Interaction of Turkish Beypazari lignite with I-2

Samples of original and acid-washed Beypazari lignite were treated with I-2 and the effects of the I-2 treatment on the coal structure was investigate d. It was found that I-2 attachment to the coal structure obeyed Langmuir-t ype of adsorption model. Treatment of coals with I-2 produced new iodine ch emical compounds and the emergence of newly created chemical iodine structu res was followed with the FTIR spectra. I-2 treatment also created charge t ransfer complexes. Increase in the free radical concentrations of the I-2-t reated coals was due to the formation of charge transfer complexes between I-2 and aromatic systems in the coal by single electron extraction from the donor to the I-2. The splitting of aromatic stretching vibrations in the F TIR spectra of I-2-treated coals towards lower wavelengths also indicated t he creation of charge transfer complexes in the coals after I-2 treatment w here the I-2 acted as the electron acceptor. (C) 2001 Elsevier Science B.V. All rights reserved.