Change in Electronic Structure of Polyenes Due to Interaction with Polyacenes and with Graphitic Strips
| Autor: | A. Nagy, C. Van Alsenoy, N. H. March, Z. Janosvalfi, Douglas J. Klein, S. Suhai, I. A. Howard |
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| Rok vydání: | 2004 |
| Předmět: |
Plane (geometry)
Band gap STRIPS Electronic structure Polyene Molecular physics Surfaces Coatings and Films law.invention Bond length chemistry.chemical_compound Cardinal point chemistry law Computational chemistry Physics::Atomic and Molecular Clusters Materials Chemistry Perpendicular Physics::Chemical Physics Physical and Theoretical Chemistry |
| Zdroj: | The journal of physical chemistry : B : materials, surfaces, interfaces and biophysical |
| ISSN: | 1520-5207 1520-6106 1089-5647 |
| DOI: | 10.1021/jp040079k |
| Popis: | Hartree−Fock calculations are first presented when a polyene is brought down parallel to the plane of some polyacenes and also, for one case, in a perpendicular orientation. Attention is given to the variation of (a) bond lengths and (b) the HOMO−LUMO energy gap. Following these numerical investigations on finite systems, some tight-binding models (Huckel-like) are worked out to illustrate the effects of different environments on the π-electron assembly in polyenes. Again the focal points are whether bond alternation is enhanced, or suppressed, and the consequences for the HOMO−LUMO energy gap. Some analytic progress proves possible for an infinite polyene chain interacting with (a) an infinite polyacene and (b) an infinite polyphenacene, when a “hopping” energy is used to couple the polyene with its “environment”. In the former model (a), with no HOMO−LUMO gap in the isolated infinite polyacene, a π−electron polyene gap is opened up. In model (b), a similar variation of the energy gap is found. For futur... |
| Databáze: | OpenAIRE |
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