Interaction of Turkish Beypazari lignite with I2

Samples of original and acid-washed Beypazari lignite were treated with I2 and the effects of the I2 treatment on the coal structure was investigated. It was found that I2 attachment to the coal structure obeyed Langmuir-type of adsorption model. Treatment of coals with I2 produced new iodine chemical compounds and the emergence of newly created chemical iodine structures was followed with the FTIR spectra. I2 treatment also created charge transfer complexes. Increase in the free radical concentrations of the I2-treated coals was due to the formation of charge transfer complexes between I2 and aromatic systems in the coal by single electron extraction from the donor to the I2. The splitting of aromatic stretching vibrations in the FTIR spectra of I2-treated coals towards lower wavelengths also indicated the creation of charge transfer complexes in the coals after I2 treatment where the I2 acted as the electron acceptor.