Charge-transfer complexes of imidazole-2-thiones with iodine

Abstract

The charge-transfer complexes between various alkyl- and aryl-substituted imidazole-2-thiones and iodine in methylene dichloride and carbon tetrachloride were studied spectrophotometrically in the u.v.-visible region. Spectral data, the formation constants, and thermodynamic functions ΔH°, ΔG°, and ΔS° have been determined and the effect of substituents on them discussed. The spectroscopic results suggest the presence of both thiol and thione tautomers involved in complex formation.