Reactions of Thiophene and Methylthiophenes in the Interlayer of Transition-Metal Ion-Exchanged Montmorillonite Studied by Resonance Raman Spectroscopy

Yuko Soma1, Mitsuyuki Soma1, Yukio Furukawa2 and Issei Harada2
1 National Institute for Environmental Studies, Yatabe, Tsukuba, Ibaraki 305, Japan
2 Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980, Japan

Abstract: The adsorption and reaction of thiophene and methylthiophenes in the interlayer of Cu2+- and Fe3+-montmorillonites were investigated by resonance Raman spectroscopy. Thiophene and 3-methyl-thiophene polymerized to form cations of polythiophene and polymethylthiophene respectively, which were characterized by absorption bands in the near-infrared region. These polymer cations formed in the interlayer were reduced to their neutral polymers if the clay-polymer complexes were in contact with water, and the formation of their neutral polymers was clearly demonstrated by their resonance Raman spectra. 2,5-Dimethylthiophene in which polymerization was hindered by methyl substitution at the 2 and 5 positions, was oxidized to 2,5-dimethylthiophene cation in the interlayer.

Key Words: Adsorption • Interlayer reaction • Montmorillonite • Polymerization • Raman spectroscopy • Thiophene

Clays and Clay Minerals; February 1987 v. 35; no. 1; p. 53-59; DOI: 10.1346/CCMN.1987.0350107
© 1987, The Clay Minerals Society
Clay Minerals Society (www.clays.org)