Search results for "ddc:540"

showing 10 items of 212 documents

Diastereoselective Synthesis of Spiro[pyrazolone-4,3′-tetrahydrothiophenes] via a Sulfa-Michael/Aldol Domino Reaction

2016

Synthesis : journal of synthetic organic chemistry 48(23), 4091-4098(2016). doi:10.1055/s-0035-1562473

Reaction conditions010405 organic chemistryChemistryOrganic ChemistryPyrazolone010402 general chemistry54001 natural sciencesCombinatorial chemistryCatalysisDomino0104 chemical scienceschemistry.chemical_compoundCascade reactionAldol reactionYield (chemistry)ddc:540medicineOrganic chemistryTetrahydrothiophenemedicine.drug
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Disordered sodium alkoxides from powder data: crystal structures of sodium ethoxide, propoxide, butoxide and pentoxide, and some of their solvates

2021

The crystal structures of NaOEt, NaOPr, NaOBu and NaOAm (Am = amyl = pentyl) were determined from powder data. These compounds crystallize in an anti-PbO structure in the space groups P 21 m and P4/nmm. Additionally, solvates with the composition NaOEt·2EtOH, NaOPr·2PrOH, NaOiPr·5iPrOH and NaOtAm·tAmOH were synthesized, and their structures were determined from single crystals. They form interesting chain structures of different compositions and topologies.

Recrystallization (geology)Sodiumchemistry.chemical_elementAlcoholCrystal structure010402 general chemistry010403 inorganic & nuclear chemistry01 natural scienceschemistry.chemical_compoundsolvateBärnighausen treeMaterials Chemistryddc:530Alkylchemistry.chemical_classificationSodium ethoxideChemistryMetals and AlloysResearch PapersAtomic and Molecular Physics and Optics0104 chemical sciencesElectronic Optical and Magnetic MaterialsisopropanolCrystallographysodium alkoxide548PXRDddc:540Alkoxidepowder dataPowder diffraction
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Synthesis of Polycyclic Indolines by Utilizing a Reduction/Cyclization Cascade Reaction

2021

European journal of organic chemistry 2021(45), 6097-6101 (2021). doi:10.1002/ejoc.202101191

Reduction (complexity)Acid catalysisCascade reactionChemistryddc:540Organic ChemistryPhysical and Theoretical Chemistry540Combinatorial chemistryEuropean Journal of Organic Chemistry
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The gas-phase chemiionization reaction between samarium and oxygen atoms: A theoretical study

2004

The Sm + O chemiionization reaction has been investigated theoretically using a method that allows for correlation and relativistic effects. Potential energy curves have been calculated for several electronic states of SmO and SmO+. Comparison with available spectroscopic and thermodynamic values for these species is reported and a mechanism for the chemiionization reaction Sm + O is proposed. The importance of spin–orbit coupling in the excited states of SmO, in allowing this chemiionization reaction to take place, has been revealed by these calculations. This paper shows the metal-plus-oxidant chemiionization reaction.

SamariumExcited statesGeneral Physics and Astronomychemistry.chemical_elementRelativistic correctionsPotential energyOxygenOxygenSamariumAtom-atom reactionsOxygen atomchemistryPotential energy surfacesExcited stateIonizationddc:540OxidationSpin-orbit interactionsPhysical and Theoretical ChemistryAtomic physicsRelativistic quantum chemistryChain reactionIonisationThe Journal of Chemical Physics
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First Study on Nihonium (Nh, Element 113) Chemistry at TASCA

2021

Frontiers in Chemistry 9, 753738 (2021). doi:10.3389/fchem.2021.753738

Shell (structure)Analytical chemistrychemistry.chemical_elementSuperheavy Elementselement 113gas phase chromatographyAtomic orbitalatomifysiikkaTASCAReactivity (chemistry)QD1-999Original ResearchIsotopeGeneral Chemistry540superheavy elementkemialliset ominaisuudetChemistryFleroviumsuperheavy elementsUnpaired electronchemistrynihoniumddc:540physical preseparationVolatility (chemistry)
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Background studies for acoustic neutrino detection at the South Pole

2011

The detection of acoustic signals from ultra-high energy neutrino interactions is a promising method to measure the tiny flux of cosmogenic neutrinos expected on Earth. The energy threshold for this process depends strongly on the absolute noise level in the target material. The South Pole Acoustic Test Setup (SPATS), deployed in the upper part of four boreholes of the IceCube Neutrino Observatory, has monitored the noise in Antarctic ice at the geographic South Pole for more than two years down to 500 m depth. The noise is very stable and Gaussian distributed. Lacking an in-situ calibration up to now, laboratory measurements have been used to estimate the absolute noise level in the 10 to …

SignalsTELESCOPEAbsolute noise levelAstrophysics::High Energy Astrophysical PhenomenaFluxFOS: Physical sciencesAstrophysics7. Clean energy01 natural sciencesIceCube Neutrino Observatorylaw.inventionIceCubeTelescopeAbsolute noise level; Acoustic neutrino detection; Neutrino flux limitNeutrino flux limitlawSIGNALS0103 physical sciencesWATERDetection theory010306 general physicsTelescopeInstrumentation and Methods for Astrophysics (astro-ph.IM)PhysicsAcoustic neutrino detector010308 nuclear & particles physicsDetectorAstrophysics::Instrumentation and Methods for AstrophysicsWaterAstronomy and AstrophysicsGeodesyAcoustic neutrino detectionNoiseNeutrino detectorPhysics and Astronomy13. Climate actionddc:540NeutrinoAstrophysics - Instrumentation and Methods for Astrophysics
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Correlations of the distribution of spin states in spin crossover compounds

1999

Abstract Short range correlations of the distribution of high spin (HS) and low spin (LS) states show up in thermal spin transition curves, decay curves of the light induced metastable HS state (LIESST state), and in structural features during the spin transitions. Correlations are due to short range interactions between the spin crossover molecules. Short range interactions may compete with omnipresent long range interactions and give rise to interesting spin transition phenomena. In this paper, the effect of correlations on the thermal spin transition in the mixed crystal system [Fe x Zn 1− x (pic) 3 ]Cl 2 ·EtOH (pic=picolylamine) is discussed. In particular the step in the thermal transi…

Spin statesCondensed matter physicsChemistrySpin transitionSpin crossoverLIESSTCorrelationInorganic ChemistrySpin crossoverLattice (order)Metastabilityddc:540Materials ChemistryMoleculeOrthorhombic crystal systemCondensed Matter::Strongly Correlated ElectronsPhysical and Theoretical ChemistryPhase transition
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Thermal- and photoinduced spin-state switching in an unprecedented three-dimensional bimetallic coordination polymer.

2005

The compound {Fe(pmd)[Ag(CN)2][Ag2(CN)3]} (pmd=pyrimidine) was synthesized and characterized. Magnetic, calorimetric and single crystal visible spectroscopic studies demonstrate the occurrence of a two-step high-spin (HS) right arrow over left arrow low-spin (LS) transition. The critical temperatures are T(c1)=185 and T(c2)=148 K. Each step involves approximately 50 % of the iron centers, with the low-temperature step showing a hysteresis of 2.5 K. The enthalpy and entropy variations associated with the two steps are DeltaH(1)=3.6+/-0.4 kJ mol(-1) and DeltaS(1)=19.5+/-3 J K(-1) mol(-1); DeltaH(2)=4.8+/-0.4 kJ mol(-1) and DeltaS(2)=33.5+/-3 J K(-1) mol(-1). Photomagnetic and visible spectros…

Spin statesCoordination polymerPolymersOrganic ChemistryEnthalpySpin transitionGeneral ChemistryCrystal structureSpin crossoverHeat capacityCoordination modesCatalysischemistry.chemical_compoundCrystallographychemistrySpin crossoverArgentophilic interactionsddc:540Single crystalChemistry (Weinheim an der Bergstrasse, Germany)
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Asymmetric Disulfanylbenzamides as Irreversible and Selective Inhibitors of Staphylococcus aureus Sortase A

2020

Abstract Staphylococcus aureus is one of the most frequent causes of nosocomial and community‐acquired infections, with drug‐resistant strains being responsible for tens of thousands of deaths per year. S. aureus sortase A inhibitors are designed to interfere with virulence determinants. We have identified disulfanylbenzamides as a new class of potent inhibitors against sortase A that act by covalent modification of the active‐site cysteine. A broad series of derivatives were synthesized to derive structure‐activity relationships (SAR). In vitro and in silico methods allowed the experimentally observed binding affinities and selectivities to be rationalized. The most active compounds were f…

Staphylococcus aureusmedicine.drug_classdrug designAntibioticsVirulenceMicrobial Sensitivity Testsmedicine.disease_cause01 natural sciencesBiochemistrybiofilmMicrobiology570 Life sciencesStructure-Activity RelationshipBacterial ProteinsAntibioticssortase ADrug DiscoverymedicineGeneral Pharmacology Toxicology and PharmaceuticsEnzyme InhibitorsCytotoxicityPharmacologyFull PaperDose-Response Relationship DrugMolecular Structure010405 organic chemistryChemistryOrganic ChemistryBiofilmFull PapersAminoacyltransferasesIn vitro0104 chemical sciencesAnti-Bacterial Agents010404 medicinal & biomolecular chemistryCysteine EndopeptidasesStaphylococcus aureusSortase Addc:540BenzamidesMolecular MedicineCysteine570 BiowissenschaftenChemmedchem
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Radical cation salts of BEDT-TTF, enantiopure tetramethyl-BEDT-TTF, and TTF-Oxazoline (TTF-Ox) donors with the homoleptic TRISPHAT anion

2011

International audience; The synthesis and crystal structures of five radical cation salts based on the organic donors bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF), racemic ethylenedithio-methyl-oxazoline-tetrathiafulvalene (EDT-TTF-MeOx) and the enantiopure (S,S,S,S) and (R,R,R,R) tetramethyl-bis(ethylenedithio)tetrathiafulvalene (TMBEDT-TTF) and the D3-symmetric anion tris(tetrachlorobenzenediolato)phosphate(V) (TRISPHAT) are reported. The salts are formulated as [BEDT-TTF][(rac)-TRISPHAT]·CH2Cl2 (1), [BEDT-TTF][(rac)-TRISPHAT]·2CH3CN (2), [(rac)-EDT-TTF-Ox][(rac)-TRISPHAT]·CH3CN (3), [(S,S,S,S)-TMBEDT-TTF][(rac)-TRISPHAT]·2CH3CN (4), and [(R,R,R,R)-TMBEDT-TTF][(rac)-TRISPHAT]·2CH3CN (…

Stereochemistry02 engineering and technologyOxazolineCrystal structure010402 general chemistry01 natural sciencesMedicinal chemistryCatalysislaw.inventionchemistry.chemical_compoundTRISPHATlawMaterials ChemistryHomolepticElectron paramagnetic resonanceGeneral Chemistry021001 nanoscience & nanotechnology0104 chemical sciences3. Good health[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistryEnantiopure drugRadical ionchemistryddc:5400210 nano-technologyTetrathiafulvaleneNew Journal of Chemistry
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