Fig. 1. Molar absorption coefficient (ε) spectra of (a) Fe(ClO₄)₃ and (b) FeCl₃ dissolved in H₂O, methanol (MeOH) and ethanol (EtOH). Thin curves (a) and (b) are the spectra with excess ClO₄⁻ and Cl⁻, respectively. Filled triangles in (b) represent the absorption bands due to [FeCl₄]⁻.