jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Ligia A. Luque-Álvarez | Guillermo Torres-Sempere | Francisca Romero‐Sarria | Luis F. Bobadilla | Tomás Ramı́rez Reina | J.A. Odriozola
Source: Microporous and Mesoporous Materials (article, 2024-07-16)
Field: Materials Science — Materials Chemistry

Controlling copper location on exchanged MOR-type aluminosilicate zeolites for methanol carbonylation: In situ/operando IR spectroscopic studies Replacing homogeneous catalytic processes by heterogeneous routes based on the utilization of solid catalysts is of great interest from an environmental point of view. Owing to their genuine pore structure, zeolites such as mordenites (MOR) have emerged as game-changing materials to enable the heterogenization of catalytic processes including methanol carbonylation. Cu-exchange zeolites take the edge over pristine zeolites, leading to enhanced catalytic performance in terms of greater activity, selectivity, and stability. Herein, the overall catalytic activity and stability can be modulated upon controlling the environment and location of copper active sites in zeolites. In this study, Cu-exchanged mordenites were strategically synthesized to investigate the role of Cu location inside of MOR cavities under working conditions by means of in situ/operando infrared (IR) spectroscopic studies. The results obtained revealed that a major proportion of Cu in the MR-8 cavities notably enhances the activity and stability of the catalyst. This study provides crucial insights for fine-tuning zeolite catalysts to achieve the heterogenization of homogeneous carbonylation processes. Aluminosilicate ; Carbonylation ; Copper ; In situ ; Methanol ; Chemistry ; Molecular sieve ; Inorganic chemistry ; Zeolite ; Catalysis ; Organic chemistry ; Carbon monoxide Catalytic Processes in Materials Science ; Metal-Organic Frameworks: Synthesis and Applications ; Zeolite Catalysis and Synthesis
Authors: Naomi Otandi
Source: Journal of Chemistry (article, 2024-08-31)
Field: Chemistry — Organic Chemistry

Effect of Catalyst Concentration on Reaction Rate in Organic Synthesis in Kenya Purpose: The aim of the study was to assess the effect of catalyst concentration on reaction rate in organic synthesis in Kenya. Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low-cost advantage as compared to field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: Increased catalyst concentration typically enhances the reaction rate by providing more active sites for the reactants to interact, thereby accelerating the reaction process. This phenomenon follows the principles of collision theory, which states that a higher concentration of catalyst molecules leads to more frequent collisions with reactant molecules, thus increasing the likelihood of successful reactions. Studies have shown that in many organic syntheses, an optimal catalyst concentration exists where the reaction rate is maximized; beyond this point, further increases in catalyst concentration may result in negligible improvements or even adverse effects due to catalyst aggregation or inhibition. Additionally, the nature of the catalyst, its dispersion in the reaction medium, and the specific reaction mechanism all play significant roles in determining the overall impact of catalyst concentration on reaction kinetics. Consequently, fine-tuning the catalyst concentration is essential for optimizing reaction conditions, improving yields, and achieving desired product selectivity in organic synthesis. Implications to Theory, Practice and Policy: Transition state theory, collision theory and michaelis menten kinetics may be used to anchor future studies on assessing effect of catalyst concentration on reaction rate in organic synthesis in Kenya. Practical guidelines are crucial for optimizing catalyst concentration in specific reaction types and industrial settings. Establishing regulatory frameworks that incentivize efficient catalyst concentration practices within industries is imperative. Chemistry ; Catalysis ; Organic synthesis ; Reaction rate ; Combinatorial chemistry ; Organic chemistry Inorganic and Organometallic Chemistry
Authors: Nataliya Karaush‐Karmazin | Jacek E. Nycz
Source: Current Organic Chemistry (article, 2024-10-23)
Field: Materials Science — Materials Chemistry

Advances in Molecular Photoswitches: From Azobenzenes to Azoquinolines Molecular photoswitches represent a dynamic and ever-growing research area based on the ability of molecules to convert (switch) between &lt;i&gt;cis-(Z)&lt;/i&gt; and &lt;i&gt;trans-(E)&lt;/i&gt; isomers. Azobenzenes are the most popular and widely employed &lt;i&gt;Z-E&lt;/i&gt; photoswitchable molecules in the development of photoresponsive, multifunctional smart materials for various applications. The promising avenues in this field include molecular fine-tuning of azobenzenebased photoswitches and the creation of single or dual-functional probes. This short overview highlights recent advances in the design of molecular photoswitches, particularly the molecular design strategies of azobenzene-based photoswitches with their structural and electronic features. Particular attention is paid to azoquinolines, which seem to be a promising alternative to azobenzenes in the design of novel multifunctional photoswitches with improved photochromic properties. Here, we have also developed the novel star-shaped multiazoquinoline photoswitch comprising individual azoquinoline-based photochromes connected to a central trisubstituted 1,3,5- triformylphloroglucinol core by quantum chemical calculations. This unique structure is favorable for independent &lt;i&gt;Z-E&lt;/i&gt; isomerization of each azoquinoline-based photochrome within one macromolecule. Chemistry ; Azobenzene ; Nanotechnology ; Molecule ; Organic chemistry Photochromic and Fluorescence Chemistry ; Organic Chemistry Cycloaddition Reactions ; Porphyrin and Phthalocyanine Chemistry
Authors: Peter O. Aina | Sukanta K. Mondal | Ali A. Rownaghi | Fateme Rezaei
Source: ACS Applied Polymer Materials (article, 2024-03-14)
Field: Chemistry — Organic Chemistry

Assessing Hydrolysis Performance of Ce(OH)<sub>4</sub>@PIM-1 Composites Functionalized with Amidoxime, Aldoxime, and Carboxylate Groups Toward Dimethyl 4-Nitrophenylphosphonate, a Nerve Agent Simulant In recent years, significant attention has been directed toward evaluating the reactivity of diverse polymers to gauge their catalytic activity against hazardous chemicals. Among these polymers, PIM-1 has emerged as an exceptional candidate due to its noteworthy attributes including high surface area, excellent solubility, and the capability to fine-tune the nitrile functional groups along its polymeric backbone. In this study, we explored the impact of different functional groups, such as amidoxime (AX), aldoxime (OX), and carboxylate (COOH), on the degradation of dimethyl 4-nitrophenylphosphonate (DMNP) in comparison to pure PIM-1 and their respective Ce(OH)4-loaded polymer composites. Remarkably, the PIM-1-AX analog exhibited the highest degree of catalytic activity (ca. 100%) among the functional groups investigated under 24 h, due to its high nucleophilicity, whereas under 1 h, Ce(OH)4@PIM-1-COOH outperformed other materials by displaying an initial hydrolysis rate of 0.058 μmol/s and a half-time of 0.38 min, on the account of its high Lewis acidity, stemming from the Ce4+ coupled with the Bronsted carboxylic acid. Overall, the findings of this study highlight the influence of the Bronsted and Lewis acid pairs in promoting the DMNP degradation kinetics, providing an alternative pathway to the commonly used nucleophilic substitution method. Nitrile ; Hydrolysis ; Chemistry ; Carboxylate ; Nucleophile ; Lewis acids and bases ; Reactivity (psychology) ; Brønsted–Lowry acid–base theory ; Catalysis ; Polymer ; Kinetics ; Polymer chemistry ; Organic chemistry Chemical Synthesis and Reactions ; Metal-Organic Frameworks: Synthesis and Applications ; Covalent Organic Framework Applications
Authors: Dhrubajit Borah | Abhilash Sharma | Rekha Rani Dutta | Indrani Bhuyan | Rupjyoti Dutta
Source: Journal of Organometallic Chemistry (article, 2024-11-16)
Field: Chemistry — Inorganic Chemistry

Recent advances in homogeneous catalysts for the acceptorless dehydrogenation of alcohols to ketones and aldehydes Chemistry ; Dehydrogenation ; Homogeneous ; Catalysis ; Organic chemistry ; Homogeneous catalysis ; Combinatorial chemistry Asymmetric Hydrogenation and Catalysis ; Catalysis for Biomass Conversion ; Innovative Microfluidic and Catalytic Techniques Innovation
Authors: Lorena Renedo | Estela Álvarez | Marta Solas | Samuel Suárez‐Pantiga | Manuel A. Fernández‐Rodríguez | Roberto Sanz
Source: Advanced Synthesis & Catalysis (article, 2024-03-01)
Field: Chemistry — Organic Chemistry

Gold‐Catalyzed Tandem Oxidation‐Migration of 3‐Propargyl Indoles: Synthesis of α‐Indol‐3‐yl α,β‐Unsaturated Carbonyls Abstract α‐Indol‐3‐yl α,β‐unsaturated carbonyl compounds are synthesized from 3‐propargyl indoles, obtained by direct propargylation of indoles, via a gold‐catalyzed tandem oxidation‐1,2‐indole migration reaction in the presence of pyridine N ‐oxides. Fine‐tuning of the catalyst and oxidant enables the reaction of 3‐propargyl indoles bearing different substituents. The order of oxidation and indole migration is determined by the terminal or internal nature of the alkyne moiety. In addition, the process can be coupled with additional reactions, allowing an increase in molecular complexity or the design of more elaborated tandem reactions. In this sense, indole derivatives bearing an alkenyl substituent at the alkyne position evolve through a gold‐catalyzed tandem oxidation‐1,2‐indole migration‐Nazarov cyclization producing α‐indolyl cyclopentenones. Chemistry ; Propargyl ; Tandem ; Catalysis ; Combinatorial chemistry ; Cascade reaction ; Organic chemistry Catalytic Alkyne Reactions
Authors: Santosh Kumar | Eric Agyeman-Duah | Marian M. Awaga-Cromwell | Victor Ujor
Source: Applied and Environmental Microbiology (article, 2024-09-11)
Field: Materials Science — Materials Chemistry

Transcriptomic characterization of recombinant <i>Clostridium beijerinckii</i> NCIMB 8052 expressing methylglyoxal synthase and glyoxal reductase from <i>Clostridium pasteurianum</i> ATCC 6013 Biological production of commodity chemicals from abundant waste streams such as whey permeate represents an opportunity for decarbonizing chemical production. Whey permeate remains a vastly underutilized feedstock for bioproduction purposes. Thus, enhanced understanding of the cellular and metabolic repertoires of lactose-mediated production of chemicals such as butanol promises to identify new targets that can be fine tuned in recombinant and native microbial strains to engender stronger coupling of whey permeate-borne lactose to value-added chemicals. Our results highlight new genetic targets for future engineering of <i>C. beijerinckii</i> for improved butanol production on lactose and ultimately in whey permeate. Clostridium beijerinckii ; Biochemistry ; Biology ; Methylglyoxal ; Biosynthesis ; Chemistry ; Xylose metabolism ; Xylose ; Gene ; Fermentation ; Enzyme ; Butanol Enzyme Structure and Function ; Enzyme Production and Characterization ; Biofuel production and bioconversion
Authors: Shiyu Zheng | Yuting He | Jiacheng Liu | Wei‐Hsiang Huang | Chih‐Wen Pao | Zhiwei Hu | Xiaoqing Huang | Yun-Hua Li
Source: ACS Applied Nano Materials (article, 2024-06-03)
Field: Materials Science — Materials Chemistry

Palladium–Tin Alloy Nanoparticles in Different Crystalline Phases for Direct Hydrogen Peroxide Synthesis Understanding the performance differences of palladium–tin (Pd–Sn) nanocrystal phases lays the foundation to fine-tune their catalytic activity in direct hydrogen peroxide (H2O2) synthesis (DHS). This study prepared hexagonal Pd3Sn2, orthorhombic Pd2Sn, and cubic Pd3Sn nanoparticles by solvothermal synthesis for DHS. The results reveal that hexagonal Pd3Sn2/TiO2 exhibits a superior DHS performance, as well as lower H2O2 degradation and hydrogenation, compared to orthorhombic Pd2Sn/TiO2, cubic Pd3Sn/TiO2, and Pd/TiO2. Detailed characterization and theoretical calculations indicate that hexagonal Pd3Sn2/TiO2 with higher PdO and SnOx contents presents lower adsorption and desorption capacities of hydrogen and oxygen than other catalysts. H2O2 can be rapidly generated once H2 and O2 are adsorbed on hexagonal Pd3Sn2/TiO2. High productivity and selectivity of H2O2 are achieved due to the lower energy barrier for the initial hydrogenation of *O2 to *OOH and the stability of H2O2 on hexagonal Pd3Sn2/TiO2 with the (102) facet. This study offers in-depth insights into Pd-based bimetallic alloys for DHS from the perspective of crystalline phase engineering. Palladium ; Alloy ; Hydrogen peroxide ; Tin ; Materials science ; Nanoparticle ; Chemical engineering ; Metallurgy ; Chemistry ; Nanotechnology ; Catalysis ; Organic chemistry Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions ; Electrocatalysts for Energy Conversion
Authors: Minghao Wang | Haomin Yu | J. C. Jiang | Wencong Xu | Guofeng Xu | Si Wu
Source: Polymer (article, 2024-12-12)
Field: Materials Science — Polymers and Plastics

Cis-trans isomerism-driven thermal and phase transitions in oleic and elaidic acids and their derived polymers Elaidic acid ; Polymer ; Phase transition ; Phase (matter) ; Materials science ; Thermal ; Polymer chemistry ; Chemistry ; Chemical engineering ; Organic chemistry ; Thermodynamics ; Physics ; Engineering Polymer composites and self-healing ; Polymer Nanocomposites and Properties ; Advanced Polymer Synthesis and Characterization
Authors: Stephanie Yen Nee Kew
Source: World Journal of Advanced Research and Reviews (article, 2024-06-06)
Field: Materials Science — Biomaterials

Green revolution: Chemical modifications of starch-based materials for sustainable plastic synthesis The pursuit of sustainable alternatives has become even more significant given the pressing global crisis associated with conventional petroleum-based plastics. Among the most promising polysaccharides, starch-based synthesized plastics have garnered a lot of attention owing to their abundance, cost-efficiency, and ability to offer a viable solution that complies with the tenets of the Green Revolution. However, their intrinsic shortcomings, such as low thermal stability and tensile strength, have underscored the need for the discovery of various modification strategies. In light of this, the present review offers insights into several types of chemical modifications, their effects on plastic properties, and the overall effectiveness of starch-based plastics as ecologically sound polymers. Through a systematic analysis of relevant literature, findings reveal that the properties of starch-based polymers are distinctly impacted by each modification method, showing varying efficacy. A feasible technique for achieving a high water absorption index in plastics may be enzymatic hydrolysis, but acidic modification could be better suited for improved moisture content and solubility. In terms of tensile strength, alkaline modification appears favorable; nonetheless, determining the optimal concentration is essential for attaining the highest tensile strength. Therefore, understanding the influences of these chemical modifications is vital to optimizing the development of greener plastics in materials science. Emerging approaches to modification were also laid out to revolutionize plastic properties by exploring new enzymes or alternative alkaline substances, fine-tuning process parameters, and innovating additive combinations, all of which are necessary for advancing the utility and practicality of modified plastics in diverse applications. Starch ; Polymer science ; Materials science ; Chemical engineering ; Biochemical engineering ; Nanotechnology ; Chemistry ; Food science ; Engineering biodegradable polymer synthesis and properties
Authors: Veronika Jelínková | Angela Dellai | Lauryne Verwaerde | Vincent Rodriguez | Michaela Fecková | Martina Vachtlová | Jan Podlesný | Milan Klikar | Bixente Sempé | Matt Hugget | Patrik Pařík | Oldřich Pytela | Frédéric Castet | Zdeňka Růžičková | Filip Bureš
Source: Chemistry - A European Journal (article, 2024-12-28)
Field: Materials Science — Materials Chemistry

Property Tuning in <i>N</i> ‐Methylpyrrole Azo‐Photoswitches via Modification of the Peripheral Substituents Differently substituted pyrrole-azo-benzene molecular photoswitches were prepared in a straightforward synthetic way. Their fundamental properties were investigated by XRD analysis, differential scanning calorimetry, thermogravimetric analysis, cyclic voltammetry, UV-Vis absorption spectroscopy, Hyper-Rayleigh Scattering, and NMR spectroscopy; the experimental results were further corroborated by DFT calculations. Thermal robustness, the HOMO/LUMO levels, and the absorption properties were altered mostly by substituting the N-methylpyrrole moiety and further fine-tuned by modifying the benzene substituents. The pyrrole substituent also proved crucial for the second-order non-linear optical (NLO) response as well as the photoswitching performance. Both fast and slow molecular switches can be designed with the half-life of the (Z) -isomer ranging from 48 seconds to 23.28 hours and the E/Z molar ratio up to 12/88. This comprehensive study allowed elucidation of the fundamental structure-property relationships and subsequently addresses the key aspects of the property tuning via substitution in molecular azo-photoswitches. Peripheral ; Property (philosophy) ; Chemistry ; Materials science ; Computer science Photochromic and Fluorescence Chemistry ; Porphyrin and Phthalocyanine Chemistry ; Molecular Sensors and Ion Detection
Authors: Alberto Belmonte | Silvia De la Flor | Osman Konuray | Xavier Fernández‐Francos | Xavier Ramis
Source: European Polymer Journal (article, 2024-04-13)
Field: Chemistry — Organic Chemistry

Analysis of the non-ideal crosslinking process in thiol-X “click” thermosets Thiol-click reactions are widely used in the preparation of thermosets. The network build-up process follows step-wise polymerization behavior, which is commonly analyzed assuming ideal step-wise behavior using well-known expressions such as the Flory-Stockmayer equation for the prediction of the gel point conversion. However, a number of factors contributing to departures from the expected ideal behavior can be identified: a) impurity of the reagents, b) complexity of the reaction mechanism and c) internal cyclization processes. In order to maximize the accuracy of predictions about the expected crosslinking behavior and therefore fine-tune the design of thermosets designed as dual-curing systems or covalent adaptable networks (CANs), it is necessary to take into consideration all these sources of non-ideality. In this work, we aim to describe the effects of such factors on the network build-up process of thiol-click thermosets, making use of the recursive methodology of Miller and Macosko. The contribution of each factor is analyzed separately and their overall combined effect is discussed in relation with real data reported in the literature and experimental results. Thermosetting polymer ; Click chemistry ; Curing (chemistry) ; Materials science ; Computer science ; Polymerization ; Ideal (ethics) ; Process (computing) ; Biological system ; Polymer chemistry ; Polymer ; Composite material ; Programming language Click Chemistry and Applications ; Photochromic and Fluorescence Chemistry ; Photopolymerization techniques and applications
Authors: Monika Lamoria | Marilyn Daisy Milton
Source: Dyes and Pigments (article, 2024-06-24)
Field: Materials Science — Materials Chemistry

Non-doped blue-light emitting D–π–A type AIEE active novel quinoxaline derivatives and their application in acidochromism and data protection Quinoxaline ; Blue light ; Doping ; Chemistry ; Combinatorial chemistry ; Photochemistry ; Optoelectronics ; Materials science ; Organic chemistry Luminescence and Fluorescent Materials ; Organic Light-Emitting Diodes Research ; Synthesis and Biological Evaluation
Authors: Yeseul Hwang | Yong Hyun Lim | Jangeon Roh | Hae Won Ryu | Kihun Nam | S. Hong | Jong‐Ki Jeon | Do Heui Kim
Source: Applied Catalysis A General (article, 2024-07-23)
Field: Chemistry — Inorganic Chemistry

Enhancing control over individual selectivities of benzene, toluene, and xylene in n-butane aromatization: Impact of reaction and catalytic parameters Chemistry ; Aromatization ; Toluene ; Benzene ; Butane ; Catalysis ; Xylene ; p-Xylene ; Organic chemistry ; m-Xylene ; Selectivity Zeolite Catalysis and Synthesis ; Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions
Authors: Guanghao Wang | Zhishan Li | Yiguang Gai | Zonghao Xu | Wenli Kang | Zhouhang Li | Hua Wang | Kongzhai Li
Source: Applied Surface Science (article, 2024-05-11)
Field: Materials Science — Materials Chemistry

In situ exsolution of Pt nanoparticles on low Pt-substituted A-site deficient perovskite for efficient CO oxidation Catalysis ; Nanoparticle ; Redox ; Perovskite (structure) ; Oxide ; Transition metal ; Materials science ; Chemical engineering ; Metal ; Rational design ; Platinum ; Noble metal ; In situ ; Platinum nanoparticles ; Oxygen ; Nanotechnology ; Inorganic chemistry ; Chemistry ; Metallurgy ; Organic chemistry Catalytic Processes in Materials Science ; Electrocatalysts for Energy Conversion ; Catalysis and Oxidation Reactions
Authors: Vishal Kumar Porwal | Erwan André | Antoine Carof | Adolfo Bastida | Cédric Carteret | Francesca Ingrosso
Source: Molecules (article, 2024-04-18)
Field: Materials Science — Materials Chemistry

Structural and Vibrational Properties of Carboxylates Intercalated into Layered Double Hydroxides: A Joint Computational and Experimental Study Layered double hydroxides (LDHs) are fascinating clay-like materials that display versatile properties, making them an extremely fertile playground for diverse applications, ranging from bio-compatible materials to the pharmaceutical industry to catalysis and photocatalysis. When intercalating organic and bio-organic species between the inorganic layers, such materials are named hybrid LDHs. The structure-property relation in these systems is particularly relevant, since most of the properties of the materials may be fine-tuned if a comprehensive understanding of the microscopic structure in the interlamellar space is achieved, especially with respect to the reorganization under water uptake (swelling). In this work, we combined experiments and simulations to rationalize the behavior of LDHs intercalating three carboxylates, the general structure of which can be given as [Mg4Al2(OH)12]A2-·XH2O (with A2- = succinate, aspartate, or glutamate and X representing increasing water content). Following this strategy, we were able to provide an interpretation of the different shapes observed for the experimental water adsorption isotherms and for the evolution of the infrared carboxylate band of the anions. Apart from small differences, due to the different reorganization of the conformational space under confinement, the behavior of the two amino acids is very similar. However, such behavior is quite different in the case of succinate. We were able to describe the different response of the anions, which has a significant impact on the isotherm and on the size of the interlamellar region, in terms of a different interaction mechanism with the inorganic layer. Layered double hydroxides ; Intercalation (chemistry) ; Carboxylate ; Photocatalysis ; Adsorption ; Materials science ; Chemistry ; Catalysis ; Chemical engineering ; Calcination ; Infrared ; Chemical physics ; Inorganic chemistry ; Organic chemistry Layered Double Hydroxides Synthesis and Applications ; Magnesium Oxide Properties and Applications ; Mesoporous Materials and Catalysis