On the blue color of triiodide ions in starch and starch fractions. I. Characterization and assignment of absorption and circular dichroism spectra of triiodide ions in amylose
1979; Wiley; Volume: 18; Issue: 4 Linguagem: Inglês
10.1002/bip.1979.360180409
ISSN1097-0282
AutoresTakashi Handa, Hirofumi Yajima,
Tópico(s)Electron Spin Resonance Studies
ResumoAbstract Four fundamental Raman lines were observed at 159, 111, 55 and 27 cm ‐1 corresponding to the I bound (I ) in amyloses with DP from 20 to 100, regardless of the degree of polymerization of I and the excitation wavelength. The spectral resolution was based on the molar extinction coefficient and molar ellipticity spectra of I . Eight bands, named, S 1 , S 2 , ⃛, S 8 from long to short wavelength, were isolated. These were found regardless of the DP . By a resonance excitation Raman study, the characteristics of S 3 and S 4 , comprising the shoulder around 480 nm, were found to be different from those of S 1 and S 2 , comprising the blue band. The assignment of the spectra was based on the electronic states of the monomeric I in the exciton‐coupled dimeric unit. It was concluded that the blue band (S 1 ,S 2 ) belonged to the long‐axis transitions and the shoulder band (S 3 ,S 4 ) to the short‐axis ones on the monmeric coordinate system.
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