jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Rosa Barranco‐García | Alberto García‐Peñas | Enrique Blázquez‐Blázquez | Jorge A. Ressia | Lidia M. Quinzani | Enrique M. Vallés | José M. Gómez‐Elvira | Ernesto Pérez | María L. Cerrada
Source: Molecules (article, 2023-05-23)
Field: Materials Science — Polymers and Plastics

Polypropylene Nanocomposites Attained by In Situ Polymerization Using SBA-15 Particles as Support for Metallocene Catalysts: Effect of Molecular Weight and Tacticity on Crystalline Details, Phase Transitions and Rheological Behavior In this study, nanocomposites based on polypropylene are synthesized by the in situ polymerization of propene in the presence of mesoporous SBA-15 silica, which acts as a carrier of the catalytic system (zirconocene as catalyst and methylaluminoxane as cocatalyst). The protocol for the immobilization and attainment of hybrid SBA-15 particles involves a pre-stage of contact between the catalyst with cocatalyst before their final functionalization. Two zirconocene catalysts are tested in order to attain materials with different microstructural characteristics, molar masses and regioregularities of chains. Some polypropylene chains are able to be accommodated within the silica mesostructure of these composites. Thus, an endothermic event of small intensity appears during heating calorimetric experiments at approximately 105 °C. The existence of these polypropylene crystals, confined within the nanometric channels of silica, is corroborated by SAXS measurements obtained via the change in the intensity and position of the first-order diffraction of SBA-15. The incorporation of silica also has a very significant effect on the rheological response of the resultant materials, leading to important variations in various magnitudes, such as the shear storage modulus, viscosity and δ angle, when a comparison is established with the corresponding neat iPP matrices. Rheological percolation is reached, thus demonstrating the role of SBA-15 particles as filler, in addition to the supporting role that they exert during the polymerizations. Tacticity ; Materials science ; Methylaluminoxane ; Polypropylene ; Polymerization ; Nanocomposite ; Chemical engineering ; Dynamic mechanical analysis ; In situ polymerization ; Post-metallocene catalyst ; Rheology ; Small-angle X-ray scattering ; Composite material ; Polymer ; Polymer chemistry ; Metallocene Polymer crystallization and properties ; Polymer Nanocomposites and Properties ; biodegradable polymer synthesis and properties
Authors: Haydar U. Zaman | Ruhul A. Khan
Source: International Journal of Advanced Science and Engineering (review, 2023-02-04)
Field: Materials Science — Polymers and Plastics

A Review on Polymer Nanocomposites and Its Applications Multiple phases that have at least one, two, or three dimensions in the nanoscale range make up a nanocomposite material.Phase interfaces are produced when material dimensions are reduced to the nanoscale level, and they are crucial for improving the properties of the material.Understanding the relationship between structure and property is directly influenced by the surface area to volume ratio of the reinforced material employed during the creation of nanocomposites.Opportunities for overcoming barriers in the medical, pharmaceutical, food packaging, electronics, and energy industries are provided by nanocomposties on entirely new scales.Polymeric nanocomposites are frequently created by directly incorporating inorganic nanoscale building pieces into polymers.Surface modification of the nanofillers is crucial in the creation of nanocomposites through dispersive blending.It has the power to make fillers more hydrophobic, improve interfacial adhesion by chemical bonding or chain entanglement, and get rid of the loose structure of filler agglomerates.The state of the art for nanoparticle/polymer composites is reviewed in the current work, along with the specific surface pretreatment methods and their uses.Particular emphasis is placed on the function of modified nanoparticles and the mechanisms involved in the enhancement of the mechanical characteristics and wear resistance of the composites. Nanocomposite ; Materials science ; Agglomerate ; Filler (materials) ; Nanoscopic scale ; Composite material ; Polymer ; Polymer nanocomposite ; Nanoparticle ; Nanotechnology ; Surface modification ; Surface energy ; Phase (matter) ; Chemical engineering Polymer Nanocomposites and Properties ; Tribology and Wear Analysis ; Polymer Nanocomposite Synthesis and Irradiation
Authors: Sema Öztürk Yıldırım | Mehmet Akkurt | Gökalp Çetin | Rahime Şimşek | Ray J. Butcher | Ajaya Bhattarai
Source: Acta Crystallographica Section E Crystallographic Communications (article, 2023-11-10)
Field: Chemistry — Inorganic Chemistry

Synthesis, characterization, crystal structure and Hirshfeld surface analysis of isobutyl 4-[4-(difluoromethoxy)phenyl]-2,6,6-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate In the title compound, C<sub>24</sub>H<sub>29</sub>F<sub>2</sub>NO<sub>4</sub>, which crystallizes in the ortho-rhom-bic <i>Pca</i>2<sub>1</sub> space group with <i>Z</i> = 4, the 1,4-di-hydro-pyridine ring adopts a distorted boat conformation, while the cyclo-hexene ring is in a distorted half-chair conformation. In the crystal, the mol-ecules are linked by N-H⋯O and C-H⋯O inter-actions, forming supra-molecular chains parallel to the <i>a</i> axis. These chains pack with C-H⋯π inter-actions between them, forming layers parallel to the (010) plane. The cohesion of the crystal structure is ensured by van der Waals inter-actions between these layers. Hirshfeld surface analysis shows the major contributions to the crystal packing are from H⋯H (56.9%), F⋯H/H⋯F (15.7%), O⋯H/H⋯O (13.7%) and C⋯H/H⋯C (9.5%) contacts. Crystallography ; Ring (chemistry) ; Crystal structure ; Carboxylate ; van der Waals force ; Chemistry ; Pyridine ; Crystal (programming language) ; Cyclohexane conformation ; Stereochemistry ; Hydrogen bond ; Molecule ; Medicinal chemistry ; Organic chemistry Crystal structures of chemical compounds ; Synthesis and biological activity ; Synthesis and Reactions of Organic Compounds
Authors: Mickey Vinodh | Shaima G. Alshammari | Talal F. Al‐Azemi
Source: Crystals (article, 2023-03-31)
Field: Chemistry — Organic Chemistry

Single-Crystal X-ray Diffraction Analysis of Inclusion Complexes of Triflate-Functionalized Pillar[5]arenes with 1,4-Dibromobutane and n-Hexane Guests Herein, we report the single-crystal X-ray diffraction analysis of supramolecular host–guest systems based on triflate-functionalized pillar[5]arenes and 1,4-dibromobutane or n-hexane. The guest molecule was stabilized inside the pillar[5]arene cavity by C–H⋯π and C–H⋯O interactions. These inclusion complexes were further self-assembled into supramolecular networks by various non-bonding interactions such as C-H⋯O, C-H⋯F, Br⋯Br, F⋯F, etc. The intermolecular interactions present in these systems were investigated in detail. One of the supramolecular systems analyzed in this study exhibited intermolecular F⋯F interactions which were operative between the adjacent pillararene rims. It was observed that the type of guest molecule considerably influenced the mutual interactions of pillararene macrocycles and their networking pattern in the crystal. The inclusion complexes were further studied by Hirshfeld surface analysis which not only provided a visual representation of the intermolecular interactions experienced by the systems but gave a quantitative account of these various interactions. Supramolecular chemistry ; Intermolecular force ; Trifluoromethanesulfonate ; Crystallography ; Molecule ; Pillar ; Chemistry ; Crystal (programming language) ; Crystal structure ; Diffraction ; Single crystal ; Inclusion (mineral) ; Stereochemistry ; Organic chemistry ; Physics ; Catalysis Supramolecular Chemistry and Complexes ; Crystallography and molecular interactions ; Advanced NMR Techniques and Applications
Authors: Aleksandar Z. Jovanović | Ana S. Dobrota | Natalia V. Skorodumova | Igor A. Pašti
Source: arXiv (Cornell University) (preprint, 2023-08-10)
Field: Materials Science — Materials Chemistry

Reactivity of Stone-Wales defect in graphene lattice -- DFT study Understanding the reactivity of carbon surfaces is crucial for the development of advanced functional materials. In this study, we systematically investigate the reactivity of graphene surfaces with the Stone-Wales (SW) defect using Density Functional Theory calculations. We explore the atomic adsorption of various elements, including rows 1-3 of the Periodic Table, potassium, calcium, and selected transition metals. Our results demonstrate that the SW defect enhances binding with the studied adsorbates when compared to pristine graphene, with carbon and silicon showing the most significant differences. Additionally, we examine the effects of mechanical deformation on the lattice by constraining the system with the SW defect to the pristine graphene cell. Interestingly, these constraints lead to even stronger binding interactions. Furthermore, for carbon, nitrogen, and oxygen adsorbates, we observe that mechanical deformation triggers the incorporation of adatoms into the carbon bond network, leading to the reorganization of the SW defect structure. This work establishes a foundation for future studies in the defect and strain engineering of graphene, opening avenues for developing advanced materials and catalysts with enhanced reactivity and performance. Graphene ; Reactivity (psychology) ; Density functional theory ; Materials science ; Carbon fibers ; Silicon ; Chemical physics ; Lattice (music) ; Adsorption ; Nanotechnology ; Computational chemistry ; Chemistry ; Composite material ; Physical chemistry ; Optoelectronics ; Composite number Graphene research and applications ; Advancements in Battery Materials ; Boron and Carbon Nanomaterials Research
Authors: Michael J. Spicuzza | Shweta Gaikwad | S. HUSS | Annemarie L. Lee | Cristina V. Craescu | Anna Griggs | Joshmi Joseph | Mark Puthenpurayil | Wilson Lin | Christopher J. Matarazzo | S. Prentiss Baldwin | Victoria Perez | Diego Rodríguez | John R. Swierk | Elizabeth Elacqua
Source: ChemRxiv (preprint, 2023-12-13)
Field: Materials Science — Materials Chemistry

Visible-Light-Mediated Diels-Alder Reactions Under Single-Chain Polymer Confinement: Investigating the Role of the Crosslinking Moiety on Catalyst Activity Macromolecular scaffolds are rapidly emerging in catalysis owing to the ability to control catalyst placement at precise locations. This spatial proximity allows for enhanced catalyst activity that may not be observed using small molecules. Herein, we describe a triphenylpyrylium (TPT)-based visible-light active single-chain polymer nanoparticle (SCNP) that facilitates the radical cation [4+2]-cycloaddition. We find that the catalytic activity is highly dependent on the styrylarene comonomer used, wherein it can act as a redox mediator under confinement, increasing the catalytic turnover (TON) by up to 30 times in comparison to free TPT in solution. Mechanistic studies indicate that TPT excited states are quenched by the acene, with the resultant radical cation formed from naphthalene-based SCNPs able to proceed in oxidizing the dienophile in the elementary step of the reaction, while leading to near quantitative yields of the cycloadduct. The TPT-SCNP demonstrates enhanced photocatalyst efficiency compared to small molecule TPT, and is also able to be recycled and reused in three iterations of the reaction prior to decreased performance caused by photobleaching. Our results overall suggest that SCNPs feature multiple subtle design elements that can impart enhanced reactivity under confinement, boding well for use as catalysts in diffusion-limited photoredox reactions. Catalysis ; Chemistry ; Photochemistry ; Moiety ; Cycloaddition ; Reactivity (psychology) ; Photoredox catalysis ; Naphthalene ; Oxidizing agent ; Diradical ; Comonomer ; Nanoparticle ; Polymer ; Combinatorial chemistry ; Nanotechnology ; Photocatalysis ; Materials science ; Ethylene ; Excited state ; Organic chemistry ; Singlet state Photochromic and Fluorescence Chemistry ; Organic Chemistry Cycloaddition Reactions ; Radical Photochemical Reactions
Authors: Kimberly A. Alley | Aidan J. Clarkson | Ayaka Uehara | Jeffrey S. Johnson
Source: ChemRxiv (preprint, 2023-10-19)
Field: Chemistry — Organic Chemistry

A Site-Specific Synthetic Route to Substituted Inda(box) Ligands Aminoindanol-derived bis(oxazoline) ligands are widely used in metal-catalyzed transformations, but the synthesis of structural derivatives is challenging. We report the gram-scale, seven-step synthesis of five bromine-functionalized in-da(box) ligands that have varied bridge substituents. The bromoinda(box) ligands undergo late-stage modification via Pd-catalyzed cross-couplings, which allows for the synthesis of 12 unique inda(box) ligands. This complementary syn-thetic route could enable the discovery of new asymmetric metal-catalyzed transformations through modification of the inda(box) ligand architecture. Combinatorial chemistry ; Ligand (biochemistry) ; Chemistry ; Oxazoline ; Catalysis ; Bromine ; Stereochemistry ; Organic chemistry Catalytic C–H Functionalization Methods ; Catalytic Cross-Coupling Reactions ; Asymmetric Hydrogenation and Catalysis
Authors: Zhongjie Huang
Source: Molecules (article, 2023-12-15)
Field: Materials Science — Materials Chemistry

Chemical Patterning on Nanocarbons: Functionality Typewriting Nanocarbon materials have become extraordinarily compelling for their significant potential in the cutting-edge science and technology. These materials exhibit exceptional physicochemical properties due to their distinctive low-dimensional structures and tailored surface characteristics. An attractive direction at the forefront of this field involves the spatially resolved chemical functionalization of a diverse range of nanocarbons, encompassing carbon nanotubes, graphene, and a myriad of derivative structures. In tandem with the technological leaps in lithography, these endeavors have fostered the creation of a novel class of nanocarbon materials with finely tunable physical and chemical attributes, and programmable multi-functionalities, paving the way for new applications in fields such as nanoelectronics, sensing, photonics, and quantum technologies. Our review examines the swift and dynamic advancements in nanocarbon chemical patterning. Key breakthroughs and future opportunities are highlighted. This review not only provides an in-depth understanding of this fast-paced field but also helps to catalyze the rational design of advanced next-generation nanocarbon-based materials and devices. Nanotechnology ; Carbon nanotube ; Materials science ; Lithography ; Nanoelectronics ; Graphene ; Photonics ; Surface modification ; Chemistry ; Optoelectronics Graphene research and applications ; Carbon Nanotubes in Composites ; Surface Chemistry and Catalysis
Authors: Federico De Biasi | Michael A. Hope | Claudia E. Avalos | Ganesan Karthikeyan | Gilles Casano | Aditya Mishra | Saumya Badoni | Gabriele Stevanato | Dominik J. Kubicki | Jonas Milani | Jean‐Philippe Ansermet | Aaron J. Rossini | Moreno Lelli | Olivier Ouari | Lyndon Emsley
Source: ChemRxiv (preprint, 2023-05-05)
Field: Chemistry — Spectroscopy

Optically enhanced solid-state 1H NMR spectroscopy Low sensitivity is the primary limitation to extending nuclear magnetic resonance (NMR) techniques to more advanced chemical and structural studies. Photochemically induced dynamic nuclear polarization (photo-CIDNP) is an NMR hyperpolarization technique where light is used to excite a suitable donor–acceptor system, creating a spin-correlated radical pair whose evolution drives nuclear hy-perpolarization. Systems that exhibit photo-CIDNP in solids are not common and this effect has, up to now, only been observed for 13C and 15N nuclei. However, the low gyromagnetic ratio and natural abundance of these nuclei trap the local hyperpolarization in the vicinity of the chromophore and limit the utility for bulk hyperpolarization. Here we report the first example of optically enhanced solid-state 1H NMR spectroscopy in the high-field regime. This is achieved via photo-CIDNP of a donor–chromophore–acceptor molecule in a frozen solution at 0.3 T and 85 K, where spontaneous spin diffusion among the abundant strongly coupled 1H nuclei relays polarization through the whole sample, yielding a 16-fold bulk 1H signal enhancement under continuous laser irradiation at 450 nm. These findings enable a new strategy for hyperpolarized NMR beyond the current limits of conventional microwave-driven DNP. CIDNP ; Hyperpolarization (physics) ; Chromophore ; Spectroscopy ; Nuclear magnetic resonance spectroscopy ; Polarization (electrochemistry) ; Spin diffusion ; Solid-state nuclear magnetic resonance ; Chemistry ; Spin isomers of hydrogen ; Nuclear magnetic resonance ; Acceptor ; Chemical physics ; Materials science ; Photochemistry ; Physical chemistry ; Diffusion ; Physics ; Stereochemistry Advanced NMR Techniques and Applications ; Solid-state spectroscopy and crystallography ; Molecular spectroscopy and chirality
Authors: Junghye Lee | Eunhye Hwang | Tae In Kim | Eunji Jin | Eunchan Cho | Young S. Park | Seung Kyu Min | Tae‐Hyuk Kwon | Wonyoung Choe
Source: ChemRxiv (preprint, 2023-10-12)
Field: Materials Science — Materials Chemistry

Nanographene-based Metal-Organic Frameworks for Engineering Energy Transfer Pathways Nanographenes are a class of extended π-conjugated molecules with great potential in photophysical and electrochemical properties. However, most nanographenes show self-aggregation due to their strong π–π interaction, resulting in struc-tures barely possessing any open π surface. We find that metal-organic frameworks (MOFs) can be an ideal platform to construct periodic arrays and pores with isolated large π-conjugated surfaces by avoiding undesired π–π interaction be-tween the nanographene molecules. Here, we report a multivariate series of nanographene-based MOFs, UMOF-2-X, utiliz-ing the graphene-like hexatopic organic linkers, hexaphenylbenzene (HPB) and hexabenzocoronene (HBC) through a mixed-linker strategy. Interestingly, UMOF-2 shows effective energy transfer between HPB and HBC linkers while sup-pressing the occurrence of linker-to-metal charge transfer from the linker to Cu metal. We successfully describe the origin of these intriguing phenomena through computational studies. Linker ; Conjugated system ; Materials science ; Molecule ; Metal-organic framework ; Graphene ; Energy transfer ; Nanotechnology ; Metal ; Chemical physics ; Polymer ; Chemistry ; Organic chemistry ; Adsorption ; Computer science Graphene research and applications ; Metal-Organic Frameworks: Synthesis and Applications ; Advancements in Battery Materials
Authors: Ye‐Qiang Han | Yuan Xie | Jianyu Zhang | Shiyu Tan | Haoke Zhang | Ben Zhong Tang | Jonathan L. Sessler | Feihe Huang
Source: ChemRxiv (preprint, 2023-07-13)
Field: Materials Science — Materials Chemistry

Fjord-Type AIEgens Based on Inherent Through-Space Conjugation Through-space conjugation (TSC) is a noncovalently electronic interaction that is emerging as a potential complement to through-bond conjugation (TBC)-based strategies for constructing luminescent materials. However, the design of efficient luminogens based on TSC is currently challenging due to a lack of established structure-property understanding. This is particularly true in the case of luminogens displaying aggregation-induced emission (AIE) effects. In this work, three terphenyl derivatives were prepared, and their photophysical properties were systemically studied. It was found that relative to the corresponding m- and p-linked analogues, the electronic interaction of TBC is weakened while the strength of TSC is commensurately enhanced in the constitutional isomer containing an o-linked Fjord-type subunit. Within this set of luminogens, the presence of a Fjord-type arrangement promotes a transformation from aggregation-caused quenching (ACQ) to AIE. Further investigations involving congeneric quaterphenyl and pentphenyl isomers support the universality of the Fjord-type unit as a framework for synthesizing AIE-active luminogens (AIEgens) with inherent TSC. This work not only provides a novel set of AIEgens but also establishes the utility of TSC in controlling the photophysical properties of nonconventional and twisted luminogens. Chemistry ; Fjord ; Quenching (fluorescence) ; Physics ; Fluorescence Luminescence and Fluorescent Materials ; Fluorine in Organic Chemistry ; Polydiacetylene-based materials and applications
Authors: Jian Yang | Xinqing Wang | Shuangshuang Ji | Yanyan Zhu
Source: Structural Chemistry (article, 2023-03-14)
Field: Chemistry — Physical and Theoretical Chemistry

Chiral discrimination of cyclodecapeptide to anti-COVID-19 clinical candidates: a theoretical study Chemistry ; Hydrogen bond ; Non-covalent interactions ; Natural bond orbital ; Molecular recognition ; Molecule ; Hydrophobic effect ; Protein–protein interaction ; Molecular dynamics ; Stereochemistry ; Computational chemistry ; Combinatorial chemistry ; Organic chemistry ; Biochemistry Crystallography and molecular interactions ; Influenza Virus Research Studies ; Chemical Synthesis and Analysis
Authors: Kazuki Miwa | Tomoya Yokota | Qian Wang | Takahiro Sakurai | Heike Fliegl | Dage Sundholm | Hiroshi Shinokubo
Source: ChemRxiv (preprint, 2023-08-29)
Field: Materials Science — Materials Chemistry

Metallaantiaromaticity of 10-Platinacorrole Complexes The aromaticity of cyclic π-conjugated organometallic compounds is known as metallaaromaticity. π-Conjugated metallacycles, such as metallabenzenes and metallapentalenes, have been investigated in order to understand the involvement of the d electrons from the metal center in the π-conjugated systems of the organic ligands. Here, we report the synthesis of Pd(II) 10-platinacorrole complexes with cyclooctadiene (COD) and norbornadiene (NBD) ligands. While the Pd(II) 10-platinacorrole COD complex adopts a distorted structure without showing appreciable antiaromaticity, the corresponding NBD complex exhibits distinct antiaromatic character due to its highly planar conformation. Detailed density-functional-theory (DFT) calculations revealed that two d orbitals are involved in the macrocyclic π-conjugation. We furthermore demonstrated that Craig–Möbius antiaromaticity is not present in the studied system. The synthesis of 10-platinacorroles enables the systematic comparison of the antiaromaticity and aromaticity of closely related porphyrin analogues, providing a better understanding of π-conjugation that involves d orbitals. Antiaromaticity ; Aromaticity ; Conjugated system ; Chemistry ; Atomic orbital ; Density functional theory ; Ring (chemistry) ; Porphyrin ; Stereochemistry ; Computational chemistry ; Crystallography ; Electron ; Photochemistry ; Molecule ; Organic chemistry ; Physics Porphyrin and Phthalocyanine Chemistry ; Synthesis and Properties of Aromatic Compounds ; Surface Chemistry and Catalysis