Search results for "fluor"

showing 10 items of 7252 documents

New methodologies in transition metal catalysis. Organofluorine chemistry as the benchmark application.

2017

A lo largo de las últimas décadas, los compuestos organofluorados han encontrado numerosas aplicaciones dentro del campo de las industrias farmacéutica y agroquímica, así como en ciencias de los materiales. Dadas las singulares propiedades del átomo de flúor, éste es capaz de inducir alteraciones significativas en propiedades físico-químicas de las moléculas como lipofilia, distribución de cargas, acidez-basicidad, capacidad de formar enlaces de hidrógeno e incluso, equilibrios conformacionales. Sin embargo, la presencia de flúor en productos naturales es escasa. De hecho, la gran mayoría de las moléculas orgánicas que contienen flúor son sintéticas. De ahí el gran interés por parte de la c…

transition metal catalysisUNESCO::QUÍMICAorganofluorine chemistrymetathesispalladium catalysis:QUÍMICA [UNESCO]gold catalysis
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CCDC 1873282: Experimental Crystal Structure Determination

2018

Related Article: Maciej Bujak, Hans-Georg Stammler, Sebastian Blomeyer, Norbert W. Mitzel|2019|Chem.Commun.|55|175|doi:10.1039/C8CC08980A

trifluoro(iodo)methaneSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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Organocatalytic Enantioselective Vinylogous Henry Reaction of 3,5-Dimethyl-4-nitroisoxazole with Trifluoromethyl Ketones

2017

The enantioselective vinylogous Henry reaction of 3,5-dimethyl-4-nitroisoxazole with trifluoromethyl ketones employing a bifunctional squaramide organocatalyst has been developed. A series of isoxazole bearing trifluoromethyl-substituted tertiary alcohols, 2-substituted (R)-1,1,1-trifluoro-3-(3-methyl-4-nitroisoxazol-5-yl)propan-2-ols, were obtained under these mild reaction conditions in good yields and moderate to good enantioselectivities

trifluoromethyl ketoneReaction conditionsNitroaldol reactionTrifluoromethyl010405 organic chemistryasymmetric synthesisisoxazoleOrganic ChemistryEnantioselective synthesisSquaramide010402 general chemistry01 natural sciencesCatalysis0104 chemical scienceschemistry.chemical_compoundchemistrysquaramide organocatalystvinylogous Henry reactionOrganic chemistryIsoxazoleBifunctionalTertiary alcoholsSynthesis
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CCDC 1448944: Experimental Crystal Structure Determination

2017

Related Article: Francis A. LeBlanc, Andreas Decken, T. Stanley Cameron, Jack Passmore, J. Mikko Rautiainen, and Thomas K. Whidden|2017|Inorg.Chem.|56|974|doi:10.1021/acs.inorgchem.6b02670

tris(111333-hexafluoro-2-(trifluoromethyl)propan-2-yl) borateSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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CCDC 644918: Experimental Crystal Structure Determination

2008

Related Article: F.Durola, L.Russo, J.-P.Sauvage, K.Rissanen, O.S.Wenger|2007|Chem.-Eur.J.|13|8749|doi:10.1002/chem.200700684

tris(88'-bis(4-Methoxyphenyl)-33'-biisoquinoline-NN')-ruthenium(ii) bis(hexafluorophosphate) acetone solvateSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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CCDC 1573313: Experimental Crystal Structure Determination

2017

Related Article: Niklas Struch, Filip Topic, Gregor Schnakenburg, Kari Rissanen, Arne Lützen|2018|Inorg.Chem.|57|241|doi:10.1021/acs.inorgchem.7b02412

tris(mu-NN'-[methylenebis(41-phenylene)]bis{1-[5-(trifluoromethyl)pyridin-2-yl]methanimine})-di-iron tetrakis(tetrafluoroborate) acetonitrile solvateSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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Search for photons with energies above 1018 eV using the hybrid detector of the Pierre Auger Observatory

2017

A search for ultra-high energy photons with energies above 1 EeV is performed using nine years of data collected by the Pierre Auger Observatory in hybrid operation mode. An unprecedented separation power between photon and hadron primaries is achieved by combining measurements of the longitudinal air-shower development with the particle content at ground measured by the fluorescence and surface detectors, respectively. Only three photon candidates at energies 1-2 EeV are found, which is compatible with the expected hadron-induced background. Upper limits on the integral flux of ultra-high energy photons of 0.027, 0.009, 0.008, 0.008 and 0.007 km-2 sr-1 yr-1 are derived at 95% C.L. for ener…

ultra high energy cosmic rays cosmic ray experimentsPhoton[ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph]AstronomyHadronFluxultra high energy cosmic rays; cosmic ray experiments7. Clean energy01 natural sciencesHigh Energy Physics - ExperimentHigh Energy Physics - Experiment (hep-ex)energy: thresholdCosmic ray experiments[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]010303 astronomy & astrophysicsHigh Energy Astrophysical Phenomena (astro-ph.HE)Physicsphoton: productionconstraint: energyCOSMIC-RAYSAugerobservatoryContent (measure theory)ComputingMethodologies_DOCUMENTANDTEXTPROCESSINGFísica nuclearfluorescenceAstrophysics - High Energy Astrophysical PhenomenalongitudinalAstrophysics::High Energy Astrophysical PhenomenaDark matterFOS: Physical sciencesCosmic rayultra high energy cosmic raysdark matterUltra high energy cosmic rays Cosmic ray experiments Astronomy and Astrophysics.Nuclear physics[ PHYS.HEXP ] Physics [physics]/High Energy Physics - Experiment [hep-ex]0103 physical sciencesultra high energy cosmic rays; cosmic ray experiments; Astronomy and Astrophysicscosmic radiation: UHEHigh Energy PhysicsCiencias ExactasPierre Auger ObservatorySPECTRUMhybridbackgrounddetector: surface010308 nuclear & particles physicsFísicaUltra high energy cosmic raysAstronomy and AstrophysicsASTROFÍSICAULTRA-HIGH ENERGYfluxExperimental High Energy PhysicsHigh Energy Physics::Experimentcosmic ray experimentshadron[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]Energy (signal processing)
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Observation of the Early Structural Changes Leading to the Formation of Protein Superstructures.

2014

Formation of superstructures in protein aggregation processes has been indicated as a general pathway for several proteins, possibly playing a role in human pathologies. There is a severe lack of knowledge on the origin of such species in terms of both mechanisms of formation and structural features. We use equine lysozyme as a model protein, and by combining spectroscopic techniques and microscopy with X-ray fiber diffraction and ab initio modeling of Small Angle X-ray Scattering data, we isolate the partially unfolded state from which one of these superstructures (i.e., particulate) originates. We reveal the low-resolution structure of the unfolded state and its mechanism of formation, hi…

unfolded stateChemistryMechanism (biology)Ab initioModel proteinamyloid superstructure SAXS Spectroscopy Fluorescence microscopy dye diffusionNanotechnologyProtein aggregationBiophysicsGeneral Materials ScienceLack of knowledgePhysical and Theoretical Chemistryconformational changesFiber diffractionparticulateprotein superstructureshydrophobicity
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Listeria monocytogenes transpeptidāzes Sortāzes A inhibitoru atlase izmantojot uz fluorescences rezonanses enerģijas pārnesi (FRET) bāzētu skrīningu

2016

Darba mērķis ir atrast jaunus inhibitorus, kas kavē Listeria monocytogenes transpeptidāzes sortāzes A veikto hidrolīzes reakciju, inhibējot sortāzes A darbību. Šī mērķa sasniegšanai tika izveidota DNS konstrukcija, kas kodē Listeria monocytogenes sortāzes A katalītisko domēnu. Tā kā vislabāk izpētīta ir Staphylococcus aureus sortāze A, papildus tika izveidota tās katalītisko domēnu kodējoša DNS konstrukcija. Ekspresija tika sekmīgi veikta E. coli ekspresijas sistēmā, abi proteīni bija šķīstoši. Sortāzes inhibitori tika atlasīti izmantojot augstas caurlaidības skrīningu, kas tika balstīts uz fluorescences rezonanses enerģijas pārnesi (FRET). 705 potenciālo inhibitoro savienojumu skrīninga re…

uz fluorescences rezonanses enerģijas pārnesi balstīts (FRET) skrīningsaugstas caurlaidības skrīningsBioloģijasortāze AListeria monocytogenes
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Flow cytometric analysis of chronic and acute toxicity of copper(II) on the marine dinoflagellateAmphidinium carterae

2001

Background Copper(II) is a heavy metal whose levels have increased in some marine ecosystems to polluting levels. Dinoflagellates, an important phytoplankton group, are at the base of aquatic food chains and bioaccumulation of copper by these microorganisms can result in complex ecosystem alterations, so we investigated how copper disturbs those cells. Methods Cytotoxic effects of sublethal and lethal copper concentrations ranging from 4.2 nM (control condition) to 3.13 μM estimated labile copper were studied in batch cultures of Amphidinium carterae. Cell morphology, motility, autofluorescence, and fluorescein diacetate (FDA)–dependent fluorescence generation were evaluated by flow cytomet…

ved/biologyIntracellular pHCopper toxicityved/biology.organism_classification_rank.speciesBiophysicschemistry.chemical_elementCell BiologyHematologyBiologymedicine.diseaseCell morphologyCopperAcute toxicityPathology and Forensic Medicinechemistry.chemical_compoundEndocrinologychemistryBiochemistryAmphidinium carteraemedicineFluoresceinChlorophyll fluorescenceCytometry
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