Search results for "Crystal"

showing 10 items of 22886 documents

Optoelectronic devices based on caesium lead halide perovskite nanocrystals

2020

Tradicionalmente, la implementación de materiales activos en circuitos fotónicos integrados se ha basado en la utilización de semiconductores III-V y vidrios y materiales ferroeléctricos dopados con iones de tierras raras. Sin embargo, en la actualidad existe una alternativa basada en (nano) materiales sintetizados por técnicas de química coloidal. La posibilidad de procesar nanomateriales en solución permite fabricar semiconductores con propiedades ópticas (emisión, absorción, dispersión de luz) que pueden diseñarse durante la síntesis. Además, su naturaleza coloidal permite integrarlas en cualquier arquitectura óptica mediante sencillas técnicas de impresión en tinta. En este contexto, lo…

nanotechnologyperovskite nanocrystalsoptoelectronicsHollow-core fibersUNESCO::FÍSICAIntegrated opticsperovskite materialscharge transportamplified spontaneous emissionlead halide perovskitesphoton recycling:FÍSICA [UNESCO]optical gain
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CCDC 1922191: Experimental Crystal Structure Determination

2019

Related Article: Julian Radtke, Kai Schickedanz, Marcel Bamberg, Luigi Menduti, Dieter Schollmeyer, Michael Bolte, Hans-Wolfram Lerner, Matthias Wagner|2019|Chemical Science|10|9017|doi:10.1039/C9SC03115D

naphtho[1'8':234][1]benzoborinino[18-cd]naphtho[1'8':456]borinino[321-jk][213]benzoxadiborepineSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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Blends of Semiflexible Polymers: Interplay of Nematic Order and Phase Separation

2021

Mixtures of semiflexible polymers with a mismatch in either their persistence lengths or their contour lengths are studied by Density Functional Theory and Molecular Dynamics simulation. Considering lyotropic solutions under good solvent conditions, the mole fraction and pressure is systematically varied for several cases of bending stiffness κ (the normalized persistence length) and chain length N. For binary mixtures with different chain length (i.e., NA=16, NB=32 or 64) but the same stiffness, isotropic-nematic phase coexistence is studied. For mixtures with the same chain length (N=32) and large stiffness disparity (κB/κA=4.9 to 8), both isotropic-nematic and nematic-nematic unmixing oc…

nematic orderMaterials sciencePolymers and PlasticsTriple pointThermodynamicsOrganic chemistry02 engineering and technology01 natural sciencesArticleliquid crystalsQD241-441Critical point (thermodynamics)Liquid crystalsemiflexible polymersPhase (matter)0103 physical sciencesLyotropicphase behaviormacromolecules010306 general physicsdensity functional theoryPhase diagramPersistence lengthGeneral Chemistry021001 nanoscience & nanotechnologymolecular dynamicsCondensed Matter::Soft Condensed MattermixturesBending stiffnessddc:540blends0210 nano-technology
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N,N-Dicyclohexylnitramine

2016

Molecules of the title compound, C12H22N2O2, are composed of an nitramine group substituted by two cyclohexane rings. The cyclohexane rings have chair conformations, with the exocyclic C—N bonds in axial orientations. In the crystal, C—H...O hydrogen bonds connect the molecules intoC(6) [-101] zigzag chains.

nitraminescrystal structureHydrogen bondChemistryStereochemistryGeneral MedicineCrystal structure010402 general chemistry010403 inorganic & nuclear chemistry01 natural sciences0104 chemical sciencesCrystalCrystallographyZigzagGroup (periodic table)hydrogen bondslcsh:QD901-999lcsh:CrystallographyIUCrData
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4-Fluoro-N-methyl-N-nitroaniline

2016

Molecules of the title compound, C7H7FN2O2, are composed of a nitramine group which is twisted with the respect to the aromatic ring, with an N—N—C—C torsion angle of −117.38 (12)°. In the molecule, the N—N bond length [1.3510 (15) Å] indicates some double-bond character, while the angle between the aromatic ring and the nitramine group rules out further delocalization in the molecule. In the crystal, C—H...F hydrogen bonds connect the molecules intoC11(6) chains along theaaxis. C—H...O hydrogen bonds form, which featureR22(12) loops and further connect these chains.

nitraminescrystal structureinter­molecular bondsHydrogen bondStereochemistryintermolecular bondsGeneral MedicineCrystal structureDihedral angle010402 general chemistry010403 inorganic & nuclear chemistryRing (chemistry)01 natural sciences0104 chemical sciencesBond lengthchemistry.chemical_compoundCrystallographyDelocalized electronAnilinechemistrylcsh:QD901-999Nitrolcsh:CrystallographyIUCrData / International Union of Crystallography
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Crystal structure of trans-di­chloridobis­[N-(5,5-di­methyl-4,5-di­hydro-3H-pyrrol-2-yl-κN)acetamide]palladium(II) dihydrate

2017

The title complex, [PdCl2(C8H14N2O)2]2H2O, was obtained by N–O bond cleavage of the oxadiazoline rings of the trans-[dichlorido-bis(2,5,5-trimethyl- 5,6,7,7a-tetrahydropyrrolo[1,2-b][1,2,4]oxadiazole-N1 )]palladium(II) complex. The palladium(II) atom exhibits an almost square-planar coordination provided by two trans-arranged chloride anions and a nitrogen atom from each of the two neutral organic ligands. In the crystal, N—HO, O—HO and O—HCl hydrogen bonds link complex molecules into double layers parallel to the bc plane. peerReviewed

nitronecrystal structurenitrileN—O bond cleavagecyclo­additionpalladium
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Crystal structure of

2017

The synthesis and crystal structure of the complex trans-[di­chlorido-bis­(N-(4,5-di­hydro-5,5-dimethyl-3H-pyrrol-2-yl)acetamide)]palladium(II) dihydrate is described.

nitronecrystal structurenitrileN—O bond cleavagepalladiumcyclo­additionResearch CommunicationsActa crystallographica. Section E, Crystallographic communications
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Direct Visualization of Molecule Deprotonation on an Insulating Surface

2012

Elucidating molecular-scale details of basic reaction steps on surfaces is decisive for a fundamental understanding of molecular reactivity within many fields, including catalysis and on-surface synthesis. Here, the deprotonation of 2,5-dihydroxybenzoic acid (DHBA) deposited onto calcite (101;4) held at room temperature is followed in situ by noncontact atomic force microscopy. After deposition, the molecules form two coexisting phases, a transient striped phase and a stable dense phase. A detailed analysis of high-resolution noncontact atomic force microscopy images indicates the transient striped phase being a bulk-like phase, which requires hydrogen bonds between the carboxylic acid moie…

noncontact atomic force microscopyCarboxylic acidCatecholsGeneral Physics and AstronomyMicroscopy Atomic ForceKelvin probe force microscopy530Calcium Carbonatechemistry.chemical_compoundDeprotonationPhase (matter)Materials TestingHydroxybenzoatesMoleculeGeneral Materials ScienceReactivity (chemistry)CarboxylateParticle Sizechemistry.chemical_classificationKelvin probe force microscopeHydrogen bondinsulating surfaceGeneral EngineeringElectric ConductivityMolecular ImagingNanostructuresCrystallographychemistrydeprotonationProtons
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Tracer migration in crystalline rock : application to geological barriers of nuclear waste storage

2016

This work deals with transport of radionuclides in the geosphere. The subject is investigated through characterisation of water conducting fractures, determining of rock transport properties and development of new methods for characterising geological samples. Here, as is often the case, radionuclide transport is investigated indirectly by characterising the structures, where the transport takes place, and directly by measuring transport properties in the gas phase. First water conducting fractures of three different types and the rock matrix surrounding them were analysed through rock samples from Olkiluoto. The analysis was done using X-ray tomography, the 14C-PMMA autoradiography techniq…

nuclear wasteperuskalliocrystalline rockdiffusionEurajokiautoradiografiamerkkiaineetläpäisevyysloppusijoitusfracturesautoradiographykulkeutuminendeep geological repositoriesradioaktiiviset aineethuokoisuusydinjätteetmurtumattransport propertiestomografiakallioperäX-ray tomographykivi
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CCDC 1519226: Experimental Crystal Structure Determination

2017

Related Article: Sabrina Antonello, Tiziano Dainese, Fangfang Pan, Kari Rissanen, Flavio Maran|2017|J.Am.Chem.Soc.|139|4168|doi:10.1021/jacs.7b00568

octadecakis(mu-2-phenylethane-1-thiolato)-pentacosakis-goldSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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