d-d Transitions of Co(III) Complexes Studied by Associated Induced Circular Dichroism

The circular dichroism (CD) induced, by tartatic acid, into magnetic dipole allowed d-d transitions of a range of Co(III) complexes, is studied experimentally and theoretically. With the aid of the results from a symmetry analysis of the independent systems/perturbation approach to CD, it is possible to interpret the experimentally determined spectra. The relative band signs and band magnitudes are found to be consistent only with a second order, geometry dependent mechanism. The results can be extended to other systems where the preferred chiral inducer/achiral chromophore adduct geometry is defined by the symmetry of the achiral chromophore.