jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Bunyaporn Todee | Patharaporn Sanae | Araya Ruengsuk | Pattarapapa Janthakit | Vinich Promarak | Jonggol Tantirungrotechai | Mongkol Sukwattanasinitt | Taweetham Limpanuparb | David J. Harding | Thanthapatra Bunchuay
Source: Chemistry - An Asian Journal (article, 2023-11-16)
Field: Chemistry — Organic Chemistry

Switchable Metal‐Ion Selectivity in Sulfur‐Functionalised Pillar[5]arenes and Their Host‐Guest Complexes Nucleophilic substitution of pertosylated pillar[5]arene (P-OTs) with commercially available sulfur containing nucleophiles (KSCN, KSAc, and thiophenol), yields a series of sulfur-functionalised pillar[5]arenes. DLS results and SEM images imply that these pillararene macrocycles self-assemble in acetonitrile solution, while X-ray crystallographic evidence suggests solvent-dependent assembly in the solid state. The nature of the sulfur substituents decorating the rim of the pillararene controls binding affinities towards organic guest encapsulations within the cavity and dictates metal-ion binding properties through the formation of favorable S-M<sup>2+</sup> coordination bonds outside the cavity, as determined by <sup>1</sup> H NMR and fluorescence spectroscopic experiments. Addition of a dinitrile guest containing a bis-triazole benzene spacer (btn) induced formation of pseudorotaxane host-guest complexes. Fluorescence emission signals from these discrete macrocycles were significantly attenuated in the presence of either Hg<sup>2+</sup> or Cu<sup>2+</sup> in solution. Analogous titrations utilizing the corresponding pseudorotaxanes alter the binding selectivity and improve fluorescence sensing sensitivity. In addition, preliminary liquid-liquid extraction studies indicate that the macrocycles facilitate the transfer of Cu<sup>2+</sup> from the aqueous to the organic phase in comparison to extraction without pillar[5]arene ligands. Pillar ; Sulfur ; Selectivity ; Host (biology) ; Metal ; Chemistry ; Ion ; Inorganic chemistry ; Combinatorial chemistry ; Materials science ; Organic chemistry ; Catalysis ; Engineering ; Biology ; Ecology Supramolecular Chemistry and Complexes ; Advanced NMR Techniques and Applications ; Radioactive element chemistry and processing
Authors: Felix Frank | Bettina Baumgartner | Bernhard Lendl
Source: Sensors and Actuators B Chemical (article, 2023-10-12)
Field: Chemistry — Analytical Chemistry

Metal-organic frameworks combined with mid-infrared spectroscopy for the trace analysis of phosphates in water Detecting traces of phosphates in water is critical for monitoring water quality in aquatic ecosystems. Mid-infrared techniques are effective for label-free and quick measurements in at-line or in-line applications, but sensitivity is limited due to high water absorption. To combat this, preconcentration schemes combined with evanescent field spectroscopy can be used to enrich the analyte in the probed volume and thereby increasing sensitivity. Metal-organic frameworks (MOFs) are versatile materials with defined porosity and tuneable chemistry, which make them ideal for selective adsorption of target molecules. In this study, an NH2-MIL-88B(Fe) (= Fe3O(NH2-BDC)3) MOF-based enrichment layer was prepared on a diamond attenuated total reflection (ATR) crystal for in situ Fourier transform infrared (FTIR) spectroscopic measurements of ortho-phosphates in water. A workflow for single-use enrichment layers was established, and an automated flow system was used to apply aqueous phosphate solutions. Using internal referencing and compensating for variation in MOF film depositions, phosphate analysis reproducibility increased from 74% to 94%. The Langmuir adsorption model was used to derive a limit of detection (LOD) of 0.18 mg L-1 phosphorus in water. Overall, this work demonstrates the effectiveness of NH2-MIL-88B(Fe) MOFs as enrichment layers for aqueous phosphate sensing. Our results provide a promising avenue for the development of sensitive and selective sensors for environmental and biomedical applications. Attenuated total reflection ; Aqueous solution ; Adsorption ; Fourier transform infrared spectroscopy ; Infrared spectroscopy ; Detection limit ; Materials science ; Phosphate ; Metal-organic framework ; Chemistry ; Analytical Chemistry (journal) ; Chemical engineering ; Inorganic chemistry ; Environmental chemistry ; Chromatography ; Organic chemistry Analytical chemistry methods development ; Analytical Chemistry and Sensors ; Minerals Flotation and Separation Techniques
Authors: Mohammad Abdul Sattar | Archita Patnaik
Source: ChemSusChem (article, 2023-02-09)
Field: Materials Science — Polymers and Plastics

Phosphonium Ionic Liquid‐Activated Sulfur Vulcanization: A Way Forward to Reduce Zinc Oxide Levels in Industrial Rubber Formulations Extensive use of zinc oxide and accelerators such as diphenyl guanidine (DPG) in the vulcanization of rubber composites entail potential environmental risks. These are pervasive contaminants of roadway runoff originating from tire wear particles (TWPs). Herein, the effect of phosphonium ionic liquids (PILs) in styrene-butadiene rubber compounds was demonstrated with reduced ZnO loading and no DPG to minimize the environmental footprint of the vulcanization process. The structure and chemistry of PILs were found to be the influencing parameters impelling the cross-linking kinetics, enabling shorter induction times. The generation of active Zn<sup>2+</sup> sites by PILs was examined through FTIR spectroscopy, calorimetry, and molecular dynamics simulations. From a tire application perspective, the PILs not only enhanced the cure kinetics but also improved the dynamic-mechanical behavior of the rubber composites. Consequently, the harm caused by TWPs to the atmosphere, fuel intake, and CO<sub>2</sub> emissions was minimal, thereby confirming the potential use of PILs in the tire industry. Phosphonium ; Vulcanization ; Natural rubber ; Zinc ; Ionic liquid ; Chemical engineering ; Chemistry ; Materials science ; Organic chemistry ; Catalysis Polymer Nanocomposites and Properties ; Conducting polymers and applications ; Nanocomposite Films for Food Packaging
Authors: Jonas Meyer | Manuela Romero | Jorg Thöming | Michael Baune | Nicholas Reimer | Ralf Dringen | Ingmar Bösing
Source: Scientific Reports (article, 2023-12-16)
Field: Chemistry — Organic Chemistry

Experimental insights into electrocatalytic [Cp*Rh(bpy)Cl]+ mediated NADH regeneration NADH plays a crucial role in many enzymatically catalysed reactions. Due to the high costs of NADH a regeneration mechanism of this cofactor can enlarge the applications of enzymatic reactions dramatically. This paper gives a thorough system analysis of the mediated electrochemical regeneration of active NADH using cyclic voltammograms and potentiostatic measurements with varying pH, electrode potential, and electrolyte solution, highlighting the system's limiting conditions, elucidating optimal working parameters for the electrochemical reduction of NAD<sup>+</sup>, and bringing new insight on the oxidation of inactive reduction products. Using [Cp*Rh(bpy)Cl]<sup>+</sup> as an electron mediator dramatically increases the percentage of enzymatically active electrochemically reduced NADH from 15% (direct) to 99% (mediated) with a faradaic efficiency of up to 86%. Furthermore, investigations of the catalytic mechanisms of [Cp*Rh(bpy)Cl]<sup>+</sup> clarifies the necessary conditions for its functioning and questions the proposed reaction mechanism by two-step reduction where first the mediator is reduced and then brought in contact with NAD<sup>+</sup>. Regeneration (biology) ; Chemistry ; Biochemistry ; Cell biology ; Biology Nanomaterials for catalytic reactions ; Electrocatalysts for Energy Conversion ; Electrochemical sensors and biosensors
Authors: Alexandros E. Alexakis | Thayanithi Ayyachi | M. A. Mousa | Peter Olsén | Eva Malmström
Source: Polymers (article, 2023-05-02)
Field: Materials Science — Biomaterials

2-Methoxy-4-Vinylphenol as a Biobased Monomer Precursor for Thermoplastics and Thermoset Polymers To address the increasing demand for biobased materials, lignin-derived ferulic acid (FA) is a promising candidate. In this study, an FA-derived styrene-like monomer, referred to as 2-methoxy-4-vinylphenol (MVP), was used as the platform to prepare functional monomers for radical polymerizations. Hydrophobic biobased monomers derived from MVP were polymerized via solution and emulsion polymerization resulting in homo- and copolymers with a wide range of thermal properties, thus showcasing their potential in thermoplastic applications. Moreover, divinylbenzene (DVB)-like monomers were prepared from MVP by varying the aliphatic chain length between the MVP units. These biobased monomers were thermally crosslinked with thiol-bearing reagents to produce thermosets with different crosslinking densities in order to demonstrate their thermosetting applications. The results of this study expand the scope of MVP-derived monomers that can be used in free-radical polymerizations toward the preparation of new biobased and functional materials from lignin. Monomer ; Thermosetting polymer ; Materials science ; Polymer chemistry ; Copolymer ; Polymerization ; Divinylbenzene ; Lignin ; Polymer ; ROMP ; Organic chemistry ; Styrene ; Chemistry ; Metathesis ; Composite material biodegradable polymer synthesis and properties ; Chemistry and Chemical Engineering ; Photopolymerization techniques and applications
Authors: Nikoleta Kircheva | Stefan Dobrev | Lyubima Dasheva | Valya Nikolova | Silvia Angelova | Todor Dudev
Source: Molecules (article, 2023-02-05)
Field: Chemistry — Organic Chemistry

Metal-Assisted Complexation of Fluorogenic Dyes by Cucurbit[7]uril and Cucurbit[8]uril: A DFT Evaluation of the Key Factors Governing the Host–Guest Recognition With the emergence of host-guest systems, a novel branch of complexation chemistry has found wide application in industries such as food, pharmacy, medicine, environmental protection and cosmetics. Along with the extensively studied cyclodextrins and calixarenes, the innovative cucurbiturils (CB) have enjoyed increased popularity among the scientific community as they possess even better qualities as cavitands as compared to the former molecules. Moreover, their complexation abilities could further be enhanced with the assistance of metal cations, which can interestingly exert a dual effect on the complexation process: either by competitively binding to the host entity or cooperatively associating with the CB@guest structures. In our previous work, two metal species (Mg<sup>2+</sup> and Ga<sup>3+</sup>) have been found to bind to CB molecules in the strongest fashion upon the formation of host-guest complexes. The current study focuses on their role in the complex formation with three dye molecules: thiazole orange, neutral red, and thioflavin T. Various key factors influencing the process have been recognized, such as pH and the dielectric constant of the medium, the cavity size of the host, M<sup>n+</sup> charge, and the presence/absence of hydration shell around the metal cation. A well-calibrated DFT methodology, solidly based and validated and presented in the literature experimental data, is applied. The obtained results shed new light on several aspects of the cucurbituril complexation chemistry. Metal ; Key (lock) ; Chemistry ; Cucurbituril ; Host (biology) ; Supramolecular chemistry ; Combinatorial chemistry ; Molecule ; Organic chemistry ; Computer science ; Biology ; Ecology Supramolecular Chemistry and Complexes ; Molecular Sensors and Ion Detection ; Crystallography and molecular interactions
Authors: Benjamin Théron | Valentin Vaillant-Coindard | Cédric Balan | Yoann Rousselin | Jérôme Bayardon | Raluca Malacea‐Kabbara | Pierre Le Gendre
Source: Dalton Transactions (article, 2023-01-01)
Field: Chemistry — Organic Chemistry

Al and Zn phenoxy-amidine complexes for lactide ROP catalysis We report the synthesis of a new generation of phenoxy-amidine ligands based on an aryloxy moiety possessing an <i>ortho-N</i>-linked trisubstituted amidine. The reaction of the phenol-amidine proligands with aluminum and zinc alkyls gave mono- or bis-ligated complexes depending on the metal/ligand ratio used. The solid-state structure of four proligands and thirteen Zn and Al complexes has been determined by X-Ray diffraction analysis. The mono-ligated complexes present an aryloxy-bridged dimeric structure, which is retained in solution in the case of Zn complexes but not with aluminum according to DOSY NMR experiments. Bis(ligated) Al and Zn complexes exhibit fluxional behaviour in solution attributed to coordination-decoordination of the amidine moiety and the rotation around the amidine C-NR'<sub>2</sub> and C-Ar bonds. These complexes were tested for the ROP of <i>rac</i>-lactide in solution and under bulk conditions. In both cases, the most performant catalysts are Zn complexes featuring a phenoxy-amidine ligand with a pendant additional dimethylamino arm. Amidine ; Moiety ; Chemistry ; Ligand (biochemistry) ; Catalysis ; Polymer chemistry ; Medicinal chemistry ; Stereochemistry ; Combinatorial chemistry ; Organic chemistry Organometallic Complex Synthesis and Catalysis ; biodegradable polymer synthesis and properties ; Ferrocene Chemistry and Applications
Authors: Lyna Bourehil | Clément Soep | Sopheak Seng | Sarah Dutrannoy | Stacy Igoudjil | Jérémy Forté | Geoffrey Gontard | Denis Lesage | Benoı̂t Bertrand | Héloïse Dossmann
Source: Inorganic Chemistry (article, 2023-08-10)
Field: Chemistry — Organic Chemistry

Bond-Dissociation Energies to Probe Pyridine Electronic Effects on Organogold(III) Complexes: From Methodological Developments to Application in π-Backdonation Investigation and Catalysis In this work, we report on the synthesis of several organogold(III) complexes based on 4,4'-diterbutylbiphenyl (C^C) and 2,6-bis(4-terbutylphenyl)pyridine (C^N^C) ligands and bond with variously substituted pyridine ligands (pyrR). Altogether, 33 complexes have been prepared and studied with mass spectrometry using higher-energy collision dissociation (HCD) in an Orbitrap mass spectrometer. A complete methodology including the kinetic modeling of the dissociation process based on the Rice-Ramsperger-Kassel-Marcus (RRKM) statistical method is proposed to obtain critical energies <i>E</i><sub>0</sub> of the pyrR loss for all complexes. The capacity of these <i>E</i><sub>0</sub> values to describe the pyridine ligand effect is further explored, at the same time as more classical descriptors such as <sup>1</sup>H pyridinic NMR shift variation upon coordination and Au-N<sup>pyrR</sup> bond length measured by X-ray diffraction. An extensive theoretical work, including density functional theory (DFT) and domain-based local pair natural orbital coupled-cluster theory (DLPNO-CCSD(T)) methods, is also carried out to provide bond-dissociation energies, which are compared to experimental results. Results show that dissociation energy outperforms other descriptors, in particular to describe ligand effects over a large electronic effect range as seen by confronting the results to the pyrR p<i>K</i><sub>a</sub> values. Further insights into the Au-N<sup>pyrR</sup> bond are obtained through an energy decomposition analysis (EDA) study, which confirms the isolobal character of Au<sup>+</sup> with H<sup>+</sup>. Finally, the correlation between the lability of the pyridine ligands toward the catalytic efficiency of the complexes could be demonstrated in an intramolecular hydroarylation reaction of alkyne. The results were rationalized considering both pre-catalyst activation and catalyst reactivity. This study establishes the possibility of correlating dissociation energy, which is a gas-phase descriptor, with condensed-phase parameters such as catalysis efficiency. It therefore holds great potential for inorganic and organometallic chemistry by opening a convenient and easy way to evaluate the electronic influence of a ligand toward a metallic center. Chemistry ; Intramolecular force ; Pyridine ; Dissociation (chemistry) ; Bond-dissociation energy ; Density functional theory ; Computational chemistry ; Bond energy ; Physical chemistry ; Stereochemistry ; Molecule ; Organic chemistry Organometallic Complex Synthesis and Catalysis ; Catalytic Alkyne Reactions ; Metal complexes synthesis and properties
Authors: Sabrina Pricl
Source: Pharmaceutics (review, 2023-07-24)
Field: Materials Science — Polymers and Plastics

The Spicy Science of Dendrimers in the Realm of Cancer Nanomedicine: A Report from the COST Action CA17140 Nano2Clinic COST Action CA17140 Cancer Nanomedicine-from the bench to the bedside (Nano2Clinic,) is the first, pan-European interdisciplinary network of representatives from academic institutions and small and medium enterprises including clinical research organizations (CROs) devoted to the development of nanosystems carrying anticancer drugs from their initial design, preclinical testing of efficacy, pharmacokinetics and toxicity to the preparation of detailed protocols needed for the first phase of their clinical studies. By promoting scientific exchanges, technological implementation, and innovative solutions, the action aims at providing a timely instrument to rationalize and focus research efforts at the European level in dealing with the grand challenge of nanomedicine translation in cancer, one of the major and societal-burdening human pathologies. Within CA17140, dendrimers in all their forms (from covalent to self-assembling dendrons) play a vital role as powerful nanotheranostic agents in oncology; therefore, the purpose of this review work is to gather and summarize the major results in the field stemming from collaborative efforts in the framework of the European Nano2Clinic COST Action. Nanomedicine ; Action (physics) ; Realm ; Engineering ethics ; Bench to bedside ; Medicine ; Nanotechnology ; Knowledge management ; Business ; Computer science ; Engineering ; Political science ; Medical physics Dendrimers and Hyperbranched Polymers ; Nanoparticle-Based Drug Delivery ; RNA Interference and Gene Delivery
Authors: Fei Wu | Yueying Wang | Shunxin Fei | Gang Zhu
Source: Nanomaterials (article, 2023-06-26)
Field: Chemistry — Organic Chemistry

Co-Promoted CoNi Bimetallic Nanocatalyst for the Highly Efficient Catalytic Hydrogenation of Olefins Bimetallic catalysts, especially non-noble metals, hold great potential for substituting for noble metals in catalytic hydrogenation. In present study, a series of CoxNiy (x + y = 6) bimetallic catalysts were prepared through the impregnation–reduction method and cyclohexene was chosen as probe-molecule to study the promotion effect of Co on the catalytic olefin hydrogenation reactions. Meanwhile, density functional theory (DFT) was utilized to investigate the formation energies and the charge distribution of CoNi bimetals, as well as the transition state (TS) searches for hydrogen dissociation and migration. The results suggest that bimetals tend to have superior catalytic performance than pure metals, and Co3Ni3 shows the highest catalytic activity on the cyclohexene hydrogenation. It was found that the charge transfer from Co to Ni and the alloying give rise to the refinement of CoNi grains and the improvement of its catalytic activity and stability. Thus, it may be possible to obtain better catalytic performance by tuning the metal/metal atomic ratio of bimetals. Bimetallic strip ; Catalysis ; Materials science ; Chemistry ; Organic chemistry Nanomaterials for catalytic reactions ; Catalytic Processes in Materials Science ; Catalysis for Biomass Conversion
Authors: Shang‐Yuan Fu | Cheng‐Han Chang | Alexander S. Ivanov | Ilja Popovs | Jeng‐Lung Chen | Yen‐Fa Liao | Hsin‐Kuan Liu | Suman Chirra | Yun‐Wei Chiang | Jui‐Chin Lee | Wei-Ling Liu | Watchareeya Kaveevivitchai | Teng‐Hao Chen
Source: Angewandte Chemie International Edition (article, 2023-09-13)
Field: Chemistry — Inorganic Chemistry

Mixed‐Valence Cu<sup>I</sup>/Cu<sup>III</sup> Metal–Organic Frameworks with Non‐innocent Ligand for Multielectron Transfer We report two novel three-dimensional copper-benzoquinoid metal-organic frameworks (MOFs), [Cu<sub>4</sub> L<sub>3</sub> ]<sub>n</sub> and [Cu<sub>4</sub> L<sub>3</sub> ⋅ Cu(iq)<sub>3</sub> ]<sub>n</sub> (LH<sub>4</sub> =1,4-dicyano-2,3,5,6-tetrahydroxybenzene, iq=isoquinoline). Spectroscopic techniques and computational studies reveal the unprecedented mixed valency in MOFs, formal Cu(I)/Cu(III). This is the first time that formally Cu(III) species are witnessed in metal-organic extended solids. The coordination between the mixed-valence metal and redox-non-innocent ligand L, which promotes through-bond charge transfer between Cu metal sites, allows better metal-ligand orbital overlap of the d-π conjugation, leading to strong long-range delocalization and semiconducting behavior. Our findings highlight the significance of the unique mixed valency between formal Cu(I) and highly-covalent Cu(III), non-innocent ligand, and pore environments of these bench stable Cu(III)-containing frameworks on multielectron transfer and electrochemical properties. Valence (chemistry) ; Metal ; Chemistry ; Ligand (biochemistry) ; Materials science ; Physics ; Crystallography ; Physical chemistry ; Organic chemistry Metal-Organic Frameworks: Synthesis and Applications ; Electrochemical Analysis and Applications ; Organic and Molecular Conductors Research
Authors: Shahir Sarasiya | Sara Sarasiya | Maged Henary
Source: Pharmaceuticals (review, 2023-09-14)
Field: Materials Science — Materials Chemistry

Exploration of NIR Squaraine Contrast Agents Containing Various Heterocycles: Synthesis, Optical Properties and Applications Squaraine dye is a popular class of contrast near-infrared (NIR) dyes. Squaraine dyes have shown the ability to be modified with various heterocycles. The indole moiety is the most notable heterocycle incorporated in squaraine dyes. A tremendous amount of work has gone into developing indole-based squaraine dyes and determining their applications. The optical properties of squaraine dyes containing an indole moiety facilitate high quantum yields and molar absorptivity, but the absorbance maxima is capped near 700 nm. This is the major limitation of indole-based squaraine dyes. In comparison, other heterocycles with larger conjugated systems such as quinoline and perimidine have demonstrated promising optical properties and immense potential for modifications, albeit with limited development. Quinoline- and perimidine-based squaraine dyes have molar extinction coefficients over 100,000 M<sup>-1</sup> cm<sup>-1</sup> and absorbances over 800 nm. This report will look at indole-, quinoline-, and perimidine-based squaraine dyes. Due to the sheer number of reported dyes, the search for indole-based squaraine dyes has been limited to reports from the past five years (2018-2023). For quinoline- and perimidine-based squaraine dyes, a holistic search was performed to analyze the optical properties and applications, due to the abovementioned limitation. This report will evaluate the three different classes of squaraines: indole-, quinoline-, and perimidine-based, to evaluate their optical properties and applications, with the goal of encouraging the exploration of other heterocycles for use in squaraine dyes. Indole test ; Quinoline ; Moiety ; Molar absorptivity ; Chemistry ; Absorbance ; Photochemistry ; Combinatorial chemistry ; Organic chemistry ; Chromatography ; Optics Photochromic and Fluorescence Chemistry ; Synthesis and Characterization of Heterocyclic Compounds ; Photochemistry and Electron Transfer Studies