jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Qing Sun | Hui He | Ying Zhou | Yu Dai | Ping Shang | Xuan‐Feng Jiang
Source: Angewandte Chemie (article, 2024-12-23)
Field: Materials Science — Materials Chemistry

Photocatalytic Hydroxylation and Oxidative Coupling Reactions Mediated by Multinuclear Au(I) Supramolecular Clusters Abstract Polynuclear Au(I) cluster photocatalysts, known for their high activity and stability, hold substantial potential in organic synthetic chemistry. This study synthesized two Au(I) supramolecular cluster catalysts with different nuclearities: a tetranuclear cluster, C1 ([(dppmAu 2 ) 2 L 1 ] • PF 6 − ), and a hexadecanuclear cluster, C2 [(dppmAu 2 ) 6 (Au 4 )( L 1 ) 4 ] • 4PF 6 − , through a multicomponent stepwise self‐assembly approach. Both cluster structures feature aurophilicity interaction motifs that endow them with exceptional photocatalytic performance, exhibiting optical band gaps of 2.27 eV and 2.41 eV, respectively. Upon photoexcitation, these clusters efficiently generate reactive oxygen species, significantly enhancing their photocatalytic efficacy for the oxidative hydroxylation of phenylboronic acids and oxidative coupling of benzylamines under mild conditions. Catalytic efficiencies exceeding 90 % were achieved. Turnover frequencies for C2 and C1 were measured at 52.045 h −1 and 6.030 h −1 , respectively, representing the highest efficiencies reported for photocatalysts to date. Compared to C1 , C2 exhibited superior photocatalytic activity, attributed to its higher photoelectric sensitivity and greater exposure of active metal sites. Using a combination of experimental data and density functional theory calculations, the plausible mechanisms were proposed for two photocatalytic reactions. This study demonstrates that the use of multicomponent cooperative self‐assembly strategy to synthesize high‐nuclearity Au(I) clusters offers innovative pathways for the development of efficient, green, light‐driven organic synthesis. Hydroxylation ; Photocatalysis ; Supramolecular chemistry ; Oxidative phosphorylation ; Chemistry ; Oxidative coupling of methane ; Photochemistry ; Catalysis ; Organic chemistry ; Molecule ; Biochemistry Nanocluster Synthesis and Applications ; Catalytic Processes in Materials Science ; Advanced Nanomaterials in Catalysis
Authors: Alexander D. Ageenkov | N. S. Bredov | А. А. Щербина | Р. Р. Хасбиуллин | Anton S. Tupikov | Mikhail A. Soldatov
Source: Polymers (article, 2024-10-21)
Field: Materials Science — Materials Chemistry

The Influence of Conditions of Polycondensation in Acid Medium on the Structure of Oligosilsesquioxanes with a Novel Eugenol-Containing Substituent Eugenol-containing oligoorganosilsesquioxanes were synthesized by the method of hydrolytic polycondensation in an active medium under various reaction conditions. The obtained products were characterized by <sup>29</sup>Si NMR spectroscopy and MALDI-TOF spectrometry. It was shown that factors such as the reaction temperature, polycondensation duration, and molar ratio between the initial alkoxysilane monomer and acetic acid may affect the molecular weight characteristics and molecular structure of the formed oligomer, like the content of stressed cyclic units (T<sub>3</sub>, DTT, TDT) and unstressed silsesquioxane units T<sub>n</sub>D<sub>m</sub>. In particular, an increase in the ratio of the initial reagents led to an increase in the content of silsesquioxane T<sub>n</sub> fragments from 28.2%<sub>mol</sub> to 41.7%<sub>mol</sub>, while the number of strained cyclic structures decreased by more than two times. An increase in the synthesis time is of no particular practical value since it was found that the composition of the oligomers synthesized for 6 h and 12 h was practically identical, as was that of the oligomers synthesized for 24 h and 48 h. A noticeable transition in the oligomer composition was observed only when the synthesis time was changed from 12 h to 24 h. Finally, it was shown that the choice of synthesis temperature had the strongest effect on the oligomer composition. The oligomer synthesized at 95 °C contained the highest amount of silsesquioxane T<sub>n</sub> fragments, >77%<sub>mol</sub>, while a T<sub>n</sub> fragment content of ~42%<sub>mol</sub> was observed during the synthesis at 117 °C. It was shown that silsesquioxanes are devitrified at room temperature (T<sub>g</sub> from -6.4 to -10.6 °C), and their thermal stability in an inert atmosphere is 300 °C. The synthesized oligomers, due to the presence of hydroxyl-containing eugenol units, may be promising binders and additives for functional epoxy-silicone paints and coating materials. Substituent ; Condensation polymer ; Eugenol ; Chemistry ; Organic chemistry ; Polymer chemistry ; Polymer Silicone and Siloxane Chemistry ; Synthesis and properties of polymers ; biodegradable polymer synthesis and properties
Authors: Yundong Ji | Jitao Feng | Changzeng Wang | Shuxin Li | Dongfeng Cao | Duan‐Ping Huang
Source: Journal of Applied Polymer Science (article, 2024-11-28)
Field: Materials Science — Materials Chemistry

Phenyl Propyl Polysiloxane‐Modified Epoxy Resin III: The Reaction Condition, Phase Structures, and Macroproperties ABSTRACT Polysiloxanes are known to significantly enhance the toughness and thermal stability of epoxy resins. However, unsatisfactory grafting or copolymerization often occurs due to compatibility issues between the two materials, resulting in noticeable phase separation and a significant reduction in strength. In this paper, the copolymerization extent of epoxy resin with polysiloxanes was enhanced through solution polymerization by refining the synthesis process. The investigation explored the impact of polymerization process parameters on the reaction extent, phase structure, and mechanical properties. The results of refractive index and epoxy value showed that the extent of copolymerization ceased to increase after a 3‐h reaction duration at 15°C, 25°C, and 40°C. The results of FTIR and NMR showed that the lower the reaction temperature, the higher the extent of copolymerization. The toughness and strength of the resins copolymerized at 15°C increased simultaneously, while the strength of the resins copolymerized at 40°C decreased. The SEM results showed that the higher the extent of copolymerization, the finer the size of the second phase of the resins and that controlling the size of the second phase to an average of about 600 nm is the key to the strengthening of the resins. It is found that a low temperature is more favorable for the occurrence of a copolymerization reaction between polysiloxanes and epoxy resin, and it is pointed out that the relationship between the extent of reaction, phase structure, and macroscopic properties is an important guide for the work on siloxane‐modified epoxy resins. Epoxy ; Materials science ; Phase (matter) ; Polymer chemistry ; Composite material ; Polymer science ; Chemistry ; Organic chemistry Silicone and Siloxane Chemistry ; Epoxy Resin Curing Processes ; Synthesis and properties of polymers
Authors: Jordan Brito | Junho Moon | Raman Hlushko | Aliaksei Aliakseyeu | Alexander K. Andrianov | Svetlana A. Sukhishvili
Source: Journal of Functional Biomaterials (article, 2024-01-23)
Field: Materials Science — Surfaces, Coatings and Films

Engineering Degradation Rate of Polyphosphazene-Based Layer-by-Layer Polymer Coatings Degradable layer-by-layer (LbL) polymeric coatings have distinct advantages over traditional biomedical coatings due to their precision of assembly, versatile inclusion of bioactive molecules, and conformality to the complex architectures of implantable devices. However, controlling the degradation rate while achieving biocompatibility has remained a challenge. This work employs polyphosphazenes as promising candidates for film assembly due to their inherent biocompatibility, tunability of chemical composition, and the buffering capability of degradation products. The degradation of pyrrolidone-functionalized polyphosphazenes was monitored in solution, complexes and LbL coatings (with tannic acid), providing the first to our knowledge comparison of solution-state degradation to solid-state LbL degradation. In all cases, the rate of degradation accelerated in acidic conditions. Importantly, the tunability of the degradation rate of polyphosphazene-based LbL films was achieved by varying film assembly conditions. Specifically, by slightly increasing the ionization of tannic acid (near neutral pH), we introduce electrostatic "defects" to the hydrogen-bonded pairs that accelerate film degradation. Finally, we show that replacing the pyrrolidone side group with a carboxylic acid moiety greatly reduces the degradation rate of the LbL coatings. In practical applications, these coatings have the versatility to serve as biocompatible platforms for various biomedical applications and controlled release systems. Materials science ; Polyphosphazene ; Degradation (telecommunications) ; Biocompatibility ; Tannic acid ; Layer by layer ; Polymer ; Nanotechnology ; Layer (electronics) ; Chemical engineering ; Organic chemistry ; Composite material ; Chemistry ; Computer science Polymer Surface Interaction Studies ; biodegradable polymer synthesis and properties ; Flame retardant materials and properties
Authors: Yaqi Dong | Juncong Yuan | Sheng He | Zhe Ma | De Chen | Chaohe Yang | Xiang Feng
Source: ChemCatChem (article, 2024-09-21)
Field: Chemistry — Organic Chemistry

Constructing Highly Efficient Catalysts for the 1‐Butene Epoxidation Abstract Epoxides are high‐valued intermediates in the production of chemicals, pharmaceuticals, perfumes, and polymers. Given the growing demand for epoxides, it is imperative to develop more environmental friendly and sustainable routes instead of the chlorohydrin process. Notably, the direct utilization of hydrogen peroxide (H 2 O 2 ) for the epoxidation reaction presents significant advantages from both environmental and economic perspectives. The review provides insights into both homogeneous and heterogeneous catalysts employed in the 1‐butene epoxidation using the green oxidant H 2 O 2 . Among the diverse range of catalysts, titanosilicate‐1 (TS‐1) has garnered extensive attention due to its exceptional selectivity and high oxygen atom utilization. The aim of this review is to illustrate various strategies for TS‐1 catalysts preparation that can lead to more versatile, higher‐performance, and greener epoxidation processes. Additionally, various potential approaches to enhance the catalyst performance of TS‐1 are highlighted, including (i) constructing specific coordination modes of Ti sites, (ii) regulating the microenvironment around Ti sites, and (iii) improving the accessibility of Ti sites. Furthermore, advances in molding TS‐1 catalysts are also introduced from the perspective of the industrialization. Finally, future research directions are discussed with emphasis on the application scope of TS‐1 to gain deeper insights into epoxidation process. Catalysis ; Chemistry ; Organic chemistry Organic Chemistry Cycloaddition Reactions ; Porphyrin and Phthalocyanine Chemistry ; Catalysis and Oxidation Reactions
Authors: Janina Roknić | Ines Despotović | Jozefina Katić | Željka Petrović
Source: Molecules (article, 2024-09-03)
Field: Materials Science — Biomaterials

Electrospun PVP Fibers as Carriers of Ca2+ Ions to Improve the Osteoinductivity of Titanium-Based Dental Implants Although titanium and its alloys are widely used as dental implants, they cannot induce the formation of new bone around the implant, which is a basis for the functional integrity and long-term stability of implants. This study focused on the functionalization of the titanium/titanium oxide surface as the gold standard for dental implants, with electrospun composite fibers consisting of polyvinylpyrrolidone and Ca<sup>2+</sup> ions. Polymer fibers as carriers of Ca<sup>2+</sup> ions should gradually dissolve, releasing Ca<sup>2+</sup> ions into the environment of the implant when it is immersed in a model electrolyte of artificial saliva. Scanning electron microscopy, energy dispersive X-ray spectroscopy and attenuated total reflectance Fourier transform infrared spectroscopy confirmed the successful formation of a porous network of composite fibers on the titanium/titanium oxide surface. The mechanism of the formation of the composite fibers was investigated in detail by quantum chemical calculations at the density functional theory level based on the simulation of possible molecular interactions between Ca<sup>2+</sup> ions, polymer fibers and titanium substrate. During the 7-day immersion of the functionalized titanium in artificial saliva, the processes on the titanium/titanium oxide/composite fibers/artificial saliva interface were monitored by electrochemical impedance spectroscopy. It can be concluded from all the results that the composite fibers formed on titanium have application potential for the development of osteoinductive and thus more biocompatible dental implants. Titanium ; Materials science ; Surface modification ; Titanium oxide ; Scanning electron microscope ; Composite number ; Chemical engineering ; Polymer ; Composite material ; Metallurgy Electrospun Nanofibers in Biomedical Applications ; Bone Tissue Engineering Materials ; Dental materials and restorations
Authors: Halynne R. Lamontagne | Mélanie Cyr | Mário C. Vebber | Sufal Swaraj | Cory S. Harris | Jaclyn L. Brusso | Adam J. Shuhendler | Benoît H. Lessard
Source: RSC Applied Interfaces (article, 2024-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

(F<sub>5</sub>PhO)<sub>2</sub>-F<sub>16</sub>-SiPc as an air-stable, high-performance n-type semiconductor with poor cannabinoid sensing capabilities (F 5 PhO) 2 -F 16 -SiPc is an air stable, n-type semiconductor for organic thin-film transistors (OTFTs), however the structural changes that enhance its stability likely cause its lack of response to cannabinoids in a sensor. Cannabinoid ; Semiconductor ; Optoelectronics ; Materials science ; Nanotechnology ; Medicine ; Internal medicine Ga2O3 and related materials ; Transition Metal Oxide Nanomaterials ; Semiconductor materials and interfaces
Authors: Ajil R. Nair | M. Gayathri Mohan | C. Raksha | Anjana Sreekumar | P. Manoj | Y.C. Sunil Kumar | Akhil Sivan
Source: Scientific Reports (article, 2024-11-30)
Field: Materials Science — Materials Chemistry

Unveiling the dual-state emissive behaviour of 4,6-diarylpyrimidin-2-amines through a plug-and-play approach We present here a series of 4,6-diarylpyrimidin-2-amine derivatives (5a-j) with tunable optical properties both in the solid and solution states. Our plug-and-play fluorophore design demonstrates that the aryl groups at the 4<sup>th</sup> and 6<sup>th</sup> positions of the 2-aminopyrimidine core enable distinct optical characteristics for each derivative. The fluorophore design concept was validated using theoretical and spectroscopic methods. The designed compounds were synthesised in moderate to good yields, and their structures were confirmed via IR, NMR, HRMS, and single-crystal XRD analyses. Optical studies revealed that varying the aryl substituents significantly impacts absorption, emission, and bandgap values in both phases. The absolute quantum yields (ϕ<sub>F</sub>) of the synthesised derivatives ranged from 8.11 to 71.00% in DMF and 5.86-29.43% in thin films, with fluorescence lifetimes (τ) between 0.8 and 1.5 ns in DMF and 0.63-3.16 ns in films, respectively. CIE (Commission Internationale de l'Éclairage) diagrams indicate blue-green emission for 5a-j in the visible spectrum. The electrochemical analysis confirmed that the HOMO/LUMO (Highest Occupied Molecular Orbital/Lowest Unoccupied Molecular Orbital) energy levels can be modulated by altering the substituent rings. These results highlight the dual-state emission properties of 2-aminopyrimidine fluorophores, demonstrating their potential for a wide range of optoelectronic and advanced applications. HOMO/LUMO ; Fluorophore ; Aryl ; Substituent ; Fluorescence ; Molecular orbital ; Band gap ; Amine gas treating ; Chemistry ; Photochemistry ; Absorption (acoustics) ; Materials science ; Derivative (finance) ; Molecule ; Optoelectronics ; Stereochemistry ; Organic chemistry ; Optics ; Physics Luminescence and Fluorescent Materials ; Molecular Sensors and Ion Detection ; Organic Light-Emitting Diodes Research
Authors: Ummu Ozgun | Hayriye Nevin Genç | Abdulkadir Sırıt
Source: Necmettin Erbakan Üniversitesi Fen ve Mühendislik Bilimleri Dergisi (article, 2024-04-30)
Field: Chemistry — Organic Chemistry

Chiral Diazadioxocalix[2]arene[2]triazine-Based Derivative as Organocatalyst for Enantioselective Michael Reaction of Nitrostyrenes with Anthrone Kiral, stereoseçici ya da enantiyoseçici sentez olarak tanımlanan asimetrik sentez bir veya daha fazla stereojenik merkez bulunduran kiral bileşiklerin sentezlenmesini sağlayan organik sentez türüdür. Bir molekülün farklı enantiyomerleri genellikle birbirlerinden farklı biyolojik aktivite gösterdiklerinden dolayı, asimetrik sentez konusu ilaç kimyası ve organik kimyada oldukça önemli bir konudur. Kiral özellik göstermeyen bileşiklerden kiral bir bileşik sentezleme yöntemleri arasında en çok tercih edilen yöntemlerden biri kiral katalizör kullanımıdır. Bu çalışmada anthron ve farklı nitrostiren türevlerinin kullanıldığı asimetrik Michael tepkimesinde kullanılmak üzere literatürde bulunmayan bir kiral katalizör sentezlenmiştir. Öncelikle kiral katalizörün başlangıç maddesi olarak literatürde bulunan diazadioksookaliks[2]aren[2]triazin sentezlenmiştir. Sentezlenen başlangıç maddesi ile (S)-(+)-1-siklohekziletilamin tepkimeye sokularak enantiyoselektif tepkimede kiral katalizör olarak kullanılacak olan madde elde edilmiştir. Çalışma süresince yapılan tüm reaksiyonlar ince tabaka kromatografisi ile izlenmiş ve elde edilen maddeler kolon kromatografisi ile saflaştırılmıştır. Saflaştırılan ürünler FTIR, 1H NMR ve 13C NMR ile aydınlatılmış ve optik çevirme açıları ölçülmüştür. Sentezlenen katalizör asimetrik Michael reaksiyonunda denenmiş, yüksek verim ve yüksek enantiyoseçicilik elde edilmiştir (%95 verim ve %98 ee). Anthrone ; Michael reaction ; Enantioselective synthesis ; Organocatalysis ; Chemistry ; Derivative (finance) ; Triazine ; Organic chemistry ; Catalysis ; Combinatorial chemistry ; Economics Chemical Reaction Mechanisms ; Synthesis and Characterization of Heterocyclic Compounds ; Synthesis and Reactions of Organic Compounds
Authors: May-Yin Low | David Danaci | Hassan Azzan | Amanda Lim Jiayi | Gordon Wu Shun Yong | Ioanna Itskou | Camille Petit
Source: ChemRxiv (preprint, 2024-03-21)
Field: Materials Science — Materials Chemistry

Physicochemical properties, equilibrium adsorption performance, manufacturability, and stability of TIFSIX-3-Ni for direct air capture The use of adsorbents for direct air capture (DAC) is regarded as a promising and essential carbon dioxide removal technology to help meet the goals outlined by the 2015 Paris Agreement. A class of adsorbents that has gained significant attention for this application is ultramicroporous metal organic frameworks (MOFs). However, the necessary data needed to facilitate process scale evaluation of these materials is not currently available. Here, we investigate TIFSIX-3-Ni, a previously reported ultramicroporous MOF for direct air capture, and measure several physicochemical and equilibrium adsorption properties. We report its crystal structure, textural properties, thermal stability, specific heat capacity, CO2, N2, and H2O equilibrium adsorption isotherms at multiple temperatures, and Ar and O2 isotherms at a single temperature. For CO2, N2, and H2O, we also report isotherm model fitting parameters and calculate heats of adsorption. We assess the manufacturability and process stability of TIFSIX-3-Ni by investigating the impact of batch reproducibility, binderless pelletization, humidity, and adsorption-desorption cycling (50 cycles) on its crystal structure, textural properties, and CO2 adsorption. For pelletized TIFSIX-3-Ni, we also report its skeletal, pellet, and bed density, total pore volume, and pellet porosity. Overall, our data enable initial process modelling and optimization studies to evaluate TIFSIX-3-Ni for DAC at the process scale. They also highlight the possibility to pelletize TIFSIX-3-Ni and the limited stability of the MOF under humid and oxidative conditions as well as upon multiple adsorption-desorption cycles. Design for manufacturability ; Adsorption ; Stability (learning theory) ; Chemistry ; Chemical engineering ; Process engineering ; Materials science ; Computer science ; Engineering ; Physical chemistry ; Mechanical engineering Catalytic Processes in Materials Science ; Industrial Gas Emission Control
Authors: Jacek K. Wychowaniec | Ezgi Irem Bektas | Jennifer Vernengo | Marcia Mürner | Marielle Airoldi | Charlotte J. C. Edwards‐Gayle | Paul Sean Tipay | Jiranuwat Sapudom | Jeremy Teo | David Eglin | Matteo D’Este
Source: ChemRxiv (preprint, 2024-03-26)
Field: Materials Science — Biomaterials

Self-assembly of Tyrosine-containing Peptides into Injectable Hydrogels with Distinct Nanostructures is Key in Determining Inflammatory Response of Macrophages Self-assembling peptides (SAPs) are fully defined nanobiomaterials offering unprecedented opportunities to control nanostructure and chemical attributes to investigate and manipulate cellular signals. To investigate the influence of chemical and morphological characteristics on inflammatory signalling in native immunity, we designed five beta-sheet SAPs: EFEFKFEFK (EF8), YEFEFKFEFK (YEF8), YEFEFKFEFK (EF8Y), YEFEFKFEFK (YEF8Y) and EYEFKFEFK (EYF8) (F: phenylalanine; E: glutamic acid; K: lysine, Y: tyrosine). The position of tyrosine in the peptide sequence dictated the distinct self-assembly into nanostructures, with sequences EF8Y, YEF8Y, EYF8 self-assembling into thin nanofibers d≈3.8 ± 0.2 nm, YEF8 self-assembling into rod-like flat ribbons d>20 nm and EF8 (control) consisting of both types of self-assembled nanostructures. These distinct nanostructures induced contrasting inflammatory response of monocytic model THP-1 cells-derived macrophages (MΦs). Presence of soluble EF8 nanofibers (at 2 mM) induced anti-inflammatory response and polarization towards an M2 state, whereas YEF8 displayed tendency for inducing pro-inflammatory response and polarization towards M1 state. The EF8Y, YEF8Y, EYF8 SAPs did not induce an inflammatory response in our models. These results were validated using peripheral blood mononuclear cells (PBMCs)-derived MΦs from human donors, confirming the critical role of the EF8 and YEF8 SAPs as possible orchestrators of the repair of tissues or inducers of pro-inflammatory state, respectively. These findings will facilitate the utilization of this family of SAPs as immunomodulatory nanobiomaterials potentially changing the course of inflammation during the progression of various diseases. Nanofiber ; Inflammation ; Tyrosine ; Nanostructure ; Inflammatory response ; Cell biology ; Peptide ; Self-healing hydrogels ; Chemistry ; Materials science ; Nanotechnology ; Biochemistry ; Biology ; Immunology Supramolecular Self-Assembly in Materials ; Immunotherapy and Immune Responses ; Antimicrobial Peptides and Activities