The relation between lyotropic and spectroscopic properties of anions in solution

Anionic effects on the charge-transfer absorption band of I^- were studied in detail. The results indicate that the spectroscopic effects of the added anions depend mainly on their power to desolvate the test ion I^-. Thus a correlation is presented between the spectroscopic and lyotropic series, with the halides forming a separate group. The mechanism of the anionic effect on this type of spectra (C.T.T.S. spectra) is discussed and some evidence is brought in favor of the continuous medium approximation which involves the ionic cavity radius as a variable.