0000000000677007

AUTHOR

R. Viruela‐martin

showing 4 related works from this author

Electronic structure of tetraphenyldithiapyranylidene : A valence effective Hamiltonian theoretical investigation

1992

We present a theoretical investigation of the electronic structure of tetraphenyldithiapyranylidene (DIPSΦ4) using the nonempirical valence effective Hamiltonian (VEH) method. Molecular geometries are optimized at the semiempirical PM3 level which predicts an alternating nonaromatic structure for the dithiapyranylidene (DIPS) framework. The VEH one‐electron energy level distribution calculated for DIPSΦ4 is presented as a theoretical XPS simulation and is analyzed by comparison to the electronic structure of its molecular components DIPS and benzene. The theoretical VEH spectrum is found to be fully consistent with the experimental solid‐state x‐ray photoelectron spectroscopy (XPS) spectrum…

HamiltoniansOptimizationValence (chemistry)ChemistryPhotoemission spectroscopyGaussian orbitalPhenyl RadicalsGeometryGeneral Physics and AstronomyElectronic structureMoleculesMolecular physicsUNESCO::FÍSICA::Química físicasymbols.namesakeMolecular geometryElectronic StructureX-ray photoelectron spectroscopyComputational chemistrysymbolsPhysical and Theoretical ChemistryIonization energy:FÍSICA::Química física [UNESCO]Hamiltonian (quantum mechanics)Phenyl Radicals ; Electronic Structure ; Pyrans ; Hamiltonians ; Geometry ; Optimization ; MoleculesPyrans
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Valence electronic structure of C60: Theoretical analysis of photoemission data

1993

Abstract We present a theoretical investigation of the valence band photoemission spectra of C 60 using the nonempirical valence effective Hamiltonian (VEH) method. The VEH-DOVS curves calculated for the C 60 molecule are found to be in excellent agreement with synchrotron-radiation photoemission spectra reported for C 60 films. A detailed interpretation of all the photoemission bands is performed in the light of the VEH results.

Valence (chemistry)ChemistryMechanical EngineeringInverse photoemission spectroscopyMetals and AlloysAngle-resolved photoemission spectroscopyElectronic structureCondensed Matter PhysicsSpectral lineElectronic Optical and Magnetic MaterialsCondensed Matter::Materials Sciencesymbols.namesakeMechanics of MaterialsCondensed Matter::SuperconductivityMaterials ChemistrysymbolsValence bandMoleculeCondensed Matter::Strongly Correlated ElectronsAtomic physicsHamiltonian (quantum mechanics)Synthetic Metals
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Theoretical determination of the geometric and electronic structures of oligorylenes and poli(peri‐naphthalene)

1992

We present a theoretical investigation of the electronic structure of oligorylenes (from perylene to heptarylene, including also the naphthalene molecule) and their corresponding polymer poly(peri‐naphthalene) (PPN) using the nonempirical valence effective (VEH) method. The geometry of the unit cell used to generate the polymer is extrapolated from the PM3‐optimized molecular geometries of the longest oligorylenes. That geometry shows some bond alternation along the perimeter carbon chains and a bond length of ≊1.46 Å is calculated for the peri bonds connecting the naphthalene units. The VEH one‐electron energy level distributions calculated for oligorylenes are used to interpret the experi…

OptimizationChemical BondsBand gapStereochemistryExtrapolationElectric ConductorsGeometryGeneral Physics and AstronomyElectronic structureMolecular physicsEnergy LevelsMolecular orbitalPhysical and Theoretical ChemistryBand Structure:FÍSICA::Química física [UNESCO]Electronic band structurePeryleneFilmsValence (chemistry)Organic PolymersChemistryElectronic Structure ; Perylene ; Naphthalene ; Organic Polymers ; Unit Cell ; Geometry ; Extrapolation ; Optimization ; Chemical Bonds ; Carbon ; Chains ; Energy Levels ; Ionization Potential ; Affinity ; Band Structure ; Electric Conductors ; Films ; PyrolysisUnit CellChainsCarbonUNESCO::FÍSICA::Química físicaBond lengthIonization PotentialMolecular geometryElectronic StructureAffinityIonization energyNaphthalenePyrolysis
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Geometric and electronic structure of dithiapyranylidine: evolution upon oxidation

1993

Abstract We present a theoretical investigation of the modifications that successive oxidation induces on the geometric and electronic structures of the π-electron donor dithiapyranylidene. The lengthening of the double bonds and the shortening of the single bonds calculated as the molecular charge increases indicate a gain of aromaticity with oxidation. Both the geometricand the electronic structure of dithiapyranylidene show a clear evolution towards those of biphenyl as oxidation takes place.

chemistry.chemical_classificationBiphenylDouble bondChemistryPhotoemission spectroscopyMechanical EngineeringMetals and AlloysX-rayAromaticityElectronic structureCondensed Matter PhysicsElectronic Optical and Magnetic MaterialsCrystallographychemistry.chemical_compoundMechanics of MaterialsComputational chemistryMaterials ChemistrySingle bondMoleculeSynthetic Metals
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