article, 2023-03-06)
Field: Chemistry — Organic Chemistry

Luminescent furo[2,3-c]isoquinolines as fluorophores - Tuning the luminophore by donor substitution A new library of the uncommon furo[2,3-c]isoquinoline scaffold has been synthesized by coupling the Ugi multicomponent reaction with a complex one-pot Pd-mediated double cyclization. The highly convergent and diversity-oriented approach has been exploited to introduce substituents with electron donor properties directly linked to the scaffold in the most representative positions 1 and/or 8. Moreover, the influence of an aromatic ring used as spacer between the scaffold and the electron donor substituent, as well as the substitution of the phenyl substituent in position 1 with a thiophene, on the photophysical properties have been investigated. Upon UV excitation part of the new molecules are intensively blue luminescent but for an amino donor substituent a significant switch to green emitters has been observed even upon eyesight. The electronic structure has been semiquantitatively rationalized by DFT and (TD)DFT calculations. Substituent ; Luminophore ; Chemistry ; Isoquinoline ; Luminescence ; Photochemistry ; Thiophene ; Molecule ; Ring (chemistry) ; Combinatorial chemistry ; Stereochemistry ; Materials science ; Organic chemistry Multicomponent Synthesis of Heterocycles ; Catalytic C–H Functionalization Methods ; Synthesis and Biological Evaluation
Authors: M. Anni
Source: Molecules (article, 2023-07-01)
Field: Materials Science — Materials Chemistry

Investigation of the Origin of High Photoluminescence Quantum Yield in Thienyl-S,S-dioxide AIEgens Oligomers by Temperature Dependent Optical Spectroscopy The development of organic molecules showing high photoluminescence quantum yield (PLQY) in solid state is a fundamental step for the implementation of efficient light emitting devices. In this work the origin of the high PLQY of two trimers and two pentamers having one central thiophene-S,S-dioxide unit and two and four lateral thiophene or phenyl groups, respectively, is investigated by temperature dependent photoluminescence and time resolved photoluminescence measurements. The experimental results demonstrate that the molecules with lateral phenyl rings show higher PLQY due to a weaker coupling with intramolecular vibrations-related to variations in the radiative and non-radiative decay rates-and indicate different molecular rigidity as the main factors affecting the PLQY of this class of molecules. Photoluminescence ; Quantum yield ; Intramolecular force ; Materials science ; Spectroscopy ; Molecule ; Photochemistry ; Chemistry ; Optoelectronics ; Optics ; Physics ; Fluorescence ; Stereochemistry ; Organic chemistry Luminescence and Fluorescent Materials ; Organic Light-Emitting Diodes Research ; Organic Electronics and Photovoltaics
Authors: Wei He | Ryan T. K. Kwok | Zijie Qiu | Zheng Zhao | Ben Zhong Tang
Source: ChemRxiv (preprint, 2023-05-17)
Field: Materials Science — Materials Chemistry

A Holistic Perspective on Living Aggregate Aggregate is one of the most extensive existing modes of matters in the world. Besides the research objectives of inanimate systems in physical science, the entities in life science can be regarded as living aggregates, which are far from being thoroughly understood despite the great advances in molecular biology. Molecular biology follows the research philosophy of reductionism that generally reduces the whole into parts to study. Although reductionism benefits the understanding on molecular behaviors, it encounters limitations when extending to aggregate level. Holism is another epistemology that is comparable important to reductionism, which claims a top-down method to explore objectives at aggregate or mesoscale level, emphasizing on the interactions and synergetic/antagonistic effects of a group of composed single entities in determining the characteristics of a whole. As a representative of holism, aggregation-induced emission (AIE) materials have made great achievements in the past two decades in both physical science and life science. In particular, the unique properties of AIE materials endow with in-situ and real-time visual methods to investigate the inconsistence between microscopic molecules and macroscopic substances, offering researchers excellent toolkits to study living aggregates. The applications of AIE materials in life science are still in its infancy and worth expanding. In this perspective, we summarize the research progresses of AIE materials in unveiling some phenomenon and processes of living systems, aiming to provide a general research approach from the viewpoint of holism. At last, insights in what we can do in the near future are also raised and discussed. Holism ; Reductionism ; Perspective (graphical) ; Epistemology ; Aggregate (composite) ; Data science ; Computer science ; Nanotechnology ; Cognitive science ; Sociology ; Psychology ; Philosophy ; Artificial intelligence ; Materials science Luminescence and Fluorescent Materials ; Nanoplatforms for cancer theranostics ; Supramolecular Chemistry and Complexes
Authors: Khadisha Zahra | Conor Byrne | Zheshen Li | Kerry Hazeldine | Alex S. Walton
Source: Nanotechnology (article, 2023-08-07)
Field: Materials Science — Materials Chemistry

Oxide-mediated nitrogen doping of CVD graphene and their subsequent thermal stability Heteroatom doping of graphene is a promising approach for tailoring its chemical and electronic properties-a prerequisite for many applications such as sensing, catalysis, and energy storage. Doping chemical vapour deposition (CVD) graphene with nitrogen during growth (<i>in situ</i>doping) is a common strategy, but it produces a distribution of inequivalent dopant sites and requires substantial modifications to the CVD growth process. In this study, we demonstrate a novel and simple oxide-mediated approach to introduce nitrogen dopants into pre-existing CVD graphene (<i>ex situ</i>doping) which achieves comparable doping densities to<i>in situ</i>doping methodologies. Furthermore, we demonstrate that thermal annealing of N-doped graphene can selectively remove pyridinic, retaining graphitic and pyrrolic nitrogen dopants, offering an attractive route to further modify graphene functionality. The methodologies we present are simple and scalable to precisely tailor graphene properties without the need to alter CVD growth protocols. Materials science ; Graphene ; Doping ; Oxide ; Thermal stability ; Nitrogen ; Chemical engineering ; Thermal ; Nanotechnology ; Metallurgy ; Optoelectronics ; Organic chemistry ; Thermodynamics Graphene research and applications ; Diamond and Carbon-based Materials Research ; Semiconductor materials and devices
Authors: Evdokia Galata | Charitomeni M. Veziri | George V. Theodorakopoulos | George E. Romanos | Evangelia A. Pavlatou
Source: Membranes (article, 2023-06-28)
Field: Materials Science — Materials Chemistry

A Combined Gas and Water Permeances Method for Revealing the Deposition Morphology of GO Grafting on Ceramic Membranes The adhesion enhancement of a graphene oxide (GO) layer on porous ceramic substrates is a crucial step towards developing a high-performance membrane for many applications. In this work, we have achieved the chemical anchoring of GO layers on custom-made macroporous disks, fabricated in the lab by pressing α-Al<sub>2</sub>O<sub>3</sub> powder. To this end, three different linkers, polydopamine (PDA), 3-Glycidoxypropyltrimethoxysilane (GPTMS) and (3-Aminopropyl) triethoxysilane (APTMS), were elaborated for their capacity to tightly bind the GO laminate on the ceramic membrane surface. The same procedure was replicated on cylindrical porous commercial ZrO<sub>2</sub> substrates because of their potentiality for applications on a large scale. The gas permeance properties of the membranes were studied using helium at 25 °C as a probe molecule and further scrutinized in conjunction with water permeance results. Measurements with helium at 25 °C were chosen to avoid gas adsorption and surface diffusion mechanisms. This approach allowed us to draw conclusions on the deposition morphology of the GO sheets on the ceramic support, the mode of chemical bonding with the linker and the stability of the deposited GO laminate. Specifically, considering that He permeance is mostly affected by the pore structural characteristics, an estimation was initially made of the relative change in the pore size of the developed membranes compared to the bare substrate. This was achieved by interpreting the results via the Knudsen equation, which describes the gas permeance as being analogous to the third power of the pore radius. Subsequently, the calculated relative change in the pore size was inserted into the Hagen-Poiseuille equation to predict the respective water permeance ratio of the GO membranes to the bare substrate. The reason that the experimental water permeance values may deviate from the predicted ones is related to the different surface chemistry, i.e., the hydrophilicity or hydrophobicity that the composite membranes acquire after the chemical modification. Various characterization techniques were applied to study the morphological and physicochemical properties of the materials, like FESEM, XRD, DLS and Contact Angle. Permeance ; Materials science ; Membrane ; Ceramic ; Chemical engineering ; Layer (electronics) ; Adsorption ; Substrate (aquarium) ; Nanotechnology ; Composite material ; Chemistry ; Organic chemistry Graphene research and applications ; Membrane Separation Technologies ; Membrane Separation and Gas Transport
Authors: Emre Yılmazoğlu | Selcan Karakuş
Source: Journal of the Turkish Chemical Society Section A Chemistry (article, 2023-10-31)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Recent Developments in Nanostructured Materials for Supercapacitor Electrodes This review focuses on nanostructures-based systems and aims to provide a comprehensive overview of recent advancements in energy storage technologies and modified energy storage materials. The transition towards a sustainable and carbon-free energy system hinges on the progress of efficient and safe energy storage technologies. Supercapacitors have garnered significant interest in diverse energy storage applications due to their rapid charge/discharge rates, high power density, and extended cycle life. Nanostructures have conclusively demonstrated their capability to significantly enhance supercapacitor electrodes' performance. MXene, an innovative category of 2D materials, has emerged as a promising candidate for energy storage applications due to its substantial surface area, exceptional electrical conductivity, and versatile characteristics. Supercapacitors, nanostructures, and MXene are the main topics of the research articles and reviews in this special issue, highlighting recent developments in the design, synthesis, and characterization of advanced energy storage materials and devices. Additionally, this study presents an in-depth investigation of various carbon-based nanomaterials, their synthesis techniques, and their performance in supercapacitors. It also emphasizes the potential of recycling waste materials for developing high-performance nanomaterials for energy storage applications. Finally, this review encourages further research and development of advanced energy storage technologies by giving readers a thorough overview of the current state-of-the-art and future directions in this rapidly expanding sector. Supercapacitor ; Energy storage ; Nanotechnology ; Electrochemical energy storage ; Nanomaterials ; Materials science ; Electrode ; Chemistry ; Power (physics) ; Electrochemistry ; Physics Supercapacitor Materials and Fabrication ; MXene and MAX Phase Materials ; Advanced Sensor and Energy Harvesting Materials
Authors: Gabriele Boschetto | Aida Todri‐Sanial
Source: The Journal of Physical Chemistry C (article, 2023-12-13)
Field: Materials Science — Materials Chemistry

Ab Initio Simulations on the Structure and Properties of Supported Core–Shell Pt Nanoparticles on Single-Layer MoS<sub>2</sub> To effectively employ core–shell nanoparticles in catalysis and sensing necessarily requires a deep atomic-level understanding of their structural and electronic properties. Moreover, for both applications, nanoparticles are usually deposited over a support material which is known to lead to significant (and often unpredictable) changes in their properties and stability. In this work, we study a number of model Pt core–shell nanoparticles supported on single-layer molybdenum disulfide (MoS2). Our aim is to investigate the effect of the support on the properties of such nanoparticles, and we do so by means of first-principles simulations in the framework of density functional theory (DFT). Here, we show that the stability and the catalytic and/or sensing properties of the supported nanoparticles correlate with both strain and charge transfer, which are concurring and competing effects. Overall, our results suggest that core–shell Pt clusters supported on MoS2 may be successfully used in catalysis and in field-effect biosensing. Molybdenum disulfide ; Nanoparticle ; Materials science ; Density functional theory ; Nanotechnology ; Molybdenum ; Catalysis ; Ab initio ; Shell (structure) ; Core (optical fiber) ; Chemical physics ; Computational chemistry ; Chemistry 2D Materials and Applications ; Advanced biosensing and bioanalysis techniques ; MXene and MAX Phase Materials
Authors: Naba Abuhafez | Andreas W. Ehlers | Bas de Bruin | Rafael Gramage‐Doria
Source: Angewandte Chemie (article, 2023-12-01)
Field: Chemistry — Organic Chemistry

Markovnikov‐Selective Cobalt‐Catalyzed Wacker‐Type Oxidation of Styrenes into Ketones under Ambient Conditions Enabled by Hydrogen Bonding Abstract The replacement of palladium catalysts for Wacker‐type oxidation of olefins into ketones by first‐row transition metals is a relevant approach for searching more sustainable protocols. Besides highly sophisticated iron catalysts, all the other first‐row transition metal complexes have only led to poor activities and selectivities. Herein, we show that the cobalt‐tetraphenylporphyrin complex is a competent catalyst for the aerobic oxidation of styrenes into ketones with silanes as the hydrogen sources. Remarkably, under room temperature and air atmosphere, the reactions were exceedingly fast (up to 10 minutes) with a low catalyst loading (1 mol %) while keeping an excellent chemo‐ and Markovnikov‐selectivity (up to 99 % of ketone). Unprecedently high TOF (864 h −1 ) and TON (5,800) were reached for the oxidation of aromatic olefins under these benign conditions. Mechanistic studies suggest a reaction mechanism similar to the Mukaiyama‐type hydration of olefins with a change in the last fundamental step, which controls the chemoselectivity, thanks to a unique hydrogen bonding network between the ethanol solvent and the cobalt peroxo intermediate. Markovnikov's rule ; Catalysis ; Chemistry ; Chemoselectivity ; Cobalt ; Silanes ; Ketone ; Transition metal ; Palladium ; Solvent ; Selectivity ; Organic chemistry ; Photochemistry ; Combinatorial chemistry ; Regioselectivity Catalytic C–H Functionalization Methods ; Oxidative Organic Chemistry Reactions ; Catalytic Cross-Coupling Reactions