### Abstract

Normal coordinate calculations have been performed for the in-plane vibrations of several trans-polyene chains from butadiene to polyacetylene in order to obtain a set of force constants commonly applicable to short and long polyenes. The force field finally obtained consists of short range forces, which are primarily determined by the frequency data on short polyenes, and long range interactions which are important in explaining the data on polyacetylene. The long range interactions between the C=C stretching coordinates as far as the fifth neighbor have significant effects on the dynamical properties of the infinite chain. Frequencies of some Raman active vibrations are greatly lowered by the long range terms to become comparable with the experimental frequencies of polyacetylene. These vibrations shift to higher frequencies steeply as the phase difference between adjacent HC=CH units increases from zero. Such steep dispersion as well as the other features of calculated dispersion curves are fully consistent with the expectation based on the Raman spectra of copoly(acetylene + acetylene-d_{2}). Further support for the dispersion curves is given by a general agreement between the experimental Raman spectra and theoretical spectra calculated for model copolymer chains using an approximate equation of resonance Raman intensity.

Original language | English |
---|---|

Pages (from-to) | 2882-2890 |

Number of pages | 9 |

Journal | The Journal of chemical physics |

Volume | 84 |

Issue number | 5 |

Publication status | Published - 1985 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Atomic and Molecular Physics, and Optics

### Cite this

_{2}): In-plane vibrations of trans-polyene chains.

*The Journal of chemical physics*,

*84*(5), 2882-2890.

**Vibrational analysis of polyacetylene and copoly(acetylene+acetylene-d _{2}) : In-plane vibrations of trans-polyene chains.** / Takeuchi, Hideo; Furukawa, Yukio; Harada, Issei; Shirakawa, Hideki.

Research output: Contribution to journal › Article

_{2}): In-plane vibrations of trans-polyene chains',

*The Journal of chemical physics*, vol. 84, no. 5, pp. 2882-2890.

_{2}): In-plane vibrations of trans-polyene chains. The Journal of chemical physics. 1985;84(5):2882-2890.

}

TY - JOUR

T1 - Vibrational analysis of polyacetylene and copoly(acetylene+acetylene-d 2)

T2 - In-plane vibrations of trans-polyene chains

AU - Takeuchi, Hideo

AU - Furukawa, Yukio

AU - Harada, Issei

AU - Shirakawa, Hideki

PY - 1985

Y1 - 1985

N2 - Normal coordinate calculations have been performed for the in-plane vibrations of several trans-polyene chains from butadiene to polyacetylene in order to obtain a set of force constants commonly applicable to short and long polyenes. The force field finally obtained consists of short range forces, which are primarily determined by the frequency data on short polyenes, and long range interactions which are important in explaining the data on polyacetylene. The long range interactions between the C=C stretching coordinates as far as the fifth neighbor have significant effects on the dynamical properties of the infinite chain. Frequencies of some Raman active vibrations are greatly lowered by the long range terms to become comparable with the experimental frequencies of polyacetylene. These vibrations shift to higher frequencies steeply as the phase difference between adjacent HC=CH units increases from zero. Such steep dispersion as well as the other features of calculated dispersion curves are fully consistent with the expectation based on the Raman spectra of copoly(acetylene + acetylene-d2). Further support for the dispersion curves is given by a general agreement between the experimental Raman spectra and theoretical spectra calculated for model copolymer chains using an approximate equation of resonance Raman intensity.

AB - Normal coordinate calculations have been performed for the in-plane vibrations of several trans-polyene chains from butadiene to polyacetylene in order to obtain a set of force constants commonly applicable to short and long polyenes. The force field finally obtained consists of short range forces, which are primarily determined by the frequency data on short polyenes, and long range interactions which are important in explaining the data on polyacetylene. The long range interactions between the C=C stretching coordinates as far as the fifth neighbor have significant effects on the dynamical properties of the infinite chain. Frequencies of some Raman active vibrations are greatly lowered by the long range terms to become comparable with the experimental frequencies of polyacetylene. These vibrations shift to higher frequencies steeply as the phase difference between adjacent HC=CH units increases from zero. Such steep dispersion as well as the other features of calculated dispersion curves are fully consistent with the expectation based on the Raman spectra of copoly(acetylene + acetylene-d2). Further support for the dispersion curves is given by a general agreement between the experimental Raman spectra and theoretical spectra calculated for model copolymer chains using an approximate equation of resonance Raman intensity.

UR - http://www.scopus.com/inward/record.url?scp=36549094839&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=36549094839&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:36549094839

VL - 84

SP - 2882

EP - 2890

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 5

ER -