Vibrational spectra and structure of polyaniline and related compounds

Issei Harada*, Yukio Furukawa, Fumitaka Ueda

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

175 Citations (Scopus)


Vibrational spectra of various forms of polyaniline have been analyzed on the basis of data of isotopically substituted analogs and model compounds. White polyaniline (1A) obtained by electrochemical reduction of as-prepared film (2S) followed by hydrazine treatment has been proved to be a genuine poly(imino-1,4-phenylene). Part of the imino-1,4-phenylene (IP) in 1A are converted into its cation (IP+) by acid treatment (1S), radical cation (IP+) by electrochemical oxidation in non-aqueous medium (doped 1A, conductive), and a structure consisting of a quinone diimine and a benzene ring (-NC6H4NC6H4-,NP) by exposure to oxygen [1A(O2)]. Alkali-treated doped 1A, whose vibrational spectra are similar to those of alkali-treated 2S (2A), is composed of IP and NP. A simple scheme of interconversion of the four unit structures, of which radical cation is related to electrical conduction, is useful to understand the complex interconversion of colors and other physicochemical properties of the polyaniline forms. Analysis of the infrared NH stretching region suggests that the polymers form hydrogen bond networks.

Original languageEnglish
Pages (from-to)303-312
Number of pages10
JournalSynthetic Metals
Issue number1
Publication statusPublished - 1989 Mar 7
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry


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