Showing papers by "Hideki Shirakawa published in 1980"
TL;DR: In this article, the structural details of doped polyacetylene (a highly conducting organic polymer) were studied using optical absorption, Raman, and infrared spectra of polyacetylenes.
Abstract: In order to elucidate the structural details of doped polyacetylene (a highly conducting organic polymer), the optical absorption, Raman, and infrared spectra of not only trans‐(CH)x doped with iodine, AsF5, and SO3 but also β‐carotene doped with iodine and SO3 were studied. The infrared spectra of two kinds of isotopically substituted polyacetylenes (CD)x and (13CH)x doped with iodine were also observed. Analysis of the experimental results shows that upon doping each of the four vibrational branches (ν1–ν4) in the 1600–900 cm−1 region of a polyene chain splits into two groups, namely, the higher frequency group and the lower frequency one. The former group consists of the ’’gerade’’ vibrations of polyene parts which are not directly attacked by dopants but are perturbed along the chain, whereas the latter is made up of the ’’ungerade’’ vibrations of the positively charged polyene part with the doped site at its center. The Raman bands in the higher‐frequency group of ν1 (mainly the C=C stretching mode) ...
278 citations
24 citations
TL;DR: In this paper, the Raman and absorption spectra of β-carotene doped with iodine and sulfur trioxide were studied, and it was shown that the doping gave significant effects on the spectra which were interpreted as arising from the transfer of an electron from a local site in β-Carotene to a dopant and the resultant shortening of the length of double-bond conjugation.
Abstract: The Raman and absorption (ultraviolet through infrared) spectra of β-carotene doped with iodine and sulfur trioxide were studied. The doping gave significant effects on the Raman and absorption spectra which were interpreted as arising from the transfer of an electron from a local site in β-carotene to a dopant and the resultant shortening of the length of double-bond conjugation. Definite information on the form of iodine in the β-carotene—iodine complex was obtained.
12 citations
TL;DR: In this paper, the hydrogen exchange reactions between H2D2 and D2-CH were studied on alkali-metal doped polyacetylene, and it was shown that at higher temperatures ( > 160° C), hydrogen in the dopedpolyacetylene is able to exchange with hydrogen in gas phase.
Abstract: The hydrogen exchange reactions between H2 —D2 and D2 —(CH), are studied on alkali-metal doped polyacetylene. The former reaction takes place under considerably mild conditions with an apparent activation energy of 13 kcal/mole (< 150° C) over [(CH)Na0 094LAt higher temperatures ( > 160° C), hydrogen in the doped polyacetylene is able to exchange with hydrogen in gas phase. Its apparent activation energy for the same material is 24 kcal/mole (160 —200° C). An equilibrium study of hydrogen isotopes in gas phase suggests that all of hydrogen atoms bonded to the doped polyacetylene are able to exchange with molecular hydrogen in gas phase. Hydrogénation of double bonds in the doped polyacetylene also proceeds at higher temperatures and higher hydrogen pressures.
4 citations