PREPARATION AND PROPERTIES OF HIGH QUALITY POLYACETYLENE
Résumé
By very careful sample preparation a trans-polyacetylene film was grown which showed an unusual weak high frequency component in the C = C stretch mode Raman line if excited with 4579 Å laser light. This is good evidence that the dispersion effect is of extrinsic origin rather than due to hot luminescence from long undisturbed conjugations. Degradation of the sample by irradiation does hardly change the line shape of the modes but increases the background scattering whereas oxydation enhances the high frequency part of the C = C stretch mode. A calculation of Raman line shapes with in an extended version of the interrupted conjugation model gave very good agreement with experimental results and proved the very strongs square roote like dependence of the transition matrix elements on the number of double bonds at least for short and medium long segments.
Domaines
Articles anciensOrigine | Accord explicite pour ce dépôt |
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