Conjugation length dependence of Raman scattering in a series of linear polyenes: Implications for polyacetylene

Autor: Konrad Knoll, Richard R. Schrock, Robert J. Silbey, H. E. Schaffer, Ronald R. Chance
Rok vydání: 1991
Předmět:
Zdroj: The Journal of Chemical Physics. 94:4161-4170
ISSN: 1089-7690
0021-9606
DOI: 10.1063/1.460649
Popis: We have measured the solid state Raman scattering spectra of a homologous series of linear polyenes, with the number of alternated double bonds varying from 3 to 12. While we find a linear dependence of the Raman shifts of resonantly coupled modes with inverse conjugation length, we have also followed the suggestion of previous work in examining the inverse square product of the several Raman frequencies as a function of the logarithm of the measured energy gap of the molecule. This provides a linear relationship, as found for trans‐polyacetylene, a result which is qualitatively consistent with the amplitude mode model of Horovitz and co‐workers. We also find, consistent with previous work on polyacetylene, a monotonic decrease in the ratios of oscillator strengths of the two strongest bands with conjugation length, as recently predicted by a series of molecular dynamics calculations. Suggested interpretations of a number of qualitative observations, including splitting of modes for shorter conjugation le...
Databáze: OpenAIRE