Magnetic circular dichroism study of GaIIICoII and FeIIICoII complexes

The MCD spectra of isostructural GaIIICoII and FeIIICoII complexes were analyzed. It was shown that the exchange interaction strongly affects the contributions of interacting ions to the spectrum of the whole complex. It was demonstrated that the MCD signal measured at low temperatures in GaIIICoII dimer comes from CoII ion while in FeIIICoII dimer the corresponding signal is mainly due to the contribution from FeIII ion. The polarization of the corresponding optical transitions for both complexes was found.