Quantum mechanical calculations of the properties of oligosilanes

0189070 - UMCH-V 20033023 RIV CZ eng C - Konferenční příspěvek (zahraniční konf.)
Toman, Petr
Quantum mechanical calculations of the properties of oligosilanes.
Conference Proceedings. Brno: Faculty of Chemistry, Brno University of Technology, 2002 - (Schauer, F.), s. 37-41. ISBN 80-214-2265-3.
[Seminar on Physics and Chemistry of Molecular Systems /7./. Brno (CZ), 13.12.2001]
Grant CEP: GA ČR GA203/99/P009; GA ČR GA202/01/0518; GA MŠMT LB98202
Výzkumný záměr: CEZ:AV0Z4050913
Klíčová slova: quantum mechanical study * polarons * oligo[methyl(phenyl)silanes]
Kód oboru RIV: CD - Makromolekulární chemie

Quantum mechanical study of polarons in oligo[methyl(phenyl)silanes] (OMPSi) was performed. The conformations of the defect-free OMPSi and OMPSi containing positive and negative polaron were optimized by measns of B3LYP method. For comparison and evaluation of the substituent effects, the conformation of the unsubstituted oligosilane was also calculated. The conformations were described by means of Si-Si bond lengths and Si-Si-Si bond angles. The negative polaron conformation shows a significant chain stretching. On the other hand, the positive polaron conformation is shrunk. The explanation is based on the changes of the electron densities. There is also a strong influence of the substituents on the conformation of the negative polaron. The middle Si-Si bond is much shorter for the substitute oligomer and the bond angles are smaller. On the other hand, the influence of the substituents on the conformation of the positive polaron is small.
Trvalý link: http://hdl.handle.net/11104/0084924