jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Bhupendra Kumar Dwivedi | Vishwa Deepak Singh | Rajendra Prasad Paitandi | Daya Shankar Pandey
Source: The Journal of Physical Chemistry C (article, 2020-07-01)
Field: Materials Science — Materials Chemistry

Controlling Aggregation and Excited-State Intramolecular Proton Transfer in BODIPYs by Incorporation of 2-(2-Hydroxyphenyl)quinazoline and Variation of Substituents A series of BODIPY-based AIEgens (QB1–QB5 and Bis-QB) containing 2-(2-hydroxyphenyl)quinazoline have been synthesized and thoroughly characterized. Photophysical properties of these compounds in solution and the aggregated state have been meticulously investigated and fine-tuned via structural modifications. These display green emission (∼530 nm) in solution and bright red emission (600–655 nm) in the aggregated/solid state with increased quantum yield. Crystal structure analyses and spectral studies revealed efficient J-type aggregation in these derivatives. Significant impact of 2-(2-hydroxyphenyl)quinazoline toward modulating intermolecular interactions and facilitating J-type stacking between BODIPY units has also been established. Moreover, the essential role of excited-state intramolecular proton transfer (ESIPT) in inducing emission in the aggregated state and tuning of ESIPT emission by variation of substituents have been supported by various studies. Intramolecular force ; BODIPY ; Stacking ; Intermolecular force ; Quinazoline ; Excited state ; Chemistry ; Aggregation-induced emission ; Photochemistry ; Quantum yield ; Proton ; Molecule ; Fluorescence ; Stereochemistry ; Organic chemistry Luminescence and Fluorescent Materials ; Porphyrin and Phthalocyanine Chemistry ; Nanoplatforms for cancer theranostics
Authors: A. Juhász | Kristóf Molnár | Abdenacer Idrissi | Angéla Jedlovszky‐Hajdú
Source: Journal of Molecular Liquids (article, 2020-05-30)
Field: Materials Science — Biomaterials

Salt induced fluffy structured electrospun fibrous matrix Electrospinning is a widely investigated and used technique for creating nano and microfibres which has a wide range of medical and pharmaceutical applications. For cell culturing and tissue engineering, it is a greatly investigated method because it resembles the extracellular matrix. Changing the electrospinning parameters we affect the properties of these systems to fine-tune it for our needs. To create a high porosity fibrous mesh for culturing different cells in a suitable three-dimensional way, we need to step forward from conventional electrospinning. In this paper, we are presenting a strategy involving the addition of inorganic salts to electrospinning solution to reproducibly synthesize nano and microfibrous fluffy 3D structures from polysuccinimide (a biocompatible and biodegradable polymer). Effect of different concentrations of LiCl, MgCl2 and CaCl2 on fibre properties are presented. Results show that the 3D structured fibrous meshes were produced in the presence of LiCl, MgCl2 or CaCl2 in a narrow concentration range. To understand the effect of salt on the resulting meshes characterization of the ion-ion and ion-solvent interactions were carried out using vibration spectroscopy and density functional theory calculation. Electrospinning ; Materials science ; Porosity ; Chemical engineering ; Polymer ; Solvent ; Salt (chemistry) ; Matrix (chemical analysis) ; Nanofiber ; Composite material ; Chemistry ; Organic chemistry Electrospun Nanofibers in Biomedical Applications ; Advanced Sensor and Energy Harvesting Materials ; Tissue Engineering and Regenerative Medicine
Authors: Florian Rauch | Johannes Krebs | Julian Günther | Alexandra Friedrich | Martin Hähnel | Ivo Krummenacher | Holger Braunschweig | Maik Finze | Todd B. Marder
Source: Chemistry - A European Journal (article, 2020-06-08)
Field: Chemistry — Organic Chemistry

Electronically Driven Regioselective Iridium‐Catalyzed C−H Borylation of Donor‐π‐Acceptor Chromophores Containing Triarylboron Acceptors We observed a surprisingly high electronically driven regioselectivity for the iridium-catalyzed C-H borylation of donor-π-acceptor (D-π-A) systems with diphenylamino (1) or carbazolyl (2) moieties as the donor, bis(2,6-bis(trifluoromethyl)phenyl)boryl (B(<sup>F</sup> Xyl)<sub>2</sub> ) as the acceptor, and 1,4-phenylene as the π-bridge. Under our conditions, borylation was observed only at the sterically least encumbered para-positions of the acceptor group. As boronate esters are versatile building blocks for organic synthesis (C-C coupling, functional group transformations) the C-H borylation represents a simple potential method for post-functionalization by which electronic or other properties of D-π-A systems can be fine-tuned for specific applications. The photophysical and electrochemical properties of the borylated (1-(Bpin)<sub>2</sub> ) and unborylated (1) diphenylamino-substituted D-π-A systems were investigated. Interestingly, the borylated derivative exhibits coordination of THF to the boronate ester moieties, influencing the photophysical properties and exemplifying the non-innocence of boronate esters. Borylation ; Iridium ; Regioselectivity ; Acceptor ; Chemistry ; Chromophore ; Catalysis ; Photochemistry ; Combinatorial chemistry ; Organic chemistry ; Physics Organoboron and organosilicon chemistry ; Catalytic C–H Functionalization Methods ; Catalytic Cross-Coupling Reactions
Authors: Ke Tian | Qingju Wang | Jin Shen | Jingyi Zhou | Zongbi Bao | Qiwei Yang | Qilong Ren
Source: Angewandte Chemie (article, 2020-04-24)
Field: Chemistry — Inorganic Chemistry

Molecular Sieving of C<sub>2</sub>‐C<sub>3</sub> Alkene from Alkyne with Tuned Threshold Pressure in Robust Layered Metal–Organic Frameworks Abstract C 2 ‐C 3 alkyne/alkene separation is of great importance; however, designing materials for an efficient molecular sieving of alkenes from alkynes remains challenging. Now, two hydrolytically stable layered MOFs, [Cu(dps) 2 (GeF 6 )] (GeFSIX‐dps‐Cu, dps=4,4′‐dipyridylsulfide) and [Zn(dps) 2 (GeF 6 )] (GeFSIX‐dps‐Zn), can achieve almost complete exclusion of both C 3 H 6 and C 2 H 4 from their alkyne analogues. GeFSIX‐dps‐Cu displays a notable advanced threshold pressure for alkynes adsorption and thus substantial uptakes at lower pressures, providing record C 3 H 4 /C 3 H 6 uptake ratios and capacity‐enhanced C 2 H 2 /C 2 H 4 sieving for a wide composition range. Metal substitution (Zn to Cu) affords fine tuning of linker rotation and layer stacking, creating slightly expanded pore aperture and interlayer space coupled with multiple hydrogen‐bonding sites, allowing easier entrance of alkyne while excluding alkene. Breakthrough experiments confirmed tunable sieving by these MOFs for C 3 H 4 /C 3 H 6 and C 2 H 2 /C 2 H 4 mixtures. Alkyne ; Alkene ; Metal-organic framework ; Stacking ; Chemistry ; Metal ; Linker ; Adsorption ; Crystallography ; Materials science ; Organic chemistry ; Catalysis Metal-Organic Frameworks: Synthesis and Applications ; Graphene research and applications ; Covalent Organic Framework Applications
Authors: Jiawei Yang | Wen Fang | Paul N. Williams | John W. McGrath | Carlos Eduardo Eismann | Amauri Antônio Menegário | Lucas Pellegrini Elias | Jun Luo | Yingjian Xu
Source: Current Pollution Reports (review, 2020-07-01)
Field: Materials Science — Materials Chemistry

Functionalized Mesoporous Silicon Nanomaterials in Inorganic Soil Pollution Research: Opportunities for Soil Protection and Advanced Chemical Imaging "Innovative actions towards a pollution free-planet" is a goal of the United Nations Environment Assembly (UNEA). Aided by both the Food and Agricultural Organisation (FAO) and its Global Soil Partnership under the 3rd UNEA resolution, a consensus from > 170 countries have agreed a need for accelerated action and collaboration to combat soil pollution. This initiative has been tasked to find new and improved solutions to prevent and reduce soil pollution, and it is in this context that this review provides an updated perspective on an emerging technology platform that has already provided demonstrable utility for measurement, mapping, and monitoring of toxic trace elements (TTEs) in soils, in addition to the entrapment, removal, and remediation of pollutant sources. In this article, the development and characteristics of functionalized mesoporous silica nanomaterials (FMSN) will be discussed and compared with other common metal scavenging materials. The chemistries of the common functionalizations will be reviewed, in addition to providing an outlook on some of the future directions/applications of FMSN. The use of FMSN in soil will be considered with some specific case studies focusing on Hg and As. Finally, the advantages and developments of FMSN in the widely used diffusive gradients-in-thin films (DGT) technique will be discussed, in particular, its advantages as a DGT substrate for integration with oxygen planar optodes in multilayer systems that provide 2D mapping of metal pollutant fluxes at submillimeter resolution, which can be used to measure detailed sediment-water fluxes as well as soil-root interactions, to predict plant uptake and bioavailability. Mesoporous material ; Nanomaterials ; Pollution ; Environmental science ; Silicon ; Environmental chemistry ; Materials science ; Nanotechnology ; Chemistry ; Metallurgy ; Catalysis Mesoporous Materials and Catalysis ; Silicon Nanostructures and Photoluminescence ; Carbon and Quantum Dots Applications
Authors: David Boucher | Jeppe Madsen | Nicolas Caussé | Nadine Pébère | Vincent Ladmiral | Claire Négrell
Source: Reactions (article, 2020-10-30)
Field: Chemistry — Organic Chemistry

Hemiacetal Ester Exchanges, Study of Reaction Conditions and Mechanistic Pathway A range of hemiacetal esters were synthesized by the reaction between carboxylic acids and butyl vinyl ether using n-dodecyl dihydrogen phosphate as catalyst. Specifically, nonanoic, propionic, acrylic, sebacic, and fumaric acids were used as substrates to prepare the corresponding hemiacetal esters. These compounds were used as model molecules to demonstrate the ability of hemiacetal ester functional groups to undergo the exchange reaction in the presence of weak carboxylic acids without any catalyst. Kinetics studies examined the eect of the carboxylic acid concentration on the exchange rate, and revealed that the exchange reaction proceeds through an associative mechanism. Hemiacetal ; Chemistry ; Organic chemistry ; Catalysis ; Ether ; Reaction mechanism ; Kinetics ; Polymer chemistry Synthetic Organic Chemistry Methods ; Polymer composites and self-healing ; Chemical Synthesis and Reactions
Authors: Geetanjali Deokar | Alessandro Genovese | Sandeep G. Surya | Long Chen | K. Saláma | Pedro M. F. J. Costa
Source: Scientific Reports (article, 2020-09-07)
Field: Materials Science — Materials Chemistry

Semi-transparent graphite films growth on Ni and their double-sided polymer-free transfer Abstract Nanorange thickness graphite films (NGFs) are robust nanomaterials that can be produced via catalytic chemical vapour deposition but questions remain regarding their facile transfer and how surface topography may affect their application in next-generation devices. Here, we report the growth of NGFs (with an area of 55 cm 2 and thickness of ~ 100 nm) on both sides of a polycrystalline Ni foil and their polymer-free transfer (front- and back-side, in areas up to 6 cm 2 ). Due to the catalyst foil topography, the two carbon films differed in physical properties and other characteristics such as surface roughness. We demonstrate that the coarser back-side NGF is well-suited for NO 2 sensing, whereas the smoother and more electrically conductive front-side NGF (2000 S/cm, sheet resistance − 50 Ω/sq) could be a viable conducting channel or counter electrode in solar cells (as it transmits 62% of visible light). Overall, the growth and transfer processes described could help realizing NGFs as an alternative carbon material for those technological applications where graphene and micrometer-thick graphite films are not an option. Graphite ; Materials science ; Graphene ; FOIL method ; Nanotechnology ; Micrometer ; Sheet resistance ; Carbon fibers ; Nanomaterials ; Carbon nanotube ; Polymer ; Electrode ; Optoelectronics ; Composite material ; Optics ; Layer (electronics) ; Chemistry Graphene research and applications ; Advancements in Battery Materials ; Radiation Effects in Electronics
Authors: Jonas F. Schlagintweit | Carolin Hintermeier | Markus R. Anneser | Eva‐Maria H. J. Esslinger | Stefan Haslinger | Fritz E. Kühn
Source: Chemistry - An Asian Journal (article, 2020-03-23)
Field: Chemistry — Organic Chemistry

Electronic Finetuning of a Bio‐inspired Iron(II) tetra‐NHC Complex by <i>trans</i> Axial Isocyanide Substitution The synthesis of trans axially substituted mono- (1 a) and bis(tert-butylisocyanide) (1 b) derivatives of the highly active homogeneous bio-inspired iron(II) olefin epoxidation (pre-)catalyst 1 bearing an equatorial macrocyclic tetra N-heterocyclic carbene and two trans axial labile acetonitrile ligands is reported. NMR spectroscopy and SC-XRD indicate a considerable π-backdonation from the iron(II) centres to the isocyanide ligand(s). The impact of isocyanide substitution on the electronic features of the complexes is studied by cyclic voltammetry revealing a significant increase in half-cell potential assignable to the reversible Fe(II)/Fe(III) redox couple with an increasing number of isocyanides as a result of their π-accepting properties: E<sub>1/2</sub> =0.15 V (1), E<sub>1/2</sub> =0.35 V (1 a), E<sub>1/2</sub> =0.44 V (1 b). Isocyanide ; Carbene ; Cyclic voltammetry ; Chemistry ; Acetonitrile ; Tetra ; Ligand (biochemistry) ; Medicinal chemistry ; Redox ; Stereochemistry ; Catalysis ; Electrochemistry ; Organic chemistry ; Physical chemistry N-Heterocyclic Carbenes in Organic and Inorganic Chemistry ; Synthetic Organic Chemistry Methods ; Polyoxometalates: Synthesis and Applications
Authors: David J. Ashworth | Jonathan A. Foster
Source: Nanoscale (article, 2020-01-01)
Field: Chemistry — Inorganic Chemistry

Blending functionalised ligands to form multivariate metal–organic framework nanosheets (MTV-MONs) with tuneable surface chemistry We report a new approach to tuning the properties of metal–organic nanosheets (MONs) by blending functionalised ligands to produce multivariate MONs (MTV-MONs). Ligand (biochemistry) ; Materials science ; Metal ; Polymer chemistry ; Copolymer ; Combinatorial chemistry ; Polymer ; Chemistry ; Composite material Metal-Organic Frameworks: Synthesis and Applications ; Magnetism in coordination complexes ; Dendrimers and Hyperbranched Polymers
Authors: Nicholas McKitterick | Frida Braathen | Magdalena A. Świtnicka-Plak | Peter A. G. Cormack | Léon Reubsaet | Trine Grønhaug Halvorsen
Source: Journal of Proteome Research (article, 2020-07-02)
Field: Chemistry — Analytical Chemistry

Magnetic Synthetic Receptors for Selective Clean-Up in Protein Biomarker Quantification Biomarker analysis by mass spectrometry (MS) can allow for the rapid quantification of low abundant biomarkers. However, the complexity of human serum is a limiting factor in MS-based bioanalysis; therefore, novel biomarker enrichment strategies are of interest, particularly if the enrichment strategies are of low cost and are easy to use. One such strategy involves the use of molecularly imprinted polymers (MIPs) as synthetic receptors for biomarker enrichment. In the present study, a magnetic solid-phase extraction (mSPE) platform, based on magnetic MIP (mMIP) sorbents, is disclosed, for use in the MS-based quantification of proteins by the bottom-up approach. Progastrin releasing peptide (ProGRP), a low abundant and clinically sensitive biomarker for small cell lung cancer (SCLC), was used to exemplify the mSPE platform. Four different mMIPs were synthesized, and an mSPE method was developed and optimized for the extraction of low concentrations of tryptic peptides from human serum. The mSPE method enabled the selective extraction of the ProGRP signature peptide, the nonapeptide NLLGLIEAK, prior to quantification of the target via LC-MS/MS. Overall, the mSPE method demonstrated its potential as a low cost, rapid, and straightforward sample preparation method, with demonstrably strong binding, acceptable recoveries, and good compatibility with MS. mMIPs are a potential low-cost alternative to current clinical methods for biomarker analysis. Biomarker ; Molecularly imprinted polymer ; Solid phase extraction ; Chromatography ; Bioanalysis ; Chemistry ; Extraction (chemistry) ; Limiting ; Biochemistry Analytical chemistry methods development ; Mass Spectrometry Techniques and Applications ; Advanced Proteomics Techniques and Applications
Authors: Alexander E. Pogonin | Artem Shagurin | M. A. Savenkova | Felix Y. Telegin | Yuriy S. Marfin | А. С. Вашурин
Source: Molecules (article, 2020-11-17)
Field: Materials Science — Materials Chemistry

Quantum Chemical Study Aimed at Modeling Efficient Aza-BODIPY NIR Dyes: Molecular and Electronic Structure, Absorption, and Emission Spectra A comprehensive study of the molecular structure of aza-BODIPY and its derivatives, obtained by introduction of one or more substituents, was carried out. We considered the changes in the characteristics of the electronic and geometric structure of the unsubstituted aza-BODIPY introducing the following substituents into the dipyrrin core; phenyl, 2-thiophenyl, 2-furanyl, 3-pyridinyl, 4-pyridinyl, 2-pyridinyl, and ethyl groups. The ground-state geometries of the unsubstituted Aza-BODIPY and 27 derivatives were computed at the PBE/6-31G(d) and CAM-B3LYP/6-31+G(d,p) levels of theory. The time-dependent density-functional theory (TDDFT) together with FC vibronic couplings was used to investigate their absorption and emission spectra. BODIPY ; Time-dependent density functional theory ; Chemistry ; Density functional theory ; Absorption spectroscopy ; Electronic structure ; Absorption (acoustics) ; Computational chemistry ; Spectral line ; Photochemistry ; Emission spectrum ; Fluorescence ; Materials science ; Physics Luminescence and Fluorescent Materials ; Molecular Sensors and Ion Detection ; Nanoplatforms for cancer theranostics
Authors: Yuba Raj Dahal | Mónica Olvera de la Cruz
Source: Soft Matter (article, 2020-01-01)
Field: Materials Science — Surfaces, Coatings and Films

Controlling protein adsorption modes electrostatically Protein adsorption on surfaces is ubiquitous in biology and in biotechnology. There are various forces required for controlling protein adsorption. Here, we introduce an explicit ion coarse-grained molecular dynamics simulation approach for studying the effects of electrostatics on protein adsorption, and 2D protein assembly on charged surfaces. Our model accounts for the spatial distribution of protein charges. We use catalase as our model protein. We find that the preferential adsorption mode of proteins at low protein concentration on a charged surface is "standing up". When the protein concentration in a solution increases to reach a critical density on the surface, the adsorption mode switches from "standing up" to a mixed state "flat on" and "standing up", which increases the lateral correlations among the adsorbed proteins. As such, the changes in the adsorption mode arise from the protein adsorption that cancel the surface charge and the protein-protein repulsion. This correlated surface structure melts as the salt concentration increases because the charged surface is cancelled by the salt ions and the proteins de-adsorb. For the case of strongly charged surfaces the "standing up" conformation remains more favorable even at high protein adsorption at low salt concentrations since in that conformation the surface charge is cancelled more effectively, generating an even more laterally correlated structure. We elucidate the effects of parameters such as surface charge density, salt concentration, and protein charges on the different adsorption modes and the structure and organization of proteins on the charged surfaces. This study provides a guide for controlling protein assembly on surfaces. Adsorption ; Chemistry ; Chemical physics ; Nanotechnology ; Materials science ; Chemical engineering ; Physical chemistry ; Engineering Polymer Surface Interaction Studies ; Microfluidic and Bio-sensing Technologies ; Electrostatics and Colloid Interactions
Authors: Thulaseedharan Nair Sailaja Sidharth | Iván Maisuls | Jutta Kösters | Alexander Hepp | Andreas Faust | Jens Voskuhl | Cristian A. Strassert
Source: Beilstein Journal of Organic Chemistry (article, 2020-12-02)
Field: Materials Science — Materials Chemistry

Naphthalonitriles featuring efficient emission in solution and in the solid state In this work, a series of γ-substituted diphenylnaphthalonitriles were synthesized and characterized. They show efficient emission in solution and in the aggregated state and their environment responsiveness is based on having variable substituents at the <i>para</i>-position of the two phenyl moieties. The excited state properties were fully investigated in tetrahydrofuran (THF) solutions and in THF/H<sub>2</sub>O mixtures. The size of the aggregates in aqueous media were measured by dynamic light scattering (DLS). The steady-state and time-resolved photoluminescence spectroscopy studies revealed that all the molecules show intense fluorescence both in solution and in the aggregated state. In THF solutions, a blue emission was observed for the unsubstituted (H), methyl- (Me) and <i>tert</i>-butyl- (<i>t</i>-Bu) substituted γ-diphenylnaphthalonitriles, which can be attributed to a weak π-donor capability of these groups. On the other hand, the methoxy- (OMe), methylsulfanyl- (SMe) and dimethylamino- (NMe<sub>2</sub>) substituted compounds exhibit a progressive red-shift in emission compared to H, Me and <i>t</i>-Bu due to a growing π-electron donating capability. Interestingly, upon aggregation in water-containing media, H, Me and <i>t</i>-Bu show a slight red-shift of the emission and a blue-shift is observed for OMe, SMe and NMe<sub>2</sub>. The crystal structure of Me allowed a detailed discussion of the structure-property relationship. Clearly, N-containing substituents such as NMe<sub>2</sub> possess more electron-donating ability than the S-based moieties such as SMe. Moreover, it was found that NMe<sub>2</sub> showed higher luminescence quantum yields (Φ<sub>F</sub>) in comparison to SMe, indicating that N-substituted groups could enhance the fluorescence intensity. Therefore, the π-donor nature of the substituents on the phenyl ring constitutes the main parameter that influences the photophysical properties, such as excited state lifetimes and photoluminescence quantum yields. Hence, a series of highly luminescent materials from deep blue to red emission depending on substitution and environment is reported with potential applications in sensing, bioimaging and optoelectronics. Chemistry ; Tetrahydrofuran ; Photoluminescence ; Luminescence ; Blueshift ; Aggregation-induced emission ; Excited state ; Fluorescence ; Dynamic light scattering ; Molecule ; Aqueous solution ; Spectroscopy ; Crystallography ; Photochemistry ; Physical chemistry ; Organic chemistry ; Nanotechnology ; Nanoparticle Luminescence and Fluorescent Materials ; Organic Light-Emitting Diodes Research ; Radical Photochemical Reactions