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Metal/conjugated polymer interfaces: A local density functional study of aluminum/polyene interactions.

Authors :
Fredriksson, C.
Lazzaroni, R.
Brédas, J. L.
Ouhlal, A.
Selmani, A.
Source :
Journal of Chemical Physics. 6/15/1994, Vol. 100 Issue 12, p9258. 7p.
Publication Year :
1994

Abstract

The interactions between aluminum atoms and model molecules representing trans-polyacetylene are studied quantum chemically by a local density functional method. We focus on the chemical and electronic structure of the organoaluminum complexes. Special emphasis is put on a comparison between results at the local spin density approximation and ab initio Hartree–Fock levels. In unmetallized polyenes, the density functional method provides a very good description of the carbon–carbon bond lengths of conjugated systems; in the case of hexatriene, it reproduces the bond dimerization in very good agreement with experimental measurements. Upon metallization, a strong covalent interaction between aluminum and carbon is found. The Al–C bond formation induces an interruption of the bond alternation pattern and reduces the π-conjugation in the oligomer, in qualitative agreement with photoelectron spectroscopy data and previous theoretical results at the Hartree–Fock level. Notably, the π-electron levels in the organoaluminum complexes maintain delocalization. In contrast to Hartree–Fock results where an aluminum atom binds to a single carbon, the interactions calculated with the local spin density approximation lead to (i) formation of multicenter aluminum–carbon bonding; (ii) near planarity of the polyene molecule; and (iii) a lower degree of charge transfer from the metal atom to the polymer. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00219606
Volume :
100
Issue :
12
Database :
Academic Search Index
Journal :
Journal of Chemical Physics
Publication Type :
Academic Journal
Accession number :
7641810
Full Text :
https://doi.org/10.1063/1.466678