Molecular Orbital Study on Electron Confinement Characteristics in Heteroaromatic Oligomers

Nobutoki, Hideharu; Koezuka, Hiroshi

doi:10.1021/jp951689a

Cited by 15 publications

(11 citation statements)

References 32 publications

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“…Furthermore, these features are consistent with the general behaviour found previously in copolymers with quantum‐well structures, i.e. copolymers with a high degree of confinement of the π‐electrons 22, 23…”

Section: Resultssupporting

confidence: 90%

Copolymers of N‐methylpyrrole and 3,4‐ethylenedioxythiophene: structural, physical and electronic properties

Ocampo

Alemán

Oliver

et al. 2006

Polymer International

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The structural, electric and electronic properties of copolymers derived from mixtures of N‐methylpyrrole and 3,4‐ethylenedioxythiophene (EDOT) with various concentration ratios have been investigated and, additionally, compared with those of the corresponding homopolymers. The electropolymerization kinetics of all the generated copolymers and the homopolymers was examined in terms of current productivity using chronoamperometry. The chemical structure of the linkages between adjacent monomers and the microstructure of the chains were investigated using Fourier transform infrared spectroscopy and quantum mechanical calculations, respectively. The results indicate that the linkages between monomeric units formed during the anodic copolymerization are of the α–α type, while the microstructure of the copolymers depends on the EDOT content. Theoretical calculations were also used to examine the electronic properties of the systems under study, while the conductivity and the electrical stability were studied using the sheet‐resistance method. Interestingly, the electric properties are consistent with the random and block microstructures predicted for the copolymers with low and high EDOT content, respectively. Copyright © 2006 Society of Chemical Industry

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Section: Resultssupporting

confidence: 90%

Copolymers of N‐methylpyrrole and 3,4‐ethylenedioxythiophene: structural, physical and electronic properties

Ocampo

Alemán

Oliver

et al. 2006

Polymer International

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“…The polymers are prime targets of recent research into properties of new materials which may be suitable for nonlinear optics and as electrical conductors. , The electronic structure of these materials can be studied experimentally by photoelectron spectroscopy (UPS) in the condensed phase (as polymers) or in the gas phase (as monomer building blocks) . Theoretical studies of oligomeric and polymeric materials can be performed by semiempirical and ab initio methods . The combined results of these studies suggest that electrical conductivity is determined by two factors: electronic structure of (monomeric) building blocks and arrangements of polymeric chains in the bulk material.…”

Section: Introductionmentioning

confidence: 99%

Photoelectron Spectroscopy Study of Orbital Interactions. Ethynylfurans

Novak

Jin

et al. 1997

J. Phys. Chem. A

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He I and He II photoelectron spectra (UPS) of isomeric mono-and bis(ethynyl)furans were recorded. The assignment of spectra was based on empirical considerations (bandwidths, He II/He I intensity variations, comparison with spectra of related molecules) and ab initio calculations. The details of orbital interactions between the ring and ethynyl π orbitals were deduced solely on the basis of experimental data. These interactions were studied for several classes of π isoelectronic molecules.

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“…Frontier Molecular Orbital Characteristics. It has been known that frontier molecular orbitals play a dominant role in determining β. − This is particularly the case when the applied electric field is a small perturbation, as in the FF method . Thus, we investigated the way in which the crystal field influences β through the shapes of the frontier orbitals.…”

Section: Resultsmentioning

confidence: 99%

Theoretical Study of Hyperpolarizabilities in Crystalline m-Nitroaniline

Nobutoki

Koezuka

1997

J. Phys. Chem. A

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A variational−perturbation method in terms of molecular orbitals (MOs) has been developed to study the effect of a permanent crystal field on hyperpolarizability (β) in van der Waals organic crystals. The method has the advantage of giving a numerical value of the dipole moment for each fragment molecule in a weakly interacting system with an accuracy comparable to the supermolecule method. Our method has been applied to a m-nitroaniline molecule in different model crystal environments to analyze the crystal field effect on the β-values. The results indicate that the crystal field induces the intramolecular charge transfer (CT) of the π-electrons from an NH2 group to a NO2 group in the highest occupied MO while the lowest unoccupied MO almost remains unchanged. From a net atomic charge analysis, the CT will be derived from the reversed polarization of the σ-electrons due to the polarized π-electrons and it will then contribute to the enhancement of the β x -value additively (βadd). The effect of the different crystal environments on the β xxx -values has been also discussed with a focus on the degree of the ground state polarization.

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Molecular Orbital Study on Electron Confinement Characteristics in Heteroaromatic Oligomers

Cited by 15 publications

References 32 publications

Copolymers of N‐methylpyrrole and 3,4‐ethylenedioxythiophene: structural, physical and electronic properties

Copolymers of N‐methylpyrrole and 3,4‐ethylenedioxythiophene: structural, physical and electronic properties

Photoelectron Spectroscopy Study of Orbital Interactions. Ethynylfurans

Theoretical Study of Hyperpolarizabilities in Crystalline m-Nitroaniline

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