jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Roeland J. M. Nolte | Xiaofei chen | Pieter J. Gilissen | Paul Tinnemans | Nicolas Vanthuyne | Floris P. J. T. Rutjes | Ben L. Feringa | Johannes A. A. W. Elemans
Source: Research Square (preprint, 2022-02-01)
Field: Materials Science — Materials Chemistry

Enantio-divergent epoxidation of alkenes with a photo-switchable phosphate manganese-salen complex Abstract The development of enantio-divergent catalysts capable of producing in a controlled fashion each of the two enantiomeric products from one substrate, is highly challenging. It requires the implementation of a switching function into the catalyst, which can reversibly change the chiral reaction environment during catalysis. Here we report a photo-switchable phosphate ligand derived from 2,2’-biphenol, which axially coordinates as the counter ion to an achiral manganese(III) salen catalyst, providing the latter with the ability to dynamically switch stereoselectivity in the epoxidation of alkenes. Both enantiomers of the chiral ligand exist as a pair of pseudo-enantiomers, which can be efficiently interconverted by irradiation with light of different wavelengths. The opposite axial chiralities of these pseudo-enantiomers are efficiently transferred to the manganese(III) salen catalyst. With this switchable ion-paired catalyst, the enantioselectivity of the epoxidation of a variety of alkenes can be controlled, resulting in opposite enantiomeric excesses of the epoxide products. This dynamic transfer of chirality from a photo-switchable counter ion to a metal complex will greatly broaden the scope of supramolecular catalysts. In future studies this photo-switchable catalyst will be used to write digital information in the form of chiral epoxides on single polymer chains. Manganese ; Phosphate ; Chemistry ; Polymer chemistry ; Photochemistry ; Organic chemistry Porphyrin and Phthalocyanine Chemistry ; Polyoxometalates: Synthesis and Applications ; Supramolecular Chemistry and Complexes
Authors: Dehai Yu | Zhile Wang | Dandan Ji | Changshui Jing | Zhaoping Song | Huili Wang | Wenxia Liu
Source: Research Square (preprint, 2022-11-03)
Field: Materials Science — Materials Chemistry

Pickering Emulsions based on Sustainable MIL-101(Fe)/CNC Hybrid Nanoparticles for Effective Photocatalytic Degradation of Aqueous Dyes Photocatalysis ; Pickering emulsion ; Chemical engineering ; Materials science ; Emulsion ; Aqueous solution ; Degradation (telecommunications) ; Adsorption ; Rhodamine B ; Aqueous two-phase system ; Nanoparticle ; Contact angle ; Nanotechnology ; Catalysis ; Organic chemistry ; Chemistry ; Composite material Pickering emulsions and particle stabilization ; Gold and Silver Nanoparticles Synthesis and Applications ; Micro and Nano Robotics
Authors: Davi Rubinho Ratero | Erick Paiva Cancella | José Geraldo Nery
Source: Journal of Material Science and Technology Research (article, 2022-12-29)
Field: Chemistry — Inorganic Chemistry

Synthesis of Microporous Cobalt Silicate using Organic Template Derived from 2,6-Dimethylpiperidinium Cations: A Potential Precursor for the Preparation of Double Perovskite Cobalt Materials Abstract: Synthesis of a microporous cobalt silicate was achieved by using 6,10-dimethyl-5-azoniaspiro[4, 5] decane bromide as structure directing agent. And physicochemical characterization was carried out using XRD, SEM, HTEM, TGA, FT-IR, BET-N2, ICP-OES and EDS. ETS-10 like structure framework was present as a competitive phase. Calcination of the cobalt silicate at 500 oC leads to a new structure. The possibility of this material be cobalt oxide was excluded since Bragg reflections at 2θ = 19.2º; 30.3º; 36.9º; 43.7º; 59.2º were absent (JCPDS#80-1538). Both the indexation of the XRD data for the calcined material which has resulted in a tetragonal unit cell (a = b = 10.39 Å and c = 12.21 Å, α = β = γ = 90°, V= 1317.4 Å3) and HTEM data indicated the cobalt silicate can be used as a precursor for the preparation of double perovskite cobalt materials. Cobalt ; Calcination ; Materials science ; Silicate ; Microporous material ; Mesoporous material ; Chemical engineering ; Inorganic chemistry ; Nuclear chemistry ; Chemistry ; Organic chemistry ; Metallurgy ; Catalysis ; Composite material Zeolite Catalysis and Synthesis ; Mesoporous Materials and Catalysis ; Layered Double Hydroxides Synthesis and Applications
Authors: Yunzhuo Li
Source: Preprints.org (preprint, 2022-10-14)
Field: Chemistry — Inorganic Chemistry

Catalytic Hydrolysis of Organophosphorus 1 Nerve Agents by Metal-organic Frameworks: What Happens Next? Organophosphorus nerve agents are amongst the most toxic chemicals known to human beings. 9 They interfere with the central nervous system, resulting in continuous muscle contractions, 10 paralysis and even death. Prohibition by many countries around the world cannot disguise the 11 remaining presence of nerve agents in stockpile storage and governmental deployment, 12 highlighting the dire need for an efficient catalyst to degrade and detoxify nerve agents by 13 hydrolysis. Metal-organic frameworks (MOFs) have raised a few eyebrows for their permanent 14 porosity, precise tunability, and lasting stability. Modern Reticular Chemistry fosters the design and 15 synthesis of well-defined crystalline MOFs with open Lewis acidic metal sites that can catalytically 16 hydrolyze nerve agents both in aqueous solution and in solid state systems, unveiling unparalleled 17 potential for MOF-based personal protection gears. In this review, a summary of the representative 18 catalytically active MOFs in nerve agent hydrolysis is discussed. MOFs are categorized by their 19 reticular structure, emphasizing the capability and mechanistic insights of each single MOF in nerve 20 agent hydrolysis. The author&amp;rsquo;s perspective on the current challenges and future directions of MOF- 21 based catalysts in real-world protection applications is also provided, which hopefully could shed some 22 light on the future development of commercially available MOF protection suits. Nerve agent ; Metal-organic framework ; Hydrolysis ; Chemistry ; Nanotechnology ; Catalysis ; Materials science ; Organic chemistry Metal-Organic Frameworks: Synthesis and Applications ; Organometallic Compounds Synthesis and Characterization ; Chemical Synthesis and Reactions
Authors: Rajasi Shukre | Thomas Ericson | Daniel K. Unruh | Hannah J. Harbin | Anthony F. Cozzolino | Chau‐Chyun Chen | Siva A. Vanapalli
Source: ChemRxiv (preprint, 2022-03-31)
Field: Chemistry — Inorganic Chemistry

Batch-Screening Guided Continuous Flow Synthesis of the Metal-organic Framework HKUST-1 in a Millifuidic Droplet Reactor Metal-organic frameworks (MOFs) are a class of crystalline and porous adsorbents, with wide-ranging applications in gas separations, membrane materials as well as sensors. Commonly used batch synthesis techniques for MOF production are limited by low productivity, high operating costs, and slow crystallization timescales, severely impeding the large-scale manufacturing of these materials. However, batch synthesis is a useful and easy technique to screen multiple reaction parameters to find an optimal chemistry. Therefore, in this study, we have used the batch process and screened a multidimensional reaction space consisting of 45 sample variations based on the crystallinity, yield and instantaneous precipitation, which could lead to tube clogging under flow conditions. We have found one optimized reaction chemistry, that could be used in flow conditions, which in this study is a novel millifluidic droplet-based reactor for the continuous synthesis of HKUST-1 crystals. The biphasic flow in the millifluidic reactor consisted of droplets of the reactant solution, dispersed in a continuous phase of silicone oil. We investigate the differences in the quality and quantity of HKUST-1 synthesized via the continuous and batch techniques. Moreover, we have demonstrated that the HKUST-1 samples prepared via the continuous synthesis in a droplet based millifluidic reactor, at an ultra-low residence time exhibit excellent physical properties comparable to that obtained for the samples prepared by the traditional batch process. A clean, easy-to-install, and reusable millifluidic reactor presented in this work may pave the path for an economically viable, large-scale synthesis of HKUST-1. Materials science ; Flow chemistry ; Continuous reactor ; Residence time (fluid dynamics) ; Chemical engineering ; Batch reactor ; Volumetric flow rate ; Process engineering ; Batch processing ; Yield (engineering) ; Crystallinity ; Residence time distribution ; Continuous flow ; Flow (mathematics) ; Computer science ; Chemistry ; Composite material ; Organic chemistry ; Catalysis Metal-Organic Frameworks: Synthesis and Applications ; Catalytic Processes in Materials Science ; Catalysis and Hydrodesulfurization Studies
Authors: Manoj P. Palve
Source: European Chemical Bulletin (article, 2022-01-24)
Field: Chemistry — Organic Chemistry

SYNTHESIS OF TETRAHYDROPYRIDINE DERIVATIVES USING IONIC LIQUID 1- BUTYL-3-METHYLIMIDAZOLIUM BROMIDE AS A GREEN CATALYST European Chemical Bulletin (ISSN 2063-5346) is a peer-reviewed journal that publishes original research papers, short communications, and review articles in all areas of chemistry. European Chemical Bulletin has eight sections, namely Ionic liquid ; Bromide ; Catalysis ; Chemistry ; Nuclear chemistry ; Organic chemistry Multicomponent Synthesis of Heterocycles ; Synthesis and Biological Evaluation ; Inorganic and Organometallic Chemistry
Authors: Jovica D. Badjić | Vageesha Liyana Gunawardana | Tyler J. Finnegan | Carson Ward | Curtis E. Moore
Source: Research Square (preprint, 2022-02-18)
Field: Chemistry — Organic Chemistry

Fuel-Driven Formation of Covalent Basket Cages Abstract Essential functions that sustain life including reproduction, signaling and mechanical motion, persist through the consump-tion of chemical fuels. Despite recent advances in developing dissipative assemblies that mimic such systems, the fuel-driven formation of covalent organic cages with the capacity to promote catalysis, folding, delivery and sequestration has yet to be demonstrated. In this work we describe the transient formation of a nanosized, tetrahedral cage (V = 5 nm3, Mw = 6150 Da) with four molecular baskets at its vertices linked via imine bonds to four aromatic amines forming the faces. Tribromo-acetic acid (TBA) acts as the chemical fuel that drives assembly of the cage via imine metathesis in addition to controlling its formation over time. Our study sets the stage for constructing large dissipative cages with spatiotemporal modes of opera-tion resembling the action of biological molecular machines. Covalent bond ; Chemistry ; Materials science ; Business ; Organic chemistry Supramolecular Chemistry and Complexes ; Covalent Organic Framework Applications ; Fuel Cells and Related Materials
Authors: Baoyi Yu | Fatma B. Hamad | Kristof Van Hecke | Francis Verpoort
Source: Proceedings of universities Applied chemistry and biotechnology (article, 2022-07-04)
Field: Chemistry — Organic Chemistry

Ruthenium indenylidene complexes bearing bis(N-Alkyl/N’-Mesityl)-sided heterocyclic carbene ligands We report on the synthesis and characterization of new ruthenium indenylidene complexes bearing two unsymmetrical N-heterocyclic carbene (NHC) ligands denoted as RuCl2(3-phenyl-1-indenylidene)bis(1-mesityl-3-R-4,5-dihydroimidazole-2-ylidene) in which R is methyl 7a and cyclohexyl 7b. Complexes 7a and 7b were analyzed using single-crystal X-ray diffraction analysis, elemental analysis, IR, NMR spectroscopy, and HRMS. The catalytic activities of complexes 7a and 7b were evaluated in olefin metathesis reactions: ring-opening metathesis polymerization (ROMP) of cis,cis-1,5-cyclooctadiene (COD) and ringclosing metathesis (RCM) of diethyl diallyl malonate (DEDAM) as well as in the isomerization of allylic alcohols. Complexes 7a and 7b failed to initiate the reactions at room temperature in all tested reactions, which might be due to the high thermal stability and low degree of lability of the Ru-CNHC bonds. At 80 °C, the complex 7a showed the best performance due to an increased initiation and a decreased steric obstruction towards the incoming substrates. Chemistry ; Carbene ; Ruthenium ; Metathesis ; Medicinal chemistry ; ROMP ; Isomerization ; Ring-opening metathesis polymerisation ; Lability ; Acyclic diene metathesis ; Steric effects ; Malonate ; Polymer chemistry ; Stereochemistry ; Polymerization ; Catalysis ; Organic chemistry Synthetic Organic Chemistry Methods ; N-Heterocyclic Carbenes in Organic and Inorganic Chemistry ; Catalytic Cross-Coupling Reactions
Authors: Noelia Maldonado | Garikoitz Beobide | Efraím Reyes | José I. Martínez | Carlos J. Gómez‐García | Óscar Castillo | Pilar Amo‐Ochoa
Source: Nanomaterials (article, 2022-02-17)
Field: Chemistry — Inorganic Chemistry

Innovative Microstructural Transformation upon CO2 Supercritical Conditions on Metal-Nucleobase Aerogel and Its Use as Effective Filler for HPLC Biomolecules Separation This work contributes to enlightening the opportunities of the anisotropic scheme of non-covalent interactions present in supramolecular materials. It provides a top-down approach based on their selective disruption that herein has been employed to process a conventional microcrystalline material to a nanofibrillar porous material. The developed bulk microcrystalline material contains uracil-1-propionic acid (UPrOH) nucleobase as a molecular recognition capable building block. Its crystal structure consists of discrete [Cu(UPrO)<sub>2</sub> (4,4'-bipy)<sub>2</sub> (H<sub>2</sub> O)] (4,4'-bipy=4,4'-bipyridine) entities held together through a highly anisotropic scheme of non-covalent interactions in which strong hydrogen bonds involving coordinated water molecules provide 1D supramolecular chains interacting between them by weaker interactions. The sonication of this microcrystalline material and heating at 45 °C in acetic acid-methanol allows partial reversible solubilization/recrystallization processes that promote the cross-linking of particles into an interlocked platelet-like micro-particles metal-organic gel, but during CO<sub>2</sub> supercritical drying, the microcrystalline particles undergo a complete morphological change towards highly anisotropic nanofibers. This unprecedented top-down microstructural conversion provides a nanofibrillar material bearing the same crystal structure but with a highly increased surface area. Its usefulness has been tested for HPLC separation purposes observing the expected nucleobase complementarity-based separation. Materials science ; Microcrystalline ; Nucleobase ; Supercritical fluid ; Covalent bond ; Chemical engineering ; Supramolecular chemistry ; Hydrogen bond ; Aerogel ; Molecule ; Nanotechnology ; Organic chemistry ; Crystallography ; Chemistry Metal-Organic Frameworks: Synthesis and Applications ; Mesoporous Materials and Catalysis ; Phase Equilibria and Thermodynamics
Authors: Aher Ravindra D. | Ishikawa Atsuhiro | Yamanaka Masahiro | Tanaka Fujie
Source: Institutional Repositories DataBase (IRDB) (article, 2022-06-06)
Field: Chemistry — Organic Chemistry

Catalytic Enantioselective Construction of Decalin Derivatives by Dynamic Kinetic Desymmetrization of C2-Symmetric Derivatives through Aldol–Aldol Annulation We have developed and investigated a catalytic desymmetrization reaction strategy that affords functionalized decalin derivatives with high enantioselectivities from C2-symmetric derivatives through aldol–aldol annulation. We identified the structural moieties of the catalyst necessary for the formation of the decalin derivative with high enantioselectivity. We elucidated the mechanisms of the catalyzed reactions: the first aldol reaction step was reversible, and the second aldol step was rate-limiting and stereochemistry-determining and was enantioselective. Using theoretical calculations guided by the experimental results, we identified the interactions between the catalyst and the transition state that led to the major enantiomer. The information obtained in this study will be useful for the development of catalysts and chemical transformations. Desymmetrization ; Decalin ; Catalysis ; Enantioselective synthesis ; Aldol reaction ; Annulation ; Organocatalysis Asymmetric Synthesis and Catalysis ; Axial and Atropisomeric Chirality Synthesis ; Molecular spectroscopy and chirality
Authors: Rameswar Bhattacharjee | Ethan T. Hare | Pere Miró
Source: ChemRxiv (preprint, 2022-11-24)
Field: Chemistry — Inorganic Chemistry

Structure, Properties, and Reactivity of Polyoxocationic Zirconium and Hafnium Clusters Hexameric tetravalent zirconium and hafnium molecular metal oxides clusters are key building blocks of many metal-organic frameworks; however, the chemical space to form all possible MOF nodes is vast, containing many potential new clusters. Our computational study provides a complete picture of the structure, properties, and reactivity of two tetrameric zirconium and hafnium [M4(μ2-η2:η2-O2)x(μ2-OH)8-2x(H2O)16]8+ polycationic clusters. The electronic structure of the studied species has the characteristic polyoxometalate oxygen-based and metal-based bands in the valence region. The energetics for the evolution of pure metal clusters into mixed-metal clusters revealed that only the incorporation of zirconium into hafnium clusters is thermodynamically favorable. We confirmed that the incorporation of up to four peroxide ligands is thermodynamically favorable; however, the experimental absence of rich peroxide species with three or more peroxides is attributed to their thermal degradation. The mechanism for peroxide incorporation involves the partial dissociation of the cluster rather than complete dissociation. Hafnium ; Zirconium ; Polyoxometalate ; Chemistry ; Cluster (spacecraft) ; Dissociation (chemistry) ; Metal ; Peroxide ; Reactivity (psychology) ; Valence (chemistry) ; Inorganic chemistry ; Electronic structure ; Crystallography ; Computational chemistry ; Physical chemistry ; Catalysis ; Organic chemistry Metal-Organic Frameworks: Synthesis and Applications ; Polyoxometalates: Synthesis and Applications ; Magnetism in coordination complexes
Authors: Tomohiko Nishiuchi | Seito Aibara | Hiroyasu Sato | Takashi Kubo
Source: ChemRxiv (preprint, 2022-04-07)
Field: Chemistry — Organic Chemistry

Synthesis of π-Extended Thiele's and Chichibabin's Hydrocarbons and Effect of the π-congestion on Conformations and Electronic States The biradicaloid of Chichibabin’s hydrocarbon exits in a unique thermal equilibrium between closed-shell singlet and open-shell triplet forms. Conceptually, the incorporation of non-planar aromatic groups, such as anthraquinodimethane (AQD), in these species could bring about stabilization of the individual singlet and triplet spin biradicaloids by creating a high energy barrier for con-formational interconversion between folded (singlet) and twisted (triplet) forms. Moreover, this alteration could introduce the possibility of controlling spin states through conformational changes induced by chemical and physical processes. Herein, we report the preparation of AQD containing, π-extended Thiele's (A-TH) and Chichibabin's (A-CH) hydrocarbons, which have highly π-congested structures resulting from the presence of bulky 9-anthryl units. The π-congestion in these substances leads to steric frustration about carbon-carbon double bonds, and creates flexible dynamic motion with a moderate activation barrier between folded singlet and twisted triplet states. These constraints make it possible to isolate the twisted triplet state of A-CH. In addition, simple mechanical grinding of the folded singlet of A-CH produces the twisted triplet. Singlet state ; Steric effects ; Chemistry ; Singlet fission ; Open shell ; Triplet state ; Chemical physics ; Computational chemistry ; Photochemistry ; Molecule ; Stereochemistry ; Atomic physics ; Organic chemistry ; Excited state ; Physics Synthesis and Properties of Aromatic Compounds ; Fullerene Chemistry and Applications ; Advanced NMR Techniques and Applications
Authors: Tomohiko Nishiuchi | Seito Aibara | Hiroyasu Sato | Takashi Kubo
Source: ChemRxiv (preprint, 2022-03-02)
Field: Chemistry — Organic Chemistry

Synthesis of π-Extended Thiele's and Chichibabin's Hydrocarbons and Effect of the π-congestion on Conformations and Electronic States The biradicaloid of Chichibabin’s hydrocarbon exits in a unique thermal equilibrium between closed-shell singlet and open-shell triplet forms. Conceptually, the incorporation of non-planar aromatic groups, such as anthraquinodimethane (AQD), in these species could bring about stabilization of the individual singlet and triplet spin biradicaloids by creating a high energy barrier for con-formational interconversion between folded (singlet) and twisted (triplet) forms. Moreover, this alteration could introduce the possibility of controlling spin states through conformational changes induced by chemical and physical processes. Herein, we report the preparation of AQD containing, π-extended Thiele's (A-TH) and Chichibabin's (A-CH) hydrocarbons, which have highly π-congested structures resulting from the presence of bulky 9-anthryl units. The π-congestion in these substances leads to steric frustration about carbon-carbon double bonds, and creates flexible dynamic motion with a moderate activation barrier between folded singlet and twisted triplet states. These constraints make it possible to isolate the twisted triplet state of A-CH. In addition, simple mechanical grinding of the folded singlet of A-CH produces the twisted triplet. Singlet state ; Chemistry ; Steric effects ; Singlet fission ; Open shell ; Triplet state ; Computational chemistry ; Photochemistry ; Chemical physics ; Stereochemistry ; Molecule ; Atomic physics ; Organic chemistry ; Excited state ; Physics Synthesis and Properties of Aromatic Compounds ; Fullerene Chemistry and Applications ; Advanced NMR Techniques and Applications
Authors: Xin Zhang | Shuo Tong | Jieping Zhu | Mei‐Xiang Wang
Source: ChemRxiv (preprint, 2022-11-01)
Field: Chemistry — Organic Chemistry

Inherently Chiral Calixarenes from Catalytic Enantioselective Transannular Arene-Arene Cross-Coupling Reaction Under the catalysis of PdBr2 and a chiral phosphoramidite ligand derived from R-3,3'-bis(trifluoromethyl)-[1,1'-binaphthalene]-2,2'-diol, the upper-rim mono (2-bromoaroyl)-substituted calix[4]arene derivatives underwent facile enantioselective desymmetrization reaction to afford 9H-fluorene-embedded inherently chiral cyclophanes in good yields with ee up to 94%. The transannular arene-arene cross coupling reaction proceeded most probably through an oxidation addition of Caryl-Br bond to ligated palladium catalyst, an unusual long range 1,5-palladium migration fol-lowed by the intramolecular arylation sequence. Because of the macrocyclic strain, the newly formed 9H-fuorene segment adopts curved structure, rendering highly rigid inherently chiral macrocycles unique chiroptical property. Enantioselective synthesis ; Desymmetrization ; Palladium ; Chemistry ; Calixarene ; Catalysis ; Intramolecular force ; Coupling reaction ; Stereochemistry ; Fluorene ; Chiral ligand ; Combinatorial chemistry ; Organic chemistry ; Molecule Supramolecular Chemistry and Complexes ; Axial and Atropisomeric Chirality Synthesis ; Synthesis and Properties of Aromatic Compounds
Authors: Hanlin Hou | Yunlei Wang | Rengan Luo | Yufei Wang | Da Zhu | Jun Zhou | Xiaojun Wu | Huangxian Ju | Jianping Lei
Source: Research Square (preprint, 2022-03-30)
Field: Materials Science — Materials Chemistry

Interlayer electron coupling pathway driven electrochemiluminescence in hydrogen-bonded organic frameworks Electrochemiluminescence ; Electron ; Coupling (piping) ; Hydrogen ; Materials science ; Chemical physics ; Photochemistry ; Chemistry ; Nanotechnology ; Physics ; Electrode ; Physical chemistry ; Quantum mechanics ; Composite material Covalent Organic Framework Applications ; Advanced biosensing and bioanalysis techniques ; Luminescence and Fluorescent Materials